#flinders range

Because of the time represented by this basin, rocks from it cover the proposed “Snowball Earth” events and provide some of the best examples of glacial processes. Those rocks are then followed by rocks from the Ediacaran period, the time just before the Cambrian when multicellular, animal life existed on Earth, but without hard parts that are easy to fossilize. In fact, the Ediacaran hills are just southwest of the area covered by this satellite image collected by the European Space Agency’s Sentinel Satellites. This is a false-color image. Different minerals and different rocks are absorbing light at different wavelengths, and those absorbances are being assigned to colors that we can see. Thus, we’re using infrared light to be able to distinguish one rock from another, one layer from another. While the rocks don’t look like this in the field, the image itself would be extremely useful because this is basically a broad-scale geologic map, collected from space. You can even make out areas of active sediment cover at the western side. The original image would be large enough to print and hang on a wall. -JBB Image credit: ESA https://flic.kr/p/2jrAweP

The original sediments were deposited on Australia's eastern edge as Pangaea's precursor supercontinent Rodinia broke up between 870 and 500 million years back, and they encompass the first complex multicellular organisms found so far in the fossil record, the enigmatic Ediacaran fauna (see http://on.fb.me/1BlFejb). As the supercontinent rifted huge basins opened that became sediment traps for the products of rivers and glaciers. At their thickest they stretch some 24km deep, and their lithology is of marine sandstones, limestones and shales. At the end of the Cambrian, between 514 and 500 million years ago they were squished and baked in a mountain building event (known as the Delamarian orogeny), and the remaining hills are but the root stumps of a mighty range. The basin inverted into a mountain range in response to some huge tectonic pressure. The area was also crucial in demonstrating the reality of the Snowball Earth events, aka the Marinoan and Sturtian glaciations, in which our whole planet more or less was covered in deep ice. Rocks in the area had striations (scratches) caused by rocks stuck onto the bottom of a glacier grinding across the, and had magnetic signatures indicating that they were close to the equator when this happened. Loz Image credit: Digital Globe, field of view around 160 square km.