1. Interpretation of the seismic stratigraphy of the phosphatic middle Miocene on the Georgia continental shelf [cartographic material] Yale Public content 1986. 2018-05-04T19:55:14Z. 2018-09-05T19:40:03Z. Kellam, Jeff A. The Survey. English. cartographic image. Public. Georgia and Georgia. Miocene and From 10 to 25 million years ago.