Austauschprozesse zwischen Kruste und Ozean. SONNE-Forschungsfahrt SO-105. Teilprojekt 2: Seismo-stratigraphische Untersuchungen am Ostpazifischen Ruecken suedlich der Garrett-Bruchzone (13 -16 S) Abschlussbericht

SIGLEAvailable from TIB Hannover: F98B819+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

KOMEX - Kurile Okhotsk Sea Marine Experiment. Cruise reports: KOMEX V and VI: RV Professor Gagarinsky Cruise 26, MV Marshal Gelovany Cruise 1. Vladivostok - Pusan - Okhotsk Sea - Pusan - Vladivostok, 30 July - 5 September 1999

SIGLEAvailable from TIB Hannover: RR 1846(88) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Fahrtbericht ueber die Sonne-Expedition 105 - EXCO Austauschprozesse zwischen Kruste und Ozean. Valparaiso - Balboa, 8. November - 30. Dezember 1995

Summary in EnglishAvailable from TIB Hannover: RR 9349(1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Refinement of Miocene sea level and monsoon events from the sedimentary archive of the Maldives (Indian Ocean)

International Ocean Discovery Program (IODP) Expedition 359 cored sediments from eight borehole locations in the carbonate platform of the Maldives in the Indian Ocean. The expedition set out to unravel the timing of Neogene climate changes, in particular the evolution of the South Asian monsoon and fluctuations of the sea level. The timing of these changes are assessed by dating resultant sedimentary alterations that mark stratigraphic turning points in the Neogene Maldives platform system. The first four turning points during the early and middle Miocene are related to sea-level changes. These are reliably recorded in the stratigraphy of the carbonate sequences in which sequence boundaries provide the ages of the sea-level lowstand. Phases of aggradational platform growth give precise age brackets of long-term sea-level high stands during the early Miocene and the early to middle Miocene Climate Optimum that is dated here between 17 to 15.1 Ma. The subsequent middle Miocene cooling coincident with the eastern Antarctic ice sheet expansion resulted in a long-term lowering of sea level that is reflected by a progradational platform growth. The change in platform architecture from aggradation to progradation marks this turning point at 15.1 Ma.An abrupt change in sedimentation pattern is recognized across the entire archipelago at a sequence boundary dated as 12.9–13 Ma. At this turning point, the platform sedimentation switched to a current-controlled mode when the monsoon-wind-driven circulation started in the Indian Ocean. The similar age of the onset of drift deposition from monsoon-wind-driven circulation across the entire archipelago indicates an abrupt onset of monsoon winds in the Indian Ocean. Ten unconformities dissect the drift sequences, attesting changes in current strength or direction that are likely caused by the combined product of changes in the monsoon-wind intensity and sea level fluctuations in the last 13 Ma. A major shift in the drift packages is dated with 3.8 Ma that coincides with the end of stepwise platform drowning and a reduction of the oxygen minimum zone in the Inner Sea.The strata of the Maldives platform provides a detailed record of the extrinsic controlling factors on carbonate platform growth through time. This potential of carbonate platforms for dating the Neogene climate and current changes has been exploited in other platforms drilled by the Ocean Drilling Program. For example, Great Bahama Bank, the Queensland Plateau, and the platforms on the Marion Plateau show similar histories with sediment architectures driven by sea level in their early history (early to middle Miocene) replaced by current-driven drowning or partial drowning during their later history (Late Miocene). In all three platform systems, the influence of currents on sedimentations is reported between 11 and 13 Ma

SO 115B-SUNDAFLUT: Seismo-Stratigraphie. Seismo-stratigraphische Untersuchungen des noerdlichen Sunda-Schelfes, suedliches Suedchinesisches Meer Endbericht

Eight generally wedge-shaped seismic sequences interpretable as prograding lowstand wedges deposited during forced regressions were recognized on the outer Sunda Shelf. The highstand systems tracts are in contrast largely missing. Seven seismic facies types and 11 sediment echo character types have been identified. They divide the outer shelf into facies or acoustic provinces and characterize the sedimentation processes in each province. The corrected depth of the lowermost onlap in each sequence marks the depth of the depositional base level below present-day sea level when that sequence was deposited. This basal level is assumed to be at or near the paleo-sea level, depending on whether current and wave erosion as well as tidal scouring have been effective. A correlation of these corrected onlap depths with the stacked Specmap curve and a #delta#"1"8O curve from the Sulu Sea permits speculative age estimates of the sea level lowstands and the sequence boundaries. According, the sequence onlaps probably correspond to sea level lowstands during oxygen isotope stages 6, 8, 10, 12, 14 and 16. Sequence 4 is probably deposited in the course of a minor sea level fluctuation during the regression from stage 11 to 10. The computed average lowstand sedimentation rates (75-200 cm/ka) based on these age estimates are comparable to the present-day rates. They represent underestimates of the lowstand rates. The development of the Late Quaternary sea level on the northern Sunda Shelf parallels that of the Sulu Sea. However, our sea level values lie generally 10-40 m below those for the Sulu Sea and may imply that either erosion has lowered the depositional base level by about this amount or that tectonic subsidence beyond that accounted for in our fault corrections has occurred. (orig.)SIGLEAvailable from TIB Hannover: F99B787 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman