plate pdf (1.7 mb)
TRANSCRIPT
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Qt
Qt
Qt
Qsl
Qsl
Qsl
Qsl
Qsl
Qsl
Qsl Qsl
Qm
Qm
Qm
Qls
Qls
Qls
Qls
Qls
Qls
Qls
Qfp
Qfp
Qfp
Qfp
Qfp
Qfp
Qfp
Qfp
Qfp
Qaf
Qaf
Qaf
Qaf
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Qaf
Qaf
Qaf
Qaf
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Qaf
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Qaf
Qd
Qd
Qc
Qc
Qc
Qc
Qc
Qc
Qc
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Qc
Qc
Qc
Qc
Qc
Qc
Qc
Qc
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Qfo
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Qfo
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Qfo
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Qfy
Qfy
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Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
Qfy
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Trd
Trd
Trd
Tb
Tb
Tb
TbTb
Tb
Kpeg
Kpeg
Kpeg
Kpeg
Kpeg
Kpeg
Kpeg
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Kqfp
Kqfp
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QUATERNARY
TERTIARY
CRETACEOUS
DEVONIAN
DEVONIAN ANDOLDER
Erosional contact
Erosional contact
Erosional contact
Intrusive contact
Intrusive contact
Intrusive contact
C O R R E L A T I O N O F M A P U N I T S
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Holocene
Pleistocene
LateCretaceous
EarlyCretaceous
Late and MiddleDevonian
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LIST OF MAP UNITS
QUATERNARY AND TERTIARY SURFICIAL DEPOSITS
Flood-plain deposits (Holocene)
Alluvial and fluvial deposits (Holocene)
Colluvium (Holocene)
Young alluvial fan deposits (Holocene)
Landslide deposits (Holocene)
Solifluction deposits (Holocene)
Debris flow deposits (Holocene)
Terrace deposits (Holocene and Pleistocene?)
Old alluvial fan deposits (Holocene and Pleistocene?)
Glacial moraine deposits (Holocene and Pleistocene?)
TERTIARY SEDIMENTARY ROCKS
Gravel-rich terrace deposits (post-Paleocene)
TERTIARY IGNEOUS ROCKS
Basalt dikes (Eocene?)
Rhyolite dikes (Tertiary)
Rhyolite (Paleocene)
CRETACEOUS IGNEOUS ROCKS
Pegmatitic dikes (Late Cretaceous?)
Biotite granite (Late Cretaceous?)
Quartz-feldspar porphyry (Late Cretaceous)
Granitoid dikes and plugs (Early Cretaceous)
Diorite dikes (Early Cretaceous)
Black Mountain intrusion (Early Cretaceous)
Goodpaster batholith (Early Cretaceous)
Main intrusive phase
Early intrusive phase
Granitic rocks of Mount Harper batholith (Early Cretaceous)
Granite of Tibbs Creek (Early Cretaceous)
Granodiorite of Brink intrusion (Early Cretaceous)
PALEOZOIC AND OLDER METAMORPHIC UNITS
Augen gneiss of Central Creek (Late and Middle Devonian)
Biotite orthogneiss (Late and Middle Devonian)
Amphibolite gneiss (Late Devonian and older)
Quartzite and metapelite (pre-Late Devonian)
Biotite±sillimanite gneiss (pre-Middle Devonian)
Biotite gneiss (pre-Late Devonian)
Contact—Dashed where inferred; dotted where concealed; queried where uncertain
Fault—Bar and ball on downthrown side where relative movement known. Dashed where inferred; dotted where concealed
Strike-slip fault—Dashed where inferred; dotted where concealed. In cross section, T indicates motion toward viewer; A, motion away from viewer
Thrust fault—Dotted where concealed
Antiform—Dotted where concealed
Synform—Dashed where inferred; dotted where concealed
Lineament—From analysis of aerial photographs
Shear zone
Minor fold—Showing strike and dip
Lineation—Showing strike and dip. May be combined with foliation symbols
Inclined
Horizontal
Foliation—Showing strike and dip. May be combined with lineation symbols
Inclined
Horizontal
Vertical
Joint—Showing strike and dip
Sample locality for U-Pb SHRIMP age date—See table 1
Placer mine or prospect—See table 2
Lode mine or prospect—See table 2
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TA
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GEOLOGIC MAP OF THE BIG DELTA B-1 QUADRANGLE, EAST-CENTRAL ALASKABy
Warren C. Day, J. Michael O'Neill, John N. Aleinikoff, Gregory N. Green, Richard W. Saltus, and Larry P. Gough
2007
See "Mapping Credits" in pamphlet.Manuscript approved for publication
June 5, 2007
Base from U.S. Geological Survey, 1958.Universal Transverse Mercator projection. 1927 North American Datum.10,000-foot grid based on Alaska coordinate system, zone 3.1,000-meter Universal Transverse Mercator grid ticks, zone 6.
Any use of trade names in this publication is fordescriptive purposes only and does not imply endorsement by the U.S. Geological Survey
For sale by U.S. Geological Survey Information ServicesBox 25286, Federal Center, Denver, CO 802251-888-ASK-USGS
ARC/INFO coverages and a PDF for this map are available athttp://pubs.usgs.gov/
SCIENTIFIC INVESTIGATIONS MAP 2975Pamphlet accompanies map
U.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL SURVEY
Printed on recycled paper
31°
APPROXIMATE MEANDECLINATION, 1958
TR
UE
N
OR
TH
MA
GN
ETIC
NO
RTH
1 7 KILOMETERS.5 0 1 2 3 4 5 6
SCALE 1:63 360
CONTOUR INTERVAL 100 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
1 5 MILES10 2 3 41/ 2
ALASKA
QUADRANGLE LOCATION
Prepared in cooperation with the
ALASKA DEPARTMENT OF NATURAL RESOURCES,DIVISION OF MINING, LAND, AND WATER
A
A'
SERPENTINE
FAU
LT
FAU
LT
BRINK
LAST CHANCE FAULT
FAU
LT
TIBBS
FEET
2000
4000
6000FEET
2000
SEA LEVEL
4000
6000
T A
A A'
SEA LEVEL
Kgtc
Kgtc
Selected Quaternary units omitted
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