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 Feb to that posterior date and there can be no doubt that from the pe riod when the lower grounds were still much under brackish or fresh water and when travertine was formed in broad ancient depressions then occupied by waters