(Table 1) Grain size results, statistical parameters and magnetic susceptibility values of disturbed sediments from ODP holes 204-1249C and 204-1245B

Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge.

Statistical grain size parameter of surface samples from Kiel Bay

Geological observations, using "free-diving" techniques (Figure I) were made in September, 1960 and March 1961 along two continuous profiles in the outer Kiel Harbor, Germany and at several other spot locations in the Western Baltic Sea. A distinct terrace, cut in Pleistocene glacial till, was found that was covered with varying amounts and types of recent deposits. Hand samples were taken of the sea-floor sediments and grainsize distribution determined for both the sediment as a whole and for its heavy mineral fraction. From the Laboratory and Field observations it was possible to recognize two distinct types of sand; Type I, Sand resulting from transportation over a long period of time and distance and Type 11, Sand resulting from little transportation and found today near to xvhere it was formed. Several criterea related to the agent of movement could be used to classify the nature of the sediment; (1) undisturbed (the sediment Cover of the Pleistocene Terrace is essentially undisturbed), (2) mixed by organisms, (3) transported by water movements (sediment found with ripple marks, etc., and (4) "Scoured" (the movement of individual particles of sediment from around larger boulders causes a slow downward movement or "Creeping" which is due to both the force of gravity and bottom currents. These observations and laboratory studies are discussed concerning their relationship to the formation of residual sediments, the direction of sand transportation, and the intensive erosion on the outer edge of the wave-cut platform found in this part of the Baltic Sea.

Barite Accumulation rates across Paleocene-Eocene Thermal Maximum (PETM)

Barite accumulation rates (BAR) have been measured from 12 DSDP/ODP site globally (DSDP site 525, 549 and ODP site 690, 738, 1051, 1209, 1215, 1220, 1221, 1263,1265 and 1266A) to reconstruct the export production across Paleocene Eocene Thermal Maximum (PETM) around 55.9 million year ago. Our results suggesting a general increase in export productivity. We propose that changes in marine ecosystems, resulting from high atmospheric partial pressure of CO2 and ocean acidification, led to enhanced carbon export from the photic zone to depth, thereby increasing the efficiency of the biological pump. We estimate that an annual carbon export flux out of the euphotic zone and into the deep ocean waters could have amounted to about 15 Gt during the PETM. About 0.4% of this carbon is expected to have entered the refractory dissolved organic pool, where it could be sequestered from the atmosphere for tens of thousands of years. Our estimates are consistent with the amount of carbon redistribution expected for the recovery from the PETM.