Summary of physical properties of rocks collected during the IODP Exp.402 in the back-arc Tyrrhenian Basin

Filina, I. Y.*; 安邊 啓明   ; 他25名*

Filina, I. Y.*; Abe, Noriaki; 25 of others*

The IODP Expedition 402 occurred from February to April of 2024 in the Tyrrhenian Sea with the primary objective of sampling the transition between the continental and oceanic tectonic domains. We have drilled two sites on the conjugate Cornaglia and Campania terraces, and four sites in the Vavilov basin. In this paper, we summarize different rock types recovered during the IODP expedition 402 that range from felsic to ultramafic composition. We present the average values of bulk density, porosity, grain density, compressional velocity, magnetic susceptibility, gamma-radiation, and thermal conductivity for different types of rocks. In particular, we report physical properties for shales and muds of the post-Messinian section including ach intervals and volcaniclastic gravel encountered in all holes, evaporites (halite, gypsum and anhydrite) of Messinian interval, and pre-Messinian shales in the continental domains, as well as basalts and diorites, granitoids/gneisses and peridotites recovered from the Vavilov basin. The data gathered from the 6 sites drilled by Expedition 402 will allow us to study the origin, formation, evolution and tectonic history of the Tyrrhenian Sea and uncover the geological processes that were active in the area at different times. The physical properties reported in this paper provide mandatory constraints for all kinds of geomodelling, such as geological, geophysical, geochemical and geodynamical studies, as well as tectonic reconstructions, which eventually will shed light on the complex tectonics of this important region.