Hagedorn, Birgit; Gersonde, Rainer; Gohl, Karsten; Hubberten, Hans-Wolfgang (2007): Petrology, geochemistry and K-Ar Age determination of De Gerlache Seamount basalts. PANGAEA, https://doi.org/10.1594/PANGAEA.743234, Supplement to: Hagedorn, B et al. (2007): Petrology, Geochemistry and K-Ar Age constraints of the dastern De Gerlache Seamount alkaline basalts (Bellingshausen Sea, Southeast Pacific). Polarforschung, 76(3), 87-94, hdl:10013/epic.28876.d001
Always quote above citation when using data! You can download the citation in several formats below.
The De Gerlache Seamounts are two topographic highs in the Bellingshausen Sea, southeastern Pacific. Petrological and geochemical studies together with K-Ar age determinations were carried out on four dredged basalt samples collected during a RV Polarstern expedition (ANT-XII/4) in 1995. Minor and trace element composition suggest alkaline basalt compositions. Compared to alkaline basalts of adjacent West Antarctica (the Jones Mountains) and of Peter I Island, the samples have lower mg-numbers, lower Ni and Cr contents and lower high field-strength elements (HFSE)/Nb and large-ion lithophile elements (LILE)/HFSE ratios. Three of the four samples have low K, Rb, and Cs concentrations relative to alkaline basalts. The K-depletion and other elemental concentrations may be explained by 1.1% melting of amphibole bearing mantle material. Additionally, low Rb and Ba values suggest low concentrations of these elements in the mantle source. K-Ar age determinations yield Miocene ages (20-23 Ma) that are similar in age to other alkaline basalts of West Antarctica (Thurston Island, the Jones Mountains, Antarctic Peninsula) and the suggested timing of onset of Peter I Island volcanism (~10-20 Ma). The occurrence of the DGS and Peter I Island volcanism along an older but reactivated tectonic lineation suggests that the extrusions exploited a zone of pre-existing lithospheric weakness. The alkaline nature and age of the DGS basalts support the assumption of plume activity in the Bellingshausen Sea.
Latitude: -65.305000 * Longitude: -90.586000
Date/Time Start: 1995-04-22T21:34:00 * Date/Time End: 1995-04-22T21:34:00
Datasets listed in this Collection
- Hagedorn, B; Gersonde, R; Gohl, K et al. (2007): (Tab.1) Major and rare earth element concentrations of dredged basalt samples at station PS2693-1. https://doi.org/10.1594/PANGAEA.743232
- Hagedorn, B; Gersonde, R; Gohl, K et al. (2007): (Tab.2) K-Ar age determination of dredged basalt samples at station PS2693-1. https://doi.org/10.1594/PANGAEA.743233