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Title: Structurally dependent source rock maturity and kerogen facies, Estancia Basin, New Mexico

Journal Article · · AAPG Bulletin
OSTI ID:86647
 [1]
  1. New Mexico Institute of Mines and Mineral Resources, Socorro, NM (United States)

The Estancia basin of central New Mexico is an asymmetric, north-south trending structural depression that originated during the Pennsylvanian. The present-day basin covers 1,600 mi{sup 2} (4,100 km{sup 2}). It is bounded on the east by the late Paleozoic Pedernal uplift, on the west by the Tertiary-age Manzano and Los Pinos Mountains, on the north by the Espanola basin, and on the south by Chupadera Mesa. Depth to Precambrian basement ranges from 9,000 ft (2,700 m) in a narrow graben in the eastern part of the basin to less than 1,500 ft (460 m) on a shelf to the west. Basin fill consists primarily of Pennsylvanian and Wolfcampian sandstones and shales in the graben and sandstones, shales, and marine limestones on the shelf Mature to marginally mature dark-gray to black Pennsylvanian shales are probable source rocks. Thermal Alteration Index ranges from 2.0 to 3.2. Shales become thermally mature with depth in the eastern graben. On the western shelf, shales become mature to the west as a result of increased heating from the Rio Grande rift. Total organic carbon exceeds 0.5% in many shales, sufficient for hydrocarbon generation. Kerogen types are mixed algal, herbaceous, and woody, indicating that gas, or possibly gas mixed with oil, was generated. Kerogens in shales of the eastern graben are entirely continental, gas-prone types. In limestones and shales of the western shelf, kerogens have a mixed marine and continental provenance, indicating that both oil and gas may have been generated on thermally mature parts of the shelf.

OSTI ID:
86647
Report Number(s):
CONF-9507131-; ISSN 0149-1423; TRN: 95:004859-0050
Journal Information:
AAPG Bulletin, Vol. 79, Issue 6; Conference: American Association of Petroleum Geologists (AAPG) Rocky Mountain Section meeting, Reno, NV (United States), 16-19 Jul 1995; Other Information: PBD: Jun 1995
Country of Publication:
United States
Language:
English