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Showing posts from January, 2015

Friday Rocks #43: Mega Ptygmatic Folds

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[caption id="attachment_618" align="aligncenter" width="610"] Mega ptygmatic folds[/caption] The above photo is taken from a field trip in 2010 to Death Valley and surrounding mountains / desert. This stop was Monarch Canyon. We (the students) are standing at a cliff edge, looking across a gorge at the opposing cliff wall. That's the best scale I can give you for this. It's huge, it's awesome.

Friday Rocks #42: Mylolisthenite

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[caption id="attachment_611" align="aligncenter" width="610"] Charlevoix mylolistelite[/caption] The injecting mylolisthenite (pale-green rock filling fracture) was created during a meteor impact. It can be found near Charlevoix, Quebec (19T 407510.00 m E, 5260539.00 m N). Find out more about the Charlevoix impact crater in an old upsection post.   Mylolisthenite is a fine grained breccia which contains various clasts in a non-melt matrix (differentiating it from pseudotachylite).