Geological Survey

Geological mapping

Overview

The Geological Survey of NSW (GSNSW) carries out geological mapping which involves identifying and recording the character and distribution of rock units at or near the Earth's surface. The surface distribution, orientation and inter-relationship of the various rock units, allow geologists to infer their three-dimensional arrangement, and to determine the structure and composition of the upper part of the Earth's crust.

The geology of the surface and near-surface of the Earth determines the potential availability of mineral, coal, petroleum, water and construction material resources. Geological mapping also provides information that is critical for land assessment, engineering construction, environmental management, and natural hazard risk assessment. This knowledge is essential to sustain modern society.

Geological Maps are often published in 1:250 000 and 1:100 000 series and are accompanied by comprehensive explanatory notes.

Geological mapping data is also integrated with geophysical datasets, mineral occurrences, geochemistry and exploration and tenement datasets to form comprehensive geoscience data packages for many areas throughout the State.

Geological mapping activities uses specialist geoscientific services, such as petrological and palaeontological advice. The WB Clarke Geoscience Centre houses the state's fossil, rock and economic mineral reference collection at Londonderry. Together with the Core Library, this centre holds an invaluable wealth of geoscience reference data as well as providing analytical services.

Current activities

Current mapping projects being conducted or being completed are over the Koonenberry, Cobar, Goulburn, Braidwood and Thomson project regions. New gravity data has been released over the Eromanga/Thomson in the far northwest and over the interpreted Bendigo/Stawell zones that extend into the far southwest. Geophysical interpretation maps are being completed over a number of 1:250 000 map sheet areas in the far northwest and far southwest of NSW. A description of the mapping projects follow.

The Koonenberry Belt in far northwest NSW wraps around and defines the eastern margin of the Curnamona Craton and has great potential for undiscovered world-class deposits. Provisional geology maps are being finalised on four 1:25 000 geology maps of inliers, twelve 1:100 000 geology maps, four 1:100 000 regolith maps and a summary 1:250 000 geology map for Tibooburra/Koonenberry region.
The Thomson Project area, which underlies the Channel Country in the far northwest, is a major greenfield region in NSW. It has potential for arc and ocean-crust related gold and base metal deposits while the area to the south of the orogen may have potential for Mississippi Valley style zinc deposits.
Mapping of the Bourke and Cobar 1:250 000 map sheet areas has produced preliminary Sussex and Byrock 1:100 000 geology maps. The Cobar Region 3D Geology Project, a collaboration between DPI, pmd*CRC and industry, began in 2005. This project assembled and integrated the available geoscientific data in the Cobar region into an integrated 3D model to help predict new target areas for mineral exploration. This project served as a model for 3D mapping carried out over the Braidwood area.
The focus of the Goulburn mapping is the publication of Goulburn Explanatory Notes, and release of the Goulburn 1:250 000 Solid Geology Map (2 sheets), and the six constituent 1:100 000 map sheets.
Geological mapping on the Braidwood 1:100 000 Project and the validation and a preliminary 3D model for the northern half of the map sheet have been completed.
The aim of the Tasmanides Project, formerly a collaborative project with pmd*CRC, is to construct a seamless 3D map of the Tasmanides so as to understand the fundamental controls on location of major ore deposits and to assist the mineral exploration industry to predict and discover new world class ore bodies in Southeast Australia. A preliminary series of internally-consistent east-west sections has been completed with the aim to construct a 3D model for the East Lachlan.
The Broken Hill Interpretive Mapping Project aims to interpret the stratigraphy of the Proterozoic in the Broken Hill region. One of the products will be a revised 1:100 000 interpretive stratigraphic map, based on the latest geophysics and existing detailed GSNSW 1:25 000 lithological mapping. The project is one of several under the auspices of the Broken Hill Exploration Initiative.
An audit and gaps report on all geological data relevant for the Greater Sydney Region has been released. The study extends from Port Stephens in the north, to Batemans Bay to the South, and Katoomba to the west. It identified the Moss Vale 1:100 000 map sheet as a priority to be mapped, so work on this sheet began in February 2007 and is soon to be completed.

Current mapping projects

Current mapping project areas are shown on the picture below. Click an area of interest to see details:

Alternatively, you may click on one of the listed items below:

For further information please contact the Geological Mapping Team.

(Last updated on 24/02/2009)