scholarly journals Significance of the Himaraya-Tibet Massif for the Global Changes. Last 2.4Ma Changes of Monsoon and Westerly Activities in the East Asia, Detected by Clay Mineral Composition in Loess-Paleosol Sequences at the Inland Area of China and Deep-Sea Sediments of the Japan Sea.

1997 ◽  
Vol 106 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Keiichi OI ◽  
Hitoshi FUKUSAWA ◽  
Shuji IWATA ◽  
Masayuki TORII
Keyword(s):  
East Asia ◽  
Mineral Composition ◽  
Clay Mineral ◽  
Deep Sea ◽  
Japan Sea ◽  
Global Changes ◽  
The Japan Sea ◽  
Deep Sea Sediments ◽  
Clay Mineral Composition

Clay mineral distribution related to rift activity, sea-level changes and paleoceanography in the Cretaceous of the Atlantic Ocean

Clay Minerals ◽  
1993 ◽  
Vol 28 (1) ◽  
pp. 61-84 ◽  
Author(s):  
M. Thiry ◽  
T. Jacquin
Keyword(s):  
Atlantic Ocean ◽  
Sea Level ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Deep Sea ◽  
Depositional Environments ◽  
Sea Level Changes ◽  
Sea Floor ◽  
Deep Sea Sediments ◽  
Bottom Waters

AbstractThe distribution of clay minerals from the N and S Atlantic Cretaceous deep-sea sediments is related to rifting, sea-floor spreading, sea-level variations and paleoceanography. Four main clay mineral suites were identified: two are inherited and indicative of ocean geodynamics, whereas the others result from transformation and authigenesis and are diagnostic of Cretaceous oceanic depositional environments. Illite and chlorite, together with interstratified illite-smectite and smectite occur above the sea-floor basalts and illustrate the contribution of volcanoclastic materials of basaltic origin to the sediments. Kaolinite, with variable amounts of illite, chlorite, smectite and interstratified minerals, indicates detrital inputs from continents near the platform margins. Kaolinite decreases upward in the series due to open marine environments and basin deepening. It may increase in volume during specific time intervals corresponding to periods of falling sea-level during which overall facies regression and erosion of the surrounding platforms occurred. Smectite is the most abundant clay mineral in the Cretaceous deep-sea sediments. Smectite-rich deposits correlate with periods of relatively low sedimentation rates. As paleoweathering profiles and basal deposits at the bottom of Cretaceous transgressive formations are mostly kaolinitic, smectite cannot have been inherited from the continents. Smectite is therefore believed to have formed in the ocean by transformation and recrystallization of detrital materials during early diagenesis. Because of the slow rate of silicate reactions, transformation of clay minerals requires a long residence time of the particles at the water/sediment interface; this explains the relationships between the observed increases in smectite with long-term sea-level rises that tend to starve the basinal settings of sedimentation. Palygorskite, along with dolomite, is relatively common in the N and S Atlantic Cretaceous sediments. It is not detrital because correlative shelf deposits are devoid of palygorskite. Palygorskite is diagnostic of Mg-rich environments and is indicative of the warm and hypersaline bottom waters of the Cretaceous Atlantic ocean.

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