| Summary: | The article of record may be found at https://gsa.confex.com/gsa/2011AM/webprogram/Paper188021.html Pangaea was likely split by the simultaneous impact of two large asteroids: one tore through the region between what is now South America and Antarctica, coming to rest over 1000 miles to the east, while the other's remnants are found southeast of the Yucatan Peninsula and north of Columbia and Venezuela. Presumed impact trails and craters, approximately 500 miles in diameter, are readily observable via Google Maps (satellite). The force of the impacts likely pushes Africa away from its initial locale, and drags North and South America from theirs. India would have been just east of impact "ground zero" - it would be propelled with great- est initial velocity from its original location, eventually slamming into Asia and forming the Himalayan range. Deformations in the seabed, essentially "wakes" created by land mass tran- sits, remain in ocean floors. North and South America would be torn from the region extending from Kamchatka southward to just east of Australia. The Andes and Rocky Mountains would form from the impacts - the land deforms before the force of the impacts releases the con- tinents on their eastward slide. The Atlantic ridge would form due to buckling, as continental transits halted. All this might have taken minutes rather than millennia. The southern impact could have created the planet's obliquity: the direction of the final 700 miles of the northern impact trajectory bends approximately 23' from its initial direction. The dual impacts' easterly direction would affect the rotation of the plane~ altering the planet's "day." Impact boundary regions remain seismically active to the present. Subsequently, rivers draining substantial basins from what is now California contributed to the formation of Monterey Canyon. The canyon was likely formed above the ocean s surface- its associated river system, extending nearly 70 miles into the Pacific basin, created oxbows, one of which is nearly 50 miles ...
|
|---|