Geochemistry of Rewalsar Lake sediment, Lesser Himalaya, India: implications for source-area weathering, provenance and tectonic setting

Das, B. K.; Haake, Birgit-Gaye

doi:10.1007/bf02919560

Cited by 107 publications

(53 citation statements)

References 47 publications

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“…The most important processes, modulating the amino acid assemblage of source material, are aerobic microbial degradation at the water-sediment interface in the shallow oxic part of Lonar Lake, anaerobic microbial degradation within the sediments and at the water-sediment interface in the deeper sub-to anoxic part of the lake, and lysis of cells and cell compounds. Generally, the amino acid spectra indicate that Lonar sediments are less degraded than sediments in other shallow freshwater environments (Verma and Subramanian 2002;Unger et al 2005;Das et al 2010) and resemble those of suspended matter or plankton (Lee 1988;Cowie and Hedges 1992). This difference is most likely attributable to the high productivity in combination with high sedimentation rates due to slope erosion during the southwest monsoon, leading to fast burial of the OM in the sediment where anoxic conditions prevent enhanced degradation (Hulthe et al 1998;Lehmann et al 2002;Moodley et al 2005).…”

Section: Resultsmentioning

confidence: 99%

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Influence of bottom water anoxia on nitrogen isotopic ratios and amino acid contributions of recent sediments from small eutrophic Lonar Lake, central India

Menzel

Gaye

Wiesner

et al. 2013

Limnology & Oceanography

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Lonar Lake is a eutrophic, saline soda lake with permanently anoxic deep water. The high pH and deoxygenation result in very elevated d 15 N of suspended particulate matter (SPM) and sediments due to denitrification and pH-related loss of gaseous ammonium. SPM and sinking particles are predominantly aquatic in origin, whereas surface sediments are of mixed terrestrial plant and planktonic source. An indicator of degradation intensity was derived from a principal component analysis of the spectral distribution of amino acids and named Lonar degradation index (LI). A ratio of individual amino acids (Ox : Anox ratio) was additionally used to determine the relative degree of aerobic vs. anaerobic degradation. These two biogeochemical indicators can be used to detect changes in degradation intensity and redox conditions in the geological history, and thus the paleoclimatic interpretation of Lonar sediments. Surface sediments can be divided into three zones: (1) a nearshore, oxic zone of predominantly aquatic organic matter, in which oxidation leads to a strong diagenetic increase of d 15 N; (2) an alluvial zone with a predominance of isotopically depleted land plant and soil organic matter degraded under oxic conditions; and (3) an anoxic, deep zone, which receives aquatic organic matter and land plant-derived material transported near the bottom and in which organic matter is well preserved due to anoxic diagenetic conditions. Lonar Lake is a crater lake with small streams and surface runoff as major water sources and no outflow. It is saline, alkaline, eutrophic, and below , 4 m water depth permanently sub-to anoxic, which is typical for closedbasin saline lakes (Eugster and Hardie 1978). The laminated sediments in the deep, permanently anoxic part of the lake provide one of the very scarce climate records in Central India (S. Prasad unpubl.). Due to their high resolution, these sediments provide an excellent archive of recent climate change. We tested common productivity and degradation proxies that are based on nitrogen isotopic ratios and amino acid assemblages for their applicability in Lonar Lake. For the current investigation terrestrial plants and soils from the inner Lonar crater as well as suspended particulate matter (SPM) were sampled. Sediment traps were installed to sample sinking particles in seasonal resolution and to study the effect of early degradation on sinking organic matter (OM). Surface sediments were analyzed to determine the state of degradation and to understand the differences in effect of early degradation under oxic and sub-to anoxic conditions. Furthermore, the ratio of the two stable carbon isotopes was used to determine the percentage of terrestrial and aquatic OM in the surface sediments and the pathways of CO 2 uptake of different plants.The nitrogen cycle in aquatic systems is often investigated using the ratio of nitrogen isotopes 15 N : 14 N of OM. This ratio, expressed as d 15 N, can serve as an indicator of the inorganic nitrogen source of aquatic plankton, and it refl...

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Section: Resultsmentioning

confidence: 99%

“…over the last decades, and sampling details as well as further information on the lakes are available in Das et al (2008).…”

Section: Samplingmentioning

confidence: 99%

Influence of bottom water anoxia on nitrogen isotopic ratios and amino acid contributions of recent sediments from small eutrophic Lonar Lake, central India

Menzel

Gaye

Wiesner

et al. 2013

Limnology & Oceanography

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“…The cold stages are characterized by high abundances of total organic carbon (Melles et al, , 2012, LOI (Fig. 6), and a higher clay content, suggesting that Cr and Ni might be absorbed by either organic matter (e.g., Sharma et al, 2004) or clay minerals (e.g., Das and Haake, 2003;Pistolato et al, 2006). Geochemical analysis of surface sediments from the lake indicates that the main source of Cr and Ni is linked to weathering products of basalts and andesite basalts found along the southern shore of Lake El'gygytgyn (Wennrich et al, 2013a).…”

Section: Cr Nimentioning

confidence: 99%

“…Because Sr is a mobile element, it tends to disappear during chemical weathering. Thus, the resulting Rb/Sr ratio in weathered rock is greater than that of unweathered rocks (e.g., Dasch, 1969). Rb/Sr ratios have been applied to define provenances and to determine the weathering history of different types of deposits, including deep-sea, alluvial, lacustrine, loess, and paleosols (e.g., Gallet et al, 1998;Goldberg et al, 2000).…”

Section: Zr Rb Sr Bamentioning

confidence: 99%

Inorganic geochemistry data from Lake El'gygytgyn sediments: marine isotope stages 6–11

Minyuk¹,

Borkhodoev²,

Wennrich

2014

Clim. Past

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Abstract. Geochemical analyses were performed on sediments recovered by deep drilling at Lake El'gygytgyn in central Chukotka, northeastern Russia (67 • 30 N; 172 • 05 E). Major and rare element concentrations were determined using X-ray fluorescence spectroscopy (XRF) on the < 250 µm fraction from 617 samples dated to ca. 440 and 125 ka, which approximates marine isotope stages (MIS) 11 to 6. The inorganic geochemistry indicates significant variations in elemental composition between glaciations and interglaciations. Interglacial sediments are characterized by high contents of SiO 2 , Na 2 O, CaO, K 2 O, and Sr and are depleted in Al 2 O 3 , Fe 2 O 3 , TiO 2 , and MgO. An extreme SiO 2 enrichment during MIS 11.3 and 9.3 was caused by an enhanced flux of biogenic silica (BSi). The geochemical structure of MIS 11 shows similar characteristics as seen in MIS 11 records from Lake Baikal (southeastern Siberia) and Antarctic ice cores, thereby arguing for the influence of global forcings on these records. High sediment content of TiO 2 , Fe 2 O 3 , MgO, Al 2 O 3 , LOI, Ni, Cr, and Zr typifies glacial stages, with the most marked increases during MIS 7.4 and 6.6. Reducing conditions during glacial times are indicated by peaks in the Fe 2 O 3 content and coinciding low Fe 2 O 3 /MnO ratios. This conclusion also is supported by P 2 O 5 and MnO enrichment, indicating an increased abundance of authigenic, fine-grained vivianite. Elemental ratios (CIA, CIW, PIA, and Rb/Sr) indicate that glacial sediments are depleted in mobile elements, like Na, Ca, K and Sr. This depletion was caused by changes in the sedimentation regime and thus reflects environmental changes.

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“…For example, an increase in the degree of weathering is accompanied by a decrease in concentrations of CaO, K O, Na O and an enrich- tive to redox conditions. REEs, Th and Sc as well as other elements (U, Rb) are least fractionated by various sedimentary process (Taylor and McLennan, 1985;McLennan, 1989McLennan, , 1993McLennan, , 2001Johnsson, 1993;Das and Haake 2003;Weltje and von Eynatten, 2004;Jin et al, 2006;Li et al, 2017). The Huadian Basin, located in northeastern China (Fig.1a), is filled by Eocene lacustrine sediments (Meng et al, , 2012bSun et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Mineralogy and geochemistry of fine-grained clastic rocks in the Eocene Huadian Basin (NE China): Implications for sediment provenance, paleoclimate and depositional environment

Meng¹,

Sachsenhofer²,

Liu³

et al. 2018

AJES

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The Huadian Basin is a small fault-controlled basin in northeast China. It is filled by the Eocene Huadian Formation comprising thick lacustrine oil shale-and coal-bearing sediments. Oil shale, mudstone and carbonaceous shale samples have been collected to determine their mineralogical and geochemical (major, trace and rare earth elements) characteristics. These data are used to evaluate sediment provenance as well as paleoclimate and depositional environment. The fine-grained sediments in the Huadian Formation are derived from felsic volcanic rocks and granites, mixed with minor amounts of mafic and sedimentary rocks. Geochemical proxies confirm sediment recycling in the source region. Clay mineralogy and indices of chemical alteration suggest that a subtropical warm and humid climate prevailed during deposition of the fine-grained sediments. The data also suggest climatic changes during deposition of the Huadian Formation, from a stable warm and humid climate causing intermediate chemical weathering (Pyrite Member), to a seasonal dry-wet climate (Oil Shale Member), to a stable warmer and more humid climate causing strong chemical weathering (Carbonaceous Shale Member). Based on inorganic proxies, the fine-grained sediments in the Huadian Formation have been deposited in an anoxic fresh-water environment. Only the sediments of the Oil Shale Member reflect fluctuating freshwater and brackish conditions. The Eocene climatic change controlled lake level variations and water chemistry. A brackish and strictly anoxic environment together with a warm and humid climate was beneficial for the formation of high quality oil shale, whereas fresh-water conditions and warm and more humid climate favored peat accumulation.______________

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Geochemistry of Rewalsar Lake sediment, Lesser Himalaya, India: implications for source-area weathering, provenance and tectonic setting

Cited by 107 publications

References 47 publications

Influence of bottom water anoxia on nitrogen isotopic ratios and amino acid contributions of recent sediments from small eutrophic Lonar Lake, central India

Influence of bottom water anoxia on nitrogen isotopic ratios and amino acid contributions of recent sediments from small eutrophic Lonar Lake, central India

Inorganic geochemistry data from Lake El'gygytgyn sediments: marine isotope stages 6–11

Mineralogy and geochemistry of fine-grained clastic rocks in the Eocene Huadian Basin (NE China): Implications for sediment provenance, paleoclimate and depositional environment

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