Valley-fill sandstones in the Kootenai Formation on the Crow Indian Reservation, south-central Montana. Quarterly report, October 1--December 31, 1996

摘要

Field investigation of the Kootenai valley-fill sandstones was begun in the first quarter. About one half of the outcrop belt was inventoried for occurrences of channel sandstone before heavy snows came to the area. Five exposures of valley-fill sandstone have been located, of these two are 15 meters (50 feet) or greater in thickness and have excellent porosity and permeability. These will be measured and studied in detail during the next field season (1997). No further field work was possible during the second quarter because of snow cover. Subsurface data is being collected, organized, and a digital database is being prepared for the project. A collection of most of the oil and gas well logs for the Crow Reservation area was donated to the project by a company that had initiated an exploration program on the reservoir several years ago. Geographix petroleum software will probably be used to manage and manipulate the data. Regional subsurface cross sections are being constructed for correlation purposes. All of the four 30 ft. x 60 ft. geologic quadrangles, the Billings, Bridger, Hardin, and Lodge Grass, have been scanned to produce a digital surface geologic data base for the Crow Reservation. These maps are currently being proofed and edited for accuracy.