Multispectral Petrography Image Analysis as a Method for Paleoenvironmental and Paleoecological Reconstruction; Applications to Earth's First Reefs
Abstract
The physical characteristics of carbonate rocks encode valuable information for paleoenvironmental inference, as well as primary mineralogy and porosity/permeability metrics that can aid the interpretation of geochemical data. To date, the most high-throughput method for assessing these facies data is qualitative description of hand samples while measuring section, mapping, or working on previous collections. Due to recent technological advances, we now can use these expert geological observations to develop quantitative facies measurements through petrographic imaging and computer vision. In our group, we are working to apply these techniques to bring high-throughput, fine-scale, geophysical data to the study of carbonate outcrops and Earth history.
Here, we present maps of two outcrops bearing lower Cambrian archaeocyathan reefs from Nevada and the Yukon Territory, Canada. At each locality, we create ~4cm/pixel base maps through drone-derived photography, and walk an approximate 10 m-spaced grid to take oriented block samples and observations. From the over 160 samples per locality, we prepare oriented polished slabs and thin sections, which we image with our new multispectral photography setup for both transmitted and reflected light. With these images, we apply a variety of computational approaches to identify grains and fossils, to assess modality and size metrics, and to quantify sedimentary textures. From these enriched datasets, we develop new insights into the ecology, sedimentology, and ultimately the impact of these reef environments on the evolution of early animals.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMPP15A..03M