13 July 2018
Friday fold: the anticline at Chickie’s Rock
Posted by Callan Bentley
Chickie’s Rock is a prominent cliff of Cambrian quartz arenite (sandstone) in Lancaster County, Pennsylvania. I visited it last month with field trippers at the eastern section meeting of the National Association of Geoscience Teachers. One of the aspects of the site is this gentle anticline with axial planar cleavage:
The yellow rectangle is my field notebook for scale. Another shot:
Happy Friday to all!
Is this the same type of quartzite observed at the Big and Little Pinnacle of Pilot Mountain in North Carolina ? Also , can you explain the how the quartzite came to be emplaced in this Piedmont region . I know they date its origin to sand – sandstone of the Iapetus shore some 540 million years ago AND that Pilot Mountain formed as an erosional remnant from the Schooley – Harrisburg peneplain . Was it part of the Ashe Formation , perhaps ? Thank you for your time and effort . Your blog provides valuable photographs of rock types and formations in our area . I saw a nice reference to your work in the Great Course series on Geology of US National Parks .
Thanks for the kind comments.
I’m not familiar w/ the NC Piedmont. These rocks are in the Valley & Ridge of Pennsylvania – I know that there have been some efforts at correlating Blue Ridge rocks w/ Piedmont rocks in Maryland and Virginia (Sugarloaf Mtn and the Antietam Fm, as I recall). But I don’t know how far that can be taken. Short answer: I don’t know. 🙂