Biology community and bottom sediments in the West Bay of the Furugelm Island, Sea of Japan

An experiment was carried out on the soft bottom in the sublitoral zone of the Furugelm Island (Peter the Great Bay, Sea of Japan) to study formation of benthic communities. Boxes with defauned sediments were placed on depths of 4, 6 and 13 m and exposed during 60 days in the summer period. Half of them were covered with a net with mesh size 2 cm to prevent effect of large predators. It was found that spatial pattern of invertebrates' sinking in the bay conforms to distribution of benthic communities. Larvae of benthic invertebrates sinks in general in places inhabited by their adult species. The main factors responsible for recolonzation are: sediment type and local hydrodynamic conditions. Heart-shaped sea urchin Echinocardium cordatum is numerically dominated in the bay on depth 3-4.5 m, but its larvae sinks in the deeper area. Community structure is supported by mature specimen migration to places inhabited by species. Predators affect largely on the species.

Lithic grain and mineral composition of sand and sandstones from the Japan and Mariana forearc and backarc (Table 3)

One hundred and twenty point counts of Oligocene to Recent sands and sandstones from DSDP sites in the Japan and Mariana intraoceanic forearc and backarc basins demonstrate that there is a clear compositional difference between the continentally influenced Japan forearc and backarc sediments, and the totally oceanic Mariana forearc and backarc sediments. Japan forearc sediments average 10 QFL%Q, 0.82 P/F, 2 Framework%Mica, 74 LmLvLst%Lv, and 19 LmLvLst%Lst. In contrast, the Mariana forearc and backarc sediments average 0 QFL%Q, 1.00 P/F, 0 Framework%Mica, 98 LmLvLst%Lv, and 1 LmLvLst%Lst. Sediment compositions in the Japan region are variable. The Honshu forearc sediments average 5 QFL%Q, 0.94 P/F, 1 Framework%Mica, 82 LmLvLst%Lv, and 15 LmLvLst%Lst. The Yamato Basin sediments (DSDP Site 299) average 13 QFL%Q, 0.70 P/F, 3 Framework%Mica, 78 LmLvLst%Lv, and 14 LmLvLst%Lst. The Japan Basin sediments (DSDP Site 301) average 24 QFL%Q, 0.54 P/F, 9 Framework%Mica, 58 LmLvLst%Lv, and 21 LmLvLst%Lst. P/F and Framework%Mica are higher in the Yamato Basin sediments than in the forearc sediments due to an increase in modal potassium content of volcanic rocks from east to west, on the island of Honshu. Site 301 possesses a higher QFL%Q and LmLvLst%Lst, and lower LmLvLst%Lv than Site 299 because it receives sediment from the Asian mainland as well as the island of Honshu. DSDP Site 293 sediments, in the Mariana region, average 0.97 P/F, 1 Framework%Mica, 13 LmLvLst%Lm and 83 LmLvLst%Lv, due to their proximity to the island of Luzon. The remaining Mariana forearc and backarc sediments show a uniform composition.

Late Quaternary carbonate and isotope stratigraphy of DSDP Site 90-594 east of South Island, New Zealand

The late Quaternary sequence off eastern South Island, New Zealand, consists of ~100 m of alternating bluish gray pelagic oozes and greenish gray hemipelagic oozes that extend uninterruptedly back to the Brunhes/Matuyama boundary (0.73 m.y.). A very high resolution (~2400 yr.) record of sediment texture, calcium carbonate content, and planktonic and benthic foraminiferal oxygen and carbon isotope composition demonstrates an in-phase cyclical fluctuation between the sedimentary parameters that closely correspond to the pelagic-hemipelagic sedimentation cycles and the isotope composition. Pelagic oozes, formed during interglacial periods of high eustatic sea level, are characterized by calcareous microfossils, relative enrichment in sand and clay sizes, high carbonate contents, reduced delta18O values, and increased delta13C values. Hemipelagic oozes, associated with glacial episodes and lowered eustatic sea level, include common terrigenous material and siliceous microfossils, are enriched in silt sizes, have low carbonate contents, high delta18O values, and low delta13C values. The history of alpine glaciations and associated erosion of the South Island of New Zealand, as expressed by the appearance of hemipelagic oozes, can be correlated directly with the major fluctuations of Northern Hemisphere ice sheets as expressed by the influence of eustatic sea-level changes on the oxygen isotope composition of both planktonic and benthic foraminifers. This high-accumulation-rate record contains conspicuous intervals of highfrequency, high-amplitude isotope variability including the presence of multiple glacial/interglacial intervals within single isotope stages, and offers one of the best sections cored to date for detailed study of the evolution and history of climate change over the last 0.75 m.y.

(Table 1) Grain size parameters of intertidal channel sand bars near Sylt, North-Frisian Wadden Sea

The aim of the present study is to investigate directional asymmetric properties and internal structures of the bedforms on the intertidal sand bars in comparison with the migration problems of the sand bodies developed in the channel systems of the tidal basin off the west coast of Schleswig-Holstein. The tidal channel sand bodies studied have 'V'-shaped outlines and are asymmetric in cross-section. Based on such knowledge it was hoped to understand and find possible factors for application to recent and ancient tidal depositional environments. The V-shaped intertidal channel sand bodies developed in the tidal environments between Sylt and Föhr Island are constantly migrating sand bars. The migration directions are in good agreement with the resultant vector mean directions of internal cross-stratification structures of asymmetric sedimentary bedforms. Finally, it is shown that the orientation of the apex of V-shaped sand bar as an equilibrium form alone can not indicate the migration direction, but that the orientation of the resultant vector mean of internal structures of sedimentary bedforms does indicate the migration direction. Based on the analyses of textural parameters of the migrating intertidal bar sands, it seems that sands of typical intertidal sand bars are negatively skewed and well sorted. The high rounding of quarz sand grains of these tidal channel sand bars seems to be an additional characteristical criterion for tidal depositional environments, as also indicated by Balazs and Klein (1972).

Grain counts and XRD mineralogy of turbidite sand and hemipelagic mud from ODP Leg 168 sites

Sequences of late Pliocene to Holocene sediment lap onto juvenile igneous crust within 20 km of the Juan de Fuca Ridge in northwestern Cascadia Basin, Pacific Ocean. The detrital modes of turbidite sands do not vary significantly within or among sites drilled during Leg 168 of the Ocean Drilling Program. Average values of total quartz, total feldspar, and unstable lithic fragments are Q = 35, F = 35, and L = 30. Average values of monocrystalline quartz, plagioclase, and K-feldspar are Qm = 46, P = 49, and K = 5, and the average detrital modes of polycrystalline quartz, volcanic-rock fragments, and sedimentary-rock plus metamorphic-rock fragments are Qp = 16, Lv = 43, and Lsm = 41. Likely source areas include the Olympic Peninsula and Vancouver Island; sediment transport was focused primarily through the Strait of Juan de Fuca, Juan de Fuca Channel, Vancouver Valley, and Nitinat Valley. Relative abundance of clay minerals (<2-µm-size fraction) fluctuate erratically with depth, stratigraphic age, and sediment type (mud vs. turbidite matrix). Mineral abundance in mud samples are 0%-35% smectite (mean = 8%), 18%-59% illite (mean = 40%), and 29%-78% chlorite + kaolinite (mean = 52%). We attribute the relatively low content of smectite to rapid mechanical weathering of polymictic source terrains, with little or no input of volcanic detritus from the Columbia River. The scatter in clay mineralogy probably was caused by converging of surface currents, turbidity currents, and near-bottom nepheloid clouds from several directions, as well as subtle changes in glacial vs. interglacial weathering products.

Granulometry and Bulk Geochemistry of Nearshore Sediments, Herschel Island, Yukon Territory, Canada

This dataset contains the results of granulometric and bulk geochemical analyses of Van Veen surface samples obtained by the Alfred Wegener Institute (AWI) in the course of the 2012 and 2013 summer field seasons. The sampling was performed along transects in depths generally <13 m, to a distance of about <5 km off Herschel Island. In 2012, 75 samples in Pauline Cove and in the vicinity of Simpson Point were obtained. Sample collection was expanded in 2013, on transects established the previous year, with additional locations in Tetris Bay and Workboat Passage. Samples consisted of approximately 100 g of the top 3-6 cm of sediment, and were frozen in the field and freeze dried at the AWI before undergoing analytical procedures. Sample locations were recorded with the onboard global positioning system (GPS) unit. Grain size distributions in our study were obtained using laser diffractometry at the AWI (Beckman Coulter LS200) on the <1 mm fraction of samples oxidized with 30% H2O2 until effervescence ceased to remove organics. Some samples were also sieved using a sieve stack with 1 phi intervals. GRADISTAT (Blott and Pye, 2001) was used to calculate graphical grain size statistics (Folk and Ward, 1957). Grain diameters were logarithmically transformed to phi values, calculated as phi=-log2d, where d is the grain diameter in millimeters (Blott and Pye, 2001; Krumbein, 1934). Freeze dried samples were ground and ground using an Elemetar Vario EL III carbon-nitrogen-sulphur analyzer at the AWI to measure total carbon (TC) and total nitrogen (TN). Tungsten oxide was added to the samples as a catalyst to the pyrolysis. Following this analysis, total organic carbon (TOC) was determined using an Elementar VarioMax. Stable carbon isotope ratios of 13C/12C of 118 samples were determined on a DELTAplusXL mass spectrometer (ThermoFisher Scientific, Bremen) at the German Research Centre for Geosciences (GFZ) in Potsdam, Germany . An additional analysis on 69 samples was carried out at the University of Hamburg with an isotope ratio mass spectrometer (Delta V, Thermo Scientific, Germany) coupled to an elemental analyzer (Flash 2000, Thermo Scientific, Germany). Prior to analysis, soil samples were treated with phosphoric acid (43%) to release inorganic carbon. Values are expressed relative to Vienna Peedee belemnite (VPDB) using external standards (USGS40, -26.4 per mil VPDB and IVA soil 33802153, -27.5 per mil VPDB).