Saturday, May 5, 2007

Oil and the Tethys Sea

In the late Triassic, 200 million years ago, Pangea began to rift apart as the Tethys Sea spread east to west, separating the northern and southern Continents. This seaway reached its maximum extent by the middle Jurassic, when it covered a swath that would later become northwest Australia, south-central Asia, southwestern Russia, the Middle East, the Mediterranean basin, the Gulf of Mexico and the Gulf Coast region. Keep in mind that the continents were still pushed together (east to west) at this time; the Atlantic had just begun to open and the Indian Ocean was yet to form.

Today, the Mediterranean Sea, the Black Sea and the Caspian Sea are remnants of the Tethys. Of more significance, oil formed within sediments of this ancient Sea, a degredation product of plankton and other organic marine debris . The oil that is pumped from the Gulf Coast region, the Gulf of Mexico, northern Africa, the Middle East and western Russia lies within Jurassic shale, a sediment of the Tethys. In like manner, the salt domes of the Gulf Coast States, most numerous in Louisiana, were deposited by the Tethys Sea.

It is both fascinating and disturbing to know that this prize of human culture, a source of so much misery and conflict, originated more than 100 million years ago, in the placid waters of the Tethys Sea.