background

The National Key Centre for the Geochemical Evolution and Metallogeny of Continents (GEMOC) formally commenced in January, 1996.  Funding started from July 1995 on very short notice, so GEMOC is operating on a 6-month delay with fund rollover.  GEMOC was based on the existing expertise and strong funding profile (dominantly ARC) of groups at Macquarie and ANU (Faculties), with collaborative links to CSIRO, AGSO and colleagues at other Australian Universities as detailed under "Participants" in Appendix 1.

This existing base provided the springboard to both broaden and deepen GEMOC’s activities, targeting large-scale problems related to understanding lithosphere evolution and the relevance of different types of crust-mantle domains to area selection for mineral exploration.
Major strengths are the diversity of the individual strands and the range of scales being used in an integrated way to interpret fundamental Earth processes.  The scales range from global, to regional, to outcrop, to the micron.

The front cover for the 1998 Report emphasises the increasing role of geophysical information (integrated with the geochemical methodologies) in imaging the lithosphere and its properties.  Parallel advances in technology and software development and novel geological applications of microbeam analysis continue to be driven by end-user needs and the knowledge required to solve major geological problems.

GEMOC has made significant advances through 1998 in imaging the lithosphere from micron to craton scales through time and some of these are profiled in the Research Highlights.
 

scientific philosophy

GEMOC's distinctiveness lies in its interdisciplinary and integrated approach to interpreting Earth’s lithosphere as a 4-dimensional dynamic system (in space and time).
 

This approach links

petrology and geochemistry
geophysics
petrophysics
tectonics

time (4th dimension)
thermal state

strategic outcomes

• Fundamental insights into the processes that create and modify the continental mantle and crust through time
• A better understanding of the assembly of the Australian continent and its geological architecture to 100-200 km depth. Analogue studies in other regions are essential to this.
• Results and concepts exportable to other terrains, including Southeast Asia and other potentially resource-rich areas of interest to Australian exploration companies
• A new conceptual framework for understanding the localisation of economic deposits, which will influence exploration strategies for new world-class ore deposits, and improve the competitiveness of the Australian exploration industry both on- and off-shore
• A realistic 3-D geological framework for the interpretation of lithospheric-scale geophysical datasets
• A training program for senior undergraduate and postgraduate students (and continuing education) that will help maintain the technological edge of the Australian mineral industry and improve the industry's ability to rapidly assimilate new concepts and methodologies
• New analytical strategies for determining the chemical and isotopic compositions of geological materials (including fluids)
• Strategic and collaborative alliances with technology manufacturers in design and application innovation
• International research, teaching, industry and technology links of benefit to Australia

Volcanoes probe the lithosphere:
The volcano echoes GEMOC’s logo and symbolises the links between the four Research Strands: Lithosphere Mapping, Crustal Evolution, Metallogenesis and Geotectonics.  Magmas and deep-seated xenoliths brought to the surface in volcanics allow us to image the structure and geochemical domains at depth, track changes in the lithosphere through time, construct the palaeogeothermal state of the lithosphere, characterise fluids mobilised from the mantle and crust and interpret the tectonic environment
Shown here is Baitou Peak at the summit of the Changbai Mountains and part of a large volcanic province at the northeastern margin of the Sino-Korean craton.  The volcanics reflect changes in the asthenospheric mantle source and the lithosphere with time as the Japan Sea opened.