Mega trah dating

Called "ejecta," this melt rock was thickest near the point of impact, becoming patchier farther away.

Chemical analysis of the glass drops, called tektites, confirms their impact origin and indicates that they are probably part of the ejecta layer.

The most likely candidate for ground zero is the Chicxulub crater, just north of Mérida, Mexico, on the coast of the Yucatán Peninsula.

Some scientists believe that the debris in question can be explained by a large volcanic eruption.

But each new report by scientists studying the phenomenon adds weight to the collision theory. The cosmic collision occurred about 65 million years ago at the boundary between two geological periods: the Cretaceous, when dinosaurs flourished on the planet and few mammals existed, and the Tertiary, when the dinosaurs had mostly vanished and mammals began to proliferate.

This clay contains an unusually high amount of the element iridium – up to 30 times more than could normally be expected.

Iridium, a heavy, brittle, metallic chemical element, is found in the Earth's core.The Brazos River site reveals not only the jumbled anomalous sandstone rocks and sharks' teeth from the tidal wave, but also this overlying, iridium-rich layer of clay.The discovery of a thick layer of glassy particles at the K/T boundary in Haiti in the early 1990s provided what many geologists feel is the last piece of evidence needed to support the collision theory.French scientist Pierre de Maupertuis proposed as early as 1750 that comets striking the Earth had caused mass extinctions by altering the atmosphere and the oceans.But the first solid evidence linking a cosmic catastrophe with the wholesale eradication of species was suggested in the late 1970s by Walter Alvarez, a geologist at the University of California at Berkeley, and his father, physicist Luis Alvarez.About 400 cubic miles of debris were carried upward by the resulting fireball. Helens, by comparison, released less than a third of a cubic mile of ash.) After several months of drifting around in the atmosphere, the finer particles began settling back to Earth, covering the entire planet with a thin layer of dust.

Tags: , ,