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 oxygen-poor atmospheres within the Proterozoic Era (the first evidence of oxygen build-up in the atmosphere).

http://www.learner.org/courses/envsci/visual/animation.php?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//category/environment