This data set is a portion of a statewide geology database, which is being compiled by the U.S. Geological Survey's National Surveys and Analysis (NSA) project, whose goal is to compile geologic, geochemical, geophysical, and other data.
Shew, Nora, Peterson, C. Shaun, Grabman, Nathaniel, Mohadjer, Solmaz, Grunwald, Daniel, Wilson, Frederic H., and Hults, Chad K., 2006, Preliminary integrated geologic map databases for the United States: Digital data for the geology of southeast Alaska by George E. Gehrels and Henry C. Berg: United States Geological Survey Open-File Report OFR 2006-????.Online Links:
This is a Vector data set.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000256
Ordinates (y-coordinates) are specified to the nearest 0.000256
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1927.
The ellipsoid used is Clarke 1866.
The semi-major axis of the ellipsoid used is 6378206.4.
The flattening of the ellipsoid used is 1/294.9787.
| Value | Definition |
|---|---|
| 98 | not mapped; NSACLASS = 98 |
| 101 | ice; NSACLASS = 101 |
| 102 | water; NSACLASS = 102 |
| 4500 | Qs - Surficial sedimentary deposits (Quaternary); NSACLASS = 100 |
| 4510 | QTv - Volcanic rocks (Quaternary and Tertiary); NSACLASS = 450 |
| 4520 | QTs - Sedimentary rocks (Quaternary and Tertiary); NSACLASS = 565 |
| 4530 | Tv - Volcanic rocks (Tertiary); NSACLASS = 1059 |
| 4540 | Ts - Sedimentary rocks (Tertiary); NSACLASS = 500 |
| 4550 | Tsv - Sedimentary and volcanic rocks, undivided (Tertiary); NSACLASS = 794 |
| 4560 | Ks - Sedimentary rocks (Cretaceous); NSACLASS = 2866 |
| 4570 | Kv - Volcanic rocks (Cretaceous); NSACLASS = 2891 |
| 4580 | Ksv - Sedimentary and volcanic rocks, undivided (Cretaceous); NSACLASS = 2865 |
| 4581 | Ksv? - Sedimentary and volcanic rocks, undivided (Cretaceous); NSACLASS = 2865 |
| 4590 | KJs - Sedimentary rocks (Cretaceous and Jurassic); NSACLASS = 2820 |
| 4591 | KJs? - Sedimentary rocks (Cretaceous and Jurassic); NSACLASS = 2820 |
| 4600 | KJv - Volcanic rocks (Cretaceous and Jurassic); NSACLASS = 2340 |
| 4601 | KJv? - Volcanic rocks (Cretaceous and Jurassic); NSACLASS = 2340 |
| 4610 | KJsv - Sedimentary and volcanic rocks, undivided (Cretaceous and Jurassic); NSACLASS = 2822 |
| 4620 | Trs - Sedimentary rocks (Triassic); NSACLASS = 4470 |
| 4621 | Trs? - Sedimentary rocks (Triassic); NSACLASS = 4470 |
| 4630 | Trv - Volcanic rocks (rhyolitic to basaltic) (Triassic); NSACLASS = 4474 |
| 4640 | Trsv - Sedimentary and volcanic rocks, undivided (Triassic); NSACLASS = 4471 |
| 4650 | Trc - Carbonate rocks (Triassic); NSACLASS = 4473 |
| 4660 | Trb - Basaltic rocks (Triassic); NSACLASS = 4420 |
| 4670 | Trsc - Clastic sedimentary and carbonate rocks, undivided (Triassic); NSACLASS = 4000 |
| 4680 | Ps - Sedimentary rocks (Permian); NSACLASS = 5766 |
| 4690 | Pv - Volcanic rocks (Permian); NSACLASS = 5810 |
| 4700 | Pc - Carbonate rocks (Permian); NSACLASS = 5765 |
| 4710 | Pas - Sedimentary rocks (Pennsylvanian); NSACLASS = 6031 |
| 4720 | Pac - Carbonate rocks (Pennsylvanian); NSACLASS = 6030 |
| 4730 | Mc - Carbonate rocks (Mississippian); NSACLASS = 6340 |
| 4740 | MDsv - Sedimentary and volcanic rocks, undivided (Mississippian and Devonian); NSACLASS = 5930 |
| 4750 | Ds - Sedimentary rocks (Devonian); NSACLASS = 6939 |
| 4760 | Dv - Volcanic rocks (Devonian); NSACLASS = 7030 |
| 4761 | Dv? - Volcanic rocks (Devonian); NSACLASS = 7030 |
| 4770 | Dsv - Sedimentary and volcanic rocks, undivided (Devonian); NSACLASS = 7020 |
| 4771 | Dsv? - Sedimentary and volcanic rocks, undivided (Devonian); NSACLASS = 7020 |
| 4780 | Dc - Carbonate rocks (Devonian); NSACLASS = 6938 |
| 4790 | Dcg - Conglomeratic rocks (Devonian); NSACLASS = 6937 |
| 4800 | Sc - Carbonate rocks (Silurian); NSACLASS = 6960 |
| 4810 | Scg - Conglomeratic rocks (Silurian); NSACLASS = 6618 |
| 4820 | Ss - Sedimentary rocks (Silurian); NSACLASS = 6619 |
| 4830 | Sv - Volcanic rocks (Silurian); NSACLASS = 6740 |
| 4840 | SOs - Sedimentary rocks (Silurian and Ordovician); NSACLASS = 6690 |
| 4841 | SOs? - Sedimentary rocks (Silurian and Ordovician); NSACLASS = 6690 |
| 4850 | SOv - Volcanic rocks (Silurian and Ordovician); NSACLASS = 6712 |
| 4860 | SOsv - Sedimentary and volcanic rocks (Silurian and Ordovician); NSACLASS = 6689 |
| 4861 | SOsv? - Sedimentary and volcanic rocks (Silurian and Ordovician); NSACLASS = 6689 |
| 4870 | SOsvc - Clastic sedimentary, volcanic, and carbonate rocks, undivided (Silurian and Ordovician); NSACLASS = 6800 |
| 4880 | KPs - Sedimentary rocks (Cretaceous to Permian); NSACLASS = 5010 |
| 4881 | KPs? - Sedimentary rocks (Cretaceous to Permian); NSACLASS = 5010 |
| 4890 | KPv - Volcanic rocks (Cretaceous to Permian); NSACLASS = 5105 |
| 4900 | KPsv - Sedimentary and volcanic rocks, undivided (Cretaceous to Permian); NSACLASS = 5011 |
| 4910 | KPsvc - Clastic sedimentary, volcanic, and carbonate rocks, undivided (Cretaceous to Permian); NSACLASS = 5271 |
| 4920 | JMsv - Sedimentary and volcanic rocks, undivided (Jurassic to Mississippian); NSACLASS = 5270 |
| 4930 | TrPc - Carbonate rocks (Triassic and(or) Permian); NSACLASS = 4521 |
| 4931 | TrPc? - Carbonate rocks (Triassic and(or) Permian); NSACLASS = 4521 |
| 4940 | TrPsv - Sedimentary and volcanic rocks, undivided (Triassic and Permian); NSACLASS = 5260 |
| 4950 | TrOsv - Sedimentary and volcanic rocks, undivided (Triassic to Ordovician); NSACLASS = 5200 |
| 4960 | TrOc - Carbonate rocks (Triassic to Ordovician); NSACLASS = 6617 |
| 4970 | PaDsv - Sedimentary and volcanic rocks, undivided (Pennsylvanian to Devonian); NSACLASS = 6095 |
| 4980 | DSv - Volcanic rocks (Devonian and Silurian); NSACLASS = 7020 |
| 4981 | DSv? - Volcanic rocks (Devonian and Silurian); NSACLASS = 7020 |
| 4990 | DOsv - Sedimentary and volcanic rocks, undivided (Devonian to Ordovician); NSACLASS = 7200 |
| 4991 | DOsv? - Sedimentary and volcanic rocks, undivided (Devonian to Ordovician); NSACLASS = 7200 |
| 5000 | DOc - Carbonate rocks (Devonian to Ordovician); NSACLASS = 6616 |
| 5010 | DSc - Carbonate rocks (Devonian and Silurian); NSACLASS = 6932 |
| 5020 | DSsc - Sedimentary rocks (Devonian and Silurian); NSACLASS = 6953 |
| 5040 | Ksvm - Melange, sedimentary and volcanic rocks, undivided (Cretaceous); NSACLASS = 2950 |
| 5041 | Ksvm? - Melange, sedimentary and volcanic rocks, undivided (Cretaceous); NSACLASS = 2950 |
| 5050 | Ksm - Melange, sedimentary rocks (Cretaceous); NSACLASS = 2950 |
| 5060 | Kvm - Melange, volcanic rocks (Cretaceous); NSACLASS = 2953 |
| 5080 | KDsd - Disrupted rocks, sedimentary rocks (Cretaceous to Devonian); NSACLASS = 2971 |
| 5090 | KDvd - Disrupted rocks, volcanic rocks (Cretaceous to Devonian); NSACLASS = 2972 |
| 5110 | pTmsv - Metasedimentary and metavolcanic rocks (pre-Tertiary); NSACLASS = 12500 |
| 5111 | pTmsv? - Metasedimentary and metavolcanic rocks (pre-Tertiary); NSACLASS = 12500 |
| 5120 | pTmc - Metacarbonate rocks (pre-Tertiary); NSACLASS = 12600 |
| 5130 | pOmsv - Metasedimentary and metavolcanic rocks (pre-Ordovician); NSACLASS = 8751 |
| 5140 | pOmc - Metacarbonate rocks (pre-Ordovician); NSACLASS = 8752 |
| 5150 | Tgb - Gabbro (Miocene and Oligocene); NSACLASS = 1254 |
| 5160 | Tgr - Granite (Miocene and Oligocene); NSACLASS = 1250 |
| 5170 | Tgd - Granodiorite (Oligocene and Eocene); NSACLASS = 1273 |
| 5171 | Tgd? - Granodiorite (Oligocene and Eocene); NSACLASS = 1273 |
| 5180 | Tg - Granodiorite (Eocene); NSACLASS = 1305 |
| 5181 | Tg? - Granodiorite (Eocene); NSACLASS = 1305 |
| 5190 | Tgt - Granodiorite and tonalite (Paleocene); NSACLASS = 1350 |
| 5191 | Tgt? - Granodiorite and tonalite (Paleocene); NSACLASS = 1350 |
| 5200 | TKt - Tonalite (Paleocene and Cretaceous); NSACLASS = 1662 |
| 5201 | TKt? - Tonalite (Paleocene and Cretaceous); NSACLASS = 1662 |
| 5210 | TKg - Granodiorite (Paleocene and Cretaceous); NSACLASS = 1655 |
| 5211 | TKg? - Granodiorite (Paleocene and Cretaceous); NSACLASS = 1655 |
| 5220 | Kgt - Granodiorite and tonalite (Cretaceous); NSACLASS = 2480 |
| 5221 | Kgt? - Granodiorite and tonalite (Cretaceous); NSACLASS = 2480 |
| 5230 | Kdb - Diorite and gabbro (Cretaceous); NSACLASS = 2494 |
| 5240 | Kum - Ultramafic rocks (Cretaceous); NSACLASS = 2495 |
| 5241 | Kum? - Ultramafic rocks (Cretaceous); NSACLASS = 2495 |
| 5250 | Kg - Granodiorite (Cretaceous); NSACLASS = 2493 |
| 5251 | Kg? - Granodiorite (Cretaceous); NSACLASS = 2493 |
| 5260 | Kd - Diorite (Cretaceous); NSACLASS = 2540 |
| 5261 | Kd? - Diorite (Cretaceous); NSACLASS = 2540 |
| 5270 | Kgb - Gabbro (Cretaceous); NSACLASS = 2550 |
| 5280 | KJd - Diorite (Cretaceous and Jurassic); NSACLASS = 2990 |
| 5281 | KJd? - Diorite (Cretaceous and Jurassic); NSACLASS = 2990 |
| 5290 | KJgb - Gabbro (Cretaceous and Jurassic); NSACLASS = 2920 |
| 5291 | KJgb? - Gabbro (Cretaceous and Jurassic); NSACLASS = 2920 |
| 5300 | Jgr - Granite (Jurassic); NSACLASS = 3410 |
| 5301 | Jgr? - Granite (Jurassic); NSACLASS = 3410 |
| 5310 | Jt - Tonalite (Jurassic); NSACLASS = 3404 |
| 5320 | JTrd - Diorite (Jurassic and(or) Triassic); NSACLASS = 3900 |
| 5330 | Trgb - Gabbro (Triassic); NSACLASS = 4320 |
| 5331 | Trgb? - Gabbro (Triassic); NSACLASS = 4320 |
| 5340 | Trg - Granodiorite (Triassic); NSACLASS = 3620 |
| 5350 | PPasy - Syenite (Permian and(or) Pennsylvanian); NSACLASS = 5875 |
| 5360 | Sst - Syenite and trondhjemite (Silurian); NSACLASS = 6730 |
| 5370 | SOum - Ultramafic rocks (Silurian and Ordovician); NSACLASS = 6750 |
| 5380 | SOq - Quartz diorite (Silurian and Ordovician); NSACLASS = 7650 |
| 5381 | SOq? - Quartz diorite (Silurian and Ordovician); NSACLASS = 7650 |
| 5390 | Ogb - Gabbro (Ordovician); NSACLASS = 7670 |
| 5391 | Ogb? - Gabbro (Ordovician); NSACLASS = 7670 |
| 5400 | Cdg - Diorite and granodiorite (Cambrian); NSACLASS = 8500 |
Q - queried unit GBS - undifferentiated intrusive and stratified rocks; item CLASS indicates predominant lithic unit (shown as stippled area in Gehrels and Berg, 1992)
The following SOURCE values are used in this dataset and all refer to Gehrels and Berg, 1992: BC006, CR012, DE008, JU012, KC013, MF011, PE006, PA006, PR003, SI009, SK015, SD016, and TR008.
| Value | Definition |
|---|---|
| 0 | hidden line |
| 2 | Stratigraphic or intrusive contact, location approximate |
| 3 | Stratigraphic or intrusive contact, location inferred or queried |
| 4 | Normal fault, location certain, digitized with upthrown side on the right (code of 1 added to ARC-PARA1 where up/down is designated in source) |
| 7 | shoreline or riverbank |
| 10 | Thrust fault, location certain, teeth on right from origin |
| 11 | Thrust fault, location approximate, teeth on right from origin |
| 12 | Thrust fault, location inferred or queried, teeth on right from origin |
| 15 | Ice contact |
| 30 | Fault, sense of displacement uncertain, location certain |
| 31 | Fault, sense of displacement uncertain, location approximate |
| 32 | Fault, sense of displacement uncertain, location inferred |
| 51 | Concealed contact |
| 52 | Concealed normal fault |
| 53 | Concealed thrust fault |
| 57 | Concealed right lateral fault |
| 58 | Concealed left lateral fault |
| 60 | Concealed fault displacement uncertain |
| 87 | Right lateral fault, location certain |
| 90 | Left lateral fault, location certain |
| 91 | Left lateral fault, location approximate |
| 93 | Coast Range megalineament |
| 99 | Bounding line (neatline) of coverage |
This data set was prepared by C. Shaun Peterson (contractor), Nora Shew (USGS), Nathaniel Grabman (USGS), and Daniel Grunwald (contractor)
U.S. Geological Survey
c/o Frederic H. Wilson
Geologist
4200 University Drive
Anchorage, Alaska 99508
U.S.A.
907-786-7448 (voice)
fwilson@usgs.gov
This data set represents part of a systematic effort to release geologic map data for the United States in a uniform manner. Geologic data in this series has been compiled from a wide variety of sources, published and unpublished, ranging from state and regional geologic maps to large-scale field mapping.
Gehrels, George E., and Berg, Henry C., 1992, Geologic map of southeastern Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1867.Online Links:
- www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=12916
Person responsible for change:
U.S. Geological Survey
c/o Nora B. Shew
Geologist
4200 University Drive
Anchorage, Alaska 99508
U.S.A.
907-786-7445 (voice)
nshew@usgs.gov
The original source material for this data set is a folded paper 1:600,000 scale map. The source map's base is an enlarged U.S. Geological Survey 1:2,000,000 scale National Atlas, Albers Equal Area projection map. The paper map was scanned and portions of the scanned image were registered to a digital 1:250,000 scale coastline base. All vector features were hand digitized on screen. Vector and polygon attributes were assigned based on the original source. Some obvious cartographic errors on the original map have been corrected in this digital version, such as solid line faults underwater are now coded as concealed. Other errors have been digitized as shown on the original map. One correction was provided by original author, Henry C. Berg. A single polygon of geologic unit KJgd is shown on the north side of Admiralty Island. Unit KJgd is not mentioned anywhere else in the original publication. This polygon is attributed as KJgb? (Henry C. Berg, oral commun, 2006). The digital data has been checked, reviewed, and edited.
This data is presented for use at a nominal scale of 1:500,000.
The complete data set consists of 20 different GIS coverages and an associated relational database of geologic units. Each coverage has the extent of a 1:250,000 scale quadrangle. There are 13 geology coverages and 7 lineament coverages. This digital data set differs from the original Gehrels and Berg (1992) map in the following ways: uses a different base and projection; does not include names of faults or geographic features, the index map showing sources used in the compilation, or the correlation chart.
Each geology coverage is a network coverage containing attributed arcs and polygons. Each polygon has a coded attribute designating the mapped geologic unit. Faults, stratigraphic contacts, and other linear features are represented as arcs. If a fault is also a stratigraphic contact, only a single arc is present. Dangling arcs may be present (faults, dike, etc.)
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- None. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data.
U.S. Geological Survey
MS 902 Box 25286 Denver Federal Center
Lakewood, CO 80225
USA
1-888-ASK-USGS (voice)
Open-File Report 2006-????
This world-wide web publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.Although all data and software published on this web-site have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.
| Data format: | ARCE |
|---|---|
| Network links: |
???? |
U.S. Geological Survey
c/o Nora B. Shew
4200 University Drive
Anchorage, AK 99508
USA
907-786-7445 (voice)
nshew@usgs.gov