ALBERT

Description: IODP Site U1309 was drilled at Atlantis Massif, an oceanic core complex, at 30°N on the Mid-Atlantic Ridge (MAR). We present the results of a bulk rock geochemical study (major and trace elements) carried out on 228 samples representative of the different lithologies sampled at this location. Over 96% of Hole U1309D is made up of gabbroic rocks. Diabases and basalts cross-cut the upper part of the section; they have depleted MORB compositions similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic and geochemical evidence of extensive melt-rock interactions. Gabbroic rocks comprise: olivine-rich troctolites (〉 70% modal olivine) and troctolites having high Mg# (82-89), high Ni (up to 2300 ppm) and depleted trace element compositions (Yb 0.06-0.8 ppm); olivine gabbros and gabbros (including gabbronorites) with Mg# of 60-86 and low trace element contents (Yb 0.125-2.5 ppm); and oxide gabbros and leucocratic dykes with low Mg# (〈 50), low Ni (~65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros are amongst the most primitive and depleted oceanic gabbroic rocks. The main geochemical characteristics of Site U1309 gabbroic rocks are consistent with a formation as a cumulate sequence after a common parental MORB melt, although (lack of systematic) downhole variations indicate that the gabbroic series were built by multiple magma injections. In detail, textural and geochemical variations in olivine-rich troctolites and gabbronorites suggest chemical interaction (assimilation?) between the parental melt and the intruded lithosphere. Site U1309 gabbroic rocks do not represent the complementary magmatic product of 30°N volcanics, although they sample the same mantle source. The bulk trace element composition of Site U1309 gabbroic rocks is similar to primitive MORB melt compositions; this implies that there was no large scale removal of melts from this gabbro section. The occurrence of such a large magmatic sequence implies that a high magmatic activity is associated with the formation of Atlantis Massif. Our results suggest that almost all melts feeding this magmatic system stays trapped into the intruded lithosphere.

Description: During the GDP-8 cruise of R/V Bosei-Maru, scientists from the Tokai University surveyed the Kinan seamount chain and the Kyushu-Palau Ridge in the Phillippine Sea. They dredged manganese nodules and ferromanganese crusts formed around basaltic tuff rocks and acid plutonic rock pebbles.

Description: Stable isotopes (δ²H and δ¹⁸O) were analyzed in water samples collected at the German Baltic Sea Coast. Transect samples were taken in June 2019, March 2020, and July 2021 at 68 spots along the Schlei, the Zingster Bodden chain, and the Rügener and Greifswalder Boddens. Additionally, at selected spots time series were sampled in biweekly to monthly intervals between March 2020 and March 2021. At shores, water was sampled with a pipette from 0.3 to 0.6 m below water surface and directly transferred into a measurement vial. In deeper parts of the boddens a Limnos sampler was used to obtain water from 0.5 to 1 m below surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. The measurement uncertainty was quantified by error propagation, including the parameters a) uncertainties of lab standards; b) errors of standard calibration; c) average standard deviation of replicate measurements. Based on this, measurement uncertainty was estimated to account 0.16 ‰ for δ¹⁸O and 0.57 ‰ for δ²H. Water chemical parameters were measured with WTW measurement devices. The data give information about a) the seasonal isotope amplitude at the sampled locations; b) spatial variability along the transects, and c) the correlation between isotopes and water chemical parameters.

Description: Stable isotopes (δ2H and δ18O) were analyzed in water samples collected at 68 spots along the Schlei, the Zingster Bodden chain, and the Rügener and Greifswalder Boddens in June 2019, March 2020, and July 2021. Transect samples were taken at shores from 0.3 to 0.6 m below water surface, using a pipette, and directly transferred into measurement vials. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with a WTW multiparameter device (Multi 3630 IDS), equipped with a WTW TetraCon 925 electrical conductivity measuring cell. The data give information about the spatial isotope variability along the transects.

Description: Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples collected near the A. P. Møller Skolen, Schleswig (Kleine Breite, Schlei), in biweekly to monthly intervals between March 2020 and March 2021. Water was sampled with a pipette from ca. 0.5 m below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with a modular WTW 3440 multiparameter devices and regularly calibrated conductivity cells (MPP 930 IDS, TetraCon® 925-P). The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Description: Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples taken near the harbour of Kloster (Hiddensee), in biweekly to monthly intervals between March 2020 and March 2021. Water was sampled with a pipette from ca. 0.5 m below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with WTW multiparameter measurement devices. The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Description: Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples collected at the Zingster Bodden chain in biweekly to monthly intervals between March 2020 and March 2021. Herefore, a Limnos sampler was used to obtain water from 0.5 to 1 m below surface. In the laboratory, a WTW 1970i conductivity meter and TetraCon 325 measuring cell were used to analyse electrical conductivity. Sub-samples were transferred into measurement vials before isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured with regularly calibrated WTW multiparameter devices. The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.