SMECTITE CONVERSION IN DIAGENESIS AND LOW GRADE HYDROTHERMAL ALTERATION FROM NEOGENE BASALTIC MARINE SEDIMENTS IN NIIGATA BASIN, JAPAN

スポンサーリンク

概要

• 論文の詳細を見る

• The smectite conversion can be divided into diagenesis and low degree hydrothermal metamorphism stages in the Nanatani formation (depth : 4250-6300m ; middle Miocene) basalt and interstratified rocks in the Niigata sedimentary basin, Japan. In the diagenesis stage, the features of smectite conversion are crystallization and recrystallization from glass or primary minerals, precipitation as fillings of vesicle and crevice in basaltic rocks. In the low grade hydrothermal metamorphism stage, the prior smectites are dissolved and recrystallized as corrensite on the early hydrothermal progression and as chlorite and talc associated with epidote, prehnite and others on the late hydrothermal progression. The thin section, XRD, SEM, TEM, EDS and bulk rock chemical analysis have documented that the mixed-layer Chl/S conversion from smectite to chlorite via corrensite is a discontinuous transformation process between diagenesis and low degree hydrothermal metamorphism. Although smectite and randomly mixed-layer Chl/S exhibit crystal growth from fine to coarse size in diagenetic process, the chlorite layer percentage has been only slightly changed in the mixed-layer Chl/S (chl, <15%). The low grade hydrothermal metamorphic corrensites are close to ideal 1 : 1 interstratified structure of mixed-layer Chl/S(chl, 45-60%) and the discrete chlorites contain a little smectite layers (chl, >90%). The Al_2O_3-FeO-MgO relation and ratio of octahedral Fe/Fe + Mg indicate that the smectite and precipitated chlorite composition are controlled by host rocks and environmental fluid in diagenesis. However the hydrothermal corrensite and chlorite have similar compositions to those in other hydrothermal metamorphism.

• 日本粘土学会の論文

著者

• Niu Ben

  Graduate School Of Science And Technology Niigata University

• Yoshimura Takahisa

  Department Of Environmental Science Faculty Of Science Niigata University

関連論文

• Preparation, Characterization, and Structures of Dinuclear Cobalt(III) Complexes Triply Bridged by Two μ-Hydroxo and One μ-Carbonato
• THE SMECTITE-TO-ILLITE TRANSITION IN THE KOYOSHIGAWAOKI WELL IN THE AKITA SEDIMENTARY BASIN, NORTHEAST JAPAN
• THE SMECTITE-TO-ILLITE TRANSITION IN THE KOYOSHIGAWAOKI WELL IN THE AKITA SEDIMENTARY BASIN, NORTHEAST JAPAN
• B20 THE SMECTITE-TO-ILLITE TRANSITION IN THE KOYOSHIGAWAOKI WELL IN THE AKITA SEDIMENTARY BASIN, NORTHEAST JAPAN
• 4 DIAGENETIC ALTERATION OF CLAY MINERALS FROM THE NEOGENE MARINE SEDIMENTS IN THE NIIGATA BASIN
• SMECTITE CONVERSION IN DIAGENESIS AND LOW GRADE HYDROTHERMAL ALTERATION FROM NEOGENE BASALTIC MARINE SEDIMENTS IN NIIGATA BASIN, JAPAN

スポンサーリンク