Geology

An existing mining company wants to establish the potential for tin and rare earth elements
within the Gibson region. A feasibility study requires the regional geology to be
understood, particularly with regards to calculating any tin resource that may be constrained
by the geological resource model.
Task A) Regional Geology Task (2 pages):
A geological column needs to be established and the geology history of the region also
needs to be determined. With respects to the geological history, any pertinent
information, faults and unconformities that exist within the region should be included
(Figure 1; Appendix 1). Within the brief summary (2 pages) of the geological history of
the region, the tectonic setting(s) should also be noted. The brief summary includes the
geological column that has the oldest unit at the base and the youngest at the top. It may
be helpful to also identify structural features, such as any faults, within this column.
Factors to be identified within the geological history include unconformities, igneous
events, deformational events, metamorphic grade and movement along faults. The plate
tectonic setting(s) need to be identified, where possible. Evidence needs to be included
regarding the principle of superposition for the geological history and appendices may be
used. Sketching the off-shore geology will help constrain aspects of the geological history
and assist in completing Task C.
(40 marks)
Task B) Cross Sections (1 page):
Two cross sections, with no vertical exaggeration, need to be constructed that best
highlights the geology of the region, including the extent of the tin resource, folds and
faults within the region (1 page):

  1. An initial cross section needs to be constructed along A-B.
  2. A second cross section running perpendicular should be constructed that best
    captures the geology features pertaining to the region.
    (30 marks)
    Task C) Tin Resource Estimate and Potential Offshore Exploration (2 pages)
    Estimate the tin resource based on the geological modelling that has been undertaken.
    Typically tin occurs in carbonaceous rocks juxtaposed next to felsic intrusions. While this
    will be only a rough initial estimate the company expects the following to be factored in:
    • Average Economic Sn Cut-off Ore Grade: 0.45% (Appendix 2)
    • Mining Depth: 220m .
    As the rare earth minerals are becoming increasingly valuable, the company has
    requested you define further exploration areas of tin and rare earth element mineralisation
    extrapolated from exiting information and located offshore.