Ports of Satan
This rather oddly named site is a lovely, harbored beach on the northern tip of the island of Crete. Its official name is Seitan Limania beach, which translates from Turkish as “ports of Satan”.
Platy limestones, one of the dominant lithologies found on the island of Crete, surround the beach. Crete is made of rocks that have been thrust upwards as Africa approached Europe, including sedimentary rocks deposited in the ancient Tethys Ocean. These thin, platy limestone layers are the remnants of ocean-dwelling organisms that sank slowly to the bottom of this great seaway before eventually turning to rock. This process produced limestones found on Crete that span ages from the Jurassic to the Eocene, a time period of about 100 million years.
The morphology of this beach testifies to much more recent geologic events. The beach sits in a gorge carved in the surrounding limestones by a flowing stream. Surface waters are mildly acidic due to the presence of CO2 in the air, which reacts to form carbonic acid. Carbonic acid will slowly dissolve limestone, causing streams to cut downwards into steep gorges as the rocks beneath dissolve away.
The gorge was created by downcutting of a stream, but the beach is now found in the middle of the gorge because of changes in sea level. For much of the last million years, sea level has been lower than today because of the presence of great ice sheets in Scandinavia and North America. When sea level dropped, the river cut the gorge much farther out into the surrounding sea. When sea level rose, the gorge partially flooded, creating a beach in the middle. One description I found even says that just offshore there are a number of boulders that help protect the modern beach from waves – those boulders were likely carried by floodwaters and stranded by the ancient shoreline before being submerged as a natural breakwater today.