Mass accumulation rates in Asia during the Cenozoic

Abstract

Summary This work establishes estimates of mass accumulation rates in 18 mostly offshore sedimentary basins in Asia since the beginning of the Cenozoic, ≈ 66 Ma. The estimates were derived from isopach maps, cross‐sections and drill holes or stratigraphic columns assuming regional similarity of the strata. Average solid phase volumes and accumulation rates were calculated for nine epochs approximately corresponding to geological periods: Palaeocene ( ≈ 66–58 Ma), Eocene ( ≈ 58–37 Ma), Oligocene( ≈ 37–30 and 30–24 Ma), Miocene ( ≈ 24–17, 17–11 and 11–5 Ma), Pliocene ( ≈ 5–2 Ma) and Quaternary ( ≈ 2–0 Ma). These rates shed new light on the geological history of Asia since the onset of the collision of India with Asia ( ≈ 50 Ma). The overall average accumulation rates curve for Asian sedimentary basins since the beginning of the Tertiary shows an exponential form with slow accumulation rates (less than 0.5 × 106 km3 Myr− 1) until the beginning of the Oligocene, more than 15 Myr after the onset of the collision. From the Oligocene onwards rates increase quickly in an exponential manner, reaching their maximum values in the Quaternary (more than 1.5 × 106 km3 Myr− 1). From these observations we suggest that extrusion and crustal shortening are complementary processes that have been successively dominant throughout the India–Eurasia collision history. At smaller scales one may distinguish between independent histories at the subcontinental and basin scales. This permits a comparison of the relative importance of tectonic and climatic erosion processes affecting the different mountain belts of Asia during the Cenozoic.

Crustal redistribution, crust–mantle recycling and Phanerozoic evolution of the continental crust

“…Furthermore, compilations of global sediment budgets indicate that erosion rates since the initiation of Northern Hemispheric Glaciation are much elevated compared to those before ca. 3 Ma (Métivier et al, 1999;Zhang et al, 2001). It should also be realized that modern rivers are not in equilibrium, but still adjusting to climate change after the Last Glacial Maximum (ca.…”

“…We also make a correction for major carbonate masses, although close to the deltas of major rivers this is rarely a significant issue within the errors of the general estimate. In some delta and submarine fan systems there has been significant seismic analysis performed and sediment volume estimates already made (e.g., many of the Asian delta systems (Métivier et al, 1999;). In these cases we simply use the published volumes for Cenozoic sediment masses.…”

A quantification of the glacial imprint on relief development in the French western Alps

“…A late Cenozoic increase in sedimentation rates has been documented in sedimentary basins occurring in widely varying tectonic settings around the world, suggesting that the associated increase in erosional flux is climatically controlled (Kuhlemann et al, 2002;Métivier et al, 1999;Molnar, 2004;Zhang et al, 2001). A contrasting view has, however, been expressed by Raymo and Ruddiman (1992), who suggested that, rather than resulting from it, increased uplift and erosion rates control late-Cenozoic climate change through increased atmospheric CO 2 drawdown by weathering reactions.…”

Phylogeny and biogeography of Chinese sisorid catfishes re-examined using mitochondrial cytochrome b and 16S rRNA gene sequences

“…Such a perspective is therefore still far from clear promoting us to pursue further studies of the molecular phylogenetics of the sisorid catfishes. It has long been recognized that paleo-drainages of major continental East Asian Rivers, draining the south-eastern Tibet plateau margin, differed markedly from their current drainage patterns (Brookfield, 1998;Clark et al, 2004;Gregory, 1925;Gregory and Gregory, 1923;Hallet and Molnar, 2001;Métivier et al, 1999;Seeber and Gornitz, 1983;Zeitler et al, 2001). In a recent study, Clark et al (2004) suggested that these rivers were once tributaries to a single southward flowing system, which drained into the South China Sea (Fig.…”