March 20, 2023

This week we’re featuring another pioneer for women known as a groundbreaking geologist and educator, Florence Bascom. Bascom attended the University of Wisconsin where she received two bachelor’s degrees. During her studies, she discovered an interest in geology but specifically in the very unknown field at that time – petrography (the study that focuses on detailed descriptions of rocks). She continued her studies and later received her master’s in geology in 1887. After completing her master’s, Bascom enrolled at Johns Hopkins University and continued her studies in petrography there. After receiving her PhD, Bascom spent the next two years as an instructor and associate professor at Ohio State University teaching geology. She then went on to Bryn Mawr College, located in Pennsylvania, and founded the department of geology in 1895. Through her devotion and leadership, it became one of the best departments in the country.

Bascom was known for her contributions to a special type of identification for acidic volcanoes, particularly focused around South Mountain, Pennsylvania. Her article, “The Structures, Origin, and Nomenclature of the Acidic Volcanic Rocks of South Mountain”, discussed various rock structures formed by the volcano. Bascom claimed that South Mountain’s rock formations had changed over time, with some rocks originally showing signs of being rhyolite, but now holocrystalline rock. These rocks defied the nomenclature used to identify rocks invented by German and English scientists, so she created prefixes to add to these pre-existing names, to identify acidic changes in rocks. The prefixes she came up with were meta-, epi-, and apo-.

Bascom also presented a second notable new conclusion regarding the cycles of erosion within Pennsylvania. Originally, scientific thought was that the Piedmont province of Pennsylvania was made by two to three erosion cycles, while she discovered that there were at least nine cycles. Bascom found this by compiling a stratigraphic record of Atlantic deposits in the province, listing the depth, unconformities, and different grain sizes (like sand, clay, or gravel). The cycles occurred over a large period of time, with six cycles occurring in the post-Cretaceous period and three occurring in the Cretaceous period. This conclusion gave scientists new ideas about erosion cycles regarding their rate of occurrence and how to define a cycle.

We honor Florence Bascom for inspiring bright young women to enter the field of geology and for the path she carved for future women in STEM.

Sources: Berkshiremuseum.org; en.wikiepedia.org;