(Table 1) Mineralogy of DSDP Leg 65 sediments

During Leg 65, four sites were drilled near the mouth of the Gulf of California where high sedimentation rates made it possible to sample young oceanic crust near the ridge crest. The oldest sediments cored were upper Pliocene siltstones (Site 483); the samples at the other sites (482, 484, and 485) were all Quaternary in age. A series of 80 sediment samples, most of them hemipelagic clays, were examined by semiquantitative X-ray diffraction and Carbonate Bomb techniques to determine their mineralogy and carbonate contents. The results of this study may be used to determine their provenance and diagenesis.

(Table 1) Bulk and clay mineralogy at DSDP Leg 66 Holes

During Leg 66 eight sites on an active margin transect off southern Mexico were drilled in order to determine the nature of ocean-continent transition across a subduction zone. Present outcrops of Mesozoic to Precambrian basement at the coast intruded by Mesozoic magmas within only 65 km of the Middle America Trench axis indicate truncation of the continental margin, tectonic removal of an accretionary zone, and consumption of ocean sediments and crust by subduction.

(Table S1) FMR and rock magnetic parameters for upper Paleocene to lower Eocene strata, Site Ancora

Previous workers identified a magnetically anomalous clay layer deposited on the northern United States Atlantic Coastal Plain during the Paleocene-Eocene thermal maximum (PETM). The finding inspired the highly controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR), isothermal and anhysteretic remanent magnetization, first-order reversal curve, and transmission electron microscopy analyses of late Paleocene and early Eocene sediments in drill core from Ancora, New Jersey. A novel paleogeographic analysis applying a recent paleomagnetic pole from the Faeroe Islands indicates that New Jersey during the initial Eocene had a ~6°-9° lower paleolatitude (~27.3° for Ancora) and a more zonal shoreline trace than in conventional reconstructions. Our investigations of the PETM clay from Ancora reveal abundant magnetite nanoparticles bearing signature traits of crystals produced by magnetotactic bacteria. This result, the first identification of ancient biogenic magnetite using FMR, argues that the anomalous magnetic properties of the PETM sediments are not produced by an impact. They instead reflect environmental changes along the eastern margin of North America during the PETM that led to enhanced production and/or preservation of magnetofossils.

Sediment, water and biomass characteristics along gradients in Kongsfjorden, Svalbard

In contrast to numerous studies on the biomass of marine microphytobenthos from temperate coastal ecosystems, little is known from polar regions. Therefore, microphytobenthos biomass was measured at several coastal sites in Arctic Kongsfjorden (Spitsbergen) during the polar summer (June-August 2006). On sandy sediments, chla varied between 8 and 200 mg/m**2 and was related to water depth, current/wave exposure and geographical location. Biomass was rather independent of abiotic parameters such as sediment properties, salinity, temperature or light availability. At three stations, sediments at water depths of 3-4, 10, 15, 20 and 30 m were investigated to evaluate the effect of light availability on microalgae. Significant differences in distribution patterns of biomass in relation to deeper waters >10 m were found. The productive periods were not as distinct as phytoplankton blooms. Only at 3-4 m water depth at all three stations were two- to threefold increases of biomass measured during the investigation period. Hydrodynamic conditions seemed to be the driving force for differences in sediment colonisation by benthic microalgae. In spite of the extreme Arctic environmental conditions for algal growth, microphytobenthos biomass was comparable to marine temperate waters.

(Table 1) Mineralogy at DSDP Leg 62 Holes

Sixty-nine sediment samples of Deep Sea Drilling Project Leg 62 were mineralogically examined by X-ray diffractometry, and gasometrically for their carbonate content. Most sediments were found to be carbonate-rich; some have up to 97% CaCO3. Many chalk or limestone samples contain chert, accounting for high quartz percentages in some analyzed samples.

Gridded results of swath bathymetric mapping of Disko Bay, Western Greenland, 2007-2008

A ship-based acoustic mapping campaign was conducted at the exit of Ilulissat Ice Fjord and in the sedimentary basin of Disko Bay to the west of the fjord mouth. Submarine landscape and sediment distribution patterns are interpreted in terms of glaciomarine facies types that are related to variations in the past position of the glacier front. In particular, asymmetric ridges that form a curved entity and a large sill at the fjord mouth may represent moraines that depict at least two relatively stable positions of the ice front in the Disko Bay and at the fjord mouth. In this respect, Ilulissat Glacier shows prominent differences to the East Greenland Kangerlussuaq Glacier which is comparable in present size and present role for the ice discharge from the inland ice sheet. Two linear clusters of pockmarks in the center of the sedimentary basin seem to be linked to ongoing methane release due to dissociation of gas hydrates, a process fueled by climate warming in the Arctic realm.

(Table S1) Qualitative and semi-quantitative abundance of magnetic particles in Paleocene-Eocene sediments

On the mid-Atlantic Coastal Plain of the United States, Paleocene sands and silts are replaced during the Paleocene-Eocene Thermal Maximum (PETM) by the kaolinite-rich Marlboro Clay. The clay preserves abundant magnetite produced by magnetotactic bacteria and novel, presumptively eukaryotic, iron-biomineralizing microorganisms. Using ferromagnetic resonance spectroscopy and electron microscopy, we map the magnetofossil distribution in the context of stratigraphy and carbon isotope data and identify three magnetic facies in the clay: one characterized by a mix of detrital particles and magnetofossils, a second with a higher magnetofossil-to-detrital ratio, and a third with only transient magnetofossils. The distribution of these facies suggests that suboxic conditions promoting magnetofossil production and preservation occurred throughout inner middle neritic sediments of the Salisbury Embayment but extended only transiently to outer neritic sediments and the flanks of the embayment. Such a distribution is consistent with the development of a system resembling a modern tropical river-dominated shelf.