From the back: "Detailed geologic maps for all areas of Kentucky, as well as reports about Kentucky's geology and mineral and water resources, are available from: Kentucky Geological Survey, 228 Mining and Mineral Resources Bldg., University of Kentucky, Lexington, KY 40506-0107."
This is an older postcard, no Internet address, so I am not sure if the Survey is still at this address.
The Legend has the color coding for the rocks of different ages - the geological periods - from oldest at the bottom to youngest at top. Alluvium means recent river deposits. Yes, geology students have to memorize these names - in order too!
The rocks in Kentucky are all sedimentary rocks. the Pennsylvanian rock formations have many layers of coal, for which KY is well-known. The electricity powering my house and my laptop comes from burning coal, sending CO2 into the atmosphere.
The black lines are faults. These are areas where one side of the earth's crust has moved relative to the other side. It could have moved sideways, or up and over, or slide down and away.
Notice the line with 'teeth' on it in the lower right or southeast portion of the state. This is Pine Mountain Fault, an area where one part of the earth's crust was shoved up and over to the northwest, and the rocks are tilted as a result.
If you drew a cross section from London KY to Middlesboro KY showing the layers underneath, it might look like this image from the KY Geological Survey.
I have not been feeling well but I am getting better. And I miss Marie's posts at vintage postcards. Oh well, keep on blogging, even if no one comments. See you Friday for PFF I hope!