Major and trace element concentrations and Sr, Nd, Hf, Pb isotope ratios of global mid ocean ridge and ocean island basalt whole-rock compositions from the GEOROC and PetDB databases (2021-2022).
Key publications:
Stracke, A., Willig, M., Genske, F., Béguelin, P., & Todd, E. (2022). Chemical Geodynamics Insights From a Machine Learning Approach. In Geochemistry, Geophysics, Geosystems (Vol. 23, Issue 10). https://doi.org/10.1029/2022GC010606
Stracke, A., Willig, M., Genske, F., Béguelin, P., & Todd, E. (2022). Chemical and radiogenic isotope data of ocean island basalts from Tristan da Cunha, Gough, St. Helena, and the Cook-Austral Islands [dataset]. GRO.data. https://doi.org/10.25625/BQENGN
This dataset contains data of a reflection seismic profile in North-Western Namibia. The measurements were carried out in continuation of the LISPWAL project aiming to decipher the lithospheric structure of the Namibian passive margin at the intersection with the Walvis Ridge (Ryberg et al., 2014a, b; 2015). Scientific aims were a) to produce a high-resolution image of the reflectivity of the lower-crustal high-velocity body revealed by wide-angle observations; b) an improved understanding of how continental crust and plume head interact, c) to investigate what the extent and volumes of magmatic underplating are, and d) to understand how and which inherited (continental) structures might have been involved and utilized in the break up process. The dataset contains seismic data, including raw and SEG Y files, of the controlled-source survey in North-Western Namibia (Kaokoveld) using near-vertical reflection seismic methods.
During the second leg of cruise BGR78 from 22th of February to 29th of March 1978 with R/V EXPLORA the following measurements have been carried out as presite- and postsite surveys of DSDP sites: (1) in the region of the eastern Walvis Ridge 4,350 km multichannel seismic reflection profiles, 4,540 km magnetic measurements, 5,000 km gravimetric measurements and sonobuoy refraction measurements on 11 stations (2) on the Guinea Plateau 740 km multichannel seismic reflection profiles in parallel with gravimetric and magnetic measurements (3) between Cape Verde islands and Mauretania 980 km multichannel seismic reflection profiles in parallel with magnetic measurements, 1,480 km gravimetric measurements and sonobuoy refraction measurements on 2 stations. The geophysical measurements show that the structure of the Walvis Ridge is determined by two main tectonic directions (WSW-ENE and SSW-NNE). Presumably the genesis of the fracture zone in the Walvis Ridge area can be traced back to the sea-floor spreading with overprinting effects due to an inhomogeneity in the mantle ("hot spot"). Both DSDP drilling projects in this part of the Walvis Ridge led to a fragmentary knowledge because site 362 got stuck at a depth of 1.100 m in the Oligocene. BGR's measurements indicate a gap of at least 1.000 m of sediments, especially from the cretaceous period, down to the (acoustic) basement. Site 363 at a submarine high has gaps in the depositional sequence and stops at a depth of 700 m shortly above the basement. So for a better understanding of the geologic development of the Walvis Ridge, further DSDP drillings with a recovery of the complete sedimentary sequence and the following basement cores are necessary. Therefore BGR's measurements of this cruise propose new DSDP sites.