Elemental geochemistry data from sediments in the Otway Basin, South Australia

Published: 24 January 2023| Version 1 | DOI: 10.17632/s95m953h4g.1
Betina Bendall


Cuttings samples from petroleum wells Sawpit 1, Sawpit 2, Katnook 4, Wynn 1, Bungaloo 1 and Jolly 1ST1 were selected for whole rock elemental geochemistry using both lab-based and Portable (pXRF) Xray Fluorescence methods. This data formed the basis of a major chemostratigraphic study used to characterise and differentiate sediments of the Early Cretaceous Crayfish Group in the Otway Basin as part a series of studies associated with the SA Department for Energy and Mining's Otway Basin 3D Basin Model and Petroleum Systems Analysis Project.


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Lab samples were sorted, washed and dried and sent to Bureau Veritas Laboratories for 50 element XRF (X ray Fluorescence) and LA ICPMS (laser ablation inductively coupled mass spectrometry) geochemical analysis. Primary preparation has been by pulverising the whole sample in a vibrating disc pulveriser. The samples have been analysed by firing a 40 gm (approx.) portion of the sample. Lower sample weights may be employed for samples with very high sulphide and metal contents. Samples for LA ICPMS have then been cast using a 66:34 flux with 4% Lithium nitrate added to form a glass bead. Weight % oxides (SiO2, Al2O3, CaO, Fe2O3, K2O, MgO, Na2O, P2O5, SO3, TiO2 and MnO) were determined by X-Ray Fluorescence Spectrometry on an oven dry (105oC) sample. Loss on Ignition results have been determined using a robotic TGA system. Furnaces in the system were set to 110oC and 1000oC. All other elements were measured by LA ICPMS on a fused bead. Samples from Sawpit 2 and Wynn 1 were sorted, washed and dried and prepared as pressed pellets and analysed for 20 elements using an Olympus Vanta handheld portable XRF device at the South Australian Core Library, Tonsley. A SA Department for Energy and Mining Report Book detailing the chemostratigraphic methodology and interpretation derived from this data is in preparation.


Elemental Geochemistry, Geological Basin