Johan August Udden

Born in Sweden in 1859, he came to the United States as a small child and later studied at Augustana College. He taught in the Midwest before turning fully toward geology, a field in which he became known for careful work on sediments, windblown deposits, and the way grain sizes can be measured and compared.

His career included teaching and research roles in Illinois and Texas, and he became especially associated with Baylor University and with geological work connected to the University of Texas. His studies of the Gulf Coast and of sediment transport helped lay groundwork for later researchers, and the grain-size scale linked with the name Udden remains part of sedimentology's history.

He died in 1932, but his reputation has lasted as both a teacher and a scientist who brought patience, field observation, and practical measurement to the study of the earth.