Mohave County miner and our mineral wealth., 1920-05-29
ASPHALT IN THE
 UNITED STATES
A Great UndevelOped Resource.

A Great Undeveloped Resource.
 Few mineral deposits in America are more promising to the prospector or more interesting to the scientist than the asphalt deposits of Califor- mia, Kentucky, and the Rocky Noun tainand Mid Continent States, accord ing to a report just issued by the Uni ted States Geological Survey, Depart ment of the Interior. There are no deposits in the United States equal in size and purity to the mysterious pitch lake. of Trinidad, from which asphalt has been taken for paving the famous thoroughfares of the world for many years without materially lowering its surface, but there is a great quantity of btuminous rock that could be used locally in surfacing our vast mileage of unimproved high ways. Native asphalt, although one of our great undeveloped natural re- sources, has not been extensively min ed because of the former abundance of asphaltic petroleum and because of our large imports, but now bitumin- ous products of many varieties obtain ed from domestic deposits could ade- quately supply the requirements in several parts of the country.
 Asphalt is formed from petroleum and is a remarkable preservative, it has long been subject of absorbing interest to the oil geologist and the paleontologist. Many of the surface deposits throughout the country, like that near Los Angeles, Calif., which yielded remains of the extinct saber- tooth tiger were formed in recent or Pleistocene time, but some are much older. The asphalt formations range in thickness from a few inches to many feet, and as they are associated with petroleum both geographically and stratigraphically and are of like origin and composition, they may be roughly assigned to the same fields.
 Abundance of Native Asphalt.
 Deposits of asphalt and allied sub stances are found in Kentucky, West Virginia, Arkansas, Missouri, Okla homa, Texas, Colorado, Nevada, Utah, and California. The richest and most extensive beds are in Oklahoma, but Utah contains the largest variety of bituminous substances. The strait graphic range of the beds is as wide as the geographic, deposits being found in strata of all ages from the Ordovician to the Recent. The oldest asphaltic formations have been ob- served in Oklahoma, and the young est, which consist of recently formed sands impregnated with bitumen, oc- cur near Carpinteria, Calif., though small superficial deposits of brea are we'll distributed throughout the coun- try. The largest deposits occur as impregnated rock and veins.
 Numerous and Varied Uses.
 Despite its wide distribution and it's suitability for many commercial uses, native asphalt has not been produced in great quantities in the United States. The demand for asphaltic material has been largely met by i'm ports and by petroleum asphalt manu- factured from the low-gravity oils of California and the Gulf coastal fields. Both materials have been satisfactory and are well known wherever asphalt products are used, but petroleum as- phalt is produced from oil of a grade suitable for fuel, for which there is a rapidly increasing demand for use in oil-burning ships. The large de- mand for asphaltic material might be met in part in bituminous rock, which could be used for paving both coun- try highways and city streets, and if carefully laid and maintained the pavements would be durable and clean and would produce relatively little noise and dust.
 European countries use large quan- titles of bituminous rock in building roads,and if the United States would adopt the same practice much oil that is greatly needed for use as fuel and for other purposes would be released. Although good pavements of bitumi- nous rock have been laid in Kansas City, Kans., Oklahoma City, Okla., and a few other cities, many rock-asphalt pavements constructed in this country have not been successful because the contractor failed to understand the nature of bituminous rock. The rock differs greatly in quality, and each deposit must be analysed and treated accordingly. Larger commercial suc- cess will probably be attained by the employment of better methods than are now generally known. The techni- cal difficulties of utilizing bituminous rock in road surfacing appear to war rant careful research by. the best chemists and paving engineers.
 Other varieties of native asphalt, notably gasoline, grahamite, and wurtzlite, are used in the manufac- ture of paint, varnish, roofing. water