The island of Abulat is a raised coral island, part of the Farasan Banks off the coast of Al Lith, where we're been working for the past few days. Intriguingly, it has an emerged coral knoll, which basically means that there are old (probably fossil) corals exposed above land. If you look at the below photo, you'll see two pillars in the center. If you look closely, you might notice the radial polyps characteristic of Acropora corals.

These emerged coral knolls contain lots of information about what used to live in the sea. I'm not a paleobiologist or a geologist, so unfortunately I have no idea how old these islands are, but you can see an exposed bivalve shell and many other mollusks and corals exposed in the rock that are still living on Red Sea reefs today. These sorts of exposed coral outcrops are commonly used by paleobiologists and geologists to understand how reefs used to look, and to understand how past disturbances have impacted reefs. Because corals and other reef organisms are made of calcium carbonate, they leave their stories behind in the rock. In special places like Abulat, those stories are exposed for all to see (no digging required).

A quick online search revealed the following Springer Image from a book by Eric Bird called Encyclopedia of the World's Coastal Landforms. You can see from the diagram below how geologists characterize different landscape forms: