Economic Geology in the United States ¹

Abstract

THE three bulletins referred to below have been issued —1 by the United States Geological Survey, which, at all times keenly alive to the importance of economic geology to the nation, has of late years been paying particular attention to the study of the mineral resources of the United States. The two first bulletins give an elaborate and detailed account of the geology of one of the most important oil-producing regions of central California. Very little accurate geological work had been done here-previously, so that the present bulletins form a useful contribution to general stratigraphical geology as well as to the special geology of oil-bearing regions. There is nothing that calls for particular notice in these bulletins; the oil appears to occur in strata of the customary type of Eocene, Lower and Middle Miocene age. Both reports are elaborate and full of detail, and the report on the-Coolinga district is noteworthy for the amount of palaeontological information that it contains and for the admirable manner in which some of the fossils referred to have been illustrated in the accompanying plates.