Chemical weathering and provenance evolution of Holocene–Recent sediments from the Western Indus Shelf, Northern Arabian Sea inferred from physical and mineralogical properties

Limmer, David R.; Köhler, Cornelia M; Hillier, S. J.; Moreton, Steven G.; Tabrez, Ali R.; Clift, Peter D.

doi:10.1016/j.margeo.2012.07.009

Cited by 38 publications

(40 citation statements)

References 79 publications

(129 reference statements)

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“…At greater depth and more distant from the coast, sedimentation rates were lower (46 KG and 144 KG, 44 cm kyr −1 ) ( Table 2). Sedimentation rates of ≥ ∼ 200 cm kyr −1 on the shelf (MC2, MC3) are in line with Limmer et al (2012), who determined a sedimentation rate of 195 cm kyr −1 in the core Indus-10 on the inner shelf at 71 m, to the east of the Hab area. In order to support our stratigraphic models, the AMS 14 C ages from intervals from above and further below the clay-silt layer in cores M32-MC1 and M32-MC5 show a difference of 40 14 C years over the interval of 7.3 cm in the latter core.…”

Section: Local Sedimentation Rates By Pb Dating Varve Chronology Andsupporting

confidence: 87%

Vertical and lateral flux on the continental slope off Pakistan: correlation of sediment core and trap results

Schulz

Rad

2014

Biogeosciences

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Abstract. Due to the lack of bioturbation, the varve-laminated muds from the oxygen minimum zone (OMZ) off Pakistan provide a unique opportunity to precisely determine the vertical and lateral sediment fluxes in the nearshore part of the northeastern Arabian Sea. West of Karachi (Hab area), the results of two sediment trap stations (EPT and WPT) were correlated with 16 short sediment cores on a depth transect crossing the OMZ. The top of a distinct, either reddish- or light-gray silt layer, 210Pb-dated as AD 1905 ± 10, was used as an isochronous stratigraphic marker bed to calculate sediment accumulation rates. In one core, the red and gray layer were separated by a few (5–10) thin laminae. According to our varve model, this contributes < 10 years to the dating uncertainty, assuming that the different layers are almost synchronous. We directly compared the accumulation rates with the flux rates from the sediment traps that collected the settling material within the water column above. All traps on the steep Makran continental slope show exceptionally high, pulsed winter fluxes of up to 5000 mg m−2 d−1. Based on core results, the flux at the seafloor amounts to 4000 mg m−2 d−1 and agrees remarkably well with the bulk winter flux of material, as well as with the flux of the individual bulk components of organic carbon, calcium carbonate and opal. However, due to the extreme mass of remobilized matter, the high winter flux events exceeded the capacity of the shallow traps. Based on our comparisons, we argue that high-flux events must occur regularly during winter within the upper OMZ off Pakistan to explain the high accumulations rates. These show distribution patterns that are a negative function of water depth and distance from the shelf. Some of the sediment fractions show marked shifts in accumulation rates near the lower boundary of the OMZ. For instance, the flux of benthic foraminifera is lowered but stable below ~1200–1300 m. However, flux and sedimentation in the upper eastern Makran area are dominated by the large amount of laterally advected fine-grained material and by the pulsed nature of the resuspension events at the upper margin during winter.

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Section: Local Sedimentation Rates By Pb Dating Varve Chronology Andsupporting

confidence: 87%

Vertical and lateral flux on the continental slope off Pakistan: correlation of sediment core and trap results

Schulz

Rad

2014

Biogeosciences

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“…Among iron oxides, the very high hematite content of Holocene samples strongly suggests a contribution from low‐latitude warm arid environments or from regions where dry climate conditions alternate with seasonal precipitations (Limmer et al, ; Zhang et al, ). On a worldwide scale, the hematite content in the clay‐sized fraction of soils is usually <1.5%, but it can reach 5% in some regions of the globe and rises even above this value in soils of Northern Argentina and southern Brazil (Carter‐Stiglitz et al, ; Nickovic et al, ).…”

Section: Resultsmentioning

confidence: 99%

Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Paleari

Delmonte

Andó

et al. 2019

Geophysical Research Letters

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We analyzed the single‐grain mineralogical composition of aeolian dust transported to central East Antarctica for provenance purposes. Comparison with data from the last glacial period shows for the first time disappearance of carbonates during the Holocene related to sea level rise and suppressed deflation from the Argentinean continental shelf, exposed during Marine Isotope Stage 2. Zeolites, related to alteration of volcanic glass in the subglacial/periglacial environment of Patagonia, show a similar behavior. The remaining minerals, remarkably similar between the two climatic periods, are compatible with a Pampean and Patagonian provenance, but Holocene data show a more pronounced volcanic and metamorphic imprint and presence of minerals related to warm climate weathering environments compatible with an additional contribution from subtropical latitudes of South America. These results do not imply a major large‐scale reorganization of atmospheric circulation after the last climatic transition.

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“…The continuously deposited terrigenous sediment in marginal seas has been regarded as an ideal archive for the investigation of continental weathering and paleoclimate change at various temporal and spatial scales [Colin et al, 2006;Lupker et al, 2013;Wan et al, 2015]. Therefore, many studies have attempted to characterize chemical weathering process and mobility of various elements by highlighting the geochemistry of river-borne sediments [Nesbitt and Young, 1982;Dupr e et al, 1996;Canfield, 1997;Gaillardet et al, 1999a;Vital and Stattegger, 2000;Bouchez et al, 2011Bouchez et al, , 2012Limmer et al, 2012;Garzanti et al, 2013;Lupker et al, 2013]. For the indication of chemical weathering based on sediment geochemistry, one key fundamental question is whether the geochemistry of siliciclastic sediments can represent the instantaneous state of chemical weathering rates.…”

Section: Introductionmentioning

confidence: 99%

Geochemistry of river‐borne clays entering the East China Sea indicates two contrasting types of weathering and sediment transport processes

Yang

et al. 2015

Geochem Geophys Geosyst

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The East China Sea is characterized by wide continental shelf receiving a huge input of terrigenous matter from both large rivers and mountainous rivers, which makes it an ideal natural laboratory for studying sediment source‐to‐sink transport processes. This paper presents mineralogical and geochemical data of the clays and bulk sediments from the rivers entering the East China Sea, aiming to investigate the general driving mechanism of silicate weathering and sediment transport processes in East Asian continental margin. Two types of river systems, tectonically stable continental rivers and tectonically active mountainous rivers, coexist in East Asia. As the direct weathering products, clays can better reflect the silicate weathering regimes within the two river systems. Provenance rock types are not the dominant factor causing silicate weathering intensity difference existed in the East Asian rivers. The silicate weathering intensity of tectonically stable river basins is primarily driven by monsoon climate, and the sediment transfer is relatively slow because of natural trapping process and increasing damming effect. The geochemistry of these river‐borne sediments can thus indicate paleo‐weathering intensities in East Asian continent. In contrast, silicate weathering intensity in tectonically active mountainous rivers is greatly limited by strong physical erosion despite the high temperature and highest monsoon rainfall. The factors controlling silicate weathering in tectonically active catchments are complex and thus, it should be prudent to use river sediment records to decipher paleoclimate change. These two different silicate weathering regimes and sediment transport processes are manifestations of the landscape evolution and overall dominate the sedimentation in Asian continental margin.

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Chemical weathering and provenance evolution of Holocene–Recent sediments from the Western Indus Shelf, Northern Arabian Sea inferred from physical and mineralogical properties

Cited by 38 publications

References 79 publications

Vertical and lateral flux on the continental slope off Pakistan: correlation of sediment core and trap results

Vertical and lateral flux on the continental slope off Pakistan: correlation of sediment core and trap results

Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Geochemistry of river‐borne clays entering the East China Sea indicates two contrasting types of weathering and sediment transport processes

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