review of coal genesis in zimbabwe and summary of … · first reports coal •david livingstone...
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REVIEW OF COAL GENESIS IN ZIMBABWE AND SUMMARY OF THE MAJOR DEPOSITS
Brent Barber - Jan 2016
First Reports Coal
• David Livingstone noted coal N of Zambezi River in Zambia in 1857.
• Carl Mauch observed coal close to the Bubye River in 1868.
• Mid-Zambezi Basin in Zimbabwe coal first reported Bari Coal Locality, confluence Katswanzwa and Ume Rivers, by Armstrong, de Noon and Payne early 1890’s.
• Albert Giese pegged claims vicinity Hwange Colliery in 1894.
Brent Barber - Jan 2016
COAL DEVELOPMENT - 1
LOWER KAROO:
• Permo-Carboniferous deposited arctic to warm temperate climatic interval.
• Late Carboniferous – Late Permian / Early Triassic = Sag Basin: Low strain lithospheric thinning prior rifting
• Coal intercalated fluvial, deltaic, paludal and shallow water lacustrine sediments
Brent Barber - Jan 2016
COAL DEVELOPMENT - 2
LOWER KAROO GROUP: MID-ZAMBEZI BASIN
Matabola Formation
• Upper Madumabisa Mudstone Member (k5c-f)
• Lower Madumabisa Mudstone Member (k5a+b)
• Upper Wankie Sandstone Member (k4)
Hwange Formation • Black Shale And Coal Member (k2-3)
• Lower Wankie Sandstone Member (k1)
Brent Barber - Jan 2016
MID
-ZA
MB
EZI B
ASI
N
Brent Barber - Jan 2016
COAL DEVELOPMENT - 3
Economic seams developed diachronous Coal And Black Shale Member and equivalent strata in Zambezi and Save-Limpopo Rift Systems.
Only sub-economic developments coal recognised younger Lower Madumabisa Mudstone Member and equivalent strata.
Brent Barber - Jan 2016
Burnt Coal
Except river sections coal measures often poorly exposed as readily weather - burnt coal, mottled brecciated rock, sometimes define outcrop.
Brent Barber - Jan 2016
CONTROLS PEAT ACCUMULATION
• Facies – telmatic / limnic / paralic
• Climatic conditions incl. temperature peat
• Organic matter input – plant types
• Nutrient supply
• Rate subsidence – compaction peat
• Water-table fluctuations - oxidation
• Water pH and Eh
Brent Barber - Jan 2016
Karoo Basin Sub-Saharan Africa
Brent Barber - Jan 2016
COAL FORMATION - 1 • Dissimilarity coal Hwange to banded coals Europe
noted Lamplugh (1907) – suggested reflected differing conditions accumulation.
• Lightfoot (1914 and 1929) argued detrital opposed in-situ origin coal citing: Lack of any seat-earths underlying seams. Interlamination bright and dull coal as representing
alternating argillaceous and organic deposition. High ash content due accumulation clastic particles with
organic matter. Largely fragmentary nature of the plant remains in the coal
as supporting maceration prior to deposition. Reputed improvement quality coal away from interpreted
basin margin.
Brent Barber - Jan 2016
COAL FORMATION - 2 • Bond (1955) initially supported coals detrital but later,
Bond (1967), concluded some in-situ accumulation, occurred explaining , "under the cool climatic conditions of Ecca [Permian] times, the rate of [plant] growth would be slow, and dead vegetation would be exposed to oxidation and particularly to mechanical fragmentation for a long time before burial, leading to a high percentage of ‘organic mush’ [inertinite macerals and ash] in the coal".
• Watson (1958 and 1960), reasoning differences due climatic variation, flora and sedimentary settings, contended none points Lightfoot established allochthonous opposed autochthonous coal formation.
Brent Barber - Jan 2016
COAL FORMATION - 3 • Main Seam generally richer vitrinite coal above
which contains more inertinite - indicates basal coals deposited stable anaerobic environments where peat, lowering groundwater, subject periodic oxidisation.
• Increased fusinitisation overlying peat - drier environments - reflected increase interlaminated dull & bright coal = greater inertinite content.
• Megascopic logging & petrological studies indicate: Relatively shallow groundwater, denoted intercalated bright and dull coal
logged 50.815 – 54.405m (3.095m). Predominantly high ash coals deposited 42.985 – 50.815m (7.830m),
supported rise ash content upwards, indicate increase groundwater level. Further increase denoted carbonaceous mudstones, containing intercalations
dull coal, logged 37.955 – 42.985m (5.030m). Rises groundwater levels, indicated carbonaceous mudstone interbedded
bright and dull coal intersected 34.500 – 37.955m (3.455m). Additional increase water depth signified mudstone 34.500m upwards.
Brent Barber - Jan 2016
COAL FORMATION - 4a
Barber (1987, 1993, 1994 & 2001)
concluded:
• The Carbo-Permian coals Lower Karoo
Group formed largely deciduous
Gangamopteris – Glossopteris flora -
flourished cold to temperate climatic
interval following Dwyka glaciation.
• Palaeo-surface postulated exhibited
subdued topographic relief.
75
25
50
30
20
Mac M : Inert L:pt
Py Other
MeanVitrinite
Reflectance
(%)
Moist Ash V.M. F.C.
Proximate Analyses (%)
Lower Wankie Sandstone Formation
De
pth
(m
)
Sa
mp
le N
o.
Macroscopic Description
Fib
rou
s d
ull c
oa
l
Brig
ht coa
l
Bri
ght
with
du
ll c
oal
Bri
ght
an
d d
ull c
oal
Du
ll w
ith
brig
ht
co
al
Du
ll c
oal
Ca
rb.M
st
Mud
sto
ne
Increasing DepthWater Table
V:t S-F
10
20
10
540
30
20
10
20
15
852 37
.5
25
.0
12
.5
6.0
4.0
2.0
10
.0
5.0
10
.0
5.0
1.5
1.0
0.5
0.7
9
0.7
5
0.7
7
20
70
50
10
Mineral matter
Petrological Description (%)
Fis
sile
Mst.
35.00
34.00
35.10
35.50
3
35.675
34.50
2
4
36.00
36.15
5
36.50 36.55
37.00 37.075
6
37.50
37.70
7
37.5037.955
8
9
39.0010
38.6238.50
39.50 39.56
40.00
12
40.24
11
40.50
40.87
41.00
13
41.50
42.00
42.50
43.00
43.50
44.00
44.50
45.00
45.50
46.00
46.50
47.00
47.50
48.00
48.50
49.00
49.50
50.00
50.50
51.00
51.50
52.00
52.50
53.00
53.50
54.00
54.50
7.0
8.0
0.2
4.4
1.4 0.7
8
0.8
10.7
6.8
32.3
30.0
11.2
12
0.7
6
2.8
3.4
1.8
15.4
0.6
1.40.7
9
29.7
9.9
2.6
2.6 59.0
56.2
57.6
4.8
37
.4
16.8
52.0
20.2
21.8
16.8
19.2
42.4
32.4
9.2
0.6
2.2
63.0
62.8
1.3
28.0
7.7
0.7
9
3.0
0.4
2.0
0.6
21.2
26.2
14.2
28.9
7.3
1.0
0.7
8
1.4
3.2
24.2
0.4
2.8
16.2
8.0
43.8
25.0
12.8
0.2
3.6
26.6
0.4
30.0
0
2.4
0.7
8
1.3
8.5
26.7
63.5
62.5
58.8
26.3
1.0
10.2
0.7
9
3.2
1.2
4.0
24
.0
0.8
19
.8
14
.0
19
.8
19.8
19.4
9.0
1.0
39.2
6.2
2.0
4.2
25.5
0.7
15.0
0.7
9
58.7
66.0
23.1
1.0
17.2
0.7
9
9.2
2.0
4.6
1.0
21.3
28.4
14.6
9.1
21.6
11.4
1.0
0.7
9
6.8
43.4
3.6
0.2
0.6
29.8
5.2
10.4
17.6
9.2
27.4
0.8
30.2
5.6
2.4
6.8
0.7
9
1.0
13.5
21.7
63.8
60.1
21.4
63.8
17
.5
1.0
20.7
1.6
13.9
16.0
1.2
21
.8
61
.059.1
21.3
1.5
18.1
18.1
56.1
1.7
24.1
17.9
50.0
1.7
30.4
23.8
1.6
35.9
38.7
1.4
20
.8
28.0
49.8
1.7
38.0
16.2
44.1
1.6
15.6
48.9
33.9
1.6
59.4
14.0
25.0
58
.8
1.7
24.7
24.7
59.5
14.3
23.7
14.8
61.4
1.7
23.7
13.2
73
.1
1.6
13.3
12.0
74.5
1.3
10.7
13.5
73.5
1.3
12.7
12.5
72
.7
1.4
12.5
13.4
38.3
1.3
24
.8
35.6
1.6
17.8
56.8
23.8
43.2
1.1
23.1
32
.6
43.2
55.9
1.4
18.4
24.3
72.8
1.3
13.2
12.7
51.1
1.1
19.6
28.2
62.7
1.3
16.1
19.9
1.0
21.6
85.0
1.0
21.8
64.7
12.5
12.4
FIGURE: 4 PROFILE WANKIE MAIN SEAM COMPARING THE INFLUENCE OF VARIATIONSIN WATER TABLE DURING DEPOSITION ON PROXIMATE ANALYSES
AND THE MACERAL COMPOSITION OF THE COAL
-B.H. W.C.C 42,61 Wankie Coalfield : Grid Ref. MK 40226510Elevation 767,84m Coal 234,50-54,05 (19.905m)Brent Barber - Jan 2016
COAL FORMATION - 4b
Major seams hyp- and autochthonous -
exotic constituents comprise greater
proportion coals overlying basal seams.
Slower rates accumulation peat cold to cool
temperate climate in interior continent,
combined mineral content Gondwana flora,
predom. factors relatively high ash Karoo
coals. However, possible derived aerially as
wind-blown loess / volcanic ash.
Inorganic matter coals finely disseminated
rendering beneficiation difficult.
75
25
50
30
20
Mac M : Inert L:pt
Py Other
MeanVitrinite
Reflectance
(%)
Moist Ash V.M. F.C.
Proximate Analyses (%)
Lower Wankie Sandstone Formation
De
pth
(m
)
Sa
mp
le N
o.
Macroscopic Description
Fib
rou
s d
ull c
oa
l
Brig
ht coa
l
Bri
ght
with
du
ll c
oal
Bri
ght
an
d d
ull c
oal
Du
ll w
ith
brig
ht
co
al
Du
ll c
oal
Ca
rb.M
st
Mud
sto
ne
Increasing DepthWater Table
V:t S-F
10
20
10
540
30
20
10
20
15
852 37
.5
25
.0
12
.5
6.0
4.0
2.0
10
.0
5.0
10
.0
5.0
1.5
1.0
0.5
0.7
9
0.7
5
0.7
7
20
70
50
10
Mineral matter
Petrological Description (%)
Fis
sile
Mst.
35.00
34.00
35.10
35.50
3
35.675
34.50
2
4
36.00
36.15
5
36.50 36.55
37.00 37.075
6
37.50
37.70
7
37.5037.955
8
9
39.0010
38.6238.50
39.50 39.56
40.00
12
40.24
11
40.50
40.87
41.00
13
41.50
42.00
42.50
43.00
43.50
44.00
44.50
45.00
45.50
46.00
46.50
47.00
47.50
48.00
48.50
49.00
49.50
50.00
50.50
51.00
51.50
52.00
52.50
53.00
53.50
54.00
54.50
7.0
8.0
0.2
4.4
1.4 0.7
8
0.8
10.7
6.8
32.3
30.0
11.2
12
0.7
6
2.8
3.4
1.8
15.4
0.6
1.40.7
9
29.7
9.9
2.6
2.6 59.0
56.2
57.6
4.8
37
.4
16.8
52.0
20.2
21.8
16.8
19.2
42.4
32.4
9.2
0.6
2.2
63.0
62.8
1.3
28.0
7.7
0.7
9
3.0
0.4
2.0
0.6
21.2
26.2
14.2
28.9
7.3
1.0
0.7
8
1.4
3.2
24.2
0.4
2.8
16.2
8.0
43.8
25.0
12.8
0.2
3.6
26.6
0.4
30.0
0
2.4
0.7
8
1.3
8.5
26.7
63.5
62.5
58.8
26.3
1.0
10.2
0.7
9
3.2
1.2
4.0
24
.0
0.8
19
.8
14
.0
19
.8
19.8
19.4
9.0
1.0
39.2
6.2
2.0
4.2
25.5
0.7
15.0
0.7
9
58.7
66.0
23.1
1.0
17.2
0.7
9
9.2
2.0
4.6
1.0
21.3
28.4
14.6
9.1
21.6
11.4
1.0
0.7
9
6.8
43.4
3.6
0.2
0.6
29.8
5.2
10.4
17.6
9.2
27.4
0.8
30.2
5.6
2.4
6.8
0.7
9
1.0
13.5
21.7
63.8
60.1
21.4
63.8
17
.5
1.0
20.7
1.6
13.9
16.0
1.2
21
.8
61
.059.1
21.3
1.5
18.1
18.1
56.1
1.7
24.1
17.9
50.0
1.7
30.4
23.8
1.6
35.9
38.7
1.4
20
.8
28.0
49.8
1.7
38.0
16.2
44.1
1.6
15.6
48.9
33.9
1.6
59.4
14.0
25.0
58
.8
1.7
24.7
24.7
59.5
14.3
23.7
14.8
61.4
1.7
23.7
13.2
73
.1
1.6
13.3
12.0
74.5
1.3
10.7
13.5
73.5
1.3
12.7
12.5
72
.7
1.4
12.5
13.4
38.3
1.3
24
.8
35.6
1.6
17.8
56.8
23.8
43.2
1.1
23.1
32
.6
43.2
55.9
1.4
18.4
24.3
72.8
1.3
13.2
12.7
51.1
1.1
19.6
28.2
62.7
1.3
16.1
19.9
1.0
21.6
85.0
1.0
21.8
64.7
12.5
12.4
FIGURE: 4 PROFILE WANKIE MAIN SEAM COMPARING THE INFLUENCE OF VARIATIONSIN WATER TABLE DURING DEPOSITION ON PROXIMATE ANALYSES
AND THE MACERAL COMPOSITION OF THE COAL
-B.H. W.C.C 42,61 Wankie Coalfield : Grid Ref. MK 40226510Elevation 767,84m Coal 234,50-54,05 (19.905m)Brent Barber - Jan 2016
COAL DEPOSITIONAL FACIES
Two end models proposed:
• Limnic
• Telmatic
Brent Barber - Jan 2016
LIMNIC DEPOSITIONAL FACIES
Duguid (1981) proposed that in the Mid-Zambezi Basin peat deposition, wedging-out within 35 km down-dip, occurred diachronously along gently shelving palaeo-shoreline areally extensive lake.
OVERFILLED LACUSTRINE BASIN
TELMATIC DEPOSITIONAL FACIES Nyambe (1999) observed abundance inertinite indicated episodes aerobic decomposition - proposed coals deposited alluvial floodplain environments – analogous Niger delta where peat accumulates linear back-swamps: Lower Wankie and equivalent Maamba Sandstones
alluvial channel deposits. Coal measures paludal floodplain accumulation.
Peat accumulation large areas governed subsidence, with fluvial channels, confined levees higher flood-plain, maintaining high water table. Detrital matter (ash) content semi-dependent proximity rivers and palaeo-topography.
Brent Barber - Jan 2016
PEAT FORMATION ALLUVIAL PLAIN FACIES
LIMNIC & TELMATIC FACIES
Concepts re-introduced Oesterlen & Lepper (2005) who over-interpreting available data hypothesised:
Supposed coal “swamp zone” adjacent palaeo-limnic shoreline stretching arc E – Hwange, via Lubimbi, Lusulu, Lubu and Busi Coal Localities to Sengwa.
All coal S lake accumulated alluvial plain.
Brent Barber - Jan 2016
HYPOTHESISED LIMNIC / TELMATIC FACIES
Oesterlen and Lepper (2005)
COAL EXPLORATION o Coal exploration was until relatively recently routinely conducted under tenure Exclusive Prospecting Orders [EPOs].
o Reports detailing work undertaken submitted ZGS.
o On expiry reports archived in ZGS library for public access.
o Summaries work completed EPOs 1 – 900 contained ZGS publications:
o Morrison (1974, 1975 and 1978):
• Bulletin 72 - EPOs 1 to 250. • Bulletin 74 - EPOs 251 to 400. • Bulletin 82 - EPOs 401 to 500.
o Oesterlan (1998): • Bulletin 102 (EPOs 501 – 600).
o Nachsel-Weschke (2002): • Bulletin 106 (EPOs 651 – 900).
Brent Barber - Jan 2016
COAL RANK
• Rank coal Mid-Zambezi Basin increases WNW direction - Lignitic at Bari in Matabola Sub-basin to Bituminous Medium to High Volatile at Hwange in Mlibizi Sub-basin.
• Variations rank of diachronous coals Mid-Zambezi Basin largely attributable differing depths burial and geothermal gradient:
W portion of the Mid-Zambezi Basin coalification enhanced increased temperatures areas buried beneath Batoka Basalt Formation - Nyblade et al. (1990) reported relatively high heat flow of 120 mW/m2 in a drillhole sunk in the Hwange.
Brent Barber - Jan 2016
Mid-Zambezi Basin
Brent Barber - Jan 2016
PRIOR ASSESSMENTS COAL DEPOSITS
• Assessments coal resources Zimbabwe undertaken behalf GSZ by Barber (2001), Harrison (1980), Macgregor (1947) and Maufe (1924) and Montan Consulting GmbH (1983).
• Additionally, using information archived ZGS and
held companies, detailed evaluations individual deposits completed Barber (1986, 1987b+ c, 1988 and In Press) and Palloks (1984 and 1987).
Note: That available on Lubimbi, which as reported by Thompson (1981) documents
investigations Industrial Development Corporation directed establishing material suitable production synthetic fuel, judged inadequate by Palloks (1984) for Coal Resource estimation.
Brent Barber - Jan 2016
RE-ASSESSMENT COAL DEPOSITS
Insufficent public domain data available at the ZGS ~ 1990’s to Present ~ to facilitate the re-evaluation resources any coal deposit in Zimbabwe.
Brent Barber - Jan 2016
COAL RESOURCES & RESERVES 1. Describe coals accordance method developed
Diessel (1982) macroscopic characterisation highly variable, laminated and thinly banded Gondwana coals which, containing organic constituents intermediate banded bituminous Carboniferous age and younger N hemisphere coals, often problematic categorise using definitions International Committee For Coal Petrology (1963 and 1971) based on lithotypes proposed by Stopes (1919 and 1935).
2. Report coal rank accordance standards adopted American Society Testing and Materials (1958 and 1991).
3. Estimate coal Resources and Reserves in accordance Australian Guidelines Estimation and Classification Coal Resources (2014).
COAL LITHOTYPES BRIGHT COAL (VITRAIN): Vitreous to sub-vitreous lustre - 5% dull bands 5mm.
Represents gelified woody material .
BANDED BRIGHT COAL (CLARAIN): Bright, thinly bedded coal, with shiny, black
satin lustre – 5 to 40% bands dull coal 5mm.
BANDED COAL (DUROCLARAIN): Approx. equal proportions, 40 – 60%, bright and
dull coal bands 5mm thick.
BANDED DULL COAL (CLARODURAIN): Predom. dull coal with uneven fracture
containing 5 – 40% bands of bright coal 5mm thick.
DULL COAL (DURAIN): Tough, dull coal, with matt lustre and uneven fracture,
containing 5% bands bright coal 5mm thick. Product oxidised organic
matter.
FIBROUS COAL (FUSAIN): Dull, dirty, friable coal with satin lustre - 5% bands
other lithotypes 5mm. Represents material subjected oxidation or fire.
Brent Barber - Jan 2016
NON - JORC(Govt & Internal Reports)
INVENTORY COAL COAL RESOURCES(Reasonable Prospects
Economic Extraction)
Inferred Inferred
↓ ↓
Indicated Indicated Probable Probable Marketable
↓ ↓ ↓ ↓
Measured Measured Proven Proven Marketable
↓
RELATIONSHIP BETWEEN JORC INVETORY COAL, COAL RESOURCES
↓
AND COAL RESERVES
No Modifying Factors Consideraton Modifying Factors:
Mining / Processing / Metallurgical/ Legal /
Marketing / Environmental / Govt / Social
Incr
eas
e G
eo
logi
cal C
on
fid
en
ce
JORC(Public Reports)
COAL RESERVES(Application Predicted Yield
And Moisture Factors)
Mid-Zambezi Basin
Brent Barber - Jan 2016
LARGER COAL DEPOSITS - ZIMBABWE
o MID-ZAMBEZI RIFT SYSTEM:
Entuba
Hwange
Lubu ??? Lubimbi ???
Lusulu
Western Areas
Sengwa N & S
o SAVE-LIMPOPO RIFT SYSTEM:
Bubye Brent Barber - Jan 2016
BUBYE COAL LOCALITY • Four of six seams, Bubye Bottom, Bubye No: 2,
Bubye Main and Bubye Top, assessed possess economic coal potential.
• Due widespread igneous activity no average coal seam quality data reported.
• Rank high ash coal based proximate analyses ranges Bituminous Medium Volatile to Anthracite. Coal possesses coking characteristics.
• Tonnage in-situ Inventory coal, Inferred standing, in Bubye E and W estimated total 438mmt. Greater proportion delineated Bubye Main and Bubye Bottom. Majority only exploitable u/g mining.
Brent Barber - Jan 2016
ENTUBA COAL LOCALITY • Palloks (1984), despite inconsistent sampling and analytical
procedures Hwange Colliery, established ±10m Main Seam decreased quality upwards.
• Basal 1.5m Main Seam straight coking coal and overlying 1.5m blend. Bulk upper portion thermal. Possibility increase av. thickness coking coal ±3 metres only slight decrease quality.
• Vitrinite reflectance 0.7 - 1.28 RoV (mean) but readings 0.7 and 1.13 RoV (mean), bhs only 270m apart area, devoid known igneous activity, contentious. Disregarding results assessed Bituminous High Volatile rank.
• In-situ Inventory coal, Indicated standing, o/c cumulative strip ratio cut-off ≤3.5m ob/t coal, estimated total 77.3mmt. Approx. 25% coking and blend coking coal .
• In-situ u/g Inventory coal, Indicated standing, with 19% coking and blend coking quality, totals 106mmt.
Brent Barber - Jan 2016
HWANGE COLLIERY • Main Seam, decreases quality upwards - composed
sub-seams variable thickness and non-established continuity.
• Bright coal developed base Main Seam formed Sub-seams 1 and parts 2 and/or 3.
• Inventory Bituminous to High Volatile Bituminous rank coal, Measured standing, estimated 1,506mmt in-situ.
• Portion o/c, cumulative strip ratio cut-off 3.5m o/b per tonne coal, totals 225.7mmt.
• Coking coal totals 472mmt with 66mmt o/c. • Coal remaining, following depletion mining,
requires assessment.
Brent Barber - Jan 2016
LUBU COAL LOCALITY
• Main seam, relatively high ash Bituminous High Volatile coal, av. 12.5m thick.
• Best quality coal, with top and bottom portions inferior, towards centre Main Seam.
• Portions low S coking coal potential.
• In-situ o/c Inventory coal of Indicated standing estimated total 334mmt – mineable relatively low strip ratio of 2.9.
• If A–Seam mined tonnage increased ±30%.
• Additional large Inferred tonnage noted to S.
Brent Barber - Jan 2016
LUSULU COAL LOCALITY
• Rank high ash Main Seam Sub-bituminous to Bituminous Medium Volatile.
• Best coal, ash content increases upwards, occurs lower portion Main Seam. Quality coal decreases to SE and SW.
• Portions Main Seam possess some coking potential.
• Coal possess high moisture retaining capacity - on drying prone spontaneous combustion.
• S content raw coal reduceable 0.6% washing S.G. 1.6.
• Coals overlying A-Seam inferior quality.
• In-situ o/c Inventory tonnage coal, cumulative strip ratio 3.5m o/b per tonne coal, estimated 402.6mmt and u/g 1,492.2mmt. Both Indicated standing.
Brent Barber - Jan 2016
SENGWA COAL LOCALITIES Sub-bituminous - Bituminous High Volatile rank non-coking
coal Main Seam. Thickness Main Seam, wedges-out E in Sengwa S and S in
Sengwa N, av 14.1m and 12.5m respectively. Central portion Sengwa S raw ash content footwall averages
±20%. Then decreases <10% before increasing, ±2m above footwall, to >20% near top.
Sulphur Sengwa S low, av 0.24% as opposed 0.75% Sengwa N. Phosphorus av 0.095% Sengwa S and 0.168% Sengwa N. High moisture content, >3.5% Air Dried, prohibatative caking. Drying coal and coaly shale prone spontaneous combustion. In-situ Inventory coal, estimated Indicated standing:
• Sengwa N: 205mmt o/c at cumulative strip ratio cut-off 3.5m o/b per tonne coal.
• Sengwa South: 302mmt coal extractable u/g.
SPONTANEOUS COMBUSTION - SENGWA
Brent Barber - Jan 2016
WESTERN AREAS COAL LOCALITY • Ash content and frequency mudstone partings increases
up dip towards outcrop. • Quality coal deteriorates upwards. • Up to ⅓ basal portion Main Seam, av ±8m, coking
potential. • S content raw coal averages 1.5. • Possible, accepting lower part Main Seam absent, that
Main and No. 1 Seams coalesce o/c, with poorer coal base upper portion Main Seam and overlying coal No. 1 Seam.
• Medium to High Volatile Bituminous Inventory coal present Main and No. 1 Seams assessed Indicate standing.
• Main Seam estimated 77.1mmt o/c and 874.8mmt u/g in-situ coal. In addition, in-situ coal No. 1 Seam estimated 28.0mmt o/c, cumulative strip ratio cut-off 3.5m o/b per tonne coal, and 143.2mmt u/g.
Brent Barber - Jan 2016