Magnetostratigraphic constraints on the development of paired fold-thrust belts/foreland basins in the Argentine Andes

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7259303

Reynolds, J H ^[1]; Damanti, J F ^[2]; Jordan, T E ^[3]

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1. Norwich Univ., Northfield, VT (United States)
2. Miami Univ., OH (United States)
3. Cornell Univ., Ithaca, NY (United States)

Development of a paired fold thrust-thrust belt/foreland basin is correlated to the flattening of the subducting Nazca plate between 28-33{degree}S. Magnetostratigraphic studies in neogene basin-filling continental strata determine local basin subsidence rates and provide relatively precise chronostratigraphic correlation between different depositional environments. The data demonstrate that most existing lithostratigraphic units are diachronous and require new tectonic interpretations. Increases in sediment accumulation rates closely correspond to changes in provenance and indicate that the Frontal Cordillera, on the Chile-Argentina border was a positive topographic province by 18 Ma. The Precordillera evolved from {approx}16 Ma to the present as thrusting migrated from west to east. Published ages from intercalated airfall tuffs constrain some sedimentary sections in the eastern Sierras Pampeanas where the earliest uplift occurred since 10 Ma. The youngest uplifts are on the west side close to continuing thrusting in the Precordillera. Not all fold-thrust belt/foreland basin pairs are associated with flat subduction, suggesting that tectonic controls exceeding the scale of individual plate segments may be important. The hydrocarbon-producing Subandean fold-thrust belt/foreland basin, located in the area of 'steep' subduction that underlies northern Argentina and Bolivia (18-24{degree}S), is also believed to have evolved since middle Miocene time. Recently initiated magnetostratigraphic studies in the Subandean foreland basin will attempt to temporally constrain the Neogene tectonic evolution for comparison with the southern region.

• OSTI ID: 7259303
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
02 PETROLEUM
03 NATURAL GAS
ARGENTINA
SEDIMENTARY BASINS
GEOLOGIC HISTORY
PALEOMAGNETISM
STRATIGRAPHY
AGE ESTIMATION
ANDES
GEOLOGIC FAULTS
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PLATE TECTONICS
SUBDUCTION ZONES
DEVELOPING COUNTRIES
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
LATIN AMERICA
MAGNETISM
MINERAL RESOURCES
MOUNTAINS
RESOURCES
SOUTH AMERICA
TECTONICS
580000* - Geosciences
020200 - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration