Dillon cutoff - basement-involved tectonic link between the disturbed belt of west-central Montana and the overthrust belt of extreme southwestern Montana

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<1107:DCBITL>2.3.CO;2· OSTI ID:5796789

O'Neill, J M ^[1]; Schmidt, C J; Genovese, P W ^[2]

---

1. U.S. Geological Survey, Denver, CO (USA)
2. Western Michigan Univ., Kalamazoo (USA)

The front of the Cordilleran fold and thrust belt in western Montana follows the disturbed belt in the north, merges with the southwest Montana transverse zone in the west-central part of the region, and in southwestern Montana is marked by a broad zone characterized by complex interaction between thrust belt structures and basement uplifts. The front margin of the thrust belt in Montana reflects mainly thin-skinned tectonic features in the north, an east-trending lateral ramp that curves southwest in the central part into the Dillon cutoff, an oblique-slip, thick-skinned displacement transfer zone that cuts through basement rocks of the Lima recess, and a zone of overlap between thin- and thick-skinned thrusts in extreme southwestern Montana. The transverse ramp and basement-involved thrust faults are controlled by Proterozoic structures.

• OSTI ID: 5796789
• Journal Information: Geology; (USA), Journal Name: Geology; (USA) Vol. 18:11; ISSN GLGYB; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
BASEMENT ROCK
FEDERAL REGION VIII
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GROUND UPLIFT
LINEAMENTS
MONTANA
MOUNTAINS
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
TECTONICS
USA
WESTERN US OVERTHRUST BELT