The anisotropy of magnetic susceptibility (AMS) of late Cretaceous ash-flow tuffs in Chisulryoung Volcanic Formation, southeastern Korea was studied to define the primary pyroclastic flow azimuth. AMS data revealed a dominant oblate fabric with a tight clustering of k3 (minimum axis of magnetic susceptibility) and shallow dispersal of k1 (maximum axis of magnetic susceptibility) and k2 (interme...

Introduction: Small cone-shaped features have been identified in several regions on Mars, e.g. in Isidis Planitia, Elysium Planitia, Amazonis Planitia, Acidalia Planitia, southern Utopia Planita, in the Cydonia Region, in Cerberus Planum, around Phlegra Montes and on several volcanic flanks. They vary greatly in size and morphology and have been compared to terrestrial features of various origi...

The potential of surfactant modified zeolites as adsorbents for mycotoxins and as carrier of the pharmaceutical drugs was investigated. Ochratoxin A OCHRA (mycotoxin) and diclofenac sodium DS (anti-inflamatory drug) were used as model substances. Surface of the clinoptilolite was modified with different amounts of quaternary ammonium ions (hexadecyltrimethyl ammonium HDTMA or octadecyldimethylb...

The evaluation of the Yucca Mountain site has evolved from intensive surface-based investigations in the early 1980s to current focus on testing in underground drifts. Different periods of site characterization activities and prominent issues concerning the unsaturated zone (UZ) are summarized. Data collection activities have evolved from mapping of faults and fractures to estimation of percola...

We present an oxygen isotope and petrologic study of four voluminous, zoned ash-flow sheets of the Southwestern Nevada Volcanic Field (SWNVF): Topopah Spring (TS, .1200 km3, 12.8 Ma), Tiva Canyon (TC, 1000 km3, 12.7 Ma), Rainier Mesa (RM, 1200 km3, 11.6 Ma), and Ammonia Tanks (AT, 900 km3, 11.45 Ma). The d18O values of quartz, sanidine, sphene, magnetite, and zircons in rhyolites and latites of...

A continuous record of Pliocene-Pleistocene East African volcanic tephra deposition has been developed from a marine sediment sequence at Ocean Drilling Program Sites 721/722 in the Arabian Sea, some 2000 km distant from Ethiopian source volcanoes. The marine depositional sequence is continuous over the Pliocene-Pleistocene interval, has a wealth of published data addressing regional paleoclima...

gomish-tappeh zn-pb-cu (ag) deposit is located 90 km southwest of zanjan, in northwestern part of urumieh-dokhtar volcano-plutonic zone. exposed rocks at the area include oligo-miocene volcano-sedimentary and sedimentary sequences as well as pliocene volcano-plutonic sequence (andesite porphyry dykes, dacitic subvolcanic dome and rhyodacitic volcanics). alteration in the deposit developed as si...

The Indian Peak volcanic field is representative of the more than 50,000 km3 of ashflow tuff and tens of calderas in the Great Basin that formed during the Oligocene-early Miocene "ignimbrite flareup" in southwestern North America. The field formed about 32 to 27 Ma in the southeastern Great Basin and consists of the centrally positioned I n d i Peak caldera complex and a surrounding blanket of...