Implications of Color and Lightness Characteristics for Lithostratigraphy of Bottom Sediments from the Chukchi Plateau, Arctic Ocean

Abstract

Marine sediment cores from the Chukchi Plateau are used to demonstrate the efficiency of digital photographic determination of sediment color and lightness, supplemented with the statistically processed data on sediment composition, for lithostratigraphy and paleoreconstructions. Several clusters were established that correspond to brown and gray sediment layers, carbonate-rich beige interlayers and specific segments of unclear lamination and/or lens-like intercalation of brownish and grayish beds. Correlation of the studied cores with other sediment cores from the region with well-established stratigraphy revealed good correspondence (though with certain specific features) to the conventional model of the Late Pleistocene–Holocene sediment accumulation in the offshore Arctic Ocean beyond shelf areas with clearly defined glacial–interglacial cyclicity. It was shown that enhanced red-color component corresponds to the enrichment of the interglacial brown sediment layers with manganese and accompanying elements. Glacial gray layers with enhanced green-color component are enriched in iron, as well as rubidium, vanadium, titanium and yttrium and bear evidence for considerable diagenetic transformations. Blue-color component is related to the high calcium content (carbonate rock fragments) in the carbonate-rich interlayers accumulated during the periods of active disintegration of continental ice sheets and iceberg-rafting of terrigenous lithic fragments. Intermediate values of the studied parameters are likely indicative of specific sedimentation environments.