Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Simulating foreland basin response to mountain belt kinematics and climate change in the Eastern Cordillera and Subandes; an analysis of the Chaco foreland basin in southern Bolivia

Todd M. Engelder and Jon D. Pelletier
Simulating foreland basin response to mountain belt kinematics and climate change in the Eastern Cordillera and Subandes; an analysis of the Chaco foreland basin in southern Bolivia
Memoir - Geological Society of America (2015) 212: 337-357

Abstract

The relative importance of crustal thickening, lithospheric delamination, and climate change in driving surface uplift and the associated changes in accommodation space and depositional facies in the adjacent foreland basin in the central Andes has been a topic of vigorous debate over the past decade. Interpretation of structural, geochemical, geomorphic, and geobiologic field data has led to two proposed end-member Tertiary surface uplift scenarios for the Eastern Cordillera and Subandes in the vicinity of the Bolivian orocline. A "gradual uplift" model proposes that the rate of surface uplift has been relatively steady since deformation propagated into the Eastern Cordillera during the late Eocene. In this scenario, the mean elevation of the region was >2 km above mean sea level (msl) by the late Miocene or earlier. Alternatively, a "rapid uplift" model suggests that the mean elevation of the Altiplano was <1 km above msl, and the peaks of the Eastern Cordillera were more than 2 km below their modern elevations until rapid uplift began ca. 10 Ma. Determining which of these uplift scenarios is most consistent with the stratigraphic record is complicated by the potentially confounding effects of global climate changes and lithospheric delamination in the stratigraphic record. In this study, we use a coupled mountain-belt-sediment-transport model to predict the foreland basin stratigraphic response to these end-member surface uplift scenarios. Our model results indicate that the location and height of the migrating deformation front play the dominant roles in controlling changes in accommodation space and grain size within the foreland basin. Changes in accommodation space and rates of sediment supply related to climate change and lithospheric delamination play secondary roles. Our results support the conclusion that the Eastern Cordillera likely gained most of its modern elevation prior to 10 Ma, in contrast with recent proposals that most of the modern elevation was obtained during the late Miocene. This conclusion is consistent with the most comprehensive paleoaltimetric analysis of the region to date.


ISSN: 0072-1069
Coden: GSAMAQ
Serial Title: Memoir - Geological Society of America
Serial Volume: 212
Title: Simulating foreland basin response to mountain belt kinematics and climate change in the Eastern Cordillera and Subandes; an analysis of the Chaco foreland basin in southern Bolivia
Affiliation: University of Arizona, Department of Geosciences, Tucson, AZ, United States
Pages: 337-357
Published: 2015
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 80
Accession Number: 2015-036125
Categories: Structural geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, sketch map
S25°00'00" - S17°00'00", W71°00'00" - W55°00'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201517
Close Modal

or Create an Account

Close Modal
Close Modal