A comparison of detrital U-Pb zircon, 40Ar/39Ar hornblende, 40Ar/39Ar biotite ages in marine sediments off East Antarctica: Implications for the geology of subglacial terrains and provenance studies

In this study we provide a comparison of the detrital U-Pb zircon, 40Ar/39Ar hornblende and 40Ar/39Ar biotite age populations from 28 glacial-diamict and glacial-marine sediment core samples located around East Antarctica (55°W to 163°E). We present 3370 new detrital age measurements of U-Pb zircon, 40Ar/39Ar hornblende, and 40Ar/39Ar biotite, in conjunction with previously published data from some of the same core sites, as well as 78 U-Pb zircon ages measured on dispersed zircons from five ice-rafted debris (IRD) layers recovered at ODP Site 1165. Our data indicate that detrital U-Pb zircon, 40Ar/39Ar hornblende and 40Ar/39Ar biotite ages faithfully document the onshore geology of source areas within East Antarctica, as expressed in their respective age populations. In addition, a number of previously unknown age populations are recorded by the combined thermochronometers. Assuming an East Antarctic provenance, this approach helps to identify otherwise hidden geologic provinces. Previously unrecognized age populations include Archean 40Ar/39Ar hornblende and biotite ages in Dronning Maud Land; 1200-1300 Ma 40Ar/39Ar hornblende ages in the Weddell Sea; ~ 1560 Ma population of U-Pb zircons from the Wilkes Land margin; and Grenvillian (1000-1200 Ma) U-Pb zircon ages from the Adélie/George V Land margin.