Contributors: Müller, Peter J, Cepek, Martin, Ruhland, Götz, Schneider, Ralph R

Date: 1997-10-19

Late Quaternary: Reconstruction of Budget and Currents...late Quaternary periods when this species was scarce or absent because...Late Quaternary: Reconstruction of Budget and Currents...late Quaternary coccolith datum levels: Validation by oxygen isotopes....late Quaternary sediment core from the Walvis Ridge and compared the results...Quaternary sediments may be subject to bias if algae with different temperature...late Quaternary sediments from the Walvis Ridge: Implications for the ...late Quaternary sediments from the Walvis Ridge: Implications for the ...late Quaternary sediment core from the Walvis Ridge and compared the results...late Quaternary coccolith datum levels: Validation by oxygen isotopes....core record while the coccolithophorid study was confined to the last ...late Quaternary sediments from the Walvis Ridge...late Quaternary periods when this species was scarce or absent because ... Abstract: Sea surface temperatures (SSTs) derived from the alkenone UK'37) record of Quaternary sediments may be subject to bias if algae with different temperature sensitivities have contributed to the sedimentary alkenone record. The alkenone-derived SST records are usually based on a UK'37-temperature relationship which was measured in culture experiments using the coccolithophorid Emiliania huxleyi (F.G. Prahl, L.A. Muehlhausen and D.L. Zahnle, 1988. Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions. Geochim. Cosmochim. Acta 52, 2303-2310). To assess possible effects of past species changes on the UK'37-temperature signal, we have analyzed long-chain alkenones and coccolithophorids in a late Quaternary sediment core from the Walvis Ridge and compared the results to SST estimates extracted from the d18O record of the planktonic foraminifer Globigerinoides ruber. Alkenones and isotopes were determined over the entire 400-kyr core record while the coccolithophorid study was confined to the last 200 kyr when the most pronounced changes in alkenone content occurred. Throughout oxygen-isotope stages 6 and 5, species of the genus Gephyrocapsa were the predominating coccolithophorids. E. huxleyi began to increase systematically in relative abundance since the stage 5/4 transition, became dominant over Gephyrocapsa spp. during stage 3 and reached the highest abundances in the Holocene. Carbon-normalized alkenone concentrations are inversely related to the relative abundances of E. huxleyi, and directly related to that of Gephyrocapsa spp., suggesting that species of this genus were the principal alkenone contributors to the sediments. Nevertheless, SST values obtained from the UK'37-temperature relationship for E. huxleyi compare favourably to the isotope-derived temperatures. The recently reported UK'37-temperature relationship for a single strain of Gephyrocapsa oceanica (J.K. Volkman. S.M. Barrett, S.I. Blackburn and E.L. Sikes, 1995. Alkenones in Gephyrocapsa oceanica: Implications for studies of paleoclimate. Geochim. Cosmochim. Acta 59, 513-520) produces unrealistically high SST values indicating that the temperature response of the examined strain is not typical for the genus Gephyrocapsa. This is supported by the C37:C38, alkenone ratios of the sediments which are comparable to average ratios reported for E. huxleyi, but significantly higher than for the G. oceanica strain. Most notably, the general accordance of the alkenone characteristics between sediments and E. huxleyi persists through stages 8 to 5 and even in times that predate the first appearance of this species (268 ka; H.R. Thierstein, K.R. Geitzenauer and B. Molfino, 1977. Global synchroneity of late Quaternary coccolith datum levels: Validation by oxygen isotopes. Geology 5, 400-404). Our results suggest that UK'37-temperature relationships based on E. huxleyi produce reasonable paleo-SST estimates even for late Quaternary periods when this species was scarce or absent because other alkenone-synthesizing algae, e.g. of the genus Gephyrocapsa. Category: geoscientificInformation Source: Supplement to: Müller, Peter J; Cepek, Martin; Ruhland, Götz; Schneider, Ralph R (1997): Alkenone and coccolithophorid species changes in late Quaternary sediments from the Walvis Ridge: Implications for the alkenone paleotemperature method. Palaeogeography, Palaeoclimatology, Palaeoecology, 135(1-4), 71-96, https://doi.org/10.1016/S0031-0182(97)00018-7 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: -20.104000 * LONGITUDE: 9.185833 * DATE/TIME: 1988-03-02T00:00:00 * ELEVATION: -2209.0 m * Penetration: 12 m * Recovery: 10.79 m * LOCATION: Walvis Ridge, Southeast Atlantic Ocean * CAMPAIGN: M6/6 * BASIS: Meteor (1986) * DEVICE: Gravity corer (Kiel type)

Contributors: Ajit Singh, Debajyoti Paul, Rajiv Sinha, Kristina J. Thomsen, Sanjeev Gupta

Date: 2016-05-01

sediments (~75ka–recent). Major oxide compositions of the core sediments...core sediments. Also shown for comparison are modern sediments from Sutlej...core sediments. Also shown for comparison are modern-river sediments from...Late Quaternary. Aeolian sediments (~150ka) in both the cores are overlain...fraction of GS core sediments. ...in a deep sea sediment core from Arabian sea (Rostek et al., 1993); 6 ...Late Quaternary. Aeolian sediments (~150ka) in both the cores are overlain...core sediments during glacial periods can be explained by increasing sediment...Late Quaternary...core sediments. ...core sediments. Also shown for comparison are modern-river sediments (...drill-sediment cores from a buried channel in the Ghaggar Plains of NW...sediments...sediment contribution from HH. The down-core Sr–Nd isotopic variability...-11 core sediments. Also shown for comparison are modern-river sediments...foraminifera in sediment core from Indian Ocean (Duplessy, 1982); 2 — ... record in a sediment core from Arabian Sea (Van Campo et al., 1982); ...core sediments (n=18) suggest binary mixing of sediments from compositionally...sediments from Ghaggar Plains, NW India: Multi-proxy records of variations...core sediments; (c and d) δ18O and δ13C of carbonate nodules from GS cores ... We report the first geochemical record in two drill-sediment cores from a buried channel in the Ghaggar Plains of NW India, which are used to infer variations in provenance, paleoclimate, and paleovegetation in the locality during the Late Quaternary. Aeolian sediments (~150ka) in both the cores are overlain by fluvial sediments (~75ka–recent). Major oxide compositions of the core sediments (n=35) generally vary between that observed for the modern-day Ghaggar/Sutlej and Yamuna river sand. The isotopic composition (87Sr/86Sr: 0.7365 to 0.7783 and εNd: −14.6 to −19.0) of core sediments (n=18) suggest binary mixing of sediments from compositionally distinct Higher Himalaya (HH) and Lesser Himalaya (LH) endmembers in the catchment, and support involvement of a river system originating in the Himalayan hinterland. Distinctly higher 87Sr/86Sr and lower εNd in the core sediments during glacial periods can be explained by increasing sediment contribution from LH (high 87Sr/86Sr and low εNd) due to an increase in glacial cover over HH. Whereas relatively less glacial cover over HH during interglacial periods resulted in more erosion and sediment contribution from HH. The down-core Sr–Nd isotopic variability clearly reflects climate-controlled sediment erosion in the Himalayan catchment. Temporal variations in δ18O and δ13C of carbonate nodules (n=27) are consistent with that reported from the Ganga interfluves. The δ13C variability (−4.1‰ to 1.2‰) in carbonates is mainly controlled by the extent of silicate (HH) versus carbonate (LH) source weathering due to significant climatic shifts. The δ13C of sediment organic matter (−27.4‰ to −23.2‰, n=24) suggests dominantly C3 plants in the catchment during the last ~75ka. More negative δ13C values in sediments during glacial periods relative to those during interglacial periods can be explained by increasing C4 abundance during interglacial periods characterized with both higher summer rainfall and mean annual temperature.

Contributors: Lamy, Frank, Klump, Jens, Hebbeln, Dierk, Wefer, Gerold

Date: 2000-08-16

cores and from North Atlantic sediments. Besides showing dominantly precession-driven...sediments, reveal a high-frequency variability of the position of the ...Late Quaternary rapid climate change in northern Chile. Terra Nova, 12...sediments from the Chilean continental slope off the southern border of...Late Quaternary rapid climate change in northern Chile. Terra Nova, 12...Late Quaternary geochemical record of sediment core GeoB3375-1 ... Abstract: Analyses of terrigenous sediments from the Chilean continental slope off the southern border of the Atacama desert (27.5°S), focusing on illite crystallinity and the Fe:Al ratio of the sediments, reveal a high-frequency variability of the position of the Southern Westerlies, which is very similar to the coeval short-term climatic events known from Greenland ice cores and from North Atlantic sediments. Besides showing dominantly precession-driven variability in precipitation over the Andes, these analyses also reveal rapid changes in weathering intensity along the Chilean Coastal Range during the last 80,000 years. These rapid changes occur at much shorter timescales than the 19-100 kyr orbital forcing of the Milankovitch cycles. Category: geoscientificInformation Source: Supplement to: Lamy, Frank; Klump, Jens; Hebbeln, Dierk; Wefer, Gerold (2000): Late Quaternary rapid climate change in northern Chile. Terra Nova, 12, 8-13, https://doi.org/10.1046/j.1365-3121.2000.00265.x Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: -27.466667 * LONGITUDE: -71.251667 * DATE/TIME: 1995-06-07T00:00:00 * ELEVATION: -1947.0 m * Recovery: 4.89 m * LOCATION: South-East Pacific * CAMPAIGN: SO102/2 * BASIS: Sonne * DEVICE: Gravity corer (Kiel type)

Contributors: N. Fagel, L.Y. Alleman, L. Granina, F. Hatert, E. Thamo-Bozso, R. Cloots, L. André

Date: 2005-01-01

sediment cores. Analyses by ICP-AES (Mn content, data from Table 3a) or...Sediment...sediments from cores CON01-604 (Posolsky Bank), CON01-603 (Continent Ridge...Late Quaternary... investigated sediment cores (plotted from South to North). Modified from...diatom-samples in any of the core sediment samples. ...Late Quaternary...sediment core: the concretions are concentrated at specific depths along...sediments. While reflecting an early diagenetic signal, the source of ...sediment cores spanning two to four interglacial stages in the northern...sedimentation rates (e.g., Academician and Continent ridges). At the site...sedimentation rates, and porewater chemistry. We conclude that vivianite...geochemical signature of sediments from cores CON01-604 (Posolsky Bank...sediment cores (plotted from South to North). Modified from Hauregard,...sediments...core sediment samples. ...sedimentation rates, and it is not a proxy for lacustrine paleoproductivity...concretions in sediment core: the concretions are concentrated at specific... sediment cores. Analyses by ICP-AES (Mn content, data from Table 3a) ... In an effort to better understand vivianite formation processes, four Lake Baikal sediment cores spanning two to four interglacial stages in the northern, central and southern basins and under various biogeochemical environments are scrutinized. The vivianite-rich layers were detected by anomalous P-enrichments in bulk geochemistry and visually by observations on X-radiographs. The millimetric concretions of vivianite were isolated by sieving and analysed by X-ray diffraction, scanning electron microscope (SEM), microprobe, infrared spectroscopy, inductively coupled plasma atomic emission spectrometry and mass spectrometry (ICP-AES, ICP-MS). All the vivianites display similar morphological, mineralogical and geochemical signature, suggesting a common diagenetic origin. Their geochemical signature is sensitive to secondary alteration where vivianite concretions are gradually transformed from the rim to the center into an amorphous santabarbaraite phase with a decreasing Mn content. We analysed the spatial and temporal distribution of the concretions in order to determine the primary parameters controlling the vivianite formation, e.g., lithology, sedimentation rates, and porewater chemistry. We conclude that vivianite formation in Lake Baikal is mainly controlled by porewater chemistry and sedimentation rates, and it is not a proxy for lacustrine paleoproductivity. Vivianite accumulation is not restricted to areas of slow sedimentation rates (e.g., Academician and Continent ridges). At the site of relatively fast sedimentation rate, i.e., the Posolsky Bank near the Selenga Delta, vivianite production may be more or less related to the Selenga River inputs. It could be also indirectly related to the past intensive methane escapes from the sediments. While reflecting an early diagenetic signal, the source of P and Fe porewater for vivianites genesis is still unclear.

Contributors: Ehrmann, Werner, Seidel, Martin, Schmiedl, Gerhard

Date: 2013-04-27

sediments in the source areas. Category: geoscientificInformation Source...sediment core GeoTü SL143...late Quaternary sediment core from the central Aegean Sea. The record ...Late Quaternary North African humid periods documented in the clay mineral...Late Quaternary North African humid periods documented in the clay mineral...sediments. Global and Planetary Change, 107, 186-195, https://doi.org/...late Quaternary sediment core from the central Aegean Sea. The record ... Abstract: The ratio between the clay minerals kaolinite and chlorite has been investigated in high resolution in a late Quaternary sediment core from the central Aegean Sea. The record spans the last ca. 105 ka. The kaolinite/chlorite ratio was used to reconstruct the fine-grained aeolian dust influx from the North African deserts, mainly derived from desiccated lake depressions. It therewith can be used as a proxy for wind activity, aridity and vegetation cover in the source area. The data document three major humid phases in North Africa bracketing the formation of sapropel layers S4, S3 and S1. They occur at >105-95 ka, 83.5-72 ka and 14-2 ka. The first two phases are characterised by relatively abrupt lower and upper boundaries suggesting a non-linear response of vegetation to precipitation, with critical hydrological thresholds. In contrast, the onset and termination of the last humid period were more gradual. Highest kaolinite/chlorite ratios indicating strongest aeolian transport and aridity occur during Marine Isotope Stage (MIS) 5b, at ca. 95-84 ka. The long-term decrease in kaolinite/chlorite ratios during the last glacial period indicates a gradual decline of deflatable lake sediments in the source areas. Category: geoscientificInformation Source: Supplement to: Ehrmann, Werner; Seidel, Martin; Schmiedl, Gerhard (2013): Dynamics of Late Quaternary North African humid periods documented in the clay mineral record of central Aegean Sea sediments. Global and Planetary Change, 107, 186-195, https://doi.org/10.1016/j.gloplacha.2013.05.010 Supplemental Information: Not Availble Coverage: EVENT LABEL: (GeoTü SL143) * LATITUDE: 38.261830 * LONGITUDE: 25.103170 * ELEVATION: -665.0 m * LOCATION: Aegean Sea * DEVICE: Gravity corer (Kiel type)

Contributors: Patrick De Deckker

Date: 2001-06-01

core and thus helps justify that the bottom portion of the core cannot...core spanning the last 40,000 calibrated years of sedimentation identifies...sedimentation rates adjusted accordingly between dated horizons. Peak ...Late Quaternary cyclic aridity in tropical Australia...core GC-2 used for radiocarbon dating ...sedimentation rate in the core and thus helps justify that the bottom ...Late Quaternary...core spanning the last 40,000 calibrated years of sedimentation identifies...Core GC2 against time in calibrated years BP. The seven aeolian peaks ...Late Quaternary...log of core GC 2. ...core (see Table 2) are represented by vertical bars in the middle diagram...from core GC-2 used for radiocarbon dating ...Quaternary sea level fluctuations, the vast Gulf of Carpentaria, in northern...core GC 2. ... During the numerous Quaternary sea level fluctuations, the vast Gulf of Carpentaria, in northern Australia, was more often a large lacustrine basin than a shallow sea. Recovery of aeolian quartz particles in a core spanning the last 40,000 calibrated years of sedimentation identifies a ~2,600year cyclic pattern of aridity. The most pronounced period peaks around 21,500 calibrated years BP, corresponding to the onstart of the period of lowest global sea level and glacial advance in New Zealand. The following peak of aeolian dust activity in Carpentaria just precedes the termination of the low sea level stand at 19,300 calibrated years BP.

Contributors: Zhongyuan Chen, Baoping Song, Zhanghua Wang, Yongli Cai

Date: 2000-01-15

sediment cores, vibrocores, surficial samples and seismic track line. ...sediment distribution. Belt A, delta front fine sand and silt, with trough...the core Cj4. Zone c, the warmest temperature period starting at ca. 7000...sediment sequences reveal a general trend of climate warming from early...late Pleistocene sediments in front of the estuarine depocenter. Gravity...core Cj4. Indicated 14C dates are based from Chen and Wang (1994). ...showing the location of sediment cores, vibrocores, surficial samples ...late Quaternary stratigraphy...Late Quaternary evolution of the sub-aqueous Yangtze Delta, China: sedimentation...sediment belts (A–D) of the Yangtze sub-aqueous delta are defined from...text. ...Sediment distribution of the sub-aqueous Yangtze Delta. Four sediment ...late Quaternary sub-aqueous Yangtze Delta. N, number; S, species; R, rare...S...late Pleistocene period (Ren and Zhen, 1980). ...late Quaternary stratigraphy of the delta consists from bottom upward ...late Quaternary stratigraphy...sediment loading within the depocenter is the major factor in causing ...sediment distribution...lithostratigraphic log of the late Quaternary sub-aqueous Yangtze Delta ... Four sediment belts (A–D) of the Yangtze sub-aqueous delta are defined from the sea-bottom sediment distribution. Belt A, delta front fine sand and silt, with trough cross stratification; Belt B, prodelta silty clay and clayey silt, with abundant burrowing and rich in organic matter; Belt C, prodelta to continental shelf sand–silt–clay, with thin layers of sand and clay interbedded; and Belt D, late Pleistocene relict sands (medium to fine grained), mixed with shell fragments. The late Quaternary stratigraphy of the delta consists from bottom upward of: late Pleistocene terrigenous (fluvial and lacustrine) sand and mud; Holocene transgressive silt, prodelta clay and delta front fine sand and silt. In addition, four pollen-spore zones (a–d) derived from these sediment sequences reveal a general trend of climate warming from early to late Holocene. The Zone c, distributed primarily within the prodelta muds, provides evidence for a temperature maximum starting at ca. 7000 years B.P. (Atlantic period). This indicates that the delta initiation was essentially coeval with the climate optimum in early Holocene. Sub-bottom seismic surveys reveal three (I–III) acoustic facies. Facies I and II are characterized by seaward remobilization of water-saturated Holocene prodelta muds; facies III is composed of highly-contorted late Pleistocene strata and mud diapirs that erupted from deep-seated late Pleistocene sediments in front of the estuarine depocenter. Gravity subsidence due to Holocene sediment loading within the depocenter is the major factor in causing the deformation of underlying unconsolidated strata. Furthermore, the sub-aqueous Yangtze Delta proper is now obviously diverting to southeast owing to the long-term, tectonically induced southward shift of the river mouth, and to the marine currents associated with the Coriolis effect. We thus predict that the large Chongming island in river mouth area will have been coalesced with the northern Yangtze coast in the recent future.

Contributors: A Kuijpers, S.R Troelstra, M.A Prins, K Linthout, A Akhmetzhanov, S Bouryak, M.F Bachmann, S Lassen, S Rasmussen, J.B Jensen

Date: 2003-03-30

core is not represented. The core location, where water depth is 620 m...sediment Fe/K ratio. Results of 14C measurements are also shown. Note ...core DS97-7P with whole-core MS, calcium carbonate content, relative abundance...core DS97-4P with grain size (>63 μm) distribution, whole-core MS, XRF...the sediment waves, indicates contour-parallel bottom currents (shown ...sediment transport and mass flow deposition, which is concluded to be ... log of core DS97-7P with whole-core MS, calcium carbonate content, relative...Late Quaternary sedimentary processes and ocean circulation changes at...Pliocene–Quaternary sedimentary sequence. ...late Quaternary depositional processes and bottom current activity on ...late Quaternary depositional processes and bottom current activity on ...sedimentation...core of south flowing LSW between 800 and 1500 m (after Dickson and Brown...sediment core information. The seabed data demonstrate the occurrence ... A study has been made of late Quaternary depositional processes and bottom current activity on the Southeast Greenland margin, using seismic, sub-bottom profiling and deep-tow side-scan sonar data as well as sediment core information. The seabed data demonstrate the occurrence of strong, southerly bottom currents prevailing on the slope and rise. Well-defined longitudinal bedforms indicate maximum mean near-bottom current velocities of up to at least 1.0 m/s at the depth stratum of Labrador Sea water (800–1500 m). Similarly strong currents occur in Denmark Strait overflow water (DSOW) at the base of the slope, whereas more basinward the maximum DSOW flow speed is lower. Iceberg plow marks were found down to about 700 m water depth. Both at the shelf edge and on the lower slope and rise the seafloor morphology is indicative of downslope sediment transport and mass flow deposition, which is concluded to be a typically glacial feature. After generally more sluggish deep-water circulation during the last glacial maximum, DSOW basin ventilation was re-established shortly before 13.3 ka. On the shelf, in front of the retreating Greenland ice margin, permanent or semi-permanent sea ice conditions prevailed until about 12.5 ka. At that time increased Irminger Current activity had resulted in warming, and East Greenland Current (EGC)-controlled iceberg drift increased. No evidence was found for a return to extreme glacial conditions or a ceasing of DSOW flow during the Younger Dryas. Abundant coarse IRD collected at greater water depth from shallow sub-seabed strata has a provenance mainly in the northern part of East Greenland (68–73°N), which demonstrates the existence of a pre-Holocene EGC system initially extending to beyond the shelf edge.

Contributors: Papay Suparan, Rien A.C Dam, Sander van der Kaars, Theo E Wong

Date: 2001-07-15

palynological analysis of core D6 sediments (hscharacteristic lowland ...Late Quaternary environmental change studies. First, the geologic, morphologic...Mid-Late Holocene, a low-energy fluvial systems and swamps existed in ...Late Pleistocene and Holocene landform development, sedimentation and ...core sediments. All taxa are shown as a percentage of the total pollen...sediment starved floodbasins. (C) The marine erosion cliff in the coastal...Late Quaternary environmental change studies. First, the geologic, morphologic...Late Quaternary...core D6 sediments (hscharacteristic lowland rain-forest tree taxa on Halmaherah...Late Quaternary...sediments (core D6). Core samples were subsampled for texture, organic...sedimentation in humid tropical lowland environments on Halmahera island...Late Pleistocene or Holocene environmental conditions is difficult to ...Late Quaternary tropical lowland environments on Halmahera, Indonesia...confidence) ranges. The sequence of core D6 is discussed in the text. ...Kao River plain sediments (core D6). Core samples were subsampled for ...core D6 is discussed in the text. The locations of cores D6 and D7 are...flooded, sediment starved floodbasins. (C) The marine erosion cliff in...palynological analysis of D6 core sediments. All taxa are shown as a percentage...Late Pleistocene and Holocene landform development, sedimentation and ...sediments and the existence of natural grasslands in the coastal zone. ... Results of a case study of landform development and sedimentation in humid tropical lowland environments on Halmahera island, eastern Indonesia, are presented with the aim to better characterise tropical lowland environments in the context of Late Quaternary environmental change studies. First, the geologic, morphologic and environmental settings of the two areas, the interior Kao River plain and the Kao coastal zone (N. Halmahera), are presented. Subsequently, data concerning Late Pleistocene and Holocene landform development, sedimentation and coastal processes are discussed. Pleistocene landform development involved volcaniclastic sedimentation, base levelling of coastal lowlands, prolonged weathering and crust formation, coastal uplift and eustatic sea level change. A conspicuous ferricrete crust in the subsoil of the coastal plain is tentatively dated with 14C AMS analysis and isotopes of organic matter encapsulated in the soil ferricrete have been determined. Due to interacting sea level change, neotectonic uplift, climatic, hydrologic and vegetational change, unequivocal evidence for anomalous Late Pleistocene or Holocene environmental conditions is difficult to obtain. During the Mid-Late Holocene, a low-energy fluvial systems and swamps existed in the interior Kao River plain; a dense open swamp/swamp forest vegetation contributed to extremely high sedimentation rates in this depositional basin. Palynological analysis of the organic swamp deposits indicates little or no change in sedimentary environmental settings and swamp vegetations, and indications for early human presence in the area. In the coastal area accretion and delta progradation occurred after the Early-Mid Holocene formation of a marine erosion cliff. Tentative evidence for early human presence in the Kao area is derived from charcoal particle frequencies in sediments and the existence of natural grasslands in the coastal zone. As most of the geologic and environmental characteristics of the tropical lowlands in the Kao area are common in eastern Indonesia, the study provides useful information for ongoing research in the region.

Contributors: A. Anil Kumar, V. Purnachandra Rao, S.K. Patil, Pratima M. Kessarkar, M. Thamban

Date: 2005-10-15

...sediment-dominated sections of the cores off Saurashtra–Ratnagiri, followed...cores on the western margin of India. Geology after Rao and Wagle (1997...late Quaternary...late Quaternary...Do...1997). ...sediments of the eastern Arabian Sea: Evidence for late Quaternary climatic...sediments in GC1. (B) Down-core variations of sedimentological parameters...sediment sections of the cores ...Down-core variations of MS in GC11. ...Down-core variations of MS in core GC14 and GC15. ...sediments were determined for 15 gravity cores recovered from the western...sediments off Indus–Gulf of Kachchh and then Mangalore–Cape Comorin....GC13. ...the sediments in GC1. (B) Down-core variations of sedimentological parameters...sediments...sediments reflect the land-derived input and, in general, are the highest...Down-core variations of MS in GC11. ... Rock-magnetic measurements along with grain size, acid-insoluble residue (AIR), organic carbon (OC), CaCO3 and δ18O of the planktonic foraminifers of the sediments were determined for 15 gravity cores recovered from the western continental margin of India. Magnetic susceptibility (MS) values in the surficial sediments reflect the land-derived input and, in general, are the highest in terrigenous sediment-dominated sections of the cores off Saurashtra–Ratnagiri, followed by the sediments off Indus–Gulf of Kachchh and then Mangalore–Cape Comorin.