Rock studies garner dinosaur insights

Press, 11 October 1988, Page 32

Rock studies garner dinosaur insights

NZPA-AAPCollege Station,

Researchers hope their study of 220 million-year-old marine rocks from Australia will offer new insights into how Earth looked during the early days of the dinosaurs. Scientists have been studying the rocks, described as the oldest yet found by scientific ocean drilling, since their recovery off the north-west continental shelf of Australia during drilling expeditions in the Indian Ocean.

Fossils in the prehistoric rocks will allow marine scientists to reconstruct the geologic history of the supercontinent, Pangaea — a massive fusion of all Earth’s con-

tinents believed to have existed more than 220 million years ago. Geologists will study the processes that separated the continents and formed ocean basins as well as consuming an ancient sea, according to the project director, Dr Philip D. Rabinowitz, of Texas A-and-M University. Scientists in the project’s drill ship Joides Resolution drilled in two underwater formations, the Exmouth and Wombat plateaus.

The Exmouth is part of the original crust of the now-extinct Tethys Sea and one of the few places in the world where scientists can examine the unaltered characteristics of an old continent and

“Drilling on the plateaus will give scientists invaluable information about the nature of ancestral oceans and continents, their sea life and their climates,” Dr Rabinowitz said.

The Australian passive margin, a geologic area that develops when continents drift apart and ocean basins form, provides clues to Earth’s ancient land shapes, he said.

As continents separate, the torn edges of these separate masses sometimes retain their forms and can be hypothetically reassembled to reveal Earth’s appearance millions of years ago.