McMurdo Dry Valleys Soil Apatite Grain Weathering Metrics from Taylor Valley, Antarctica

Mineral apatite is the ultimate source of the essential nutrient phosphorus to the soil ecosystem. In order to assess the biogeochemical weathering of apatite grains in the dry, basic soils of the McMurdo Dry Valleys, we collected nine surface soil samples from the Fryxell and Bonney Basins of Taylor Valley. After separating more than 50 individual soil apatite grains from each sample, we used scanning electron microscopy to quantify the morphology and surface etching of apatite grains to determine the degree of weathering. We developed three metrics to quantify the degree of weathering: aspect ratio, percent crystal faces, and a qualitative pitting index. This dataset contains the raw data from analyzing the morphology of more than 600 grains using the software ImageJ. Samples were collected during January 2013. The samples from the Bonney Basin (LB) were collected 21 Jan 2013, and the samples from the Fryxell Basin (LF) were collected 18 January 2013. Samples were processed and analyzed 2014-2016.