Highstand shedding, increased sediment production and export during sea-level highstands, is a sedimentation pattern frequently found in sedimentary basins surrounding rimmed, flat-topped carbonate platforms. Highstand bundling, increased number of turbidites deposited during sea-level highstands (interglacials), was demonstrated clearly for the Tongue of the Ocean sedimentary basin of the Bahamas. For the last 300 kyr sea-level changes also influenced the timing of calciturbidite deposition in the sedimentary basins surrounding Pedro Bank (Caribbean). The frequency of calciturbidite input shows a clear highstand bundling pattern with a three times higher input during interglacial than during glacial marine isotope stages. For most of the transgressions rapid renewed bank-top flooding was recorded by the onset of calciturbidite deposition. Almost all of the regressions show sediment reorganisation on the upper slope resulting in calciturbidite or debris flow deposition. Compositional variations, skeletal and non-skeletal components, were point-counted in carbonate gravity deposits from Exuma Sound (Pleistocene, Bahamas) and the Southern Provence Basin (SPB; Turonian-Coniacian, SE France). The Bahamian gravity deposits were deposited in an environment in which sedimentation was controlled by eustatic sea-level variations while in contrast the SPB sedimentation was strongly influenced by tectonic processes. Earlier studies have shown that compositional variations of gravity deposits can be linked to different sources on the carbonate margin, i.e. platform interior, edge, and slope. In the Bahamian cores (ODP Leg 101, Site 632A) two types of deposits, calciturbidites and debris flows were present. The calciturbidites show variations in their skeletal and non-skeletal components that depend on the position of sea level; highstand (flooded platform top) vs. lowstand (exposed platform top). In contrast, the composition of the debris flows remains unaltered through time and shows a dominance of platform edge derived sediments. In addition, it was noted that the debris flows were deposited during regressions in sea level. Gravity flow deposits in the SPB were deposited during a sea-level rise associated with a series of earthquakes related to the opening of the SPB. They show a mix of sediments with components derived from the platform interior, the platform edge as well as the upper slope. The study shows that the composition of calciturbidites and debris flows can be used to determine which process, eustatic sea-level variations or tectonic processes, triggered sediment redeposition. The results will not only help to understand the origin of redeposited sediments in sedimentary basins, but will also aid to differentiate between tectonic and sea level induced time lines along carbonate platform to basin transects. These distinct peculiarities of carbonate systems provide guidelines for defining sequences and systems tracts in carbonate provinces.

West: -80.0000 East: 20.0000 North: 75.0000 South: .0000

West: NaN East: NaN North: NaN South: NaN

West: NaN East: NaN North: NaN South: NaN

Expedition: 101

Provider: SEDIS Publication Catalogue

Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2010-083773 (c.f. for more detailed metadata)

This metadata in ISO19139 XML format