Petrologic studies have been made on sixteen samples of the Lower Beaumont clay collected from localities varying both horizontally and vertically on The Rice Institute campus, Houston, Texas. The samples were analyzed to determine the percentage of clay and other minerals, the variety and types of heavy minerals present, the percentage of the heavy mineral suite comprised by each type of mineral, and the size distribution of the zircons. The main concern of this thesis is with the heavy minerals. For many years geologists have been aware that a study of heavy minerals, that is, minerals with a density greater than 2.9* would yield information concerning the source, mode of transportation, depositional environment, and maturity of a sediment. The details of how these characteristics can best be obtained, however, are not obvious. This paper will discuss the possibility of using the character of the heavy mineral suite and the size distribution of the zircons as a guide to the origin and environment of formation of the Lower Beaumont clay. It is the intent of the Department of Geology at The Rice Institute to make a continuing study of the size distribution of heavy minerals of sediments from all types of depositional environments and from the site of deposition upstream to the fresh source rock (Rogers, 1956). The present Investigation is the first in this series.