Large Asteroceras Ammonite from UK Black Ven Marls

Description: This is a classic UK genus from a world-class collecting locality. It rests comfortably, angled on a flat matrix base. There has been no crushing or distortion to the specimen. This one would definitely compliment any serious ammonite collection.

Background: Originally known as the Black Marl Beds. The Black Ven Marls (averaging 43m in thickness), are a succession of blue-black mudstones and shales containing the occasional limestone bands and nodules. Although the colour is due to the presence of finely disseminated iron pyrite, it does not denote that the sea-bed, at the time of the formation of theses beds, was always in an anaerobic state. At 17.6m above the base is the Flatstone Bed (Bed 83d). This is well renowned for its fine specimens of the Asteroceras turneri ammonite, which are preserved in yellow and brown calcite.