Met this rock this weekend. Rensselaer Plateau, Rensselaer Co. NY. (north america) what is going on? to the left is a rather tough grainy sedimentary rock, blends into foliated rock with flat cut face and black and white weathering, and then to right, finer grained rock. The general rock type here is called Graywacke, which seems to me to be garbage pail rock. Whatever falls into the sea and turns into rock, counts. In a 60 foot stretch of this along the road it morphed into so many textures... born in deep sea and shoved over the continent when an island arc smashed us 500my ago.
Here is a closeup. VERY messy. to the left is friable rock with layers facing us, but the layers leaving the white weathered lines is perpendicular to that. I guess it is turbulent in the deep sea.
more textures all within a few feet of each other
Dunno how this bit formed. Squiggly yellow green stuff, epidote?
this is only a tiny taste of all the morphs that this Rensselear Plataeu Graywacke does.
Tried to find an online summary of the place but they don't make a LOT of sense. The geology of the Taconic orogeny is still confusing.
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