Abstract Interactions between the solid Earth and climate, both on local and global scales are increasingly being considered as important within the sphere of the Earth and ocean sciences. For example, it has long been recognized that opening and closure of oceanic gateways, as a result of continental break-up and collision processes, can lead to changes in oceanic circulation patterns and so to changes in climate ( Kennett 1977 ; Haug et al. 2001 ; von der Heydt & Dijkstra 2006 ). In addition, uplift of mountain chains can disrupt atmospheric circulation by deflecting the jet stream and altering planetary climatic belts ( Tada 2004 ), as well as generating orographic rainfall concentration and rain shadows in the immediate vicinity of mountainous topography ( Jiang et al. 2003 ). However, the most dramatic example of the solid Earth affecting climate is the proposed relationship between the growth of the topography in Central Asia during the Cenozoic and the intensification of the Asian monsoon. Asia is not the only continent to have a monsoon, but this monsoon is by far the most powerful and is driven by the temperature differences between the Eurasian continent and the Indian and Pacific Oceans ( Webster et al. 1998 ; Clift & Plumb 2008 ), which causes a circulation reversal to the normal Hadley circulation in South and East Asia during the summer. In particular, growth of the Tibetan Plateau has been cited as being a trigger for a much stronger summer monsoon than might

Abstract The potential links between uplift of the Himalaya and Tibetan Plateau and desertification of inland Asia have been a long-considered problem in geology. Although a close link between the two has been suggested by theoretical climatic simulations, not enough geological data has existed to test the theory. Here, we conducted semi-quantitative field observations of a Neogene fluvial sequence at the Yecheng section on the southwestern margin of the Tarim Basin in order to confirm the origin and mode of deposition of the aeolian siltstone, determine the onset timing, evaluate quantitatively the temporal evolution of its deposition and its relationship to the tectonically driven surface uplift of NW Tibet. The results suggest a close link between the uplift of northwestern Tibet, alluvial fan formation, dust emission from Taklimakan Desert and the deposition of loess on the alluvial fans.

Abstract Cenozoic sedimentary successions along the southern margin of the Tarim Basin, western China, reach up to 10 km in thickness. The two studied sections, the Yecheng and Aertashi, comprise c . 4.5 km and c . 7.0 km of clastic sedimentary rocks respectively. The base of the Yecheng section has been dated palaeomagnetically to be about 8 Ma. Age control of the Aertashi section is based on 87 Sr/ 86 Sr measurements (for the basal marine bed), together with magnetostratigraphy and regional stratigraphic correlation. The lower part of each section is mainly composed of fine-grained mudstone and fine sandstone, which makes up the Wuqian Group (Miocene). The palaeoenvironment is low-energy, meandering and braided streams. The middle part is composed of red mudstone, sandstone with thin conglomerate beds, which make up the Artux Formation (Pliocene). The palaeoenvironment is a distal- to mid-fan environment. The uppermost part of the section, known as the Xiyu Formation (Plio-Pleistocene), consists of cobble and boulder conglomerate intercalated with massive siltstone lenses, which formed as proximal alluvial fan and aeolian deposits. Neogene red beds passing upward into upward-coarsening conglomerate and debris-flow deposits record the change in palaeoslope related to uplift of the northern margin of Tibetan Plateau. The formation of aeolian dunes at c . 8 Ma, and underlying playa lake deposits (as at Aertashi), may indicate an arid, enclosed basin in the southern Tarim after this time. Sedimentological characteristics, together with grain size distribution and geochemistry of siltstone bands in the Xiyu and Artux Formations, point to an aeolian origin. This indicates that the Taklimakan Desert and the regional climate regime may have been fully developed by the Early Pliocene. The onset of aeolian sedimentation in the southern Tarim Basin coincided with uplift of the northern Tibetan Plateau, as inferred from the lithofacies change. Tibetan Plateau uplift resulted in the shift of sedimentary environments northwards into the southern Tarim Basin, and could well have triggered the onset of full aridity in the Taklimakan region as a whole.

Abstract A thick, calcareous, clastic megabed of late Maastrichtian age has been known for sometime in western and central Cuba. This megabed was formed in association with the bolide impact at Chicxulub, Yucatán, at the K/T boundary, andiscomposed of a lower gravity-flow unit and an upper homogenite unit. The lower gravity-flow unit is dominantly composed of calcirudite that was formed because of collapses of the Yucatán, Cuban, and Bahamian platform margins and subsequent accumulation in the lower slope to basin margin environment. The gravity flow probably was triggered by a seismic wave induced by the impact, although a ballistic flow may have triggered collapse in the case of proximal sites (Yucatán margin). The upper homogenite unit is composed of massive and normally graded calcarenite to calcilutite that was formed as a result of large tsunamis associated with the impact and deposited in wider areas in the deeper part of Paleo-western Caribbean basin. Slight grain-size oscillations in this unit probably reflect the influence of repeated tsunamis. The large tsunamis were generated either by the movement of water into and out of the crater cavity or by the large-scale slope failure on the eastern margin of the Yucatán platform. In upper slope to shelf environments, gravity-flow deposits and homogenite are absent, and a thin sandstone complex influenced by repeating tsunami waves was deposited.

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