A minor update to Version 1.0: Lu Hf and O isotope data structure and delivery.
Isotopic data from rocks and minerals have the potential to yield unique insights into the composition and evolution of the Earth's crust and mantle. Time-integrated records of crust and mantle differentiation (as preserved by the U-Pb, Sm-Nd and Lu-Hf isotopic systems, for example) are important in a wide range of geological applications, especially when successfully integrated with other geological, geophysical, and geochemical datasets. However, such integration requires (i) compilation of comprehensive isotopic data coverages, (ii) unification of datasets in a consistent structure to facilitate inter-comparison, and (iii) easy public accessibility of the compiled and unified datasets in spatial and tabular formats useful and useable by a broad range of industry, government and academic users. This constitutes a considerable challenge, because although a wealth of isotopic information has been collected from the Australian continent over the last 40 years, the published record is fragmentary, and derived from numerous and disparate sources. Unlocking and harnessing the collective value of isotopic datasets will enable more comprehensive and powerful interpretations, and significantly broaden their applicability to Earth evolution studies and mineral exploration.
As part of the Exploring for the Future (EFTF) program (https://www.ga.gov.au/eftf), we have designed a new database structure and web service system to store and deliver full Lu-Hf isotope and associated O-isotope datasets, spanning new data collected during research programs conducted by Geoscience Australia (GA), as well as compiled literature data. Our approach emphasises the links between isotopic measurements and their spatial, geological, and data provenance information in order to support the widest possible range of uses. In particular, we build and store comprehensive links to the original sources of isotopic data so that (i) users can easily track down additional context and interpretation of datasets, and (ii) generators of isotopic data are appropriately acknowledged for their contributions.
This system delivers complete datasets including (i) full analytical and derived data as published by the original author, (ii) additional, normalised derived data recalculated specifically to maximise inter-comparability of data from disparate sources, (iii) metadata related to the analytical setup, (iv) a broad range of sample information including sampling location, rock type, geological province and stratigraphic unit information, and (v) descriptions of (and links to) source publications. The data is delivered through the Geoscience Australia web portal (www.portal.ga.gov.au), and can also be accessed through any web portal capable of consuming Open Geospatial Consortium (OGC)-compliant web services, or any GIS system capable of consuming Web Map Services (WMS) or Web Feature Services (WFS).
Version 1.0 of this Record (Waltenberg et al., 2021) described the database system and web service tables, and featured normalised Lu-Hf data that utilised CHondritic Uniform Reservoir (CHUR) parameters from Blichert-Toft and Albarède (1997). It also presented full tabulated datasets compiled from the North Australian Craton as part of the initial EFTF (2016–2020) program, comprising 5974 individual analyses from 149 unique rock samples. This update (version 1.1) enacts minor changes to some field names within the web services tables to ensure consistency with other web services offered by GA, and for normalised Lu-Hf data, it applies the CHUR parameters of Bouvier et al. (2008) to the entire dataset. The digital datasets presented by Waltenberg et al. (2021) have also been supplemented by more recent analyses collected as part of GA projects in Queensland and New South Wales, in collaboration with the relevant State geological surveys. Version 1.1 does not include an updated tabular data release; the digital dataset available via the web portal now comprises 7630 individual analyses from 180 unique rock samples.
