Geology of the eastern part of the Centralia - Chehalis coal district, Lewis and Thurston Counties, Washington

This report gives the results of geologic investigations made in 1948 and 1949 in the eastern part of the Centralia-Chehalis coal district of southwest Washington. Detailed geologic mapping and stratigraphic studies were supplemented by core drilling. The core drilling tested the thickness and physical character of the individual coal beds and aided in determining the continuity of the beds. It is hoped that the information on coal resources thus obtained will provide basic data useful in the development and utilization of the coal, which furnished one of the natural bases for the potential industrial growth of this region. Exploratory drilling for oil and gas has been thus far unsuccessful and suggests that geological conditions in the area mapped are not favorable for the accumulation of petroleum; the geologic information obtained during this investigation may, however, be helpful in delimiting areas in other parts of western Washington that may be favorable for exploratory drilling.