Not logged in
Data Publisher for Earth & Environmental Science

Hagedorn, Birgit; Gersonde, Rainer; Gohl, Karsten; Hubberten, Hans-Wolfgang (2007): Petrology, geochemistry and K-Ar Age determination of De Gerlache Seamount basalts. PANGAEA,, 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 citation above when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

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
PS2693-1 (PS35/155) * Latitude: -65.305000 * Longitude: -90.586000 * Date/Time: 1995-04-22T21:34:00 * Elevation: -773.0 m * Location: Southeast Pacific * Campaign: ANT-XII/4 (PS35 06AQANTXII_4) * Basis: Polarstern * Method/Device: Dredge (DRG) * Comment: Basalt (max. 50x30x20 cm)
2 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text — use the following character encoding: