D. Foster Hewett (known to friends and acquaintances as Foster Hewett) During the years from 1885 to 1893, George Hewett was in charge of operating mines in Colorado and Wyoming and generally visited his son once a year in Washington, D.C. In Colorado in the summers of 1888 and 1892, D. Foster Hewett visited his father, who encouraged him to study mineralogy. From 1903 to 1909 Hewett investigated, mapped, and reported on mineral resources involving many commercially important minerals in the US, Mexico, Canada, and Peru. Most notably, he was primarily responsible for discovering the Minas Ragra vanadium ore deposit, thus revolutionizing the production of vanadium steel. In autumn 1921 Hewett began an extensive mapping program for the geology and ore deposition of the southern
Great Basin — the program, with various periods of interruption, occupied him until he was no longer fit for strenuous fieldwork. His Great Basin research started in
Nevada's Goodsprings mining district. In 1924 Hewett announced his discovery of the close association of
dolomitization with deposition of lead and zinc ores. This discovery soon became used as a guide by geologist all over the world to identify such ore deposits of lead and zinc. He subsequently demonstrated that some classic ore deposits in Europe were encased in hydrothermal dolomite like the Goodsprings ores, but some lead and zinc deposit, such as those associated with the
mines of Laurium, have no dolomite mantles. After completing his study in the Goodsprings area, he did geological mapping of the much larger area of the Ivanpah Quadrangle, which covers about 3,900 square miles (10,100 square kilometers) in the northeastern part of the
Mojave Desert of southeastern California and southern Nevada. There he demonstrated remarkable continuity between underlying
Precambrian rocks and overlying
Paleozoic rocks. ==Awards and honors==