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(TH REE V CR OS SIN G) ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 00GF 00HS l l l l 5134 MA78-90 MA78-86 MA78-88 MA78-87 MA78-88 MA78-95 MA78-93 MA78-98 MA78-99 MA78-96 MA78-94 MA78-97 MA78-85 MA78-81 MA78-82 MA78-83 MA78-84 MA78-101 MA78-111 MA78-112 MA78-110 MA78-108 MA78-109 MA78-104 MA78-103 MA78-105 MA78-107 MA78-106 MA78-102 12 26 11 10 10 13 21 14 28 17 17.5 14.5 103 o 45 ' 00 " 46 o 30 ' 00 " (SP RING CR EEK ) 103 o 52 ' 30 " 46 o 30 ' 00 " (WI LLIA MS LA KE) (MA RMA RTH) (IVES) (PRETTY BUTTE) 103 o 45 ' 00 " 46 o 22 ' 30 " 103 o 52 ' 30 " 46 o 22 ' 30 " (MARMARTH SE) (BOYCE CR EEK EAST) Cartographic Compilation: E. L. Kadrmas & S.S. Kranich North Dakota Geological Survey 24K: BycC W - c Edward C. Murphy, State Geologist Lynn D. Helms, Director Dept. of Mineral Resources Geologic Symbols This project supported, in part by the U.S Geological Survey, Department of Interior, under assistance awards 02ERAG0016 and 05ERAG0053. UNIT DESCRIPTIONS Economic coal deposits are those that meet the minimum criteria established by coal companies operating surface mines in North Dakota. These economic criteria include a minimum cumulative coal thickness of ten feet-typically occuring in less than two beds, a minimum individual bed thickness of at least 2.5 feet, a ratio of overburden to coal thickness of not more than 10:1, a minimum of 25 feet of overburden, and a maximum depth to coal of approximately 150 feet. Economic Coal Deposits l Geology Undifferentiated T. 1 35 N . T. 1 34 N . Lignite Reserves Boyce Creek West Quadrangle, North Dakota R. 105 W. R. 104 W. Other Features Unpaved Road MN 1980 Magnetic North Declination at Center of Sheet 12 o 30 ' 0 0.5 1 Miles Scale 1:24,000 Standard Parallels 46 o 22 ' 30 " and 46 o 30 ' 00 " USGS 7.5 M inute T opographic Map Con tour Interval 20 Feet Lambert Con fo rmal Co nic Projection 1927 North American Datum NGVD 1929 Road Layer Rectified to 2003 NAIP Digital Orthophoto Boyce Creek West Quadrangle, North Dakota Extent of Local Lignite Reserves Coal thicknesses were determined by interpretation of electric logs from individual drill holes. Gamma and density logs were typically available for coal exploration holes but, oil wells were often limited to a gamma log run through surface casing. Includes Coal Exploration NDGS/USGS drill holes, Sub-surface Mineral drill holes, Oil & Gas drill holes, and NDSWC drill holes. ! ( Data Points Drill Hole Numbers ! MA78-109 Thickness (in feet) of Mineable Lignite ! 10 Edward C. Murphy 2008
