(Table 4) Contents of P2O5 and REE in phosphorites from Pacific seamounts

Changes in concentration levels and speciation of heavy metals during sedimentation on example of a typical semi-closed bay, where bottom sediments have formed due to river run-off, are under consideration. It is shown that due to desorption of mobile manganese, zinc and copper entered the bay with river suspended matter, their total contents in bottom sediments decrease and percentages of lithogenic forms increase. Contents and speciation of iron in bottom sediments are determined by its participation in coagulation of river colloids in the mixing zone and by mechanical differentiation of sedimentary material.

Sediment Trap Data in the northwest Mediterranean Sea from the MedFlux project (2003 - 2005)

MedFlux sampling was carried out at the French JGOFS DYFAMED (DYnamique des Flux Atmospheriques en MEDiterranee) site in the Ligurian Sea (northwestern Mediterranean), 52km off Nice (431200N, 71400E) in 2300m water depth. In 2003, a mooring with sediment trap arrays was deployed 6 March (day of year, DOY 65) and recovered 6 May (DOY 126); this trap deployment will be referred to as Period 1 (P1). The array was redeployed a week later on 14 May (DOY 134) and recovered again on 30 June (DOY 181); this trap deployment will be referred to as Period 2 (P2). Indented-rotating sphere (IRS) valve traps were fitted with TS carousels to determine temporal variability of particulate matter flux. TS traps were fitted with ''dimpled'' spheres. Vertical flux at 200m depth is considered to be equivalent to new or export production, and traps sampled at 238 and 117m during P1 and P2, respectively. We also collected TS material at 711m during P1 and at 1918m during P2. Upon recovery, samples were split using a McLaneTM WSD splitter to allow multiple chemical analyses. Here we report 2003 data on TS particulate mass, and the contributions of organic carbon (OC), opal, lithogenic material and calcium carbonate to mass. In 2005, traps were deployed as described above for 55 d during a single period from 4 March (DOY 63) to 1 May (DOY 121). TS traps were fitted with ''dimpled'' spheres. TS particulate matter was collected from 313 to 924 m.

Sediment Trap Data from the CARIACO Ocean Time Series (1995-2010)

The Cariaco Basin is a 1400-m-deep depression approximately 160 km long by 70 km wide located off the central Venezuelan coast . It is connected to the Atlantic Ocean by a sill ~100-m-deep, and two slightly deeper channels that breech it; Canal Centinela (146-m-deep) and Canal de la Tortuge (135-m-deep). High surface production rates and restricted circulation result in anoxic waters below ca. 275 m. The depth of the oxycline varies between 250 and 320 m and is independent of density. Rather, fluctuations in oxycline depth appear to be due to lateral intrusions of Caribbean Sea water that are linked to eddies along the continental shelf. A mooring with five sediment traps (Z, A-D) is located in the eastern Cariaco Basin. Traps A-D have been in place since November 1995. Trap A is located in oxic waters at 226 ± 6 m. Trap B is located at 407 ± 3 m and Trap D is located at 1205 ± 3 m. Trap C was located at a depth of 880 ± 2 m from Jan. 1996 to Nov. 2000, and was moved to 807 ± 2 m in Nov. 2000. A fifth trap, Z, was added in November 2003 at 110 m for the first 6 months, and at 150 m thereafter. All five sediment traps are coneshaped with a 0.5 m**2 opening that is covered with a baffle top to reduce turbulence. The mooring is deployed for six-month intervals and each sample collection cup is filled with a buffered 3.2% formalin solution as a preservative for the accumulating organic matter. The cups are numbered 1-13, with cup 1 collecting for the two-week interval immediately following deployment, and cup 13 collecting for the 2 weeks immediately before recovery.

Nd and Sr isotope compositions, REE concentrations and Al/Ca ratios of different phases of surface sediments in the South Pacific

The radiogenic isotope composition of neodymium (Nd) and strontium (Sr) are useful tools to investigate present and past oceanic circulation or input of terrigenous material. We present Nd and Sr isotope compositions extracted from different sedimentary phases, including early diagenetic Fe-Mn coatings, "unclean" foraminiferal shells, fossil fish teeth, and detritus of marine surface sediments (core-tops) covering the entire midlatitude South Pacific. Comparison of detrital Nd isotope compositions to deep water values from the same locations suggests that "boundary exchange" has little influence on the Nd isotope composition of western South Pacific seawater. Concentrations of Rare Earth Elements (REE) and Al/Ca ratios of "unclean" planktonic foraminifera suggest that this phase is a reliable recorder of seawater Nd isotope composition. The signatures obtained from fish teeth and "nondecarbonated" leachates of bulk sediment Fe-Mn oxyhydroxide coatings also agree with "unclean" foraminifera. Direct comparison of Nd isotope compositions extracted using these methods with seawater Nd isotope compositions is complicated by the low accumulation rates yielding radiocarbon ages of up to 24 kyr, thus mixing the signal of different ocean circulation modes. This suggests that different past seawater Nd isotope compositions have been integrated in authigenic sediments from regions with low sedimentation rates. Combined detrital Nd and Sr isotope signatures indicate a dominant role of the Westerly winds transporting lithogenic material from South New Zealand and Southeastern Australia to the open South Pacific. The proportion of this material decreases toward the east, where supply from the Andes increases and contributions from Antarctica cannot be ruled out.

Flux of ice-rafted detritus in the Fram Strait

A three-year particle flux record from the eastern Fram Strait, between Greenland and Svalbard, revealed a rather untypical seasonal flux pattern compared to other particle flux studies from the Nordic Seas. In the eastern Fram Strait this pattern is characterised by a sudden four- to six-fold increase of the particle flux in January, when no daylight is available to support any biological productivity. Comparison with sea-ice distribution maps led to the conclusion that the sudden increase in the flux is due to ice-rafted detritus released from sea ice, which originated from the Svalbard archipelago and from the northern Barents Sea. Detailed grain size analyses of the silt fraction indicated the >10 µm fraction of the lithogenic matter to be clearly enriched due to IRD input. Even more important is the observation that lithogenic material >40 µm occurs exclusively during the ice-rafting event and, therefore, appears to be a suitable indicator for IRD transported on sea ice. Thus, in addition to coarse IRD (e.g. >500 µm), which is mainly derived from icebergs, the analysis of fine IRD >40 µm in deep-sea sediments can be used to reconstruct paleo-sea-ice extensions.