(Table 1) Major and trace elements analyses from FAMOUS-Project and DSDP Site 54-424

Hydrothermal deposits "sensu stricto" have been recovered during the FAMOUS cruise and Leg 54 of the Deep Sea Drilling Project near the Galapagos Spreading Centre. The studied sediments, mainly composed of clay material, have very poor REE concentrations, below about ten ppm. The shale-normalized patterns are characterized by a significant enrichment in heavy rare earths and show a negative Ce anomaly. The magnitude of this anomaly fluctuates but is generally lower than the seawater Ce anomaly. The geochemical characteristics of these hydrothermal deposits are in contrast with those of metalliferous sediments which are more enriched in trace elements, especially in REE.

Isotopic and chemical compositions of DSDP site 18-174 sediments

The Astoria submarine fan, located off the coast of Washington and Oregon, has grown throughout the Pleistocene from continental input delivered by the Columbia River drainage system. Enormous floods from the sudden release of glacial lake water occurred periodically during the Pleistocene, carrying vast amounts of sediment to the Pacific Ocean. DSDP site 174, located on the southern distal edge of the Astoria Fan, is composed of 879 m of terrigenous sediments. The section is divided into two major units separated by a distinct seismic discontinuity: an upper, turbidite fan unit (Unit I), and an underlying finer-grained unit (Unit II). Both units have overlapping ranges of Nd and Hf isotope compositions, with the majority of samples having e-Nd values of -7.1 to -15.2 and eHf values -6.2 to -20.0; the most notable exception is the uppermost sample in the section, which is identical to modern Columbia River sediment. Nd depleted mantle model ages for the site range from 2.0 to 1.2 Ga and are consistent with derivation from cratonic Proterozoic source regions, rather than Cenozoic and Mesozoic terranes proximal to the Washington-Oregon coast. The Astoria Fan sediments have significantly less radiogenic Nd (and Hf) isotopic compositions than present day Columbia River sediment (e-Nd=-3 to -4; [Goldstein, S.J., Jacobsen, S.B., 1987. Nd and Sr isotopic systematics of river water suspended material: implications for crustal evolution. Earth. Planet. Sci. Lett. 87, 249-265; doi:10.1016/0012-821X(88)90013-1]), and suggest that outburst flooding, tapping Proterozoic source regions, was the dominant sediment transport mechanism in the genesis and construction of the Astoria Fan. Pb isotopes form a highly linear 207Pb/204Pb - 206Pb/204Pb array, and indicate the sediments are a binary mixture of two disparate sources with isotopic compositions similar to Proterozoic Belt Supergroup metasediments and Columbia River Basalts. The combined major, trace and isotopic data argue that outburst flooding was responsible for depositing the majority (top 630 m) of the sediment in the Astoria Fan.

40Ar-39Ar dating and isotopic composition of groundmass and felspar samples from core AND-2A

The AND-2A drillcore (Antarctic Drilling Program-ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Ar-39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Ar-39Ar ages, indicating that the AND-2A drillcore recovered <230 m of Middle Miocene (~128-358 m below sea floor, ~11.5-16.0 Ma) and >780 m of Early Miocene (~358-1093 m below sea floor, ~16.0-20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of ~19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within ~17.5-18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the 'proto-Mount Morning' as the main source.

Morphological, chemical and physical characteristics of cryosolic soils from Arctic Canada

Cryosols are permafrost-affected soils whose genesis is dominated by cryogenic processes, resulting in unique macromorphologies, micromorphologies, thermal characteristics, and physical and chemical properties. In addition, these soils are carbon sinks, storing high amounts of organic carbon collected for thousands of years. In the Canadian soil classification, the Cryosolic Order includes mineral and organic soils that have both cryogenic properties and permafrost within 1 or 2 m of the soil surface. This soil order is divided into Turbic, Static and Organic great groups on the basis of the soil materials (mineral or organic), cryogenic properties and depth to permafrost. The great groups are subdivided into subgroups on the basis of soil development and the resulting diagnostic soil horizons. Cryosols are commonly associated with the presence of ground ice in the subsoil. This causes serious problems when areas containing these soils are used for agriculture and construction projects (such as roads, town sites and airstrips). Therefore, where Cryosols have high ice content, it is especially important either to avoid these activities or to use farming and construction methods that maintain the negative thermal balance.

Geochemistry of ocean floor and forearc serpentinites

We provide new insights into the geochemistry of serpentinites from mid-ocean ridges (Mid-Atlantic Ridge and Hess Deep), passive margins (Iberia Abyssal Plain and Newfoundland) and fore-arcs (Mariana and Guatemala) based on bulk-rock and in situ mineral major and trace element compositional data collected on drill cores from the Deep Sea Drilling Project and Ocean Drilling Program. These data are important for constraining the serpentinite-hosted trace element inventory of subduction zones. Bulk serpentinites show up to several orders of magnitude enrichments in Cl, B, Sr, U, Sb, Pb, Rb, Cs and Li relative to elements of similar compatibility during mantle melting, which correspond to the highest primitive mantle-normalized B/Nb, B/Th, U/Th, Sb/Ce, Sr/Nd and Li/Y among subducted lithologies of the oceanic lithosphere (serpentinites, sediments and altered igneous oceanic crust). Among the elements showing relative enrichment, Cl and B are by far the most abundant with bulk concentrations mostly above 1000 µg/g and 30 µg/g, respectively. All other trace elements showing relative enrichments are generally present in low concentrations (µg/g level), except Sr in carbonate-bearing serpentinites (thousands of µg/g). In situ data indicate that concentrations of Cl, B, Sr, U, Sb, Rb and Cs are, and that of Li can be, increased by serpentinization. These elements are largely hosted in serpentine (lizardite and chrysotile, but not antigorite). Aragonite precipitation leads to significant enrichments in Sr, U and B, whereas calcite is important only as an Sr host. Commonly observed brucite is trace element-poor. The overall enrichment patterns are comparable among serpentinites from mid-ocean ridges, passive margins and fore-arcs, whereas the extents of enrichments are often specific to the geodynamic setting. Variability in relative trace element enrichments within a specific setting (and locality) can be several orders of magnitude. Mid-ocean ridge serpentinites often show pronounced bulk-rock U enrichment in addition to ubiquitous Cl, B and Sr enrichment. They also exhibit positive Eu anomalies on chondrite-normalized rare earth element plots. Passive margin serpentinites tend to have higher overall incompatible trace element contents than mid-ocean ridge and fore-arc serpentinites and show the highest B enrichment among all the studied serpentinites. Fore-arc serpentinites are characterized by low overall trace element contents and show the lowest Cl, but the highest Rb, Cs and Sr enrichments. Based on our data, subducted dehydrating serpentinites are likely to release fluids with high B/Nb, B/Th, U/Th, Sb/Ce and Sr/Nd, rendering them one of the potential sources of some of the characteristic trace element fingerprints of arc magmas (e.g. high B/Nb, high Sr/Nd, high Sb/Ce). However, although serpentinites are a substantial part of global subduction zone chemical cycling, owing to their low overall trace element contents (except for B and Cl) their geochemical imprint on arc magma sources (apart from addition of H2O, B and Cl) can be masked considerably by the trace element signal from subducted crustal components.

(Table 1) Summary of basalt unit thickness, vesicularity, number of flow units, and average porosity at ODP Site 135-839

An inflatable drill-string packer was used at Site 839 to measure the bulk in-situ permeability within basalts cored in Hole 839B. The packer was inflated at two depths, 398.2 and 326.9 mbsf; all on-board information indicated that the packer mechanically closed off the borehole, although apparently the packer hydraulically sealed the borehole only at 398.2 mbsf. Two pulse tests were run at each depth, two constant-rate injection tests were run at the first set, and four were run at the second. Of these, only the constant-rate injection tests at the first set yielded a permeability, calculated as ranging from 1 to 5 * 10**-12 m**2. Pulse tests and constant-rate injection tests for the second set did not yield valid data. The measured permeability is an upper limit; if the packer leaked during the experiments, the basalt would be less permeable. In comparison, permeabilities measured at other Deep Sea Drilling Project and Ocean Drilling Program sites in pillow basalts and flows similar to those measured in Hole 839B are mainly about 10**-13 to 10**-14 m**2. Thus, if our results are valid, the basalts at Site 839 are more permeable than ocean-floor basalts investigated elsewhere. Based on other supporting evidence, we consider these results to be a valid measure of the permeability of the basalts. Temperature data and the geochemical and geotechnical properties of the drilled sediments all indicate that the site is strongly affected by fluid flow. The heat flow is very much less than expected in young oceanic basalts, probably a result of rapid fluid circulation through the crust. The geochemistry of pore fluids is similar to that of seawater, indicating seawater flow through the sediments, and sediments are uniformly underconsolidated for their burial depth, again indicating probable fluid flow. The basalts are highly vesicular. However, the vesicularity can only account for part of the average porosity measured on the neutron porosity well log; the remainder of the measured porosity is likely present as voids and fractures within and between thin-bedded basalts. Core samples, together with porosity, density, and resistivity well-log data show locations where the basalt section is thin bedded and probably has from 15% to 35% void and fracture porosity. Thus, the measured permeability seems reasonable with respect to the high measured porosity. Much of the fluid flow at Site 839 could be directed through highly porous and permeable zones within and between the basalt flows and in the sediment layer just above the basalt. Thus, the permeability measurements give an indication of where and how fluid flow may occur within the oceanic crust of the Lau Basin.