Arc and forearc rifting in the Tyrrhenian subduction system

Abstract

The evolution of forearc and backarc domains is usually treated separately, as they are separated by a volcanic arc. We analyse their spatial and temporal relationships in the Tyrrhenian subduction system, using seismic profiles and numerical modelling. A volcanic arc, which included the Marsili volcano, was involved in arc-rifting during the Pliocene. This process led to the formation of an oceanic backarc basin (~ 1.8 Ma) to the west of the Marsili volcano. The eastern region corresponded to the forearc domain, floored by serpentinised mantle. Here, a new volcanic arc formed at ~ 1 Ma, marking the onset of the forearc-rifting. This work highlights that fluids and melts induce weakening of the volcanic arc region and drive the arc-rifting that led to the backarc basin formation. Later, the slab rollback causes the trench-ward migration of volcanism that led to the forearc- rifting under the control of fluids released from the downgoing plate.

Episodic evolution of a protracted convergent margin revealed by detrital zircon geochronology in the Greater Caucasus

“…Migration and reactivation of arcs, forearc basins, and back‐arc basins appear to be common processes in active Mediterranean arc systems (e.g. Balázs et al, 2022; Corradino et al, 2022), and similar transitions may yet emerge in additional relict arc systems. This study and prior work (Vasey et al, 2021) suggest that the forearc to back‐arc transition in the Caucasus region occurred over an interval of ~40 m.y., between a ~40 m.y.…”

Generation of the Quaternary Normal Faults in the Messina Strait (Italy)

“…It is widely recognized that the northern Tyrrhenian basin developed from the Tortonian to the late Miocene, the central Tyrrhenian (Vavilov basin) from the Early Pliocene to the Late Pliocene and the southernmost Tyrrhenian (Marsili basin) since Pleistocene (e.g., [56,[85][86][87][88][89]). Explaining this peculiar space-time evolution of that basin as an effect of slab sinking must face many difficulties, as discussed in some papers [27][28][29]41,74].…”

Large silicic magma chambers at the Moho depth characterize the multi-level plumbing system of back-arc spreading ridge

“…Although the presence of deep, large, relatively cold and SiO2-rich magma reservoirs placed below hotter and SiO2-poor storage zones is a paradox from a thermal perspective, the 'reverse' zonation of the plumbing system of MAV and some of the surrounding Aeolian volcanoes can be explained by the presence of a continuous refilling of hot and hydrated basaltic melts from the asthenosphere 16 . We propose a conceptual model (Fig.…”

“…In particular, an open question concerns the location of possible magma chambers hosting evolved magmas with important implications for the mechanisms of the accretion and evolution of the oceanic crust. Here we report combined petrological and potential field (gravity and magnetic) data on the Marsili axial volcano (MAV, Southern Tyrrhenian Sea, Italy), which represents the ridge of the Marsili oceanic back-arc basin associated with the subduction of the Ionian Sea below the Calabrian Arc [13][14][15][16]1b). MAV is a NNW-SSE elongated, 70 x 30 km ridge rising 3200 m from the seafloor.…”