Late Miocene coesite-eclogite exhumed in the Woodlark Rift

Suzanne L. Baldwin, Laura E. Webb, Brian D. Monteleone

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

Late Miocene-Pliocene eclogites were exhumed in the Woodlark Rift of eastern Papua New Guinea, an actively extending region west of the Woodlark Basin seafloor spreading center. We report the discovery of coesite in late Miocene eclogite from the lower plate of one of the D'Entrecasteaux Islands metamorphic core complexes within the Woodlark Rift. Zircon crystallization temperatures (650-675 °C) and 238U/206Pb age (ca. 8 Ma), and rutile thermometry (695-743 °C) combined with garnet-pyroxene thermometry (600-760 °C) and garnet-pyroxene-phengite barometry (18-27 kbar), indicate that the coesite-eclogite was exhumed from mantle depths (≥90 km) to the Earth's surface at plate tectonic rates (cm yr-1). This late Miocene coesite-eclogite is the youngest exhumed ultrahigh-pressure (UHP) rock on Earth, and its preservation ahead of the westward-propagating seafloor spreading center forces reevaluation of models for UHP exhumation, as well as the geologic and tectonic evolution of the Woodlark Rift.

Original languageEnglish (US)
Pages (from-to)735-738
Number of pages4
JournalGeology
Volume36
Issue number9
DOIs
StatePublished - Nov 3 2008

Keywords

  • Coesite-eclogite
  • Ultrahigh-pressure exhumation
  • Woodlark Rift

ASJC Scopus subject areas

  • Geology

Fingerprint Dive into the research topics of 'Late Miocene coesite-eclogite exhumed in the Woodlark Rift'. Together they form a unique fingerprint.

  • Cite this