Geology & Earth Science

Applin, Esther Richards, Alva E. Ellisor & Hedwig T. Kniker | "Subsurface Stratigraphy of the Coastal Plain of Texas and Louisiana"

  • Offprint of the paper proving that microfossils could be used to date the layers of the Earth’s crust, a key insight of modern geology.

    Author Esther Richards Applin (1895-1972) was an petroleum geologist at the Rio Bravo Oil Company. “In a paper presented at a Geological Society meeting in 1921 by her supervisor at Rio Bravo, Applin suggested that microfossils could be used to date strata. She was ridiculed by more experienced geologists for her audacity... To verify her claim, Applin worked with Alva Ellisor and Hedwig Kniker to find ways to separate the fossils from the matrix of the cuttings. In 1925, the three coauthored a paper that detailed the sequences and oil-bearing zones in the Gulf Coast using microfossils” (Biographical Dictionary of Women in Science p. 46).

  • ...reprinted for private circulation from Bulletin of the American Association of Petroleum Geologists, Vol. 9, No. 1, January-February 1925. [Tulsa, OK]: American Association of Petroleum Geologists, 1925.

    44 page offprint. Original tan wrappers printed in black. 1 plate, 1 illustration within the text. Library ticket to the base of the spine and both wrappers, sticker, security label, and “discard” ink stamp to rear blank, security sticker to the final page of the text, library ink stamp to the title. Some pencilled notes to the upper wrapper and title. Corners and gutter creased, minor creasing of the upper wrapper from the top left to the lower right. Good condition.