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141 results on '"Katsuta, Nagayoshi"'

5. Decadal–centennial-scale solar-linked climate variations and millennial-scale internal oscillations during the Early Cretaceous

Author

Hasegawa, Hitoshi, Katsuta, Nagayoshi, Muraki, Yasushi, Heimhofer, Ulrich, Ichinnorov, Niiden, Asahi, Hirofumi, Ando, Hisao, Yamamoto, Koshi, Murayama, Masafumi, Ohta, Tohru, Yamamoto, Masanobu, Ikeda, Masayuki, Ishikawa, Kohki, Kuma, Ryusei, Hasegawa, Takashi, Hasebe, Noriko, Nishimoto, Shoji, Yamaguchi, Koichi, Abe, Fumio, Tada, Ryuji, and Nakagawa, Takeshi

Published
2022
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12. Sedimentary rhythm of Mn-carbonate laminae induced by East Asian summer monsoon variability and human activity in Lake Ohnuma, southwest Hokkaido, northern Japan

Author

Katsuta, Nagayoshi, Naito, Sayuri, Ikeda, Hisashi, Tanaka, Kuniaki, Murakami, Takuma, Ochiai, Shinya, Miyata, Yoshiki, Shimizu, Mayuko, Hayano, Asuka, Fukui, Konami, Hasegawa, Hitoshi, Nagao, Seiya, Nakagawa, Mayuko, Nagashima, Kana, Niwa, Masakazu, Murayama, Masafumi, Kagawa, Masako, and Kawakami, Shin-ichi

Published
2020
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19. Rhythmic iron‐oxide bands of Navajo Sandstone concretions and Kimberley banded claystone: Formation process and buffering reaction rate by diagenetic alteration.

Author

Katsuta, Nagayoshi, Sirono, Sin‐iti, Umemura, Ayako, Kawahara, Hirokazu, Masuki, Yuma, Yoshimizu, Chikage, Tayasu, Ichiro, Murakami, Takuma, and Yoshida, Hidekazu

Subjects
*PYRITES, *WATER-rock interaction, *SANDSTONE, *SEDIMENTARY rocks, *IGNEOUS rocks, *DIFFUSION coefficients, *FERRIC oxide, *IRON oxides
Abstract

Both igneous and sedimentary rocks affected by water–rock interaction commonly form rhythmic Fe‐oxide bands that provide information on palaeo‐groundwater. This study investigated the formation of Fe‐oxide banded patterns of concentrically banded concretions from the Jurassic Navajo Sandstone (United States) and banded claystone 'zebra rock' from the Neoproterozoic Johnny Cake Shale Member (Western Australia). Micro‐X‐ray fluorescence imaging of both samples revealed uniformly banded patterns of asymmetrical Fe content peaks. This study proposes that their formations were caused by diffusion, with a pH buffering reaction of Fe2+ and O2 due to dissolution of earlier materials by acidic fluids. Based on the model, it is suggested that the acid fluids for Navajo diffused towards the inner side of the concretion, and that for Kimberley they penetrated oblique or perpendicular to bedding. In addition, the Fe‐oxide precipitation has resulted from pH rises of acidic fluids because of diagenetic alteration of earlier calcite concretion in Navajo and that of earlier pyrite‐bearing claystone in Kimberley. The interpretation for Kimberley is based on the δ34S values (<−20‰) of zebra rock, suggesting that the alunite and Fe‐oxide resulted from the supply of SO42− and Fe2+ produced as a result of pyrite oxidation in earlier rocks. The formation rate of the Fe‐oxide band was estimated from the constant width of the Fe peaks and the expected diffusion coefficient for Fe2+ through the rock matrix, and it was found to be on the order of years for Navajo and on the order of tens of years for Kimberley. [ABSTRACT FROM AUTHOR]

Published
2024
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20. Sample pretreatment effects on isotopic compositions of oxygen and sulfur in BaSO4 derived from atmospheric sulfate.

Author

Kagawa, Masako, Katsuta, Nagayoshi, Naito, Sayuri, Masuki, Yuma, Yoshimizu, Chikage, Chiba, Hitoshi, and Tayasu, Ichiro

Subjects
*METEOROLOGICAL precipitation, *ATMOSPHERIC aerosols, *DIETHYLENETRIAMINEPENTAACETIC acid, *SULFUR, *SULFATES
Abstract

Rationale: Preparation of BaSO4 from samples of atmospheric rain, snow, and aerosols has been used for δ18O and δ34S analyses. In the present study, we investigated the effect of various sample pretreatments on δ18O and δ34S values determined from a Na2SO4 reagent solution and samples of atmospheric precipitation to improve assay time and cost efficiency. Methods: BaSO4 was prepared from a Na2SO4 solution by (a) evaporative concentration, (b) evaporation to dryness, (c) evaporation to dryness after adding HCl, and (d) evaporation to concentration after adding HCl, followed by cooling and then precipitation using a BaCl2 solution. To analyze the atmospheric precipitation samples for δ18O, BaSO4 prepared from the samples was treated with diethylenetriaminepentaacetic acid (DTPA) and SO42− and separated chromatographically. The values of δ18O and δ34S were measured using a continuous‐flow elemental analyzer coupled to an isotope‐ratio mass spectrometer. Results: The δ34S values in BaSO4 precipitated from Na2SO4 solution determined by methods (a)–(c) were consistent within precisions of ±0.5‰. The δ18O values of methods (a) and (b) were consistent within ±0.2‰, whereas the δ18O values of methods (c) and (d) increased with increasing HCl concentrations. Similar results were obtained from samples of atmospheric precipitations. The δ18O values from DTPA‐treated BaSO4 were consistent with those obtained by chromatographic separation within ±0.5‰. Conclusions: We found no significant differences in the effects of various pretreatments (acidification, heating, concentration, and drying) on δ18O and δ34S values in sulfate from samples of atmospheric precipitation and aerosols extracted as BaSO4 if HCl was not added to the sample before heating and BaSO4 was treated with DTPA for the δ18O analysis. [ABSTRACT FROM AUTHOR]

Published
2023
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41. Siberian Permafrost Thawing Accelerated at the Bølling/Allerød and Preboreal Warm Periods During the Last Deglaciation

Author

Katsuta, Nagayoshi, primary, Matsumoto, Genki I., additional, Hase, Yoshitaka, additional, Tayasu, Ichiro, additional, Haraguchi, Takashi F., additional, Tani, Eriko, additional, Shichi, Koji, additional, Murakami, Takuma, additional, Naito, Sayuri, additional, Nakagawa, Mayuko, additional, Hasegawa, Hitoshi, additional, and Kawakami, Shin‐ichi, additional

Published
2019
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43. Quantitative micro‐X‐ray fluorescence scanning spectroscopy of wet sediment based on the X‐ray absorption and emission theories: Its application to freshwater lake sedimentary sequences

Author

Katsuta, Nagayoshi, primary, Takano, Masao, additional, Sano, Naomi, additional, Tani, Yukinori, additional, Ochiai, Shinya, additional, Naito, Sayuri, additional, Murakami, Takuma, additional, Niwa, Masakazu, additional, and Kawakami, Shin‐ichi, additional

Published
2019
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44. Interannual changes in radiocesium concentrations in annually laminated tufa following the Fukushima Daiichi Nuclear Power Plant accident

Author

Katsuta, Nagayoshi, primary, Miyata, Yoshiki, additional, Murakami, Takuma, additional, Mino, Yoshihisa, additional, Naito, Sayuri, additional, Yasuda, Koji, additional, Ochiai, Shinya, additional, Abe, Osamu, additional, Yasuda, Atsushi, additional, Morimoto, Maki, additional, Kawakami, Shin-ichi, additional, and Nagao, Seiya, additional

Published
2019
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46. Paleoclimate variability in continental Asia revealed by chemical analyses of Lake Baikal sediment

Author

Murakami, Takuma, Katsuta, Nagayoshi, Takamatsu, Takejiro, Takano, Masao, Yamamoto, Koshi, Nakamura, Toshio, and Kawai, Takayoshi

Subjects
湖底堆積物, バイカル湖とフブスグル湖, 14C年代, アジア大陸, 古気候変動
Abstract

Lake Baikal sediment contain information for understanding of long-term climate changes in the in the continental interior. In the present study, we analyzed abundances of biogenic silica and uranium in the core sediment (BDP93-2 and BSS06-G2) from Buguldeika saddle in southern part of the lake. The uranium concentration shows a similar fluctuation pattern with the biogenic silica concentration (as a paleotemperature proxy) on a glacial and interglacial scale (i.e., 100-kyr periodicity), whereas these two chemical components an inverse correlation on a centennial to millennial scale during the interglacial and interstadial periods. This means that sedimentation process of biogenic silica and uranium in Lake Baikal is different from each other, suggesting that the uranium concentration of sediment is paleclimate proxy different from palotemperature proxy (i.e., paleomoisture proxy). Also, comparison of the Baikal uranium concentration with the Hovsgol detrital component indicates a positive correlation during the late Holocene each other. Based on the above assumption, climate of continental Asia become wet condition during the interglacial and interstadial periods and dry condition during the glacial periods. In addition, the climate during interglacial and interstadial periods is characterized by alternation of cold-wet and warm-dry conditions., 第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告

Published
2011

47. AMS ^<14>C dating of sediment core BSS06-G2 from Lake Baikal, Russia : Toward decoding the variation of bulk-chemical composition

Author

MURAKAMI, Takuma, KATSUTA, Nagayoshi, TAKAN0, Masao, YAMAMOT0, Koshi, WATANABE, Takahiro, NAKAMURA, Toshio, and KAWAI, Takayoshi

Abstract

Lake Baikal is one of the largest lakes in the world and located in the eastern Eurasia. The sediment has recorded various informations of paleoenvironmental changes in Eurasian continent. We measured AMS ^C dating of a BSS06-G2 (39.0 cm length) sediment core samples in Buguldeika Saddle of Lake Baikal. As a result, we found that variations of chemical abundances in BSS06-G2 core correlated with that of ice-rafted debris content in deep-sea sediments of the North Atlantic., ロシア・バイカル湖はユ-ラシア大陸東部に位置する世界最大の淡水湖であり、その湖底堆積物には大陸内部で生じた環境変動の歴史が詳細に記録されている。今回、バイカル湖南部･ブグルジェイカ鞍部で採取されたグラビティーコア(BSS06-G2、全長：39cm)について、名古屋大学タンデトロン加速器質量分析計により^C年代測定した結果、BSS06-G2コアの全岩化学組成含有量と北大西洋の深海堆積物中の漂流岩屑(Ice-Rafted Debris)含有量との間に、明瞭な変動パターンの対比が認められた｡, 第22回名古屋大学年代測定総合研究センターシンポジウム平成21(2009)年度報告

Published
2010

48. Periodic variation of paleoenvironments found by PCA of 27 kyr geochemical records of Lake Hovsgol sediment

Author

Murakami, Takuma, Katsuta, Nagayoshi, Yamamoto, Koshi, Takamatsu, Nobuki, Takano, Masao, Matsumoto, Genki I, Oda, Takefumi, Horiuchi, Kazuho, and Kawai, Takayoshi

Abstract

Geochemical proxy-records in a continuous 27 kyr (thousand years) core sediment from Lake Hovsgol in northwest Mongolia provides a detailed history of the response of the lake itself and the surrounding watershed to climate change during the last glacial to Holocene period. Principle component analysis (PCA) of 19 major and trace elements, total inorganic carbon (TIC), and total organic carbon (TOC) in the bulk-sediment samples revealed that the 21 chemical components are grouped by four assemblages: Group-1 components -Na, Mg, Ca, Sr, and TIC, hosted in carbonate minerals (calcite, dolomite, and magnecian calcite); Group-2 -Ni, Cu, and Zn, recognized as biophilic trace metals, and TOC; Group-3 -Al, K, Ti, V, Fe, Rb, Cs, Ba, and Pb, composed of rock-forming minerals; Group-4 -Cr, Mn, and As, sensitive to redox condition of sediment. The four element assemblages were originated from relevant 3 factors in subsidence. The group-1 and group-2 components of authigenic products in the lake are end member on the PC-1 score. The group-3 components of detrital materials from watershed contribute to the PC-2 score. The group-4 components of redox sensitive elements contribute to the PC-3 score, which are not the end member due to a small amount. The first two PC scores possibly suggest a sequential record of paleomoisture evolutions of central Asia. Especially, a variability of PC-2 score indicates erosion/weathering intensity of watershed which might be controlled by the ratio of vegetation cover associated with moisture change. A periodic variation on ~8. 7 kyr cycle was observed in the PC-2 score profile of detritus inputs of Lake Hovsgol over the last glacial and Holocene period. The decrease of detritus input of the lake coincided with the timing of dramatic supply of moisture from Asian monsoon regime and North At1antic region to Baikal watershed to which Lake Hovsgol belongs. Our geochemical records demonstrate that climate system of continental interior Asia was strongly influenced by climate change on a Milankovitch scale as well as a sub-Milankovitch one., 第21回名古屋大学年代測定総合研究センターシンポジウム平成20(2008)年度報告

Published
2009

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