North Dakota Geological Survey Edward C. Murphy, State Geologist 24K: LstB - sg Lynn D. Helms, Director Dept. of Mineral Resources Surface Geology Lost Bridge Quadrangle, North Dakota
) E E (C R R A O o ' " o ' " D F N F 102 52 30 102 45 00 A ) R. 96 W. R. 95 W. (FIGURE 4 R ANCH) (M 47o 37' 00" 47o 37' 30" Tsb !(22 Qls Qls Tsb Edward C. Murphy Tsb Qls Qls 2007
Qal Tsb
Qal Tsb EXPLANATION Qls
Qls Qal QUATERNARY SYSTEM
Qls Tsb RECENT
Qlsr Landslide Deposits - Recent
Variable mixture of strata and deposits that have slid to the base of steep slopes. Qls
Qal OAHE FORMATION Qls Qal Alluvium Qal
Qls Brownish gray to black sand, silt, clay, and lenses of gravel; flood- plain deposits along recent drainages. Includes lower terrace Qls deposits. Typically less than 50 feet thick. Qal Qat T. 1 48 N. RECENT/PLEISTOCENE
T. 1 47 N. Qls Landslide Deposits
Variable mixture of strata and deposits that have slid to the base of Qls Qls Tsb Qls steep slopes. Qls Qls PLEISTOCENE Qls
Qls COLEHARBOR GROUP
Qls Qat Qls Qls Terrace Deposits Qls Qls Five- to 20-foot-thick layers of sand and gravel (consisting of Qls Qls Qls Qls Qls silicrete, chert, flint, agate, petrified wood, and siltstone found Qls beneath flat to gently undulating slopes adjacent to many of Tsb Qls Qls the major cteeks and rivers. Qls Qls TERTIARY SYSTEM
Qls Qls Qls Qlsr MIOCENE/OLIGOCENE Qls Qls Qls Qls Qls ) Qls Ta ARIKAREE FORMATION N Qls Qls I Qls A Qls T )
N Qls W U S
O Buff-colored tuffaceous sandstone, siltstone, and fresh water
E M
E
R Qls R carbonate. E A E D
D Qls N
L Qls Qls A
L Qls Qls I M ( K Qlsr H
T Qls EOCENE R O N ( Tsb Qls Tc !(22 CHADRON FORMATION Sandy and pebbly mudstone and clayey sandstone.
EOCENE/PALEOCENE
Tgv GOLDEN VALLEY FORMATION
Camels Butte Member Alternating beds of yellowish brown to brown, micaceous Tsb sandstone, siltstone, mudstone, claystone, and lignite.
Bear Den Member Brightly colored, kaolinitic claystone, mudstone, and sandstone, typically overlain by a thin silicious bed (silcrete) or lignite.
PALEOCENE
Tsb SENTINEL BUTTE FORMATION
Alternating beds of grayish brown to gray sandstone, siltstone, mudstone, claystone, and lignite.
Tgv Geologic Symbols
Qal Known contact between two geologic units.
Approximate contact between two geologic units.
Inferred (unknown) contact between two geologic units.
Qls Other Features
Tsb Water
!(22 State Highway
Tsb Unpaved Road Tc
Ta
Tgv
Ta
Qat Tc
T. 1 47 N.
T. 1 46 N. !(22 Qal Qat o ' " 47o 30' 00" 47 30 00 ) (D S o 'R. 1"00 W. (OAKDALE) o ' " U IN N A 102 52 30 102 45 00 N T C N E U N O T E M R R E N E o ' W D L 13 30 ) IL K Scale 1:24,000 ( MN 0 0.5 1
Miles Lambert Conformal Conic Projection Standard Parallels 47o 30 ' 00" and 47o 37 ' 30" Lost Bridge Quadrangle, North Dakota 1927 North American Datum NGVD 1929 USGS 7.5 Minute Topographic Map Contour Interval 20 Feet 1970 Magnetic North Declination at Center of Sheet Road Layer Rectified to 2003 NAIP D igital Orthophoto Cartographic Compilation: Elroy L. Kadrmas