The Cloos Papers largely document Ernst Cloos's field work and research. The majority of the material deals with the Blue Ridge and Piedmont areas, but there is field material on his early work (1930-1932) in the Sierra Nevadas as well as work on Texas (1955) and Oregon (1957-1958). The materials include his extensive field notebooks in Series 5, his writings in Series 6 which are based on the field work, and his research material and annotated maps in Series 7.
Some of the notebooks, research material and writings relate to Cloos's consulting work. There are notebooks, research and articles for his work for the Thomasville Stone and Lime Company and for the Humble Oil Company (later the Esso Research Production Company) in Oregon, Oklahoma, and Texas. Cloos also did consulting work (1948-64) for the Maryland firm Harry T. Campbell Sons' Corporation. This work was continued by Cloos's colleague Hans Eugster, and except for one report in Series 6, the materials are in Eugster's papers Ms. 209.
Cloos was quite active in the geological profession, but little of this is documented in the collection. Dr. Cloos's wife retained his correspondence, and it is likely the professional activities are outlined there. There is a small amount of material on the Geological Society of America (1966, 1968) and the National Academy of Sciences (1963, 1971-73) in Series 3. There are also a few items relating to committee work (1969-70) at Hopkins and a clay workshop (1968) he offered at the University of Georgia.
Cloos succeeded Joseph T. Singewald, Jr. as chairman of the Geology Department in 1952. The one file of Geology Department records which survived in Cloos's papers was correspondence relating to the history of the department compiled by Singewald for President Bowman in the 1940s.
Cloos's papers contain information on three of his colleagues. After Joseph Singewald's death, Cloos prepared "Memorial to Joseph T. Singewald, Jr." (1964). The materials in the Singewald series relate to compiling this memorial. Cloos also prepared a memorial for his close friend Robert Balk. The correspondence relating to this is in Series 1. In addition Balk's widow gave Cloos Balk's research papers. These have been removed to form a separate manuscript collection. Cloos also collected material about his brother Hans Cloos. Hans's reprints and letters are in Series 2.