Limmer,D.R., Kohler（oの頭に¨）,C.M., Hillier,S., Moreton,S.G., Tabrez,A.R. and Clift,P.D.(2012): Chemical weathering and provenance evolution of Holocene-Recent sediments from the Western Indus Shelf, Northern Arabian Sea inferred from physical and mineralogical properties. Marine Geology, 326-328, 101-115.

『物理学的および鉱物学的性質から推定された北部アラビア海の西インダス棚からの完新世堆積物の化学風化と起源の展開』

『Abstract
　We present a multi-proxy mineral record based on X-ray diffraction and diffuse reflectance spectrophotometry analysis for two cores from the western Indus Shelf in order to reconstruct changing weathering intensities, sediment transport, and provenance variations since 13 ka. Core Indus-10 is located northwest of the Indus Canyon and exhibits fluctuations in smectite/(illite + chlorite) ratios that correlate with monsoon intensity. Higher smectite/(illite + chlorite) and lower illite crystallinity, normally associated with stronger weathering, peaked during the Early-Mid Holocene, the period of maximum summer monsoon. Hematite/goethite and magnetic susceptibility do not show clear co-variation, although they both increase at Indus-10 after 10 ka, as the monsoon weakened. At Indus-23, located on a clinoform just west of the canyon, hematite/goethite increased during a period of monsoon strengthening from 10 to 8 ka, consistent with increased seasonality and/or reworking of sediment deposited prior to or during the glacial maximum. After 2 ka terrigenous sediment accumulation rates in both cores increased together with redness and hematite/goethite, which we attribute to widespread cultivation of the floodplain triggering reworking, especially after 200 years ago. Over Holocene timescales sediment composition and mineralogy in two localities on the high-energy shelf were controlled by varying degrees of reworking, as well as climatically modulated chemical weathering.

Keywords: Indus Shelf; diffuse reflectance spectrophotometry; clay mineralogy; magnetic susceptibility』

1. Introduction
2. Background
　2.1. Regional setting
　2.2. Clay mineralogy
　2.3. Diffuse reflectance spectrophotometry (DRS)
　2.4. Magnetic susceptibility
　2.5. Records of Holocene monsoon evolution in Asia
3. Methodology
　3.1. Clay mineralogy
　3.2. Diffuse reflectance spectrophotometry (DRS)
　3.3. Magnetic susceptibility
　3.4. Bulk density
　3.5. Age model
4. Results
　4.1. Clay mineralogy
　4.2. Magnetic susceptibility, DRS and bulk density
　4.3. Temporal variations in clay mineralogy
5. Discussion
　5.1. Clay mineralogy as provenance tool: comparing onshore to offshore
　5.2. Clay mineralogy as a weathering proxy
　5.3. Response to Holocene sea level rise and monsoon intensification
6. Conclusions
Acknowledgements
References

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