Inorganic chemical analyses of black shale from wells in the National Petroleum Reserve in Alaska
Core samples of Mississippian through Upper Cretaceous black shale, siltstone, and limy mudstone from 24 test wells in the National Petroleum Reserve in Alaska (NPRA) have been analyzed for trace elements in order to provide data on regional background concentrations for inorganic geochemical exploration. This study was made because the authors had noticed that several of the rock units cored in the subsurface were associated with surface geochemical anomalies or small mineral deposits in the areas where they crop out. In the southwestern part of the NPRA, the heavy-mineral concentrates from sediments of streams that flow over shale and graywacke of the Lower Cretaceous Fortress Mountain and Torok Formations are unusually rich in lead, arsenic, and silver. Southeast of the NPRA, in the foothills of the Philip Smith Mountains, stream sediments in areas of Permian to Lower Cretaceous shale locally contain anomalously large amounts of zinc and thorium. In addition, the high organic-carbon content of the Shublick Formation, Jurassic (part) Kingak Shale, and lowest Cretaceous pebble shale unit in the subsurface in the Prudhoe Bay area indicate that they may be rich in trace metals. Outcrops of the Shublik in the Brooks Range locally contain much copper, molybdenum, vanadium, and rare-earth elements, and the high gamma-radiation characteristic of the pebble shale unit in the subsurface shows that it is rich in uranium and thorium. The shale section with the most important known metallic deposits is the Mississippian shale and chert now assigned to the Kuna Formation. The distribution of vanadium and nickel may also be of interest in oil exploration. Hughes and others found higher V/Ni ratios in the Prudhoe-Barrow types of oil than in the Umiat-Simpson types and attributed these higher ratios to sources in the Shublik Formation and Jurassic (part) Kingak Shale.
- OSTI ID:
- 7128838
- Journal Information:
- United States Geological Survey, Professional Paper; (USA), Journal Name: United States Geological Survey, Professional Paper; (USA); ISSN XGPPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020200* -- Petroleum-- Reserves
Geology
& Exploration
023000 -- Petroleum-- Properties & Composition
04 OIL SHALES AND TAR SANDS
040402 -- Oil Shales & Tar Sands-- Surface Methods
ACTINIDES
ALASKA
ALKALINE EARTH METAL COMPOUNDS
ARSENIC
BARITE
BARIUM COMPOUNDS
BARIUM SULFATES
BITUMINOUS MATERIALS
BLACK SHALES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHATTANOOGA FORMATION
CHEMICAL ANALYSIS
CHEMISTRY
COPPER
DRILL CORES
ELEMENTS
ENERGY SOURCES
EXPLORATION
EXPLORATORY WELLS
FEDERAL REGION X
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC FORMATIONS
GEOLOGY
INORGANIC PHOSPHORS
LEAD
MATERIALS
METALS
MINERALS
MOLYBDENUM
NICKEL
NORTH AMERICA
OIL SHALES
ORGANIC MATTER
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORS
PHOSPHORUS COMPOUNDS
RARE EARTHS
RESERVES
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SEMIMETALS
SILTSTONES
SILVER
STRATEGIC PETROLEUM RESERVE
STRATIGRAPHY
SULFATE MINERALS
SULFATES
SULFIDES
SULFUR COMPOUNDS
THORIUM
TRACE AMOUNTS
TRANSITION ELEMENTS
URANIUM
USA
VANADIUM
WELLS
ZINC
ZINC COMPOUNDS
ZINC SULFIDES