Detail image of schist outcrop in northern Idaho. Rock is primarily yellow-orange with darker banding visible, with some bands compressed into wavelike pattern by metamorphic processes. A smattering of pale green lichen is visible.
Detail of highly metamorphosed rock outcrop in northern Idaho. Rock is mostly black and white in a sort of reticulated pattern, with two reddish inclusins (garnets I think? ) visible. Mineral specks in the black rock can be seen reflecting more vividly colored glints of orange and blue if one looks closely.
Detail of gneiss boulder in northern Idaho. The rock is full of contrasting bands of dark gray and white, with the banding folded by metamorphic processes into an overall L-shape.
Detail of roadcut in northern Idaho. Top right of image is mostly full of dark black stone (amphibolite?) marbled with veins of white, while lower left is mainly banded schist with an overall rusty hue, and with obvious folding and boudinage. Some vertical lines of dynamite drill holes from the road cut are visible in the scene.
#RockinTuesday Last week I took a little tour to photograph some of the oldest rocks in Idaho. Here are four details from the Priest River Metamorphic Core Complex, with ages from around 1.6 to 2.6 billion years.
#geology #idaho #idahogeology #idahopanhandle #schist #gneiss