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 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/

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

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 / 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 R O N ( Tsb Qls Tc !(22 Sandy and pebbly mudstone and clayey sandstone.

EOCENE/

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