The Aptian-Albian interval (124.5-97.0 Ma) was a critical time both globally and for the Tethyan domain. In the Tethyan domain it was the time when a united Neo-Tethyan subduction zone became established between the future site of the Alps and Southeast Asia and greatly accelerated the rate of north-south convergence throughout the Tethyan region. A consequent widespread transgression on both Laurasian and Gondwanian margins deposited Orbitolina limestones and associated clastics on wide continental shelf areas. On the sea-floor of the Neo-Tethys ocean, organic-rich siliceous black shales, radiolarites, and turbidites with minor amounts of carbonates were deposited. Siliceous black shales accumulated under euxinic conditions of restricted small ocean basins of the Neo-Tethyan realm and along their margins. These areas received large amounts of organic debris from deltaic areas and coastal plains of the neighbouring continental shelves.