Abstract An abandoned subsurface Oya tuff quarry in Japan had abundant salt efflorescence in winter. Besides salt weathering, freeze-thaw weathering and slaking were likely to occur because of winter temperatures below 0 °C and the presence of swelling clays in the rock. Field surveys were performed to collect salts. Thenardite and gypsum were detected by X-ray diffraction (XRD) as the main salts, along with zeolites as secondary minerals. Oya tuff is categorized into three types for practical usage. To investigate petrophysical differences among the three types of Oya tuff, mercury intrusion porosimetry and tensile strength tests were performed. To determine the influence of petrophysical properties on salt weathering, freeze-thaw weathering and slaking (wet-dry weathering), all three types of Oya tuff were used for experiments. Prismatic specimens, the bases of which were sunk into distilled water, were used for the freeze-thaw and slaking experiments and Na 2 SO 4 saturated solution was used for the salt-weathering experiment. The results show that the specimens subjected to salt weathering were the most severely damaged. The coarse-type Oya tuff sustained the most severe damage, whereas the fine type received the least. There was a large amount of debris in the coarse type, but less in the fine type. The weathering susceptibility index WSI was also calculated from the results of the pore size analyses and tensile strength. The index decreases with increasing weathering cycles representing resistant rocks. The phenomena of weathering of Oya tuff were explained by three weathering experiments on three kinds of tuff. The WSI may be useful as a practical indicator of rock weathering.

Abstract Paleontological resources (fossils) are the remains of life preserved in a geologic context. Fossils may consist of the physical remains of a biological organism such as a tooth, bone, shell, leaf, cone, seed, or wood. Evidence of biological activity may sometimes be preserved in rocks, hence tracks, traces, burrows, coprolites (fossil dung and feces), and nests represent other valuable types of paleontological resources. The fossil record reveals an extremely rich diversity of ancient organisms preserved in the Earth's strata (layers of rock). The fossil record of life on Earth spans nearly every period of geologic history from Precambrian bacteria, billions of years old, to more recent Pleistocene or Holocene cave fossils dating back only a few thousand years. Together, fossils from around the world yield significant scientific and educational information regarding the history of life on Earth. From the moment of death for an organism, a wide array of agents and forces work toward the breakdown and destruction of its physical remains. Raup and Stanley (1978) identify and describe biological, chemical, and mechanical variables associated with the destruction of biological remains. Only a very small percentage of all living organisms become part of the fossil record, and of those, an even smaller percentage have been discovered, collected and studied. The preservation of fossils and the associated biases in the fossil record are directly attributable to the organism's morphologic composition, rate of post-mortem burial, environment of deposition, diagenetic variables, tapho-nomic (after death) factors, and the post-depositional geologic history of

Abstract Eight different types of acid tuffs of the Eger Castle (Hungary) and two tuffs from nearby quarries have been studied in detail. Mapping of wall sections reveals that tuffs show weathering forms that are similar to common sedimentary rocks, such as limestones or sandstones. Different lithologies display various weathering features. On pumice-rich tuff ashlars relief due to selective weathering, weathering crusts, multiple flakes and scales occur, while crumbling is common on layered flow tuffs. Conversely, cemented tuff types do not show deep weathering. Pore-size distribution rather than effective porosity controls the weathering susceptibility of tuffs. Frequent larger micropores are the main causes of freeze-thaw-related weathering. Besides clays, newly formed gypsum and calcite are the weathering-related index minerals. Schmidt hammer rebound values mark the weathering process when quarry stones and ashlars of historic walls are compared.