An early Miocene (∼20 Ma) paleogeographic reconstruction for paleoclimate modelling

Abstract

The current Asian monsoon system is considered to have formed in the late Oligocene–early Miocene, but the mechanisms of the monsoonal system are not fully understood. A knowledge of paleogeography is essential for understanding past climatic change. A reliable paleogeographic reconstruction for the early Miocene is essential to provide key boundary conditions for early Miocene climate modelling studies. However, the temporal–spatial distribution of key geographic features such as seaways and mountain belts that control climate change differ for various published early Miocene paleogeographic reconstructions, which thus require updating with new geological data. Here we present a new reconstruction of global paleogeography for the early Miocene (∼20 Ma). We used a four-step methodology and integrated various types of geological data into a coherent plate tectonic model using GPlates and ArcGIS to reconstruct the paleogeography. Based on previous paleogeographic reconstructions and our compiled geological data, we further constrained and revised the land–sea distribution in several key regions (i.e., the Paratethys Sea, Sunda Shelf, Bohai Sea–Yellow Sea, Barents Sea–Kara Sea, and Hudson Bay); the paleodepths of the Paratethys Sea, Mediterranean Sea, and key seaways (i.e., the Atlantic–Mediterranean Gateway, eastern Tethys Seaway, Indonesian Gateway, Panama Seaway, Fram Strait, and Greenland–Scotland Ridge); and paleoelevations of high mountains and plateaus (i.e., the Tibetan Plateau, North American Cordillera, Andes, East Africa, and Antarctica). The new and improved early Miocene paleogeographic reconstruction is available for use in climate models to facilitate early Miocene climate modelling studies.