Metamorphic stage

Submitted by chee.ng on Thu, 02/11/2023 - 13:56

Terms used to describe the stage of metamorphism of rocks based on the nature of the change in pressure and temperature conditions to which the rocks are subjected. Definitions are taken or derived from:
Fettes, D and Desmons, J (eds.) 2007, Metamorphic Rocks: a classification and glossary of terms — Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Metamorphic Rocks: Cambridge University Press, 244p.

Metamorphic facies

Submitted by chee.ng on Thu, 02/11/2023 - 13:33

A metamorphic facies is defined by a repeatedly occurring and thus predictable set of stable mineral assemblages in metamorphic rocks. Such metamorphic mineral assemblages crystallize and are stable over a range of externally imposed physical conditions, most crucially lithostatic pressure and temperature, and thus the facies define areas in two-dimensional plots of pressure–temperature space. There is a demonstrable/proven relationship between mineral composition and bulk rock chemical composition and a consistent relationship through geological time.

CRIRSCO mineral resource reporting

Submitted by chee.ng on Thu, 02/11/2023 - 13:30

Terminology defined by the Committee for Mineral Reserves International Reporting Standards (CRIRSCO; https://www.crirsco.com/) based on the International Reporting Template (IRT; https://www.crirsco.com/docs/CRIRSCO_International_Reporting_Template_November_2019.pdf). The IRT is a document that draws on the best of the CRIRSCO-style reporting standards, the JORC Code (Australasia), SAMREC Code (South Africa), Reporting Code (UK / Western Europe), CIM Guidelines (Canada), SME Guide (USA) and Certification Code (Chile).

Vertical/depth reference systems

Submitted by admin on Sat, 21/10/2023 - 06:54

The point or level from which heights and depths are measured and referenced to for an entity or activity. Typically these are expressed relative to a common global or regional reference datum such as the Australian Height Datum (AHD) or can be related to local reference systems. Specific emphasis is placed on elevation references used by resource exploration and drilling programs, whereby depths are measured relative to local reference datums or specific parts of a borehole/drilling platform. Concepts in this vocabulary include both reference datums (e.g.

Geological feature type

Submitted by admin on Sat, 21/10/2023 - 06:50

This vocabulary lists the fundamental types of geological features that are used to define the geological framework/4D evolution of Western Australia and are relevant to the duties of the Geological Survey of Western Australia. A geological feature is a physical or conceptual feature that is hypothesized to exist coherently in the Earth and that results from geological processes (definition largely derived from SWEET ontology http://sweetontology.net/realmGeol#geologicfeature).

Australian physiographic units

Submitted by chee.ng on Wed, 27/09/2023 - 09:05

A list of physiographic units in Australia that provide a consistent framework for mapping soils and landforms at national and regional scales, compiled at a continental scale. The list was defined by Pain et al. (2011; https://www.clw.csiro.au/aclep/documents/PhysiographicRegions_2011.pdf)* and built on the work of Jennings and Mabbutt (1986). It recognises a subdivision of the Australian onshore continent into three physiographic divisions, 23 physiographic provinces and 220 physiographic regions.

Western Australian mineral fields and districts

Submitted by chee.ng on Thu, 21/09/2023 - 17:07

The State of Western Australia is divided into various Mineral Fields that represent administrative land subdivisions under which mining is administered in the State according to Section 16 of the Mining Act 1978. Some mineral fields are further subdivided into Districts. Mineral field and district boundaries can be changed by proclamation under the Mining Act 1978 — the listing provided is current as of June 2023. Each mineral field or district is characterized by a two-digit prefix code used for map representations and tenement indexing.

Western Australian coordinate reference systems

Submitted by chee.ng on Thu, 21/09/2023 - 17:01

The coordinate reference systems (geographic and projected) used and referred to within Western Australia. It includes historical and current reference systems, Universal Transverse Mercator (UTM) zones, and, where applicable, notations based on the EPSG registry (https://epsg.io/). Some concepts are included to account for legacy data/maps with limited information.