18. The Pampa del Tamarugal Forearc Basin in Northern Chile: The Interaction of Tectonics and Climate

  1. Cathy Busby2 and
  2. Antonio Azor3
  1. Peter Nester and
  2. Teresa Jordan

Published Online: 30 JAN 2012

DOI: 10.1002/9781444347166.ch18

Tectonics of Sedimentary Basins: Recent Advances

Tectonics of Sedimentary Basins: Recent Advances

How to Cite

Nester, P. and Jordan, T. (2011) The Pampa del Tamarugal Forearc Basin in Northern Chile: The Interaction of Tectonics and Climate, in Tectonics of Sedimentary Basins: Recent Advances (eds C. Busby and A. Azor), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9781444347166.ch18

Editor Information

  1. 2

    Department of Earth Science, University of California, Santa Barbara CA 93106, USA

  2. 3

    Departamento de Geodinámica, Universidad de Granada, Campus de Fuentenueva, s/n, 18071 Granada, Spain

Author Information

  1. Department of Earth and Atmospheric Sciences, Cornell University, Snee Hall, Ithaca, NY 14853, USA

Publication History

  1. Published Online: 30 JAN 2012
  2. Published Print: 30 DEC 2011

ISBN Information

Print ISBN: 9781405194655

Online ISBN: 9781444347166

SEARCH

Keywords:

  • forearc basin;
  • hyperarid climate;
  • syntectonic sediments;
  • nonmarine depositional environments;
  • monocline

Summary

The nonmarine Pampa del Tamarugal forearc sedimentary basin has existed on the west flank of the Andes Mountains in northern Chile from Late Oligocene to modern times. The highly elongate, trench-parallel intramassif basin lies on continental crust and overlaps the roots of the Cretaceous through Eocene magmatic arc. The basin fill is lensshaped with a central axis that reaches 1000-1800m thickness, tapering eastward to the western edge of the Altiplano plateau and volcanic arc, and westward to a low range that is the erosional relict of a Mesozoic arc system. Most of the sedimentary fill was derived from erosion of the Andes and eruption of the Western Cordillera volcanic arc. For at least the first half of its history (∼25-11 Ma), the entire basin was a sediment trap, but during the last 11 million years the northern half largely ceased accumulation of strata while accumulation in the south decelerated. The basin exhibits first-order sedimentary responses to a climate that evolved from semi-arid to hyperarid, while simultaneously exhibiting first-order expressions of∼3000m of tectonic and surface uplift of the eastern margin of the basin that was contemporaneous with its fill. During the Early and Middle Miocene, ∼2000m of uplift accumulated across a set of stair-step-like small-scale westfacing monoclines, whereas during the Late Miocene through Quaternary the eastern 30-45km of the basin became the limb of a single long-wavelength west-facing monocline that produced another ∼1000m of uplift.