pillow lavas are locally conspicuous. A unit consisting of dark, thinly bedded sandstone and siltstone, lccally ranging to several hundred feet thick, is lowermost in the exposed section. The middle division consists of about 3,500 feet of mixed andesi.:e and basalt volcaniclastic rocks ~ lahar, tuff breccia, volcanic sandstone, and conglomeratic beds which rest on relatively thin, fossiliferou...

Abstract A large caldera cluster consisting of at least four calderas (Omine, Odai, Kumano‐North and Kumano calderas) existed in the central–southern part Kii Peninsula approximately 14–15 Ma. On other hand, thick Middle Miocene ash‐flow tuffs, referred to as Muro Ash‐flow Tuff Sekibutsu Member, are distributed northern Peninsula. Although these tuffs considered have erupted from central‐southe...

From an Indonesian volcanic tuff taken from parent material layer of Andisols profile, it was separated ‘nanoclay’ fraction <200 nm particle size. The exhibits pH-dependent charge characteristic due to the presence allophane in tuff. Therefore, can be utilized as a natural anionic adsorbent since its separation process conditioned proceed at pH <4.0. This study aims compare phosphate adso...

Detection and verification of underground nuclear explosions (UNEs) can be improved with a better understanding the nature extent explosion-induced damage in rock effect this on radionuclide migration. Much previous work area has focused centimeter- to meter-scale manifestations damage, but predict permeability for migration, observations at smaller scales are needed determine deformation mecha...

The Okote Member from the northeast Turkana Basin of Kenya represents an exceptionally good archive of Early Pleistocene archaeological and fossil sites. Field study of the lower Okote Member and underlying deposits was conducted in detail at two sets of outcrops (500 to 1000 m long) separated by some 22 km of modern landscape. The examined sections (10 to 15 m thick) preserve two facies: inter...

Abstract A Paleozoic arc that formed by southward subduction of the Rheic oceanic plate beneath northern Gondwana has long been inferred, but its history and geochemical signatures remain poorly understood. New U-Pb ages, juvenile εHf signatures, trace-element composition data young zircons from tuffs at two southern Laurentia sites indicate their derivation a continental was active ca. 328 to ...