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You are browsing the archive for 2011 September 07.

7 September 2011

Another updated aftershock plot…

A up-to-date tally of the aftershocks from the Mineral, Virginia earthquake is presented as a time vs. magnitude plot.

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Graded bed from the Billy Goat Trail

Spotted this one Monday on the newly-rerouted section of the Billy Goat Trail’s Loop A, in Chesapeake and Ohio Canal National Historical Park. This graded bed was deposited as a turbidite in the Iapetus Ocean, sometime in the time-frame of 700 to 460 million years ago. It was metamorphosed 460 Ma during the late Ordovician Taconian Orogeny, and that’s probably when the little quartz veins formed, too. Click on it …

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