Age determinations of rocks from Vestfjella and Ahlmannryggen in Antarctica


Autoria(s): Peters, Matthias; Lippolt, Hans Jürgen; Rittmann, Ursula; Weber, Klaus
Cobertura

MEDIAN LATITUDE: -72.550000 * MEDIAN LONGITUDE: -8.000000 * SOUTH-BOUND LATITUDE: -73.500000 * WEST-BOUND LONGITUDE: -15.000000 * NORTH-BOUND LATITUDE: -71.700000 * EAST-BOUND LONGITUDE: -1.000000

Data(s)

18/07/1989

Resumo

The Proterozoic country rock at Ahlmannryggen consists of flat lying basaltic lo andesitic lava flows and sedimentary rocks intruded by dioritic sills (Borgmassivet Intrusives). The suites display a typical platform cover. K-Ar age determinations gave maximum ages of about 1200 Ma on the magmatic rocks. All these suites were intruded bv Proterozoic dikes dated also at about 1200 Ma. Localiy the Proterozoic rocks have a slaty cleavage grading into mylonitic texture which strike parallel to the Jutul Penck graben. Such tectonic structures were dated at 525 Ma using syntectonic white micas. Evidence of the break-up of Gondwana during the Early Jurassic/Triassic is given by dikes at Ahlmannryggen and lava flows, dikes and sills at Vestfjella. At Ahlmannryggen the initial rift phase is documented by the development of the Jutul Penck graben and the intrusion of the 200-250 Ma continental-tholeiitic dikes striking parallel to the graben axis. The lava flows, dikes and sills at Vestfjella represent a later stage of the Gondwana break-up at about 180 Ma that probably reflects the initial stage of the opening of the Weddell Sea.

Formato

application/zip, 2 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.763219

doi:10.1594/PANGAEA.763219

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Peters, Matthias; Lippolt, Hans Jürgen; Rittmann, Ursula; Weber, Klaus (1989): Field relations, petrography and K-Ar Age determinations on Magmatic Rocks from Neuschwabenland, Antarctica. Polarforschung, 59(1/2), 35-44, hdl:10013/epic.29631.d001

Palavras-Chave #40Ar STP; 40K; Age, 40K/40Ar Potassium-Argon; Age, dated; Age, dated standard deviation; Age dated; Age std dev; Ahlmannryggen; Ahlmannryggen, Neuschwabenland, Antarctica; Area; Area/locality; Argon-40 at standard pressure; Label; Minerals; Potassium 40; Rock; Rock type; Sample code/label; Site; Vestfjella; Vestfjella, Kraul Mountains, Neuschwabenland, Antarctica
Tipo

Dataset