Giant landslide deposits in northwest Argentina

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6652963

Fauque, L; Strecker, M R; Bloom, A L

Giant Quaternary landslide deposits occur along mountain fronts in the structural transition zone between the high-angle reverse-fault-bounded Sierras Pampeanas and the low-angle thrust belt of the Sierras Subandinas. There are two modes of occurrence: (1) chaotic masses without distinct geometry, and (2) masses with distinct lobate geometry similar to glacial moraines. Type (1) deposits occur where the moving rock mass followed a narrow valley and blocked the drainage. Many of these caused subsequent formation of lakes and changed the sedimentation processes on pediments at the mountain fronts. In type (2) deposits, lateral and frontal ridges are up to 10 m higher than the interior parts; in some places pressure ridges within the lobes are well preserved. Type (2) deposits show reverse grading and were deposited on relatively smooth pediments or alluvial fans. The lobate geometry strongly suggests that type (2) deposits are a product of flowage and are debris stream or sturzstrom deposits (sense of Heim, 1932 and Hsu, 1975). All investigated deposits occur in areas of demonstrated Quaternary faulting and are interpreted as the result of tectonic movements, although structural inhomogeneities in the source area may have been a significant factor for some of the landslides. No datable materials have yet been found associated with the deposits.

• Research Organization: Servicio Geologico de Argentina, Buenos Aires
• OSTI ID: 6652963
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ARGENTINA
LANDSLIDES
GEOLOGY
TECTONICS
ALLUVIAL DEPOSITS
GEOLOGIC FAULTS
GEOMETRY
ORIGIN
QUATERNARY PERIOD
SEDIMENTS
STRATIGRAPHY
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
LATIN AMERICA
MATHEMATICS
SOUTH AMERICA
580100* - Geology & Hydrology- (-1989)
580201 - Geophysics- Seismology & Tectonics- (1980-1989)