Bryan, Kirk

(b. Albuquerque, New Mexico, 22 July 1888; d. Cody, Wyoming, 21 August 1950)

geology, geomorphology.

Bryan’s parents taught in the Presbyterian Indian School in Albuquerque, and his father later practiced law in the same town. He was educated in the Albuquerque public schools and received the B.A. from the University of New Mexico in 1909. Then, with the encouragement of H.E. Gregory, professor of geology at Yale, Bryan entered that college as an undergraduate, receiving his second B.A. in 1910 and the Ph.D. in 1920.

From 1912 to 1926 Bryan was associated with the U.S. Geological Survey. During part of this time, 1914–1917, he also served as instructor in geology at Yale, and in 1918–1919 he was a private in the Army Corps of Engineers. Later he received a commission and served as a second lieutenant in the geological section of the army general headquarters. From 1926 until his death, Bryan taught at Harvard. He belonged to the American Association for the Advancement of Science, the Geological Society of America, the Geological Society of Washington, the Geological Society of Boston, the American Academy of Arts and Sciences, and the Society of Military Geologists, holding office in most of these societies. He was married in 1923 to Mary MacArthur.

The Kirk Bryan Fund, established by the Geological Society of America in 1951, supports the Kirk Bryan Award, which is presented, usually annually, for a significant published contribution to geomorphology or a related field.

Bryan’s professional career began in the Geological Survey, where he was assigned to work on the general problem of water resources, particularly of groundwater in arid and semiarid regions. This work was directly predicated on the assumption that it had an immediate human use, and this “human” orientation played a significant role in his professional studies for the rest of his life. Bryan’s work for the Geological Survey produced a series of publications reflecting his concern with irrigation, dam sites, and groundwater resources. His subsequent writings deal more with man’s history, an interest reflected in his collaboration with archaeologists. Throughout, however, he was equally concerned with the processes of earth change and with geological history.

Bryan’s first major contribution was the description of arid-climate landforms and discussion of the processes that led to them (1922); the fieldwork and basic observation had been carried out in the fall and early winter of 1917. The study “Erosion and Sedimentation in the Papago Country, Arizona” was a byproduct of a survey of watering places in that desert area. In this work the use of the term “pediment” to describe a plain formed at the foot of mountains through the processes of erosion normal to the desert was firmly established in the literature of landscape evolution, although Bryan adapted the term from a 1912 report on desert surfaces by Sidney Paige. Bryan envisaged the pediment as a slope of transportation veneered with a few inches or a few feet of debris in transit. He indicated that the slope of the pediment surface changed with the size of particle in transport. He planned and, with the help of several graduate students, partially completed a field program to study the geology and geomorphology of the Rio Grande depression in New Mexico and southern Colorado. Among other things, this program focused on the history and origin of pediments.

Bryan’s recognition of the pediment as an important topographic element in an arid landscape reflected his own geographic heritage. He was raised in the semiarid New Mexico Territory and spent the first fifteen years of his professional career in arid and semiarid lands, so it is not surprising that he was sensitive to the effects and changes of climate. In his initial study of pediments (1922) Bryan postulates the possibility that an increase in rainfall accounted for the dissection of many of the pediments in the Papago country. In that same study he outlined what came to be known as the “alluvial chronology” of late Pleistocene and Recent time in the southwest. The alternate periods of alluviation and erosion that he described were attributed to fluctuations of climate marked particularly by changes in effectiveness of precipitation. The assumption that climatic changes have taken place within the immediate geological past demanded the evidence for those changes. This Bryan sought in the soils, recent sediments, and landscape. In 1943 he and C. C. Albritton, Jr., published “Soil Phenomena as Evidence of Climatic Change,” a paper that summarizes his interest in soils as climatic indicators and marks the beginning of a general interest in paleosoils on the part of geologists.

In 1932 Bryan wrote on the use of pollen in the reconstruction of North American Pleistocene climate. The technique had been used for many years in Europe but was little known in America; his continued interest was instrumental in establishing palynology in the United States. Likewise, Bryan early recognized that the rigorous climate existing beyond the margins of the Pleistocene glaciers must have expressed itself by extensive frost action in the upper few feet of soil and rock. The effect of modern periglacial climate, as well as that of the past, was being reported by European workers in the 1920’s. It was Bryan who drew the attention of American workers to the possibility of using frost forms as stratigraphic and environmental indicators. In 1946 he published a summary statement of the nature of the frost action on soils and coined the term “cryopedology” for its study.

In 1924 and 1925, Bryan participated in an archaeological expedition of the Smithsonian Institution to the Chaco Canyon in New Mexico. His goal was to determine, if possible, the conditions that led to the rise and fall of prehistoric Pueblo Bonito. The field study was the beginning of a long association between Bryan and archaeologists, although the report was not published until 1954. In 1940 the “Geologic Antiquity of the Lindenmeier Site” in Colorado was published in collaboration with L. L. Ray. It and the report on Sandia Cave, New Mexico (1941), stand as models of the application of geological studies to archaeological sites and problems.

BIBLIOGRAPHY

I. Original Works. See “Erosion and Sedimentation in the Papago Country, Arizona with a Sketch of the Geology,” in Bulletin of the United States Geological Survey, no. 730 (1922), pp. 19–90. A list of publications is in Esper S. Larsen, Jr., “Memorial to Kirk Bryan,” in Proceedings of the Geological Society of America, Annual Report for 1950 (1951), pp. 91–96. Posthumous publications and some minor earlier papers are not listed.

II. Secondary Literature. Brief accounts of Bryan’s life are given by Larsen (see above) and Frederick Johnson, “Kirk Bryan–1888–1950,” in American Antiquity, 16 (1951), 253.

Sheldon Judson