Antarctic Science 21(6), 593–607 (2009) & Antarctic Science Ltd 2009 doi:10.1017/S0954102009990241 Provenance and post-depositional low-temperature evolution of the James Ross Basin sedimentary rocks (Antarctic Peninsula) based on fission track analysis MARTIN SVOJTKA1, DANIEL NY´ VLT2, MASAKI MURAKAMI1*, JITKA VA´ VROVA´ 3, JIRˇ ´I FILIP1 and PETR MIXA2 1Institute of Geology, Academy of Sciences, v.v.i., Rozvojova´ 269, 16500 Praha 6, Czech Republic 2Czech Geological Survey, Kla´rov 3, 118 21 Praha, Czech Republic 3Institute of Geochemistry, Charles University, Albertov 6, 12843 Praha 2, Czech Republic *current address: Department of Earth and Planetary Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-0033, Japan
[email protected] Abstract: Zircon and apatite fission track (AFT) thermochronology was applied to the James Ross Basin sedimentary rocks from James Ross and Seymour islands. The probable sources of these sediments were generated in Carboniferous to Early Paleogene times (,315 to 60 Ma). The total depths of individual James Ross Basin formations are discussed. The AFT data were modelled, and the thermal history model was reconstructed for samples from Seymour Island. The first stage after a period of total thermal annealing (when the samples were above 1208C) involved Late Triassic cooling (,230 to 200 Ma) and is followed by a period of steady cooling through the whole apatite partial annealing zone (PAZ, 60–1208C) to minimum temperature in Paleocene/Early Eocene. The next stage was the maximum burial of sedimentary rocks in the Eocene (,35 Ma, 1.1–1.8 km) and the final cooling and uplift of Seymour Island sedimentary rocks at ,35 to 20 Ma.