Australia: The Land Where Time Began

A biography of the Australian continent 

MAPCIS - Massive Australian Precambrian-Cambrian Impact Structure

See also The Massive Australian Precambrian-Cambrian Impact Structure (MAPCIS) part one

The geological researcher Daniel Connelly has been accumulating evidence in support of the presence of a very large impact structure that he proposes was formed by the impact of an asteroid that was about 30 miles in diameter in the centre of Australia, 300 km southwest of Alice Springs in the Northern Territory, about 545 Ma. He suggests it is the the largest impact site detected so far on Earth. He suggests it struck with such force that it possibly changed the history of the Earth. He presented his findings at the annual conference of the Geological Society of America held in Portland, Oregon on October 19-21.

According to Connelly, the proximal ejecta from the impact led to the formation of Ayer's Rock (Uluru), as enormous amounts of crustal rocks were blasted into the atmosphere, with the generation of large amounts of carbon dioxide that triggered a greenhouse effect that is suggested by Connelly to have led to the Cambrian Explosion.

Connelly has spent thousands of hours working on the project and is convinced the proposed MAPCIS is valid, "I'm very interested in finding allies willing to push the research forward, finance expeditions, drill core samples into the impact melt sheet and verify this impact."

Among the evidence accumulated by Connelly are:

Pseudotachylite, a rare rock type created by intense friction, has been found in arcing deposits up to 100 miles (about 161 km) long and miles wide that ring the proposed impact zone to the southwest. According to experts on impact craters, when pseudotachylite deposits occur in such large amounts they are associated with impact craters. Similar deposits, though on a smaller scale, are present at the Vredefort Impact Crater in South Africa.

Radiating out in opposite directions from that of the impact blast zone is an extensive web of ground faults that are believed to have formed as a result of the impact forces as an asteroid plunged 25 miles (40 km) into the crust.

In many places, in an almost worldwide distribution, a geological "fingerprint" in the form of feldspar and zircon deposits dating to 545 Ma at the Precambrian/Cambrian Boundary has been found in such places as a large swathe across North Africa, Israel and Jordan. In some places the presence of these zircons has been seen as anomalous. In all cases they have the same age of 1.12 Ga, as have the zircons of the Musgrave Geological Province rocks, the proposed impact site of the asteroid, suggesting the impact was the source of deposits of these minerals that appear to be out of place at various sites in other parts of the world.

In a number of places, such as eastern Australia, Tasmania, New Caledonia and New Zealand, as well as at the impact zone, unusual concentrations have been found of osmiridium, a rare natural alloy of osmium and iridium, all deposits of which are at the Precambrian/Cambrian boundary. This pair of platinum group elements, that are often present at the impact sites of asteroids, as occurs at the Sudbury Crater in Ontario, Canada, where there is a large nickel mine, suggests they are ejecta from the blast.

Connelly suggests the impact may have cracked and rotated the continental crust along the Tasman Line, possibly initiating the eventual separation and rifting away of Tasmania, New Zealand and New Caledonia.

There are also a pair of proven impact craters hundreds of miles to the northeast of MAPCIS, that are both of the same age as the MAPCIS, the Foelsche Crater and the Kelly West Crater. They are strongly suggested by Connelly to both be the result of chunks from the MAPCIS that broke off the main body of the bolide a short time before impact, and they are on the proposed flight path for the bolide.

He suggests the geologic age of all 3 impact sites were reset to the same age of 545 Ma. He suggests the bolide approached from the northeast at up to 70 km/s at a low angle, chunks dropping off as it neared the impact site.

Sources & Further reading

  1. MAPCIS, The Case for a Massive Australian Precambrian/Cambrian Impact Structure


  1. The hunt for MAPCIS
  2. The downrange geomorphology of MAPCIS
  3. Massive Australian Precambrian/Cambrian Impact Structure
  4. Age Dating MAPCIS
  5. Age Dating MAPCIS
  6. Possible Impact at Precambrian-Cambrian Boundary and its influence on Biosphere


Author: M. H. Monroe
Last Updated 08/06/2011



Journey Back Through Time
Experience Australia
Aboriginal Australia
National Parks
Photo Galleries
Site Map
                                                                                           Author: M.H.Monroe  Email:     Sources & Further reading