Tectono-stratigraphic evolution of the intermontane Tarom Basin (NW sectors of the Arabia-Eurasia collision zone): insights into the vertical growth of the Iranian Plateau margin

The intermontane Tarom Basin of NW Iran (Arabia-Eurasia collision zone) is located at the transition between the Iranian Plateau (IP) to the SW and the Alborz Mountains to the NE. This basin was filled by Late Cenozoic synorogenic red beds that retain first-order information on the erosional history of adjacent topography, the vertical growth of the plateau margin and its lateral (orogen perpendicular) expansion. Here, we perform a multidisciplinary study including magnetostratigraphy, sedimentology, geochronology and sandstone petrography on these red beds. Our data show that widespread Eocene arc volcanism in NW Iran terminated at ~ 38-36 Ma, while intrabasinal synorogenic sedimentation occurred between ~ 16.5 and < 7.6 Ma, implying that the red beds are stratigraphically equivalent to the Upper Red Formation. After 7.6 Ma, the basin experienced intrabasinal deformation, uplift and erosion in association with the establishment of external drainage. Fluvial connectivity with the Caspian Sea, however, was interrupted by at least four episodes of basin aggradation. During endorheic conditions the basin fill did not reach the elevation of the plateau interior and hence the Tarom Basin was never integrated into the plateau realm. Furthermore, our provenance data indicate that the northern margin of the basin experienced a greater magnitude of deformation and exhumation than the southern one (IP margin). This agrees with recent Moho depth estimates, suggesting that crustal shortening and thickening cannot be responsible for the vertical growth of the northern margin of the IP, and hence surface uplift must have been driven by deep-seated processes

Tectono-stratigraphic evolution of the intermontane Tarom Basin (NW sectors of the Arabia-Eurasia collision zone): insights into the vertical growth of the Iranian Plateau margin

The intermontane Tarom Basin of NW Iran (Arabia-Eurasia collision zone) is located at the transition between the Iranian Plateau (IP) to the SW and the Alborz Mountains to the NE. This basin was filled by Late Cenozoic synorogenic red beds that retain first-order information on the erosional history of adjacent topography, the vertical growth of the plateau margin and its lateral (orogen perpendicular) expansion. Here, we perform a multidisciplinary study including magnetostratigraphy, sedimentology, geochronology and sandstone petrography on these red beds. Our data show that widespread Eocene arc volcanism in NW Iran terminated at ~ 38-36 Ma, while intrabasinal synorogenic sedimentation occurred between ~ 16.5 and < 7.6 Ma, implying that the red beds are stratigraphically equivalent to the Upper Red Formation. After 7.6 Ma, the basin experienced intrabasinal deformation, uplift and erosion in association with the establishment of external drainage. Fluvial connectivity with the Caspian Sea, however, was interrupted by at least four episodes of basin aggradation. During endorheic conditions the basin fill did not reach the elevation of the plateau interior and hence the Tarom Basin was never integrated into the plateau realm. Furthermore, our provenance data indicate that the northern margin of the basin experienced a greater magnitude of deformation and exhumation than the southern one (IP margin). This agrees with recent Moho depth estimates, suggesting that crustal shortening and thickening cannot be responsible for the vertical growth of the northern margin of the IP, and hence surface uplift must have been driven by deep-seated processes

Neogene Tectono-Stratigraphic Evolution of the Intermontane Tarom Basin: Insights Into Basin Filling and Plateau Building Processes Along the Northern Margin of the Iranian Plateau (Arabia-Eurasia Collision Zone)

The intermontane Tarom Basin of NW Iran (Arabia-Eurasia collision zone) is located at the transition between the Iranian Plateau (IP) to the SW and the Alborz Mountains to the NE. This basin was filled by upper Cenozoic synorogenic red beds that retain first-order information on the erosional history of adjacent topography, the vertical growth of the plateau margin and its orogen perpendicular expansion. Here, we perform a multidisciplinary study including magnetostratigraphy, sedimentology, geochronology and sandstone petrography on these red beds. Our data show that Eocene arc volcanism in the region terminated at 38-36&nbsp;Ma, while intrabasinal synorogenic sedimentation (endorheic conditions) occurred from at least 16.2 to&nbsp;&lt;7.6&nbsp;Ma, implying that the red beds are stratigraphically equivalent to the Upper Red Formation. After 7.6&nbsp;Ma, the basin experienced intrabasinal deformation, uplift and erosion with the establishment of external drainage. Fluvial connectivity with the Caspian Sea, however, was interrupted by at least four episodes of basin aggradation. During endorheic conditions, the basin fill did not reach the elevation of the plateau interior and hence the Tarom Basin was never integrated into the plateau. Furthermore, our provenance data indicate that the northern margin of the basin (Alborz Mountains) experienced a greater magnitude of Miocene deformation and erosional exhumation than the southern one (IP margin). This agrees with recent Moho depth estimates, suggesting that crustal shortening and thickening cannot be responsible for the vertical growth of the northern margin of the IP, and hence surface uplift must have been driven by deep-seated processes

The Origin and Early History of NOW as It Happened

The NOW database of fossil mammals came to be through a confluence of several initiatives spanning multiple decades. The first public version of NOW database was released in 1996 and the first Advisory BoardNOW Databaseadvisory board was established the year after. Originally, NOW stood for Neogene of the Old World but with the gradual expansion of the database the acronym was eventually reassigned to stand for New and Old Worlds. The structure of what would become NOW was originally cloned from the ETE databaseEvolution of Terrestrial Ecosystems (ETE) Database of the Smithsonian Institution and the first NOW version accessible over the internet was a node of the ETE databaseEvolution of Terrestrial Ecosystems (ETE) Database. The first standalone, online version of NOW was launched in 2005 and the first formal steering groupNOW Databasesteering group was established in 2009. During its existence, NOW has been funded, directly or indirectly, by several organizations but fundamentally it has always been an unfunded community effort, dependent on voluntary work by the participants.Peer reviewe