Transcript location and exploration of ore

Location of Australian ore
deposits
e.g. iron ore, copper ore, gold and
diamonds
Iron Formation
• Most Iron ores are derived
from ancient sediments known
as banded iron formations
(BIFs). These sediments are
composed of iron oxide
minerals deposited on the sea
floor. Particular environmental
conditions are needed to
transport enough iron in sea
water to form these deposits,
such as acidic and oxygenpoor atmospheres within the
Proterozoic Era (the first
evidence of oxygen build-up in
the atmosphere).
http://www.learner.org/courses/envsci/visual/animation.p
hp?shortname=anm_ironformations
Formation of Diamonds
•
The formation of diamonds began very early in the earth's history,
when the condensation of solid matter into a sphere caused the
centre of the planet to become subjected to incredible extremes of
temperatures and pressure.
•
It was these conditions that caused deposits of carbon to begin to
crystallise deep in the earth. As the earth's surface cooled, volcanic
activity forced streams of magna (liquid rock) to the surface,
carrying with it the diamond crystals. Later, the
diamond-bearing rock hardened, encasing the diamonds in
vertical volcanic "pipes".
•
But not all diamonds are found where they first came to
the surface. Subsequent erosion of the topsoils over
millions of years washed some of the diamonds into
streams and rivers, and sometimes as far away as the sea.
http://www.oresomeresources.com/media_centre_view/category/media_video_diamond_formation/section/media/parent/
Argyle Diamond Mine
•
The Argyle diamond mine is located in the Kimberley region in the Australian state of
Western Australia. The Argyle mine is located on a volcanic pipe.
Copper Formation
• Copper is found in association with many other metals and deposit
styles. Copper is either formed within sedimentary rocks, or
associated with igneous rocks.
• Sometimes granites erupt to surface as volcanoes, and copper
mineralisation forms during this phase when the granite and
volcanic rocks cool via hydrothermal circulation.
• Sedimentary copper forms within ocean basins in sedimentary
rocks. Generally this forms by salt water from deeply buried
sediments discharging into the deep sea, and precipitating copper
and often lead and zinc sulfides directly onto the sea floor. This is
then buried by further sediment.
Gold Formation
•
Gold deposits are formed via a very wide variety of geological processes.
Plate tectonics is the underlying mechanism for generating gold deposits.
•
Most gold deposits are sourced from metamorphic rocks because it is
thought that the majority are formed by dehydration of basalt during
metamorphism. The gold is transported up faults by hydrothermal waters
and deposited when the water cools too much to retain gold in solution.
Location of Australian volcanoes
and Mines
http://www.oresomeresources.com/interactives_view/resource/interactive_operating_mines_in_australia_map/section/resources/parent//categor
y/environment