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令和元年（2019 年）東日本台風による斜面変動に関して，宮城県丸森町とその周辺に発生した斜面崩壊地の岩石と土層の諸物性，および岩手県重茂半島と普代村の斜面崩壊地付近の岩石物性について調査した．その結果，表層崩壊が多発した花崗閃緑岩斜面では，土層は，主に原位置風化により，表層に向かって物理的・化学的風化が進行していた．すべり面は，風化程度の小さな高透水性の粗粒土からなり，ハロイサイト（10 Å）が含まれていた．凝灰岩斜面では，すべり面の斜面勾配が小さい（5º ～10º）崩壊が発生しており，土層は粘性土であり，すべり面は低透水性であり，一部にはスメクタイトとハロイサイトが含まれていた．堆積岩斜面では表層崩壊が発生しており，すべり面には泥質岩起源のスメクタイトを多く含む低透水性の粘性土と硬質な砂礫質岩が露出していた．重茂半島・普代村と丸森町の花崗閃緑岩の鉱物組成は類似していた．また，重茂半島の溶結凝灰岩は，花崗閃緑岩と比較すると，風化を受けやすい黒雲母を欠く細粒の岩石であった．We investigated rock and soil properties for the slope failures induced by Typhoon Hagibis on October 2019 near Marumori Town, Miyagi Prefecture, and the Omoe Peninsula and Fudai Village in Sanriku coastal area, Iwate Prefecture. The soil layer was physically and chemically weathered toward the ground surface mainly due to in-situ weathering in the granodiorite slope where shallow slope failure occurred frequently. The slip plane consisted of weakly weathered, highly permeable, coarse-grained soil and contained halloysite (10 Å). Cohesive soil layer was formed in the tuff slope where some slope failures occurred along the gentle slip plane (5º to 10º). Soil in the slip plane was low permeability, and smectite and halloysite are contained. Some shallow slope failures occurred on the sedimentary rock slopes, and harder gravelly rock and low-permeable cohesive soil containing a large amount of smectite derived from muddy rock were exposed on the slip plane. The mineral compositions of granodiorite were similar each in the Omoe Peninsula, Fudai Village and Marumori Town. Compared to granodiorite, the welded tuff in the Omoe Peninsula was fine-grained rock lacking biotite which is easily weathered.

岩石の多様性を理解する上で、化学的多様性と形成年代、なかでも成因が重要である。岩石には、火成岩と変成岩、堆積岩の3つの成因がある。火成岩では固体が溶融し液体になり固化する、堆積岩では固体が離脱、移動し、再構成される、変成岩では固体が別の固体に再結晶する、というそれぞれの素過程がある。素過程ごとにいくつかの作用があり、作用ごとにいくつかの要因があり、それらにより多様性が形成されている。素過程における要因だけでなく、地球の冷却過程や表層環境の変遷など、長い時間スケールでの変化を反映した多様性もある。岩石の多様性の変化は、地球の不可逆な変化を記録している。地球初期にできた固体にはいくつかの由来の火成岩があり、もっとも根源的な成因の岩石となっている。火成岩は、岩石の多様性に大きな改変を起こす、弁証法的な発展過程をしている。, The Factors of chemical variety, formation age, and the origin are important for making the rock diversity. There are the three origins of igneous, sedimentary, and metamorphic in rocks. In an elementary process of igneous rocks, solid (rock) turns into liquid (magma), and solidify (rock). In sedimentary rocks, solid (rock) breaks and moves as fragments, solute, reconstruct to rock. In metamorphic rocks, solid (rock) recrystallizes to rock. There are some functions for every elementary process, and some factors involving for every function. The functions and factors form the rock variety. The rock diversity reflected the change with long time scales, such as a cooling process of the Earth and modification of the surface environment of the Earth. Mode change of the rock diversity is recording an irreversible change of the Earth. The first solids in the early Earth were made from igneous rocks which formed by the different processes from magmatism. An igneous process is the principle of origin. The igneous process developing dialectical causes the large diversity of rock., 論文, Article

Meaning of chronological data for petrological studies was reviewed. Mizutani and Shibata (1983) estimated duration of lithification after initial deposition of sediment as 17 million years using a combination of radiolarian fossil and 87Rb-87Sr whole rock isochron ages. Harayama (1992) reported a youngest exposed granitoid pluton on Earth from the Northern Alps, central Japan, based on the K-Ar hornblende and biotite ages， Rb-Sr biotite age，and fission track zircon age. Metamorphic rocks generally record ages of many equilibrium stages during metamorphic evolution. Katayama (2004) confirmed five stages of zircon growth in ultra-high pressure metamorphic rocks from the Kokchetav massif，and estimated their exhumation speed as 0.5-0.6 cm/year using Secondary Ion Mass Spectrometry., 名古屋大学年代測定総合研究センターシンポジウム報告

The permeability of Kimachi sandstone in triaxial compression failure process was investigated by laboratory experiments. Tests were carried out under a constant confining pressure of between 5.0 and 15.0 MPa with a constant pore pressure of 2.0 MPa until axial strain reached approximately 5.0%. The stress-strain relation was linear under low differential stress and gradually became nonlinear as peak differential stress approached. In the tests under confining pressure of 5.0 and 7.5 MPa, the permeability decreased in the elastic region and then increased as the peak strength approached. The permeability continued to increase at first in residual strength region, and then it decreased at axial strain of approximately 4.0%. In the tests conducted under higher confining pressure, the variation in the permeability was small until axial strain of 5.0%. It appeared that failure types were different depending on confining pressure from the observation of the thin sections made from the specimens after tests. In the tests under 5.0 MPa confining pressure, a macroscopic fault occurred in the test pieces. On the other hands it did not occur in the tests under higher confining pressures. It was suggested in the elastic FEM analyses that the failure types were influenced by the end constraint.

Remote-sensing technique, which can survey wide area in short time, is very useful for geological study of the surface of the earth and planets. However, when we use remote-sensing data of the earth's surface to detect some minerals, two things should be considered: First, we can only use some limited wavelength region which can penetrate through atmosphere. Second, in most case, surface materials are composed of complex mixture of minerals. Thus, mixtures of minerals should be studied on their diffuse reflectance spectra. In recent years, the increasing concentration of atmospheric carbon dioxide has become serious problem. In order to solve this problem, we have to know the distribution of carbonate rocks which are main reservoirs of the carbon dioxide and are widely distributed on the earth. Moreover, carbonate rocks are important as host rocks of many valuable ore minerals. We studied calcite (CaCO3) which is a common and representative carbonate mineral. To study on diffuse reflectance spectra of mineral mixtures, we mixed some phyllosilicates (clay minerals, mica) with calcite, because they are considered as important minerals coexisted with calcite and as main constituents of terrestrial sedimentary rocks. They occur as primary, detrital components or alteration products formed during diagenesis. Diffuse reflectance spectrum of calcite has some characteristic absorption due to vibration of C-O bond from the Near-Infrared (NIR) to Infrared (IR) region (e.g. Salisbury et al., 1988). But we are not able to employ all these features to detect calcite when we use the remote-sensing data because of interruption by many obstacles. For example, absorption by atmosphere is one of the largest problems and as well it becomes the first problem mentioned above. Molecules of H2O and CO2 in the atmosphere partially absorb the emitted light from the earth's surface. This is why we can only use the limited wavelength regions which permit penetrating through the atmosphere. The sensors equipped with the satellites measure within these usable wavelength regions. Table one shows the bands of the sensors of two resource investigation satellites (data from RESTEC (Remote Sensing Technology Center) and ERSDAC (Earth Remote Sensing Data Analysis Center)). These wavelength regions of the sensors cover many absorption bands of natural minerals due to molecular vibration., 資料番号: AA0063352046

Based on the gravity and geomagnetic anomaly data, the 3-D structure of the Takamatsu crater is investigated in detail. The Bouguer gravity anomaly in and around the crater suggests that the diameter and the depth of the crater are 4 km and 1.4 km, respectively. The geomagnetic anomaly shows a pair of negative and positive anomalies above the crater. These anomalies can be explained by a magnetized (4 A/m) layer with a thickness of 200 m at the bottom of the crater., 資料番号: AA0063352015