Metaconglomerate (Proterozoic; Medicine Bow Mountains, Wyoming, USA)
Metaconglomerate from the Precambrian of Wyoming, USA (cut slice; public display, Wyoming Geological Survey, Laramie, Wyoming, USA)
Metaconglomerate is a scarce metamorphic rock having a clastic texture - the original clasts are still evident (click on the photo to zoom in). Some have stretched pebbles from tectonic deformation.
Metaconglomerates in Wyoming's Medicine Bow Mountains sometimes have unusual components such as diamonds, gold, and uranium minerals. The sample seen here is an auriferous, quartz-pebble metaconglomerate. The dark yellowish and reddish-brown coloration is from iron oxide staining.
Locality: unrecorded/undisclosed site in the Medicine Bow Mountains, southeastern Wyoming, USA