structural study of the west red lake area
TRANSCRIPT
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Complex Structural Study
of the
West Red Lake Area
Northwestern Ontario, Canada
BY:
Vadim Galkin, Ph.D., Dr.Sc., P.Geo.
Consulting Geologist
69 Yore Road
Toronto, Ontario Canada
M6M 1W8
Tel: 416-653-0590
Cell: 647-501 0590
E-mail: [email protected]
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Table of Contents
Introduction ......................................................................................................................................................... 3
Structural Lineament Analysis............................................................................................................................ 6
Comparison of Au occurrences and different groups of lineaments spatial distribution.................................. 19
Lineaments Processing with 1000x1000m averaging window......................................................................... 21
Lineaments Processing with 500x500m averaging window............................................................................. 39
Lineaments processing with 250x250m averaging window. ............................................................................ 49
Lineaments processing with 100x100m averaging window. ............................................................................ 59
Physical Modeling............................................................................................................................................. 69
Plastic modeling results .................................................................................................................................... 76
Elastic Modeling Results .................................................................................................................................. 83
Structural Analysis and Physical Modeling. Conclusions and recommendations. ........................................... 92
Analysis of Lineament Orientations ............................................................................................................... 102
Geological/geophysical data and Structural Analysis..................................................................................... 106
Structural Analysis and geological/geophysical data. Conclusions ............................................................... 132
References:...................................................................................................................................................... 133
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Introduction The Hy Lake Gold properties lie on the Pipestone Bay - St. Paul Bay Deformation zone and host the
past producing Rowan Lake Gold Mine (Hy Lake Gold/Goldcorp), the past producing Mount Jamie Mine
(Hy Lake Gold) and the past producing Red Summit Mine (Hy Lake Gold) (Fig.1). The properties, which
have been explored only to very shallow depths, are underlain by the same geology and structure as these
three past producers and have been subjected to limited underground exploration. The properties host
numerous gold occurrences, which have seen limited drill testing, and potential exists to expand upon these
gold mineralized zones both along strike and at depth [1].
Fig.1, after [2]
The detail geology/geophysics/geochemistry of the area is out of this study’s scope. I conducted the
Lineament Analysis and Modeling as if there were no geological data available for the area. The only
exception – I used the distribution of main Au occurrences known for the area (shown usually as stars of
different colour). In accord with our agreement, though, some additional analyses of the results against geo-
data can be done later as short-term-project, and will be incorporated as an Appendix into the current report.
Method of Complex Structural Analysis (Fig. A) used here includes the following consequent techniques:
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- Lineament (fault and fractures) Analysis using aerial and satellite data of various sources available for
purchase or free of charge on the Net. The analysis itself is purely manual procedure. Hence, apart from
natural occasional human errors, and distortions or the flaws of the images, no artificial systemic errors
( such as automatic processing bias) affect the results
- Physical (analogue) modeling of the main lineament/structural frame mechanical response to the
different geodynamic conditions
- Processing of the data with various computer programs (custom-built and commercial) and creating
contour maps of lineament densities and strain levels for the area
- Analysing the data and outlining the areas which should be the Primary Exploration Targets from the
standpoint of the method ideology
Another part of the method (see below) is not touched here:
- Analyzing the resulted maps and schemes along with geological/geophysical/geochemical data
Yet, in my view, this part is the most important exercise. The deliveries (contour maps etc.) must be used
to analyse them along with available geological/geophysical/geochemical and prospecting data to make
recommendations for future ground exploration.
The application of the method to the area in question seems to be very logical. Most gold occurrences
there are somehow associated with deformational structures such as quartz vein systems, breccias etc. The
outlining and analyzing the spatial distribution of lineaments (modern and old faults and fractures) constitute
the quintessence and main purpose of the Complex Structural Analysis technique.
The agreed area for the analysis was 80 sq km. The boundary effect distorts the automatic contouring,
that is why the study area should normally be larger than the studied object itself.
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Fig. A. Main stages of the method applied to the area.
The last part of the method has not been completed in full yet.
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Structural Lineament Analysis Lineaments can be defined as linear surface features, visible on a map. Accordingly, one may speak
of topographic, photo-, satellite, geological, geophysical lineaments etc. In our study we deal with photo- and
topographic lineaments. These linear features, as a matter of fact, represent the surface reflection (projection)
of either a geological body (such as a dyke or a layer, bed, intrusion) or of a plane of anomalous physical
property/-ies such as fault rupture, zone of mechanical weakness (or hardness), zone of high (low)
permeability etc. Hence, by studying lineaments we indirectly study the surface pattern of the physical
properties, mainly – the distribution of fractures and faults projection on the earth’s surface.
Lineament analysis as a method of obtaining new geological information has been in existence for at
least 50 years. “Pros” and “contras” of the method have been discussed in numerous papers. The method is
considered to be a “mainstream” in hydrogeology, where the direct links between water accumulation and
fractures density pattern has been proved. Direct link with mineralization is not that straightforward, since the
mineralization is often geologically old, and the lineaments observed are believed to be of somewhat recent
age. On the other hand, more and more data are being published that prove the fact that the visible lineaments
inherit to rather larger extent the pattern of pre-existing fractures.
In 1980-s a lot of papers were published with the results showing that statistically relevant correlation
exists between regional ( or even global) network of lineaments and spatial distribution of the mineral
deposits [3]. Even relatively recently [4] Carlos J.Chernicoff et al. argued that there exists an undoubtful
crustal lineament control on magmatism and mineralization in north-western Argentina. We will leave the
discussion outside the limits of the current study. Let us note, nevertheless, that while there might be a
disagreement amongst the geologists with regard to spatial correlation of mineral deposits versus lineaments,
everybody agrees that a lot of ore deposits are controlled by fault and fracture networks. The fact is that as
descending” from global and regional scale to more “prosaic” local geology and tectonics many vague
lineaments most often turn into real faults and fractures.
Anyhow, it seems to have become a conventional view that, if taken in combination with other
geological methods and applied with precaution, the technique might provide a researcher with new kind of
valuable information which would have remained hidden otherwise. This study takes into consideration only
lineaments and their distribution, without preliminary geological/geophysical/geochemical data analysis.
The lineament analysis was completed using several different datasets:
- Airphotos (black and white, georeferenced manually) 1:60,000 with the resolution ~1.3 m/pixel - 2
images that cover the whole area (Fig. 2 ,a)
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- Airphotos (black and white, georeferenced manually) 1:20,000 with the resolution ~0.3 m/pixel -
several images that cover most parts of the claim areas (Fig. 2 ,b)
- Google Earth colour image that cover the whole area with resolution about 2 m/pixel, georeferenced
manually (Fig. 2 ,c)
- Landsat 7TM panchromatic – resolution 15 m/pixel (Fig. 2 ,d)
- Digital Elevation data (spatial resolution ~ 15 m/pi). (Fig. 2 ,e)
All lineaments were divided (ranged) into four groups - main, secondary tertiary and circul;ar. The drawing
itself has been done in ArcGIS environment.
Tertiary lineaments can be seen as straight lines due to changes in surface pattern or color nuances in the
image ( Fig. 3). The length of tertiary lineaments in this study was about 30-250 m.
Secondary lineaments can be seen as straight lines due to changes in surface pattern or color nuances
extended through several hundred meters. They are 700 m-1800 m long for the area image ( Fig. 4).
Main lineaments can be clearly traced through at least 1/2 of a map or longer, they are of considerable width
(may be represented as series of closely placed parallel lineaments) and long ~ 4 -10 km for the area image
(Fig. 5).
Circular lineaments (Fig.6 ) can be seen and drawn using both the colour changes and the pattern. Circular
lineaments did not play an important role in this study – they are relatively infrequent, and no
It is important to note that the lower limit for the lineament’s length (minimal length of tertiary lineament)
is scale dependant. The image with 0.3-1.3 m/pi resolution allows seeing and drawing very short
lineaments – 4-5 m long. The number of the features to draw would become enormous - hundreds of
thousands and/or millions. Since the analysis is done manually, it would take several months of work for
one person, which is unreasonable. That is why the researcher has to spend some time just evaluating the
right scale with which to start. In our case the area was ~ 80 sq km, so the analysis if the tertiary
lineaments was done using the screen scale (ArcMap scale toolbar) 1:4,000. The screen covers apprx
1kmX600m at such magnification.
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Fig.2. Data used for Lineament Analysis: a) Air Photos 1: 60000, b) Air Photos 1: 20000, c) Google Earth
georeferenced image acquired, d) Landsat 7TM panchromatic, e) Digital Elevation Model
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We observed 80,620 tertiary, 743 secondary, 46 main and 47 circular lineaments for the area (Fig. 3-
7). Note that the absence of lineaments in the lake areas is purely due to invisibility (covered by water). This
fact must be taken into account during the interpretation of the results.
The total number of different groups of lineaments, and the number intersections between each type
of the main 4 groups of lineaments were calculated and exported as an Excel sheet Table.1.
Table 1
Calculation was done with specially designed software written for ArcView 3.2 using different averaging
window size. In this study we used 100mx100m, 250x250m, 500x500m and 1000x1000m windows.
The data then was processed and interpreted with Surfer software. The resulted maps are contour maps of
lineament (lineament intersections) densities. The maximums on such maps represent the areas with the
highest lineament population (density), and therefore, with the highest permeability for any fluid flow
passing through the system. Apparently, an amount of fluid flowing through the zone with maximum
lineament (intersections) density is larger with comparison to the minimum, and the mineralization is more
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likely to occur in the maximum density zone.
We also used some weighting procedure during the interpretation.
Weighing is somehow arbitrary and reflects the researcher’s conception of the lineaments nature and
origin. From mechanical standpoint fractures and faults (which we observe as lineaments) form in some
hierarchic order, usually from the smallest first to the largest. The fracture’s shape must be similar to a
square or disc. So, the lineament, say, 200 m long may cut into the rock down to approximately 200m, and
the main lineament 6 km long accordingly, to 6 km down. Such a conception may be an oversimplification,
yet the tendency of the longer and wider lineaments to penetrate deeper than shorter ones is a well established
geological fact.
Apparently, an amount of fluid flowing through the main lineament is larger with comparison to the
tertiary one, and the mineralization is more likely to occur in the vicinity of the main lineament. Therefore, it
makes sense to weigh (assign the importance value) the main lineament heavier than secondary, and much
higher than tertiary. In our processing we used the following weighting coefficients: tertiary – 1, secondary
– 3, main – 10, circular -5. The intersections, accordingly, became weighted, since the weighted numbers for
different groups changed. In the areas where the mineralization is controlled, to some extent, by intrusive
magmatism and volcanism it is reasonable to weigh the circular structures heavier than small linear features.
These circular structures may reflect location of eroded intrusive bodies, volcanoes or their translucent
projections onto the surface.
By the same token, though, if the geological data suggest that the mineralization occurs at shallow
depth and related to, say, rather small intrusive bodies, then the role (weight) of tertiary/secondary
lineaments and their intersections would be more important (heavier weight). Since this study does not
involve geology/geophysics/geochemistry consideration in detail, we will show contour maps built with
different weighing procedures.
From general considerations the locations with maximal densities of lineaments/intersections
will be considered as the most favourable for mineralization to occur, since those areas must have the
highest permeability for circulating fluid.
Application of different averaging window sizes gives some ideas about the regional significance of
the max/min density zones. Sometimes, when moving from smaller to larger averaging window size the
maximums disappear and/or shift to another location. In such a case one can reasonably assume that the
maximums reflect the very local (and relatively shallow) structural situation. As often, though, the
maximums stay at the same location, just growing in size. Such a pattern suggests the existence of deeper
and more regional source of the tectonic disturbance in the area. Again, depending on the geological model
accepted for the mineralization in the study area, either smaller or larger window results may be chosen as
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more important from the exploration standpoint.
All the processing and result representation have been done using Projected Coordinate System
NAD83_UTM_Zone_15N.
All the aerial photos and Google Earth image have been geo-referenced manually. Without special
software and tedious procedure this process cannot be done with high level of spatial precision. That is
why despite the high resolution of the images themselves (0.3-1.3 m) the spatial error may often be of 10-
15 m order. This fact does not strongly affect the results, though. The pattern, the spatial distribution of
zones with different lineament densities is really important. Lineament analysis does not give the exact
targets for immediate drilling, rather provides some clues for further ground exploration.
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Comparison of Au occurrences and different groups of lineaments
spatial distribution.
Some observations can be made just considering the position of the known Au occurrences
against the lineaments. Obviously, we cannot look at the tertiary lineaments – they are so frequent that any
occurrence will fall onto one or another lineament. Secondary lineaments intervals are on average – 75-100
m, and (Fig.8b) almost all the occurrences lie on the lineaments and their intersections. Still, such
interpretation is somehow questionable.
Fig.8 a
Fig.8 b
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There are no doubts, though, that there is strong spatial correlation between the main lineaments and
gold occurrences (Fig.8a). The correlation is positive – 19 versus 10 occurrences are located on the
lineaments and/or their intersections.
Strong negative correlation exists between circular lineaments and Au. None of the gold occurrences
fall in the immediate vicinity of the circular lineaments.
Apparently, some additional analysis of accompanying geological data is needed for making any
recommendation for further exploration.
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Lineaments Processing with 1000x1000m averaging window.
Window 1000x1000m is the most reliable in terms of the calculating procedure (it does not contradict
to what was just said above, since we are talking pure math here). For any such window there usually are
many tertiary, at least few secondary/main and very often at least one circular lineament. So, during the
calculation and automatic contouring the window is never empty, meaning that the interpolation can be done
smoothly. The perfect illustration – the areas of the lakes. Since we have no data for the lakes, the
interpretive program would take the numbers of the lineaments as equal to zero. Interpolation will be done
using this zero value, although we know that the real situation is different.
Using window with, say 50x50m size, we would get very abrupt drops in contours, somehow losing
the clearness of the interpretive picture.
Fig. 9-22 show contour maximums maps built using different groups of lineaments, their intersection
and weighting procedures. One can see that the maximums may “appear “ and “disappear”, they become
stronger or weaker, they may also shift a bit in the different maps. In most cases we leave on the map only
maximums as opposed to all contours in transparent mode (as it is shown in Fig. 8). Such presentation allows
using a real world image as a background, and helps to avoid irrelevant information.
Yet one question should be discussed with regard to maximum cut-offs. The method is not intended to
obey to strict statistical rules. And every region is geologically unique. Same can be said about the
lineaments. Their distribution can be fairy even, and in such a case the min-max values of their densities
won’t be of a huge difference. The cut-offs, say, 75% of the max value (or even higher) could be appropriate
to map the maximums. As another extreme – the lineament distribution can be very uneven, and cut-offs of
30% of max value can be used. We do not want the maximum to be neither too small-size nor too large. In
the first case, one cannot be absolutely sure that there was no error made during the manual procedure of
drawing or during the processing. In the second case, one can obtain maximums (targets) which cover more
than 50% of the area, and that definitely would not make sense from the exploration standpoint. So, the
mapping of the maximums is a compromise between the statistics and practicality. Understanding of this
issue becomes particularly important when we walk down the size of the averaging window. The smaller the
size the more cautious one will have to be sometimes in terms of choosing the cut-offs.
All the maps have many common features. By overlaying all the individual maps and extracting areas
where 3 or more individual maps maximums intersect obtained the “averaged” scheme shown in Fig.23-24.
In these maps three groups of targets for future exploration can be outlined: Primary – red; 2-nd order–green,
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blue – 3-rd order.
As we already mentioned, the detail data of other nature have not been used for the area. Because of
this fact, we cannot easily choose “the most correct” map for exploration purposes, neither we must be in
favor of “averaged” scheme. The next necessary step would be testing the obtained maps against the
geology/geophysics/geochemistry, ongoing data collection, or/and field testing of the lineament anomalies.
If one of the maps proved to be the best with regard to new flow of the collected data, then we can use
such a map as an exploration tool for the future work planning.
At this point we can only make a following conclusion:
Obtained contour maps of lineament densities repeatedly show areas with higher densities in several
spatial stable locations. These zones are considered as the most favorable for mineralization from the
method foundations standpoint and may be recommended as the first target zones for future exploration
activities.
The size of the averaging window (1000x1000m) suggests that the actual position of the maximums on the
ground may vary within a couple of hundred meters limits.
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Fig. 9 . Hy Lake Properties. An example of the contour map (1000m window, all intersections unweighed).
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Fig.10 Hy Lake Properties. Density Contour Map of All Lineaments (no weighting)
Averaging window 1000x1000m
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Fig.11 Hy Lake Properties. Maximum Density Areas of “All Lineaments weighed”
Averaging window 1000x1000m
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Fig.12 Hy Lake Properties. Maximum Density Areas of “All Lineament Intersections unweighted”
Averaging window 1000x1000m
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Fig.13 Hy Lake Properties. Maximum Density Areas of “All Lineament Intersections weighted”
Averaging window 1000x1000m
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Fig.14 Hy Lake Properties. Maximum Density Areas of “Tertiary_Tertiary Intersections”
Averaging window 1000x1000m
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Fig.15 Hy Lake Properties. Maximum Density Areas of “Tertiary Lineaments”
Averaging window 1000x1000m
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Fig. 16 Hy Lake Properties. Maximum Density Areas of Secondary Lineaments”
Averaging window 1000x1000m
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Fig. 17 Hy Lake Properties. Maximum Density Areas of Secondary Lineaments Intersections
Averaging window 1000x1000m
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Fig.18 Hy Lake Properties. Maximum Density Areas of Main/Tertiary Lineaments Intersections (no weighting)
Averaging window 1000x1000m
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Fig.19 Hy Lake Properties. Maximum Density Areas of Main/Tertiary Lineaments Intersections (weighed)
Averaging window 1000x1000m
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Fig 20 . Hy Lake Properties. Maximum Density Areas of Main/Secondary Lineaments Intersections (weighed - darker green - and unweighted).
The outlines are almost identical. Averaging window 1000x1000m
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Fig.21 Hy Lake Properties. Maximum Density Areas of Main/Main Lineaments Intersections
Averaging window 1000x1000m
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Fig. 22 Hy Lake Properties. Maximum Density Areas of Secondary/Tertiary Lineaments Intersections
Averaging window 1000x1000m
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Fig. 23 Hy Lake Properties. All Maximums in transparent mode and Targets: red – Primary, green – 2-nd order, blue – 3-rd order.
Averaging window 1000x1000m
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Fig. 24 Hy Lake Properties. All Maximums in transparent mode and Targets – on top of the Google Earth image:
red – Primary, green – 2-nd order, blue – 3-rd order. Averaging window 1000x1000m
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Lineaments Processing with 500x500m averaging window.
Fig. show contour maps built using different groups of lineaments, their intersection and weighting
procedures. One can see that the maximums may “appear “ and “disappear”, they become stronger or weaker,
they may also shift a bit in the different maps.
By overlaying all the individual maps and extracting areas where 3 or more individual maps
maximums intersect obtained the “averaged” scheme shown in Fig.32-33.
Same as for the 1000x1000m window results we cannot choose “the most correct” map for exploration
purposes, neither we must be in favor of “averaged” scheme. The next necessary step would be testing the
obtained maps against the ongoing data collection, or/and field testing of the lineament anomalies.
If one of the maps proved to be the best with regard to new flow of the collected data, then we can use
such a map as an exploration tool for the future work planning.
At this point we can only make a following conclusion:
Obtained contour maps of lineament densities repeatedly show areas with higher densities in several
spatial stable locations. These zones are considered as the most favorable for mineralization from the
method foundations standpoint and may be recommended as the first target zones for future exploration
activities.
The size of the averaging window (500x500m) suggests that the actual position of the maximums on the
ground may vary within a hundred of meters limits.
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Fig.25 Hy Lake Properties. All Lineaments Maximums weighed (green) and unweighted (pink). Almost identical contours.
Averaging window 500x500m
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Fig.26 Hy Lake Properties. All Lineaments Intersections Maximums weighed (grey) and unweighted (blue).
Averaging window 500x500m
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Fig.27 Hy Lake Properties. Main (reddish) and Main/Main (pinkish) Intersections Maximums.
Averaging window 500x500m
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Fig.28 Hy Lake Properties. Tertiary Lineaments and their Intersections Maximums. Pink – Tertiary, Grey – Tertiaty/Tertiary.
Averaging window 500x500m
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Fig.29 Hy Lake Properties. Secondary and Secondary/Secondary Lineaments Intersections Maximums.
Averaging window 500x500m
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Fig.30 Hy Lake Properties. Main/Tertiary Lineaments Intersections Maximums.
Averaging window 500x500m
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Fig.31 Hy Lake Properties. Main/Secondary Lineaments Intersections Maximums.
Averaging window 500x500m
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Fig.32 Hy Lake Properties. All Maximums in transparent mode and Targets
red – Primary, green – 2-nd order, blue – 3-rd order. Averaging window 500x500m
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Fig.33 Hy Lake Properties. All Maximums in transparent mode and Targets – on top of the Google Earth image:
red – Primary, green – 2-nd order, blue – 3-rd order. Averaging window 500x500m
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Lineaments processing with 250x250m averaging window.
Fig.34-40 show contour maps built using different groups of lineaments, their intersection and
weighting procedures. One can see that the maximums may “appear “ and “disappear”, they become stronger
or weaker, they may also shift a bit in the different maps.
By overlaying all the individual maps and extracting areas where 3 or more individual maps
maximums intersect obtained the “averaged” scheme shown in Fig.41-42.
Same as for the 1000x1000m and 500x500mwindow results we cannot choose “the most correct”
map for exploration purposes, neither we must be in favor of “averaged” scheme. The next necessary step
would be testing the obtained maps against the geo-data , or/and field testing of the lineament anomalies.
If one of the maps proved to be the best with regard to new flow of the collected data, then we can use
such a map as an exploration tool for the future work planning. The advantage of the 250x250m window,
though, is that if proved realistic it would give the most spatially precise prediction of the favorable zones.
Obtained contour maps of lineament densities repeatedly show areas with higher densities in several
spatial stable locations. These zones are considered as the most favorable for mineralization from the
method foundations standpoint and may be recommended as the first target zones for future exploration
activities.
The size of the averaging window (250x250m) suggests that the actual position of the maximums on the
ground may vary within several tens of meters limits.
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Fig.34 Hy Lake Properties. Tertiary and Tertiary/Tertiary Intersections Maximum
Averaging window 250x250m
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Fig. 35 Hy Lake Properties. Secondary and Secondary/Secondary Intersections Maximum
Averaging window 250x250m
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Fig.36 Hy Lake Properties. Main and Main/Main Intersections Maximums
Averaging window 250x250m
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Fig.39 Hy Lake Properties. Secondary/Tertiary Intersections Maximums
Averaging window 250x250m
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Fig. 40 Hy Lake Properties. All Intersections Maximums weighed and unweighed
Averaging window 250x250m
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Fig.41 Hy Lake Properties. All Maximums in transparent mode and Targets
red – Primary, green – 2-nd order. Averaging window 250x250m
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Fig. 42 Hy Lake Properties. All Maximums in transparent mode and Targets – on top of the Google Earth image:
red – Primary, green – 2-nd order. Averaging window 250x250m
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Lineaments processing with 100x100m averaging window. Fig.43-50 show contour maps built using different groups of lineaments, their intersection and weighting
procedures. One can see that the maximums may “appear “ and “disappear”, they become stronger or weaker,
they may also shift a bit in the different maps.
By overlaying all the individual maps and extracting areas where 3 or more individual maps
maximums intersect obtained the “averaged” scheme shown in Fig.49-50.
Same as for the 1000x1000m, 500x500m and 250x250m window results, we cannot choose “the most
correct” map for exploration purposes, neither we must be in favor of “averaged” scheme. The next
necessary step would be testing the obtained maps against the geo-data.
If one of the maps proved to be the best with regard to new flow of the collected data, then we can use
such a map as an exploration tool for the future work planning. The advantage of the 100x100m window,
though, is that if proved realistic it would give the most spatially precise prediction of the favorable zones.
At the same time, as we already mentioned, the smaller the size of the window the less reliable
become the exact spatial positions of the maximums and their absolute magnitudes, since the number of
secondary, main and circular lineaments is not usually statistically large for such a window. Still, with
cautiousness, the results can be very useful in combination with other data.
Obtained contour maps of lineament densities repeatedly show areas with higher densities in several
spatial stable locations. These zones are considered as the most favorable for mineralization from the
method foundations standpoint and may be recommended as the first target zones for future exploration
activities.
The size of the averaging window (100x100m) suggests that the actual position of the maximums on the
ground may vary within tens of meters limits.
Fig 51shows maximums schemes obtained for various window sizes on one page. One can see that
the position of the maximums are more o less stable spatially.
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Fig. 43 Hy Lake Properties. All Lineaments Maximums weighed (grey) and unweighed (red).
Averaging window 100x100m
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Fig.44 Hy Lake Properties. All Lineaments Intersections Maximums weighed (yellow) and unweighed (green).
Averaging window 100x100m
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Fig.45 Hy Lake Properties. Main Lineaments (red) and Main/Main Intersections (turquoise) Maximums.
Averaging window 100x100m
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Fig. 46 Hy Lake Properties. Secondary Lineaments (orange) and Secondary/Secondary Intersections (green) Maximums.
Averaging window 100x100m
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Fig.47 Hy Lake Properties. Tertiary Lineaments (green) and Secondary/Secondary Intersections (blue) Maximums.
Averaging window 100x100m
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Fig.48 Hy Lake Properties. Secondary/Tertiary Lineaments Intersections Maximums unweighed (orange) and weighed (pink).
Averaging window 100x100m
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Fig.49 Hy Lake Properties. All Maximums in transparent mode and Target Areas. Yellow circles –
spatial coincidence between maximums and gold occurrences.. Averaging window 100x100m
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Fig.50 Hy Lake Properties. All Maximums in transparent mode and Target Areas.
Yellow circles – spatial coincidence between maximums and gold occurrences. Averaging window 100x100m.
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Physical Modeling Main earth crust and/or uppermost mantle heterogeneities (such as deep faults and fault zones as well
as favourable pattern of faults and their intersection) are considered to be the locations of magma generation
and penetration, sedimentary basins development, high permeability zone formation, metamorphic processes
and fluid flow canalization. The last two lead to remobilization and re-precipitation (redistribution) of ore,
oil, gas etc.
Spectrum of deposit types that are mainly controlled by faults geometry and pattern is extremely wide
ranged – from diamonds and PGM to oil and gems.
It would seem to be simple, then, at least at a first glance, to design some structural exploration
method: one must find and outline all major faults in the area of interest, outline zones of maximal faults
densities and “knots” of fault intersections, and these resulted spots should be the most favourable for deposit
finding.
There are, though, two problems for this procedure to be easily fulfilled.
First problem. It is not always possible to establish all major faults at once, especially when one studies an
area with an overburden or just because of absence of any reliable geological data.
Second problem. Theoretical consideration as well as experimental results and geological practice indicat e
that only a few among many faults (fractures in experimental works) and their intersections play controlling
role in deposit location whereas others serve either as pathways for deposit mass supply or don’t affect
geological system at all. This phenomenon becomes clear from the following simple experiment which
everyone can reproduce at leisure time.
Let us take a rubber eraser and make several cuts on one of its facets. Then, press eraser from two sides
horizontally. You will immediately see that openings form along some cuts (which are parallel or close to
parallel to the direction of compression) whereas other cuts do not manifest themselves. Now try to press
eraser in different direction, bend it, twist it, and play with it around. You will find a number of
deformational patterns, yet initial system of cuts is the same. This experiment gives may be too general, yet a
good analogy of faults /strain field interaction in nature (cuts represent faults and strain field - pressure
applied by your fingers).
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The First problem can be solved by lineament analysis of relief, air- and satellite images, radar images,
geophysical fields etc.
Lineaments are superficial “traces” of buried faults, and their visibility even through hundreds of
meters of overlaying sediments is well explained from the mechanical standpoint. Many specialists in
mechanics believe that any fault with substantial length (say, 2 km) behaves as a very mobile structure, since
even in a dormant tectonic environment cumulative stress on it happens to become greater than the average
strength of rocks. Once formed, such faults manifest themselves in tiny movements which are not significant
in magnitude but still keep the faults active. These continuous movements can be seen through later
structures as lineaments – faults or fracture zones with constant, often pendulum-like (pulsating) type of little
displacements.
Thorough lineaments analysis and subsequent processing of lineament data allows us to find the most
important (main) structures which control the system mechanical behaviour.
Yet, to overcome the Second problem (see above) and find which high fracture density zones must
be explored first and foremost we have to do some additional discriminative analysis. We need to select those
faults and their intersections, those high fracture density zones which were the most geologically active and
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dominant in the area under study. There is no way to crack this problem theoretically since the real faulted
volume behaves as a non-linear system for which mechanical equations proved to be insoluble.
There is, nevertheless, a way around, namely, tectonophysical (physical, analogue) modeling.
Physical modeling deals with simulation of real geotectonic processes by using analogue materials
instead of rocks, and substituting natural tectonic stresses, temperatures and pressures by specifically selected
laboratory conditions. While deforming selected models with initial fault structures again and again, one has
to register all newly formed strain structures (usually with digital camera) and, then, analyze dozens of
images to select and outdraw repeating zones of high strain.
Many-year experience of research indicates, that no matter what orientation of stress and what
materials one chooses, he will always find only a few of such zones of highest strain with astonishingly
stable spatial location!
These zones in experiments and their analogues in nature, called structural (tectonic)
concentrators, indicate the most favorable localities for any type of mineral deposit.
Let us consider the implementation of such method for Red Lake area.
Some preliminary words need to be said about the physical modeling foundations relevant to the case-
study:
Basically, tectonic deformation, as any deformation, consists of three consecutive stages: elastic
(reversible), plastic and rapture (permanent, irreversible). When the plastic stage is short in time and
insignificant in magnitude we usually describe the deformation as brittle – it occurs under relatively low
temperature and/or high stresses and high strain rate.
During all these stages in the inhomogeneous geological media (faults are the most important of
heterogeneities) mineralization tends to localize in the (or close to) zones of low compressive and/or high
tensional stresses. Generally speaking, we may say that mineralized fluids move from zone of high
compressive stresses into zones of openings (raptures, fractures, faults) and low compressive (or high
tensional stresses) where they precipitate and form ore bodies.
Thus, if we use physical modeling to allocate the most favourable zones for deposit discovery we
have to find zones of: high rapture deformation or, in other words, zones with high density of fractures and
openings – so called ‘dilation (dilatation) zones’, or in the areas of relatively low compressive stress
compared to adjacent high-stressed zones.
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To cover all three stages of deformation in experiments we have to use two different types of
materials (this is just a nature of the modeling and will not be discussed here) and, accordingly, two different
series of experiments have to be conducted: elastic deformation (reversible) and plastic + rupture
deformation (irreversible).
Deformations have occurred (or might have occurred) many times, under different thermodynamic
and tectonic conditions. That is why we need to study separately several (namely, eight) strain regimes –
group of mainly “pure shear” with four different orientations of compression and group of mainly “simple
shear” with four different orientations of shearing.
The model itself was made with clay dope whose mechanical properties satisfy, in general, the
demands of The Theory of Similarity for this class of analogue modeling.
In the clay block with dimensions 20x20x2 cm a series of vertical cuts was made. These cuts represent main
lineaments (faults) obtained from lineament analysis of the satellite images. The same fault-template was
used in all experiments, yet its orientation relative to stress varied in each case.
Mainly Pure Shear Group. Mechanical sketch of this situation may be represented as follows.
Figure B. Mechanical sketch of the mainly pure shear group of deformation.
The results of experiments were recorded with digital camera, and shots were interpreted separately. Zones of
openings along existing faults as well as new fractures and areas of high plastic deformations were outlined.
Due to large distortions of initial pattern of faults during the deformation we copied these contours to the
initial template and corrected their position to match with real lineaments pattern.
Mainly Simple Shear Group. Mechanical sketch of this situation may be represented as follows (Fig 28).
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Figure C. Mechanical sketch of the mainly simple shear group of deformation
Simple shear is considered as an ideal situation which is seldom to exist in earth crust, some kind of trans-
pressure (additional compression perpendicular to red arrow on the figure above) or trans-tension occurs
usually. In our experiments such additional shortening was at a range of 7-10%.
Zones of openings along existing faults as well as new fractures and areas of high plastic deformations were
outlined. Due to large distortions of initial pattern of faults during the deformation we copied these contours
to the initial template and corrected their position to match with real lineaments pattern.
All contours of high deformations in eight experiments were overlaid on one picture, and dividing into four
districts of strain level was made as following:
1-white - zones of zero strain – no strain was recorded in all experiments.
2-blue – zones of weak strain – strain was recorded in only one experiment
3-yelow- zones of medium strain – strain was recorded in 3-4 experiments
4-red - zones of high strain – strain was recorded in 5 or more experiments.
Finally, the table of strain intensity was made, with the following values for strain levels:
• zones of zero strain -0
• zones of weak strain – 1
• zones of medium strain – 3
• zones of high strain – 10.
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For those cells which contained several areas of different strain-levels, simple weighting was applied.
Some emphasis must be put on the interpretation of the results. In our view, actual location of zones of high
strain (and, thus, of high possible permeability and destruction of rocks) should be obtained from lineament
scheme. In case of mismatch of lineaments densities and high-strain zones locations an additional
consideration from regional geology data must be taken into account for one to decide which result should
overrule the other. In other words, final targets must not be selected based on quantitative coefficients only –
this particular case-study has not yielded sufficient amount of data to apply purely quantitative analysis..
Elastic modeling
Optical modeling simulates the very first stage of deformation – elastic deformation. Optically active
materials, such as plexiglas and gelatines are used to be the most suitable for this purpose. Optically active
materials while placed between polarizing films and deformed show rainbow-coloured pattern similar to
what one can observe in rock thin sections under the microscope. The more “reddish” colors show higher
stresses, the more bluish – lower stresses. The higher the order of rainbow spectrum the higher stress is.
When all the experiments have been done we’ve outlined the patterns of high, medium and low
stresses/deformations for each of the experiment. Overlaying these patterns onto each other we usually find
that in the model (in the region under study) such zones exist where the deformation was high in, say, 5 and
more out of all experiments.
These ‘cumulative’, repeating zones of high deformation in the plastic/rapture series and zones of low
stresses (or openings, dilation zones) in elastic series both represent the favourable places for the deposit
discovery.
The results of physical modeling may be used for exploration targeting independently. Better still, though, to
use them as overlays over the results of lineament analysis. It is those locations where the highest densities
of lineaments, lowest elastic strains and highest plastic/rupture strains come along that must be treated
as the most favourable for any type of mineralization to occur.
The following lineament scheme was used for the modeling ( Fig.52). It is apparent that the scheme is
simpler than the main lineaments image (Fig.5). The reason for this was mostly technical – the size of the
model put some restriction on the number of the possible cuts in the model. Such a mismatch, surely, plays
some role in distorting the results. Nevertheless, my experimental experience tells that it is the spatial pattern
of lineaments that is the most important part. After all, the modeling is intended to give some ideas of the
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system behaviour rather than all the answers. We want to see how the main faults play together, and which
combinations of the fault systems lead to formation of most dilatational structures, and where the new faults
and fractures form.
Fig. 52. Main lineaments used for the plastic/elastic modeling
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Plastic modeling results Altogether 8 experiments have been done – Fig. 53-63. Every experiment was photographed and,
then, all the zones of maximal deformations were outlined as it was shown in Fig.54. We tried to use all the
possible schemes of loading in terms of compression/shearing orientations.
Overlaying all the results onto each other we can find the areas where the deformations always were
high ( Fig. 63, red), and we can also see zones of medium (green), low (blue) and zero (white)deformations.
Processing the results with specially designed software we also created Surfer contour maps for high
deformation areas. Such maps are necessary for the mutual analysis with the lineament schemes in GIS
environment. Again, we used 4 averaging window sizes - 100m, 500m, 250m and 100m. These results will
be shortly discussed later.
Plastic group of experiments, basically, suggests that zones of main lineaments intersections represent
areas with the highest cumulative deformations. These zones – from the modeling standpoint – may be
taken as the most favourable for the future exploration activities.
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Fig.53 Plastic deformation, experiment 1. Initial state before deformation.
Fig. 54 Plastic deformation, experiment 1. Model state after deformation. Red outlines – zones of high strain.
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Fig.55 Plastic deformation, experiment 2. State after deformation.
Fig.56 Plastic deformation, experiment 3. State after deformation.
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Fig.57 Plastic deformation, experiment 4. State after deformation.
Fig. 58 Plastic deformation, experiment 5. State after deformation.
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Fig.59 Plastic deformation, experiment 6. State after deformation.
Fig. 60 Plastic deformation, experiment 7. State after deformation.
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Fig. 61 Plastic deformation, experiment 8. State after deformation.
Fig.62 Deformational zones overlay of all 8 experiments
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Fig. 63 Plastic deformation experiments evaluation. In red – zones of highest deformations in most
experiments, green – zones of medium deformations, blue – low deformations.
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Elastic Modeling Results
Altogether 12 experiments have been done – Fig. 64-79. Every experiment was photographed and, then, all the zones
of maximal deformations were outlined. We tried to use all the possible schemes of loading in terms of
compression/shearing orientations.
Remember that for the elastic field we are looking for the areas with lowest stresses or dilational zones.
Overlaying all the results onto each other we can find the areas where the deformations always were lowest ( Fig. 79,
red).
Processing the results with specially designed software we also created Surfer contour maps for high
deformation areas. Such maps are necessary for the mutual analysis with the lineament schemes in GIS environment.
Again, we used 4 averaging window sizes - 100m, 500m, 250m and 100m. These results are shortly
discussed later.
Elastic group of experiments suggests that most zones of main lineaments intersections represent areas with the
lowest stresses. These zones – from the modeling standpoint – may be taken as the most favourable for the future
exploration activities.
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Fig.64 Light-table and deforming device have been used for the elastic experiments
Fig.65 Initial state of one of the experiments. Polarizing sheets are crossed. No interference colors, since the
model is not deformed.
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Fig.66 Elastic experiment 1. Interference colors show the elastic strain pattern ( reversible strain).
Fig.67 Elastic experiment 2.
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Fig. 78 Deformational zones overlay of all 11 experiments.
Fig.79 Elastic deformation experiments evaluation. In red – zones of lowest deformations in most
experiments, green – zones of medium deformations, blue – high elastic deformations
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Structural Analysis and Physical Modeling. Conclusions and
recommendations.
Fig.80-87 illustrate overlays of the modeling maximums and lineament maximums for different averaging
window sizes.
Those zones where all the maximums are in spatial coincidence are considered as the most
favorable for mineralization from the method foundations standpoint and may be recommended as the
first target zones for future exploration activities.
1. Structural analysis of the area was completed using 5 different datasets: aerial photos 1:60,000
and 1:20,000 scale ( resolution 1.3 and 0.3 m/pixel); Landsat 7TM panchromatic image with the
spatial resolution of 15m/pixel; Shuttle acquired Digital Elevation data (spatial resolution ~15
m/pixel), and ge-orefernced Google Earth image ~2m/pixel resolution
2. Obtained contour maps of lineament densities (averaging windows 1000, 500, 250 and 100m)
repeatedly show areas with high lineament (and their intersections) densities in several spatially
stable locations. These zones are considered as the most favorable for mineralization from the
method foundations standpoint, and may be recommended as the first target zones for future
exploration activities (Fig.23-24, 32-33, 41-42, 49-50).
3. Analogue modeling results show that there exist some spatially stable zones with the highest
deformation (plastic) or the lowest stress (elastic) in various geodynamic stress fields (Fig.63, 79).
These zones – from the modeling standpoint – may be taken as the most favourable for the future
exploration activities.
4. In the Red Lake area several locations exist where all the maximums (modelind and lineament
analysis ) are either in spatial coincidence or in close proximity to each other (Fig.80-87). From
the Complex Structural analysis standpoint, these zones should be taken as the first-order targets
for the future exploration activities
5. 19 out of 29 U prospects are spatially linked to main lineaments. Such spatial correlation is
significant, though not in the mathematical terms, but when taking into account the small portion
of the area occupied by the main lineaments ((Fig.8a). From the Complex Structural Analysis
standpoint, the vicinities of the main lineament (and their intersections in particular) structures
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should be taken as the targets for the future exploration activities.
6. Further analysis of the obtained results together with all the geological/geophysical and
geochemical data may provide an additional insight for better understanding of the spatial
distribution of the gold mineralization in the area. First and foremost, I would suggest using the
detail geological maps and follow the areas where obtained with CSA maximums overlay
favorable geological formations or their boundaries. Second, soil anomalies (government data
exists) may be considered against the results of this study. Geophysical data may be also
invaluable.
7. The results of the drilling may provide additional insights with regard to as how the various
lineament features may influence future exploration program in the Red Lake area.
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Fig. 80 Hy Lake Properties. All Maximums in transparent mode, Elastic (green) and Plastic (red) Deformation Maximums, and Target Areas.
Red outlines – Primary Targets, yellow – Secondary Targets. Averaging window 100x100m
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Fig. 81 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Red outlines – Primary Targets, yellow – Secondary Targets. Averaging window 100x100m
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Fig. 82 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 250x250m
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Fig.83. Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 250x250m
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Fig. 84 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 500x500m
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Fig. 85 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 500x500m
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Fig. 86 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 1000x1000m
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Fig. 87 Hy Lake Properties. Target Areas ( modeling and lineament analysis together)
Averaging window 1000x1000m
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Analysis of Lineament Orientations
Processing of the directional data very often involves construction and analyzing of rose-diagrams
and their spatial variation.
Rose-diagram can be defined as a circular histogram plot which displays directional data and the frequency
of each class (Fig.88). Radial distance indicates the relative frequency of an observation at a certain azimuth.
Fig.88. Rose diagrams – see explanation in the text.
Two types of rose diagrams are used – full (Fig. 88 , left) and half rose diagrams –
northern 180-degrees (Fig. 88, right).
Rose diagrams are commonly used in sedimentary geology to display palaeocurrent data, or the
orientation of particles. In structural geology rose diagrams are used to plot the orientation of joints and
dykes. Wind directions and frequencies (meteorology and geography) can also be plotted on rose diagrams.
In this study rose diagrams were used to visualize the preferred directions and frequency of the
lineaments, and their spatial distribution over the Hy Lake Properties. We used half rose diagrams to describe
Secondary Lineaments on the property (Fig. 89). Basically, the longer and narrower the peaks in any
particular direction is, the stronger and more spatially bound is the lineament system.
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Similar to lineament densities calculation, the counting and rose diagram drawings were made with
different averaging window sizes – 500x500m and 1000x1000m. To process the lineaments and build the
diagrams we used the originally designed software.
Fig. 89 shows the rose-diagram distribution with 500 m window. Transparent yellow zones highlight
the areas with strongly directionally bound sets of lineaments.
It is easily seen that the whole area can be divided into at least three zones with different patterns of
the lineament directional distribution. Western and Eastern (or rather the south-eastern) parts both have
several well developed sets of lineaments, which cover these areas with “star-like” type of the rose diagrams.
The Central zone shows quite different design – one can see here the intersection of two zones with the
domination of NW (Az ~ 300), NE (Az~60) and either WE or NS oriented lineament systems. Another
notable feature – NE system in the Central zone changes direction while going southward along the Golden
Arm Lake. The general direction stays the same – NE – but the Az bends from 55-60N to 40-45N.
Fig. 90 shows the rose-diagram distribution with 1000x1000 m averaging window. The picture is,
basically, very much alike to the one for 500m window, yet the Central zone becomes sort of “loose”.
As we already emphasized, we do not make any exploration conclusions from the results of this
study, since the geological/geophysical/geochemical data must be analyzed along with the lineament analysis
results.
Still, some (very general) suggestions can be made. The existence of several well-developed systems
of lineaments (Western and Eastern blocks) makes it possible for dilation zones to form during almost any
deformational event, whatever the stress-field was. If gold precipitated under E-W compression the east-west
oriented faults and fractures (lineaments) would produce dilation zones. Compression N-S , NW-SE, NNW,
NEE, NE-SW – there is always a lineament system available to supply the dilation zones. Then, there would
be no exploration preference with regard to the orientation of the lineaments.
The Central Zone is, somehow, different. Available lineament systems are in (relative to the previous
case) shortage, and one can think of some unfriendly orientation of the deformational event when no system
would produce good dilation zones. By the same token, though, if the event was favourable, the dilation
would be significant in size, and would play the main role for gold precipitation. Actual tectonic history
should be analyzed to make any further recommendations
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Fig.89. Rose diagrams for Secondary Lineaments distribution. 500x500m window. Transparent yellow zones highlight the areas with strongly dominated sets
of lineaments.
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Geological/geophysical data and Structural Analysis. The geology of the Red Lake district has been described quite a few times. This addition
to the Structural Analysis report will only use some briefs which seem to be important with
regard to the exploration activities on the Hy Lake Properties.
§1. First of all, we would like to mention some results from the GIS Weight-Of-Evidence
study [ 5 ] conducted on the Red Lake District.
The GIS analysis of geological and geochemical factors that form part of an Archean
lode-hosted gold deposit model provides useful predictors that can assist in the exploration for
new deposits in an established gold camp such as the Red Lake greenstone belt. Prospectivity
maps generated through GIS modeling have highlighted (validated) well-known Au exploration
districts, and more importantly have identified less explored areas with no known gold
producers. Although the details of the study are not discussed here the conclusion seems to be
very important : the whole Hy Lake Property (Fig.91 , area F) has similar signatures as the areas
associated with already developed rich gold prospects. This region is among a few worthy of
exploration follow-up.
Fig.91.
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§2. The interpretation of the age of gold mineralization in the Red Lake district – here
and below we cite [ 6 ] - has evolved from largely synvolcanic, to pre-regional deformation and
metamorphism and associated with strike-slip faulting within the interval of 2722 to 2710 Ma , to
syndeformation, related to tectono-magmatism within the interval 2720 to 2700 Ma, to late
tectonic at ca. 2700 Ma. MacGeehan and Hodgson (1982) proposed three periods of
mineralization (here and further the highlighting is ours) that include an early synvolcanic stage,
followed by two younger syn-to late-deformation stages that predated emplacement of late mafic
to felsic dikes. Menard et al. (1999) proposed two stages of gold mineralization, with the main
stage corresponding to D2 and occurring between 2720 to 2715 Ma and a subsequent but
lesser event in terms of total gold content at around ca. 2700 Ma, represented by auriferous
quartz-pyrite-tourmaline vein-type deposits (e.g., Buffalo mine) hosted by the ca. 2718 Ma
Dome stock. A model age for galena calculated from samples of gold, chalcopyrite, pyrite, and
galena using the western Superior province model indicated a first stage of gold mineralization in
the Red Lake district responsible for the formation of the Campbell-Red Lake deposit at ca. 2865
Ma and a much younger stage for gold mineralization at the Madsen and Starratt-Olsen deposits
at ca. 2715 to2709 Ma (Gulson et al., 1993).
In terms of exploration, the main stage of gold mineralization clearly postdates
volcanism of the Balmer assemblage at 2990 to 2960 Ma and is contemporaneous with
emplacement of the ca. 2718 Ma Dome and McKenzie stocks as well as the Hammell Lake
pluton. The <2747 Ma conglomerate from the Huston assemblage in the Red Lake mine occurs
at an important interface between Mesoarchean and Neoarchean strata and highlights the
proximity of the Campbell-Red Lake deposit to a folded regional unconformity , supporting the
empirical spatial and genetic (?) relationship between large gold deposits and regional
unconformities in the district and in greenstone belts elsewhere. These regional
unconformities result from, or are associated with, large-scale protracted tectonic (faulting
and uplift), magmatic, and hydrothermal event(s) to which large gold deposits are empirically
related. The unconformities may also provide a first-order guide to the favourable erosion
levels for mineralization (Robert., 2001). In Red Lake, this paleosurface represents a key
first-order exploration target, as 25.9 M oz (94%) of the 27.6 M oz Au found so far in the
district (production, reserves, and resources) is contained in three deposits adjacent to the
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unconformity (Dubé et al., 2003) . It is proposed that areas of high potential for gold
exploration in Red Lake occur in the rocks of the Balmer assemblage within 500 m to 1 km of
the unconformity.
It seems, therefore, necessary to consider this exploration approach along with the targets
obtained by the Structural Analysis.
The distribution of the Balmer and Confederation Formations can be taken from the
following geological maps (Fig.. 92, 93 ). The first map, composed by Riley (1974) – Fig. 92 ,
is the most detailed at 1:12,000 scale. The second map – 1:50,000 – is available as a vector SHP
file package at OGS, and it is from this map that the contours of the Balmer-Confederation
Groups have been extracted for comparison with our results.
The two maps differ in some details, particularly for the western part of the property, to
the west of the anticline nose; but for the Balmer-Confederation Groups and Main Unconformity
Boundaries they are almost identical.
Fig. 94 shows the fields of the Balmer-Confederation Groups ( transparent blue) and
2000m corridor (1000m perpendicular to the unconformity in both directions) as a yellow
outline.
By overlapping the results of the Structural Analysis (with 1000/500/250/100m window
size) onto this map we obtained Fig. 95-98.
We must remember that the exploration lead described above (highlighted in bold italic)
is just an empirical conclusion made in [ 6 ]. S till, if the authors are right, then the Structural
Analysis Targets which fall into the area of Balmer/Confederation Unconformity Corridor
(windows 500m and 100m) must be taken as Primary Targets, and Structural Analysis
Targets which fall into the Balmer-Confederation Formations field ( mainly in the Eastern
part of the property) should be considered as Second-Order Priority Targets.
It is important to note, that recently R.Bob Singh [ 7 ] published another version of the
geological map for the area under discussion ( Fig. 99). This map is similar to the discussed
above ( Fig.92, 93) in terms of the contours of the main assemblages, but is significantly
different in the interpretation of the important fault structures. Singh introduces a series of thrust
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faults in the area, superimposed onto the main regional anticline in such a way, that the thrusts
dip, basically, in opposite directions to the limbs of the anticline fold – to the south/south-east on
the northern limb (which itself dips to the NE), and to the NW on the south limb (which dips to
the SE).
If proven right the implications of the new interpretation may be very important for
the gold exploration in the area. It is my strong recommendation that this issue should be
addressed and resolved rather sooner than later.
Fig. 92 Geological Map 1:12 000. Riley, 1978, OGS 2406
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Fig. 94 Balmer and Confederation Formation (blue) coverage and 2000 m unconformity corridor (yellow)
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Fig. 95 Structural Targets (1000x1000m window) on Balmer and Confederation Formation (blue) coverage and 2000 m unconformity corridor (yellow)
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Fig. 96. Structural Targets (500x500m window) on Balmer and Confederation Formation (blue) coverage and 2000 m unconformity corridor (yellow)
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Fig. 97 Structural Targets (250x250m window) on Balmer and Confederation Formation (blue) coverage and 2000 m unconformity corridor (yellow)
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Fig. 98 Structural Targets (100x100m window) on Balmer and Confederation Formation (blue) coverage and 2000 m unconformity corridor (orange)
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Fig. 99 Geology of the Newman Todd claim group including surrounding areas . Redstar Technical Report, 2009
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§ 3. Many parts of the Properties have been covered by several geophysical surveys during the past three
decades. The results of the three surveys described briefly below seem to be worthy to analyze along the
Structural Analysis Targets. We extracted and digitized all the conductors’ coordinates from the reports and
put them as additional layer in GIS environment (Fig. 100-101).
1. AngloGold. ASSESSMENT WORK REPORT. TIME-DOMAIN AIRBORNE EM SURVEY AND
INTERPRETATION. Red Lake Geophysical Survey (2003)
This report describes the acquisition and interpretation of a time-domain electromagnetic survey conducted
by SPECTREM AIR LIMITED for the Anglogold - Rubicon Minerals Corporation Joint Venture. The survey
was performed in the middle of 2000, and the interpretation of the results performed in late 2001 by the
technical staff of AngloGold and Rubicon Minerals.
Results of the survey indicate that the geology can be mapped by the conductivity and magnetic signatures.
There is a complex magnetic fabric that has been outlined, and discontinuities, shears or faults have been
inferred to explain the discontinuous structure. The linear magnetic highs are interpreted to be due to
ultramafic and mafic rocks of the volcanic sequences, and also local iron formations. Bed rock conductors
are attributed to either pyrrhotite, sulphide iron formations or graphitic argillites. ( Fig.100, blue dots).
2. DIGHEMv SURVEY FOR REDSTAR GOLD CORP. RIVARD RED LAKE AREAS ONTARIO,
Report #2123A, FUGRO AIRBORNE SURVEYS; 52M01SE2028 OGS
This report describes the logistics and results of a DIGHEMv DSP airborne geophysical survey carried out
for Redstar Gold Corp., over three properties located near Red Lake, Ontario. Total coverage of the survey
blocks amounted to 223 km. The survey was flown from November 3 to November 5, 2002.The purpose of
the survey was to detect zones of conductive mineralization and to provide information which could be used
to map the geology and structure of the survey areas.
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The survey properties contain numerous anomalous features, many of which are considered to be of
moderate to high priority as exploration targets. Most of the inferred bedrock conductors appear to warrant
further investigation using appropriate surface exploration techniques. Areas of interest may be assigned
priorities on the basis of supporting geophysical, geochemical and/or geological information. ( Fig.100,
orange dots, conductors undifferentiated)
3. COMBINED MAGNETIC, ELECTROMAGNETIC, VLF AND RADIOMETRIC HELICOPTER
SURVEYS BLOC : PIPESTONE RED LAKE AREA, ONTARIO, SIAL Geosciences Inc., 2000.
An EM survey allowed detecting three types of electric conductors: Bedrock, Superficial and Positive In-
Phase conductors. Among these three ( see the report for additional details) we are most interested in the
Bedrock conductors.
TYPE l (Bedrock conductors)
Most of the time, the EM anomalies line up from line to line to draw the conductor axis. When a
conductor is made up of EM anomalies characterised by well-defined and narrow negative In-Phase and
quadrature components, this type of conductor is often related to massive sulphide and/or graphite
mineralised beds. Under such circumstances, the quantitative interpretation (conductance and depth) of each
anomaly is done by assuming a vertical tabular model. This choice is justified because this model is the best
one to represent narrow conductors, typical of sulphur and graphical mineralisations.
The results of the first two surveys, though may be used for local analysis and targeting, in terms of
coverage of the area are of minor importance as compared to the SIAL results. It is this last map that we used
for the analysis against the Lineament Analysis results ( Fig.101).
Fig.102 shows the main trends of the bedrock EM anomalies on the Hy Lake Properties. The
comparison with the previous picture may question if the NS trends are that obvious, but there are no doubts
with regard to diagonal systems and WE trend in the western part of the area.
In Fig.103 the overlap of the Main lineaments onto the EM anomalies speaks in favour of the close
proximities between many of the lineaments orientation/ location and EM anomalies. It definitely puts an
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additional weight to the direct “material” correlation between the geological/geophysical features and surface
optically recognized linear structures (lineaments).
The consideration of the Structural Analysis Targets along with the EM anomalies, therefore, may be
of value in terms of exploration.
Fig. 104-107 show overlaps of the EM anomalies and Structural Targets (obtained with 1000m,
500m, 250m and 100m averaging window size) described in the submitted report.
The spatial proximities of the targets obtained by the two studies are outlined as transparent grey
circles.
These areas may represent the locations most favourable for gold mineralization and should be
considered as Primary Targets for further exploration.
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Fig.103. Bedrock EM Anomalies and Main Lineaments. It is clearly seen mutual spatial proximity of both in many cases, especially for NE and WNW trends.
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Fig.104. Structural Targets (1000x1000m window) and bedrock EM Anomalies. Grey circles outline the areas of overlapping.
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Fig. 105. Structural Targets (500x500m window) and bedrock EM Anomalies. Grey circles outline the areas of overlapping.
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Fig. 106. Structural Targets (250x250m window) and bedrock EM Anomalies. Grey circles outline the areas of overlapping. White lines show two EM
anomalies trends in the central part of the area.
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Fig. 107 . Structural Targets (100x100m window) and bedrock EM Anomalies. Grey circles outline the areas of overlapping. White lines show two EM
anomalies trends in the central part of the area.
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§ 4. Recently published Technical Report on the Newman-Todd Property for Redstar Gold
Corp. [ 7 ] must be reviewed thoroughly, in my opinion, since it may provide Hy Lake with very
promising exploration lead. Omitting all the details of this study, which can be reviewed in [ 7 ],
we will cite only the part dealing exclusively with the immediate spatial proximity to the Hy
Lake claims (area of the Abate Lake).
According to [ 7 ], gold mineralization at Newman Todd appears to be focused along
discreet structural corridors (Fig.108 ).
Fig. 108. Structural breccia corridor and structural interpretation [ 7 ].
These structural corridors appear to cross cut the breccias system and are therefore
termed “secondary or second order” structures. These corridors can be traced from the nearby
Rivard property and through Geophysics (Mag) onto the Newman Todd property. Hole NT-042
which intersected 25.70 g/t gold over 1.0 metres was lost in a fault zone prior to intersecting the
breccias corridor.
The structural corridors may merge at depth as they do in the active mines in Red Lake.
Data collected by Redstar to date suggest that the breccias system is more focused at depth and
may represent and significant depth extent to the gold mineralization.
Fig. 109 represents the overlapping of the main lineaments onto the Abate Lake
structutal corridor. One can see that almost the whole breccias structure is bound by the two NE
oriented main lineaments. The next picture ( Fig.110) shows the secondary lineaments on top of
the Abate
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Fig. 109. Overlapping of the main lineaments onto the Abate Lake structural corridor. In green – area of the breccias corridor.
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Lake target scheme. First, it can easily be seen that two of the Redstar “secondary” structures coincide with
our secondary lineaments. Second, if we follow the main (first-order structure) to the NE into Hy Lake
Properties there are at least three additional cross-cuts of this structure by the secondary lineaments (red
circles). It is important to recall that the 1-st Order structure is also marked by EM anomalies (Fig. 111, [ 9 ]).
Fig.111. EM anomalies [5] over the Abate Lake structural corridor
All things taken together make the area to the south /south-east of Rowan Lake the one of the Primary
Targets for further exploration. The particular attention may be paid to the possibility that the gold
mineralization occurs only where the secondary (in general, minor) structures intersect the major one. Then,
the drilling the sections in between may yield no mineralization at all, misleading the exploration.
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Structural Analysis and Geological/Geophysical Data Conclusions
In this addition to the Structural Study we tried to consider the results along with some geological and
geophysical data available for the property. This is not an exhaustive consideration, since the drilling data,
geochemical data and detail mapping of the mineralization was left out of scope. Such analysis will, possibly,
be done in the near future. So far, the following conclusions can be made:
1. Hy Lake Property (Fig. 91, area F) has the same or similar signatures as do the areas
associated with already developed rich gold prospects. This region is among a few worthy of
exploration follow-up.
2. Structural Analysis Targets which fall into the area of Balmer/Confederation Unconformity
Corridor (windows 500m and 100m) must be taken as Primary Targets, and Structural
Analysis Targets which fall into the Balmer-Confederation Formations field ( mainly in the
Eastern part of the property) should be considered as Second-Order Priority Targets.
3. The implications of the new geological interpretation published in [3] (Fig. 99) may be very
important for the gold exploration in the area. It seems that this issue should be addressed in
the nearest future
4. Fig. 104-107 show overlaps of the EM anomalies and Structural Targets (obtained with 1000m,
500m, 250m and 100m averaging window size). These areas may represent the locations most
favourable for gold mineralization and should be considered as Primary Targets for further
exploration.
5. The area to the south /south-east of Rowan Lake seem to be one of the Primary Targets for
further exploration. The particular attention may be paid to the possibility that the gold
mineralization occurs only where the secondary (in general, minor) structures intersect the
major one
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References: 1. HyLake Press Release, MAY 15, 2008 – Toronto, Ontario.
2. HyLake_Fact_PDAC_Sheet_v2[1]. Spring, 2010
3. Jonathan Selby, Patterns in the crust: a key to ore discovery, Geology Today, September-October
1987:160-164
4. Carlos J. Chernicoff, Jeremy P. Richards, Eduardo O. Zappettini Crustal lineament control on
magmatism and mineralization in northwestern Argentina: geological, geophysical, and remote
sensing evidence, Ore Geology Reviews, 21 (2002) 127–155
5. Gold prospectivity maps of the Red Lake greenstone belt: application of GIS technology.J R Harris,
M Sanborn-Barrie, D A Panagapko, T Skulski, J R Parker. Canadian Journal of Earth Sciences.
Ottawa: Jul 2006. Vol. 43, Iss. 7; pg. 865, 29 pgs 6. Dubé, B., Williamson, K., V. MCNICOLL, Malo, M, T. SKULSKI, T. TWOMEY, M. SANBORN-
BARRIE Timing of Gold Mineralization at Red Lake, Northwestern Ontario, Canada: New
Constraints from U-Pb Geochronology at the Goldcorp High-Grade Zone, Red Lake Mine, and the
Madsen Mine Economic Geology BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS.
VOL. 99December 2004 NO.8 Pp1611-1641 7. Technical Report on the Newman-Todd Property RED LAKE MINING DIVISION, NW ONTARIO
for REDSTAR GOLD CORP. Prepared by R. Bob Singh, P. Geo.,October 1, 2009.
8. AngloGold. ASSESSMENT WORK REPORT. TIME-DOMAIN AIRBORNE EM SURVEY AND
INTERPRETATION. Red Lake Geophysical Survey (2003)
9. DIGHEMv SURVEY FOR REDSTAR GOLD CORP. RIVARD RED LAKE AREAS ONTARIO,
Report #2123A, FUGRO AIRBORNE SURVEYS; 52M01SE2028 OGS
10. COMBINED MAGNETIC, ELECTROMAGNETIC, VLF AND RADIOMETRIC HELICOPTER
SURVEYS BLOC: PIPESTONE RED LAKE AREA, ONTARIO, SIAL Geosciences Inc., 2000.