[X] My Assistant

[NMRguy]

A new article from space.com:

http://space.com/scienceastronomy/060601_big_crater.html


The authors have used airborne radar imaging and sensitive gravity measurements to infer that a very large impact crater lies under half a mile of ice in the Wilkes Land region of East Antarctica. These measurements suggest that the crater has a diameter of 300 miles. This would be more than twice the size of Chicxulub, the crater that led to the demise of the dinosaurs.

If this mass anomaly does indeed turn out to be of impact origin, then it would certainly be cause for major disruption in Earth’s biosphere. The most obvious extinction event without a known cause is the Permian-Triassic, the so-called “Great Dying” that eliminated about 90 percent of all marine species and 70 percent of terrestrial vertebrate species.

My problem with this speculation is that other evidence simply does not support asteroid impact for End Permian. To my knowledge, the strata at the end of the Paleozoic Era (aprox. 251 million years ago) do not show any evidence of rare metals (eg. iridium) or shocked quartz. Both of these have been found in abundance at the Cretaceous-Tertiary boundary. Also, chances are not great that a meteorite would actually hit continental crust since oceanic crust, which is recycled every 200 million years, comprises 60% of the Earth’s crust. Maybe someone with more knowledge on this subject can comment.

[RNeuhaus]

After studying the Australia and Antartica map, both continents, the south of Australia and the north of Antartica have an inside arch, so it increases the suspicsion of the big crater impact.

If the Moon was a mass of Earth, the lost mass and the add mass by the other Mars' size planet (only hypothesis) would be a part of Earth which was a "sea" before the formation of Earth's continents were all connected into one huge landmass called Pangaea. This huge supercontinent was surrounded by one gigantic ocean called Panthalassa which might probably was the impact zone between the Earth and the other "Mars' size alike".

http://volcano.und.edu/vwdocs/vwlessons/le...ea/Pangea1.html

The above Web has a peculiar theme which is how will the continent be formed within 50 millions years. North and South America are separeted. Mediterrean Sea will be much bigger and open, Spain and North Africa will be joined, and Australia will be higher than Guinea.

http://www.scotese.com/earth.htm

The above Web URL have very interesting details about the History of Earth concerning to plates, climate, etc.

The oldest and supercontinent known was Rodinia, which formed 1100 million years ago. The Late Precambrian was an "Ice House" World, much like the present-day.

Rodolfo