This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
The Quarterly journal of the Geological Society of London . PROCEEDINGS OF THE GEOLOGICAL SOCIETY is again succeeded by finegrained grey gneiss much contorted but dipping southeast probably at high angle Still higher beds of quartzite appear dipping at to and thus though the immediate junction is not seen apparently unconformable