Ardol Formation

The Ardol Formation is a geologic formation located in Tacua Province in the southwestern Aurlûnor Velande, dating to the upper Lothranic period between 186 and 183 million years ago. It is named after the ancient city of Ardol, settled by Celestial Elven immigrants thousands of years ago. The formation preserves a regressive sequence, with three distinct members (in order of lowest/oldest to highest/newest): the limestone-dominated Hyalmambal Member, the the Lócesíre Member dominated by mudstones and shales, and the beach sandstone of the Anaróremar Member. This order of rock progression, deposited over the course of nearly three million years, shows an ocean receding and becoming land, as the boundary between the Lothranic and Dracian periods is commonly thought to have been defined by a minor extinction event and rapid climate change.

The Hyalmambal member preserves a pelagic marine fauna with numerous large reptiles and ammonites, though the Lócesíre member has also turned up plesiosauroid remains and even a theropod washed out to sea. Most fossils of the Anaróremar member are shells of brachiopods or mollusks.