Paleomagnetic of lower Cretaceous sediments from the Argo and Gascoyne Abyssal Plain

Lower Cretaceous sediments were sampled for magnetostratigraphy at three sites. ODP Site 765 and DSDP Site 261, in the Argo Abyssal Plain, consist primarily of brownish-red to gray claystone having hematite and magnetite carriers of characteristic magnetization. ODP Site 766, in the Gascoyne Abyssal Plain, consists mainly of dark greenish-gray volcaniclastic turbidites with magnetite as the carrier of characteristic magnetization. Progressive thermal demagnetization (Sites 765 and 261) or alternating field demagnetization (Site 766) yielded well-defined polarity zones and a set of reliable paleolatitudes. Magnetic polarity chrons were assigned to polarity zones using biostratigraphic correlations. Late Aptian chron M"-1"r, a brief reversed-polarity chron younger than MOr, is a narrow, 40-cm feature delimited in Hole 765C. Early Aptian reversed-polarity chron MOr is also present in Hole 765C. Polarity chrons Mir through M3r were observed in the Barremian of all three sites. Valanginian and Hauterivian polarity chrons can be tentatively assigned to polarity zones only in Hole 766A. The paleolatitude of this region remained at 35° to 37°S from the Berriasian through the Aptian. During this interval, there was approximately 16° of clockwise rotation, with the oriented sample suites of Site 765 displaying a Berriasian declination of 307° to an Aptian declination of 323°. These results are consistent with the interpolated Early Cretaceous apparent polar wander for Australia, but indicate that this region was approximately 5? farther north than predicted.

Abundance of mesozooplankton from nine cruises in Northern Adriatic Sea during NA64

The NA64-Mesozooplankton dataset contains biogeochemistry and mesozooplankton data collected in a series of 9 cruises in the Northern Adriatic completed from January 1965 to September 1965 monthly, and December 1965. Biogeochemistry sampling was undertaken using 5L Nansen bottles fired at 0m, 5m, 10m, 20m, 30m and/or bottom depths. The dataset includes 709 samples analysed for nitrate, phosphate, temperature, salinity and density. Mesozooplankton sampling was undertaken at the same locations as for biogeochemistry, using two different net (Hensen non-closing and Appstein closing net). The dataset includes 146 samples analysed for mesozooplankton composition (at higher taxonomic level), abundance and volume settlement. After sedimentation and volume measurement, the fish larva and fish eggs were extracted from samples (egss of Engraulis encrasicholus were determined). Chaetognaths were partly isolated. Identification at higher taxonomic level of zooplankters was completed. Taxonomic identification was done at Smithonian Mediterranean Centre in Salambo. After sedimentation and volume measurement, the fish larva and fish eggs were extracted from samples (egss of Engraulis encrasicholus were determined). Chaetognaths were partly isolated. Identification at higher taxonomic level of zooplankters was completed. Taxonomic identification was done at Smithonian Mediterranean Centre in Salambo.

Biogeochemistry from nine cruises in Northern Adriatic Sea during NA64

The NA64-Mesozooplankton dataset contains biogeochemistry and mesozooplankton data collected in a series of 9 cruises in the Northern Adriatic completed from January 1965 to September 1965 monthly, and December 1965. Biogeochemistry sampling was undertaken using 5L Nansen bottles fired at 0m, 5m, 10m, 20m, 30m and/or bottom depths. The dataset includes 709 samples analysed for nitrate, phosphate, temperature, salinity and density. Mesozooplankton sampling was undertaken at the same locations as for biogeochemistry, using two different net (Hensen non-closing and Appstein closing net). The dataset includes 146 samples analysed for mesozooplankton composition (at higher taxonomic level), abundance and volume settlement. Temperature was measured with a standard oceanographic thermometers. Salinity was determined by titration after Mohr-Knudsen using standardised water I.C.E.S. Copenhagen with 0,01 permil accuracy. Density was calculated using the following equation Sigma-t = T - (sigma 0 + 0,1324) 1 - At + Bt (sigma 0 - 0,1324). Phosphate samples for the determination of nutrients were collected in 500 ml and filtrated through 0,3 µm membrane filter. 3ml of cloroform was added to stabilize the samples. They were analysed after few days in the laboratory on land. Nitrate samples for the determination of nutrients were collected in 500 ml and filtrated through 0,3 µm membrane filter. 3ml of cloroform was added to stabilize the samples. They were analysed after few days in the laboratory on land.