Duncan Sandstone (OKPd;0)

CLINTON- "Duncan Sandstone," Pd, light-gray and reddish-brown, cross-bedded, fine-grained sandstone and mudstone conglomerate with some interbedded yellowish-gray and reddish-brown shales; thickness, about 200 feet; gradational into the Cedar Hills Sandstone northward and into the Flowerpot Shale northward and westward. OKLAHOMA CITY- Mainly red-brown to orange-brown fine-grained sandstone, with some mudstone conglomerate and shale; grades northward into "Cedar Hills Sandstone" and "Chickasha Formation". Thickness, 450 feet near Chickasha, 300 feet near Oklahoma City, and 100 feet or more near Okarche. (El Reno Group) ARDMORE-SHERMAN- Sandstone, white to buff, fine- to coarse-grained, moderately indurated, with interbedded mudstone conglomerates and siltstones; thickness, 100 to 400 feet, decreasing southeastward. (El Reno Group)

State	Oklahoma
Name	Duncan Sandstone
Geologic age	Phanerozoic \| Paleozoic \| Permian
Original map label	Pd
Primary rock type	sandstone
Secondary rock type	conglomerate
Other rock types	shale; siltstone
Lithologic constituents	Major Sedimentary > Clastic > Conglomerate (Bed) Sedimentary > Clastic > Sandstone (Bed) Minor Sedimentary > Clastic > Siltstone (Bed) Sedimentary > Clastic > Mudstone > Shale (Bed)
Map references	Heran, W. D., Green, G. and Stoeser, D. B., 2003, A Digital Geologic Map Database of Oklahoma: U. S. G. S. Open File Report 03-247
Unit references	Heran, W. D., Green, G. and Stoeser, D. B., 2003, A Digital Geologic Map Database of Oklahoma: U. S. G. S. Open File Report 03-247 Carr, J.E. and Bergman, D.L., 1976, Reconnaissance of the water resources of the Clinton quadrangle, west-central Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 5, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by J.E. Carr, 1972, and R.O. Fay, 1975.) Cederstrand, J.R., 1996d, Digital geologic map of Clinton quadrangles, west-central Oklahoma: U.S. Geological Survey Open-File Report 96-373, (2 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology [http://ok.water.usgs.gov/gis/geology/clinton.html] [http://ok.water.usgs.gov/gis/geology] Bingham, R.H. and Moore, R.L., 1975, Reconnaissance of the Water Resources of the Oklahoma City quadrangle, central Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 4, Scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by R.H. Bingham and R.O. Fay, 1973.) Cederstrand, J.R., 1996i, Digital geologic map of Oklahoma City quadrangles, central Oklahoma: U.S. Geological Survey Open-File Report 96-378, (2 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology [http://ok.water.usgs.gov/gis/geology/okc.html] [http://ok.water.usgs.gov/gis/geology] Hart, D.L., 1974, Reconnaissance of the water resources of the Ardmore and Sherman quadrangles, southern Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 3, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by D.L. Hart, and R.O. Fay, in 1970.) Cederstrand, J.R., 1996a, Digital geologic map of Ardmore-Sherman quadrangles, south-central Oklahoma: U.S. Geological Survey Open-File Report 96-370, (3 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology [http://ok.water.usgs.gov/gis/geology/ardmore.html] [http://ok.water.usgs.gov/gis/geology]
Geographic coverage	Caddo - Canadian - Cleveland - Garvin - Grady - Greer - Kingfisher - Kiowa - McClain - Oklahoma - Stephens - Washita