Thermal history of Australian passive margin cover sequences accreted to Timor during Late Neogene arc–continent collision, Indonesia

摘要: Paleotemperature indicators and apatite fission track analysis of Australian continental margin cover sequences accreted to the active Banda arc–continent collision indicate little no heating during rapid late Neogene uplift exhumation. Thermal maturation patterns vitrinite reflectance, conodont alteration illite crystallinity show that peak paleotemperatures (PPT) increase with stratigraphic structural burial. The highest PPT is found in northern hinterland accretionary wedge, which was beneath progressively thicker parts upper plate towards north. Major discontinuities pattern are associated position major thrust ramps such as those forming Ramelau/Kekneno Arch (RKA). for Upper Triassic strata south RKA 60–80°C, similar to, many cases lower than, correlative age equivalent units drilled on NW Shelf. Permian Lower sedimentary over younger within north have 100–220°C. Thrust sheets approximately 90°C higher than frontally accreted. Metamorphism northernmost these yield >300°C. stacking yields an inverted thermal profile decreasing discontinuously downward (towards foreland). timing constrained by ages from mostly sequences. Ages primarily coeval deposition evidence annealing, whereas almost completely annealed range 1.8±0.5–19.2±9.7 Ma. clustering into two distinct groups indicates boundary partial annealing zone has remained some time at a interval slope rise margin. this present shelf column due greater thickness post-breakup facies units. rise, produces vertical increasing depth. Lack any long confined lengths all requires recent exhumation stack, coincident phases Pliocene–Pleistocene documented throughout Timor. These data preclude pre-Late Miocene tectonic burial or pre-Pliocene