Beschreibung
We propose to recover long sediment cores from Laguna Potrok Aike, a 770 ka old maar lake in the dry steppe of southern Patagonia (Province of Santa Cruz, Argentina). Seismic surveys demonstrate that ~400 m of pelagic sediments were deposited in the lake centre underlain by a yet unknown thickness of volcaniclastic breccias. Based on this seismic data, three primary and three alternative drilling sites were selected: (1) from the deepest part to obtain a continuous and high-resolution record of climatic and environmental changes and to unveil the phreatomagmatic history including more precise age constrains for the maar-diatreme formation from the volcaniclastic sediments below, (2) from a subaquatic lake level terrace at 35 m water depth to constrain the range of lake level variations and (3) from an angle hole passing through lacustrine sediments and the crater wall into the molassetype basement rocks to study the impact of explosive volcanism, post-eruptive structural evolution and early processes of sedimentation in a relatively young maar-diatreme structure. Within the framework of an international and interdisciplinary scientific approach the recovered sediments will be used to test hypotheses related to this two broad themes: • High-resolution quantitative climate and environmental reconstructions from orbital and suborbital (multimillennial) down to decadal timescales supported by multiple dating (e.g. 14C, OSL, Ar/Ar) and stratigraphic correlation (e.g. pollen, tephra, paleomagnetics) with emphasis on marine – ice core – terrestrial linkages and incorporation of results from GCM climate simulations; • Detailed analyses of volcanic rocks and sediments provide insights into processes related to phreatomagmatic explosions and early sedimention in a mid-Pleistocene maar lake. Never before the entire lacustrine sediment record has been recoverd and underlying volcaniclastic sediments have been drilled and investigated in a young maar-diatreme structure. An international team of scientists has been attracted to cooperate in the framework of PASADO to develop a comprehensive environmental, climatic and volcanological data set. Proposed science management and drilling operation plans have the objective to achieve all necessary technical and scientific needs to make PASADO internationally successful .