By: magic-gigapans
Image: Callan Bentley, Mid-Atlantic Geo-Image Collection
License: Creative Commons Non Commercial ⧉

Uploaded: 8 May 2020
Last Updated: 20 May 2020

1.44 gigapixels
57,548 x 25,060 pixels
191.8 in X 83.5 in at 300dpi
59 pixels per inch

This is a classic outcrop in Appalachian stratigraphy. Overall, it shows the transition from the passive margin sedimentation (limestone) of the Cambrian and early Ordovician Sauk and Tippecanoe epeiric seas into the increasing clastic (sand and mud) influence of active margin sedimentation associated with the onset of the Taconian Orogeny (to the east) in the late Ordovician. This particular gigapan shows only the lowest part of the sequence, the New Market limestone (thick bedded) and the contact with the base of the Lincolnshire limestone (thin bedded) at right (downhill; up section; younger strata). Further downhill (up section; younger strata); the strata get darker and muddier, and bentonite layers show evidence of nearby volcanic eruptions. I'll gigapan those later...