Petrophysical characteristics of hydrothermally altered volcaniclastic-rich sedimentary rocks on the Naturaliste Plateau, offshore southwestern Australia (IODP Site U1513)

Drilling at Site U1513 recovered the Lower Cretaceous volcaniclastic-rich sedimentary sequence on the Naturaliste Plateau and Mentelle Basin, offshore southwestern Australia. The sequence exhibits distinct lithologic characteristics, attributed to volcanism and subsidence occurred during the breakup between Greater India and Australia-Antarctica. It consists of sandstones, siltstones, and silty claystones with abundant volcanic clasts, lithics, and hydrothermal alteration. This study characterizes petrophysical properties of the sequence and correlate them with lithologic and mineralogical features. The properties show noticeable variations. Our results confirm that the petrophysical characteristics are associated with grain size, volcanic matter, organic content, as well as hydrothermal alteration minerals.