Science: Fossils to Gasoline

Psephomancy, the antique Greek art of divination by plucking pebbles from a heap, is today a $2,500,000-a-year study of the U.S. oil industry. Its present name is micropaleontology, and its new methods were explained last week at the University of Chicago conference (see p. 63) by Geologist Carey Gardiner Croneis.

Geologists use the microscopic fossils brought up in the borings when wells are drilled to identify and correlate oil-bearing rock formations. The rock that overlies oil deposits consists of petrified muck of swamps where dinosaurs sloshed, and of seas where ichthyosaurs swam. In the pertrified muck geologists find the dinosaurs’ infinitesimal contemporaries because they are bored up intact and in great numbers. In the Carboniferous period and before, when the earth’s coal and oil deposits were formed, there prospered a hard-shelled order of protozoa, the Foraminifera, which were sometimes two inches but usually less than a millimeter across. Micropaleontologists watch for these and do not overlook the fragmentary remains of such creatures as worms, starfish, sea urchins, etc. When oilmen strike a wildcat gusher, they sometimes spend from $1,000 to $2,500 for an analysis of the microfossils which characterize it, so that finding another such well will depend less on luck.

First commercial micropaleontology was undertaken about 1920 in Houston and Dallas by Humble Oil and Refining Co., Rio Bravo Oil Co., Atlantic Refining Co. In 20 years micropaleontology has become a favorite course of budding geologists because of the jobs it offers. An expert Texas micropaleontologist can diagnose the age and character of 100 underground samples a day, making a geological index of 3,000 to 4,000 feet of drilling. In California, where petroleum signs are more complex, scientists must identify about 100 types of fossils in each sample, and analysis is far slower. All told, some 500 fossil experts are hired by Gulf Coast and California oil producers to divine the meaning of the “pebbles” they dig up.