Deciphering Paleogene platforms from a “Lost Domain” in the Western Neo-Tethys

According to classical literature, two Paleogene platforms developed along the northern and southern margins of the Neo-Tethys Ocean. Similar platforms have been recognized on the southern margin of a “lost domain” consisting of an independent microplate known as the “Mesomediterranean Microplate” ( MM ) in the westernmost Neo-Tethys Ocean. This microplate underwent tectonic dismantling and drifting during the opening of the western Mediterranean. The individualized blocks collided with the European and African palaeomargins during the Miocene, forming the Neo-Alpine chains of the western Mediterranean. The regional reconstruction and lateral correlation of Paleogene deposits have provided valuable insights into the paleogeographic and geodynamic evolution of this lost domain. The most representative Paleogene successions lie unconformably over the Palaeozoic basement and Mesozoic sedimentary cover. The sedimentary evolution, source areas, peleoclimate and palaeoenvironments recognized along the Betic and Maghrebian (Rif, Tell, Calabria-Peloritani Arc) chains have also been compared. Reconstructions of the MM using GPlates software have placed the original position of these platforms approximately at 30° N, and between 5°W and 10°E. Along the southern border of this microplate, a northward transition towards continental areas and a southward transition into deeper marine domains were identified. Additionally, distinctions were made between areas with complete Paleogene successions and those with condensed successions, as well as between carbonate-dominated and siliciclastic-dominated platforms.