The effects of accretion, erosion and radiogenic heat on the metamorphic evolution of collisional orogens

A. D. Huerta, L. H. Royden, K. V. Hodges

Research output: Contribution to journalArticle

78 Scopus citations

Abstract

Petrological and thermochronological data provide our best record of the thermal structure of deeply eroded orogens, and, in principle, might be used to relate the metamorphic structure of an orogen to its deformational history. In this paper, we present a two-dimensional thermal model of collisional orogens that includes the processes of accretion and erosion to examine the P-T evolution of rocks advected through the orogen. Calculated metamorphic patterns are similar to those observed in the field; metamorphic temperatures, depths and ages generally increase with distance from the toe of the orogen; P-T paths are anti-clockwise, with rocks heating during burial and early stages of unroofing, followed by cooling during late-stage unroofing. The results indicate that peak metamorphic temperatures within the core of a collisional orogen and the distance from the toe of an orogen to the metamorphic core can be related to the relative rates of accretion, erosion and plate convergence. Model orogens displaying high metamorphic temperatures (> 600 °C) are associated with low ratios of accretion rate to plate convergence velocity and with high heat flow through the foreland. Model orogens with metamorphic cores far from the toe of the orogen are associated with high ratios of accretion rate to erosion rate. Calculated metamorphic gradients mimic steady-state geotherms, and inverted thermal gradients can be preserved in the metamorphic record, suggesting reconsideration of the concept that the metamorphic record does not closely reflect geothermal gradients within an orogen.

Original languageEnglish (US)
Pages (from-to)349-366
Number of pages18
JournalJournal of Metamorphic Geology
Volume17
Issue number4
DOIs
StatePublished - Jul 1 1999
Externally publishedYes

Keywords

  • Accretion
  • Erosion
  • Metamorphism
  • Orogeny
  • Radiogenic heat

ASJC Scopus subject areas

  • Geology
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'The effects of accretion, erosion and radiogenic heat on the metamorphic evolution of collisional orogens'. Together they form a unique fingerprint.

  • Cite this