cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.1594/gfz.sddb.1016
title: Relative paleointensity record for CON01-603-2

description: We established a mastercurve “Baikal 200” of relative paleointensity, which represents a new synthetic paleomagnetic archive for Central Eurasia. The synthetic record is composed of mean values of the six records with respect to a sliding time window of 2 ka. This compilation has been restricted to the last 200 ka in order to maintain a representative population of points (between 2 and 68). However, we present this synthetic record together with individual records and the reference paleointensity curve (Fig. 11) for the following reasons:

– Each relative paleointensity record has a different resolution (e.g., sedimentation rates in CON 01-605-3 are five times higher than in VER 98-1-14). During stack procedure, smoothing of the data had the effect of lowering the resolution of the paleomagnetic information.

– This stack does not provide more information on timing of the geodynamo changes since the records are tuned to ODP Site 984.
DOI: 10.1594/gfz.sddb.1017
title: Paleointensity versus age of all the sedimentary sequences of the present study

description: Paleointensity versus age of all the sedimentary sequences of the present study, of the synthetic curve resulting from its compilation from other curves, and of the reference curve from ODP Site 984 (Channell, 1999). For the compilation, data have been averaged using a sliding window of 2 ka (the variance is marked by the grey shadow). Dashed lines show some of the correlations. The grey lines show the location of the low paleointensities related to geomagnetic excursions. Note that the lowest paleointensities in the time span of Blake are at c. 129 ka. (see Fig.11)
DOI: 10.1594/gfz.sddb.1018
title: Downcore variations of the ARM for  VER 98-1-14

description: Anhysteretic remanent magnetisation (ARM) measurements, free of the effect of the dia-, para- and superparamagnetic components, provide an estimation of the magnetic remanence carriers, mainly of single-domain (SD) grain size. The clay-rich layers are characterised by a high, the daitomaceous layers by a low ARM level.
DOI: 10.1594/gfz.sddb.1019
title: Downcore variations of the TOC and TS for VER 98-1-14

description: Total organic carbon (TOC) and total sulphur (TS) were determined using a LECO CS-225-Analyser. The clay-rich layers are characterised by low levels of TOC and TS. The diatomaceous layers, indicating high-biogenic productivity, show high levels of TOC and TS.
DOI: 10.1594/gfz.sddb.1020
title: Downcore variations of the opal content for the sedimentary sequence of VER98-1-14

description: Opal content was obtained by measuring the NaCO3 leached solution by inductive coupled plasma with an optical emission spectrometer (ICP-OES). The clay-rich layers are characterised by a low level of opal content. The diatomaceous layers are characterised by a high level of opal content.
DOI: 10.1594/gfz.sddb.1021
title: Downcore variations of the water content for the sedimentary sequence of VER 98-1-14

description: The water content was determined from samples retrieved with cylindrical syringe samplers, weighed wet and weighed again after freeze-drying. The clay-rich layers are characterised by a low, the diatomaceous layers are characterised by a high level of water.
DOI: 10.1594/gfz.sddb.1022
title: Downcore variations of the water content for the sedimentary sequence of VER 98-1-14 (pilot)

description: The water content was determined from samples retrieved with cylindrical syringe samplers, weighed wet and weighed again after freeze-drying. The clay-rich layers are characterised by a low, the diatomaceous layers are characterised by a high level of water.
DOI: 10.1594/gfz.sddb.1023
title: Downcore variations of rock magnetic parameters for the sedimentary sequence of VER98-1-14

description: Downcore variations of rock magnetic parameters and simplified lithological description for the sedimentary sequence VER 98-1-14. Here, MIS are denoted by numbers in the lithological column. The black squares filled intervals mark occurrences of greigite characterised by a high magnetic susceptibility (κLF) in parts, with a low coercive mineral dominating the magnetic signal (S-ratio close to 1), a high SIRM/κLF, a strong loss of ARM intensity between the demagnetisations steps 50 and 65 mT and finally a deviation of the inclination of ARM. The dark grey intervals mark occurrences of magnetite dissolution, with a low S-ratio resulting from relative higher hematite content in the ferromagnetic components. The assignment of greigite and dissolved magnetite is based on subsequent interpretation. Magnetic susceptibility (κLF) vs. S-ratio for the sedimentary sequence VER 98-1-14 showing S-ratio gathered around 0.95 in glacial sediments and scattered from 0.7 to 1 in interglac
DOI: 10.1594/gfz.sddb.1024
title: High temperature measurements of magnetic susceptibility in clay-rich layers

description: High temperature measurements of magnetic susceptibility in clay-rich layers. Magnetite, characterised by a Curie temperature of 590 °C, dominates the signal.
DOI: 10.1594/gfz.sddb.1025
title: High temperature measurements of magnetic susceptibility in clay-rich layers for VER98-1-14

description: High temperature measurements of magnetic susceptibility in clay-rich layers. Magnetite, characterised by a Curie temperature of 590 °C, dominates the signal.
DOI: 10.1594/gfz.sddb.1026
title: High temperature measurements of magnetic susceptibility in diatomaceous layers for VER98-1-1

description: High temperature measurements of magnetic susceptibility in diatomaceous layers. Most of the weak susceptibility is still present up to the temperature of 670 °C and carried by hematite.
DOI: 10.1594/gfz.sddb.1027
title: High temperature measurement of the saturation magnetisation for VER98-1-14

description: It shows a loss of a part of the signal at temperatures between 350 and 400 °C, typical disintegration temperatures for greigite. The remaining signal disappears above a temperature of 590 °C, typical for magnetite.
DOI: 10.1594/gfz.sddb.1029
title: Hysteresis measurements (uncorrected and corrected for the paramagnetic influence) for VER98-1-1 at core depth of 240.3cm.

description: Hysteresis measurements of a greigite dominated clay -rich layer with single-domain behaviour hysteresis loop for VER98-1-1.
DOI: 10.1594/gfz.sddb.1030
title: Hysteresis measurements (uncorrected and corrected for the paramagnetic influence) for VER98-1-1 at core depth of 520.7cm.

description: Hysteresis measurements of a magnetite dominated clay-rich layer with pseudosingle-domain behaviour     of the hysteresis loop for VER98-1-1.
DOI: 10.1594/gfz.sddb.1031
title: Hysteresis measurements (uncorrected and corrected for the paramagnetic influence) for VER98-1-1 at core depth of 580.6cm.

description: Hysteresis measurements of a hematite dominated diatomaceous layer with pseudosingle to multidomain behaviour of the hysteresis loop for VER98-1-1.
DOI: 10.1594/gfz.sddb.1032
title: Day plot data of hysteresis parameters of representative samples for VER98-1-14, VER98-1-1 and VER98-1-3

description: The day plot (Fig. 6B; Day et al., 1977) indicates that samples with S-ratios &gt;0.95 plot rather in the single-domain (SD) to pseudosingle-domain (PSD) range. Samples with S-ratios between 0.9 and 0.95 instead, plot rather in the PSD to the multidomain (MD) range. Low S-ratio samples are not greatly dispersed and have ratios of Bcr/Bc and Mrs/Ms of 3.5 and 0.1, respectively.
DOI: 10.1594/gfz.sddb.1033
title: Downcore variations of rock magnetic parameters (ARM, S-ratio and HIRM) for CON01-603-2 and VER98-1-14

description: No significant HIRM change is observed at the transition between oxidising and reducing conditions in the sediment (Fig. 9A). This implies that HIRM is not affected by redox conditions and further confirms that the “hard” magnetic mineral content is the best tracer of detrital input (Peck et al., 1994). On the other hand, the S-ratio seems to be related to the redox conditions in the sediment (see Section 7.2). The ARM has also to be considered with caution as it is mainly influenced by the ferrimagnetic contribution, which is itself influenced by post depositional processes. This is seen in Fig. 9 where ARM variations are partly influenced by S-ratio variations.
DOI: 10.1594/gfz.sddb.1034
title: XRF titanium, iron counting and ratio Fe/Ti for CON01-603-2 and VER98-1-14

description: In selected intervals, we measured titanium and iron contents in parallel to rock magnetic parameters (Fig. 9). Titanium content is a good reflection of detrital input since minerals containing titanium are not very sensitive to dissolution. Iron, however, is rather mobile and involved in the redox history of highly porous sediments: the spike of iron observed on top of the sedimentary column (Fig. 9A) marks the redox front. We observed a strong similarity between the titanium and HIRM curves: the detrital input decreases from the late glacial to the Holocene. In ancient sediments, HIRM and titanium display similar variations with high values in glacials and low values in interglacials (Fig. 9B).
DOI: 10.1594/gfz.sddb.1035
title: Downcore variations of the S-ratio for CON01-603-2, CON01-604-2, CON01-605-3, VER98-1-1, VER98-1-14

description: In interglacial sediments, the magnetic assemblages depict changes in the sedimentation rate, which are traced using the ratio of magnetite over hematite (S-ratio). At the beginning of interglacials, the sedimentation rate is constant with an assemblage magnetite+greigite (high S-ratio), and at the end of some interglacials, the sedimentation rate decreases with a predominance of hematite (low S-ratio).
DOI: 10.1594/gfz.sddb.1036
title: Downcore variations of relative sulphur content, estimated by XRF counting,  for CON01-603-2

description: Increased presence of greigite (high SIRM/κLF) coincides with maximum sulphur contents observed at the beginning of interglacial stages (Fig. 11A). At similar levels in another sediment core of Lake Baikal, Watanabe et al. (2004) observed pyrite mineralization. They attributed these pyrite-rich levels to mineralization at sediment/water interface under anoxic bottom water conditions. However, we prefer to interpret the greigite as a result of magnetite transformation when sulphate reduction occurs in the interglacial sediments. Peak sulphur contents would therefore be due to sulphur mineralization within the sediment and would not result from an enrichment of the sediment in sulphur at the sediment/water interface.
DOI: 10.1594/gfz.sddb.1038
title: Downcore variations of SIRM/κLF for CON01-603-2

description: Increased presence of greigite (high SIRM/κLF) coincides with maximum sulphur contents observed at the beginning of interglacial stages (Fig. 11A). At similar levels in another sediment core of Lake Baikal, Watanabe et al. (2004) observed pyrite mineralization. They attributed these pyrite-rich levels to mineralization at sediment/water interface under anoxic bottom water conditions. However, we prefer to interpret the greigite as a result of magnetite transformation when sulphate reduction occurs in the interglacial sediments. Peak sulphur contents would therefore be due to sulphur mineralization within the sediment and would not result from an enrichment of the sediment in sulphur at the sediment/water interface.
DOI: 10.1594/gfz.sddb.1039
title: Downcore variations of SIRM/κLF for VER98-1-14

description: Higher abundance of greigite during glacial intervals also coincides with small increases of the S content (Fig. 11B). Greigite levels in glacial sediments cannot be correlated between cores (Fig. 12), which suggests that greigite concentrations are driven by local processes. We suggest that faecal pellets could be a suitable microenvironment for sulphate reduction. And while greigite could potentially act as proxy for faecal pellets in glacial sediments, unfortunately, we cannot rely on this possible indicator since the greigite is very sensitive to onshore alterations after sampling (Snowball and Thompson, 1990).
DOI: 10.1594/gfz.sddb.1042
title: Data concerning preparation of pollen concentrates and graphite targets and results of dating.

description: Laboratory processing of concentrates was aimed at the removal of non-sporomorph organic matter by means of chemical treatment, micro-sieving and heavy  liquid seperation. The optained concentrates were checked under the microscope and sample purity was estimated on the basis of particle counts. The results of AMS 14C dating show differences in the sedimentation rate among three sites of Lake Baikal.
DOI: 10.1594/gfz.sddb.1046
title: Age models based on palaeomagnetic measurements for the two cores analysed, CON01-603-2 (Continent Ridge) and VER98-1-14 (Academician Ridge) showing the correlation points to the reference record

description: Palaeomagnetism was the method used for dating sediments older than the time span covered by AMS 14C dating. Geomagnetic palaeointensities recorded in Lake Baikal sediments were tuned to a reference curve (the record from ODP Site 984, Channell, 1999) whose chronology is well constrained (Demory et al., 2005a-this volume and Demory et al., 2005b-this volume). The palaeointensity record from ODP Site 984 is of high quality, is well dated and covers the time span of the present study. Anchored by a geomagnetic excursion (the Iceland basin event, dated at 186–189 ka according to Channell et al. (1997)), this age model is constrained by 55 correlation points for a time span of ca. 200 ky. The age models for both core sections in the interval 100–150 ky are shown in Fig. 2.
DOI: 10.1594/gfz.sddb.1047
title: Diatom valve concentration in wet sediment, diatom frustule accumulation rate and biovolume accumulation rate in dry sediment plotted against an age scale for CON-01-603-2

description: At both sites, the lowest dry bulk density values (ca. 0.40 g cm−3) correspond to intervals with high diatom concentrations and high sediment accumulation rate. By contrast, the top and bottom of the sections analysed, rich in clay minerals, have high dry bulk density but low diatom concentration and sedimentation rate (Fig. 3).
DOI: 10.1594/gfz.sddb.1048
title: Data for the relative percentages of the dominant diatom taxa related to core depth for CON01-603-2

description: Dissolution was high throughout the profile—in most cases, only 10–20% of the valves considered as pristine (Fig. 4). High relative percentages of A. baicalensis and of benthic Fragilaria (sensu lato) were positively correlated (r=0.29 and r=0.26, respectively) to samples with large proportions of pristine valves. There were no significant relationships between this index of dissolution and any of the other dominant taxa. Fragmentation of the valves was also high. On average only 45% of the total count was represented by whole valves (Fig. 4) and high percentages of non-fragmented valves were positively correlated with the percentages of pristine valves. The percentages of pristine valves showed high variation (20–70%) and by contrast with the dissolution index, they were significantly correlated with the variations in percentages of many dominant taxa.
DOI: 10.1594/gfz.sddb.1049
title: Biovolume accumulation rates for the dominant planktonic taxa plotted against age for CON01-603-2

description: S. grandis is by far the species that contributes the most to the total biovolume accumulation rate with a peak value just above 4×106 μm3 cm−2 year−1. Its relative contribution is over 50% in most samples (Fig. 5). Only taxa such as S. carconeiformis, C. ornata and the vegetative cells of A. skvortzowii contribute significantly (with maximum around 0.6×106 μm3 cm−2 year−1). Other taxa, despite having large relative percentages in parts of the interglacial contribute little to the total BVAR. Biovolumes for benthic taxa were not calculated but their contribution to the total biovolume accumulation rate can be considered negligible as most of these taxa are of small size and the intervals in which they dominate in relative percentages correspond to low diatom valve accumulation rate.
DOI: 10.1594/gfz.sddb.1050
title: Diatom record (in relative percentages) and the biovolume accumulation rates for VER98-1-14

description: The diatom succession at Academician Ridge is similar to the one from Continent Ridge and the two records, despite having very different sampling resolution, can be easily compared on the basis of their main floristic changes (Fig. 6). BVAR at Academician Ridge is about half that of Continent Ridge. There are also marked differences in the relative abundance of some taxa. At Academician Ridge, S. grandis and A. baicalensis are more abundant and S. formosus and C. sp. cf. operculata are less abundant than at Continent Ridge. The large peak in vegetative cells of A. skvortzowii found at Continent Ridge (DAZ 2) is absent at Academician Ridge, and is the most striking difference between the two records.
DOI: 10.1594/gfz.sddb.1052
title: Diatom concentration for Continent Ridge core CON01-603-5

description: All diatoms in the analysed section were extensively affected by dissolution with only c. 1% of valves in a “pristine” condition. Diatom concentrations were generally extremely low throughout MIS 3 and across the MIS 3/2 transition with samples containing a mixture of extant and extinct species (Fig. 4).
DOI: 10.1594/gfz.sddb.1054
title: %dry weight and %loss on ignition for CON01-603-5

description: %dry weight and %loss on ignition for CON01-603-5
DOI: 10.1594/gfz.sddb.1055
title: Composition of major oxide in bulk sediments from lake Baikal: ICP-AES data from P-rich samples

description: The sediment cores were sampled with a resolution of 10 cm, resulting in a total of 290 samples (Table 2). Around 250 mg of dried sediments was mechanically crushed through 100–200-μm mesh then processed by an alkaline digestion (Lithium meta-borate) in a Pt crucible at 1000 °C for 1 h. The residue was dissolved over night in a nitric acid matrix and then major and minor elements (Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Si, Sr, Ti) were analysed by Atomic Emission Spectrometry ICP-AES (Thermo Optek Iris Advantage, Royal Museum for Central Africa, Tervuren, Belgium). Y and Au internal standards were used to correct for instrumental drift. For both trace and major elements analyses, external calibrations were performed using artificial standard solutions and dissolved mineralised natural rock standard (e.g., BHVO-1, DWA, CCH-1 SGR-1, JGB-1).
DOI: 10.1594/gfz.sddb.1058
title: Major composition (wt.%) of concretions, ICP-AES measurements

description: In order to get a complete geochemical signature, 14 P-rich concretions, chosen among the different cores, were acid digested (Table 3a and Table 3b). In a clean laboratory, 1.7 to 36 mg of concretions were digested overnight in a concentrated mixture of Suprapur acid (3 ml HCl/2 ml HNO3/1 ml HF) at 90 °C in sealed Teflon beakers. After evaporation to dryness, the residue was dissolved in 2.5 ml of 2% HNO3 Suprapur and diluted to 12 ml with Milli-Q water. During the same procedure, we have also dissolved and analysed, for comparison, a pure vivianite from Anlua, Cameroon (tubular crystals, MRAC collection).
DOI: 10.1594/gfz.sddb.1060
title: Unit-cell parameters and Mn(Fe+Mn) ratios of vivianites from Lake Baikal

description: The unit-cell parameters (Table 4) were calculated with the least-squares refinement program LCLSQ 8.4 (Burnham, 1991), from the d-spacings corrected with an internal standard of Pb(NO3)2.
DOI: 10.1594/gfz.sddb.1066
title: Vertical profiles of settling particles in the water column.

description: During 16 months of deployment, 239 g m−2 dry matter settled in the 40-m trap, with an average flux of 14.9 g m−2 month−1 (Table 2 and Fig. 2). The content of organic carbon was 21.9% at that depth and that of total nitrogen 1.6% (Table 2 and Fig. 2). The resulting atomic C/N ratio of 15 indicated that the sedimented material resulted from the autochthonous production by suspended phytoplankton and that terrigenous input is likely to be negligible at that site. The amount of pigments gathered during the 16 months deployment in the 40-m trap was 193.1 μmol m−2 for chlorophyll a and 797 μmol m−2 for chlorophyllide a+pheopigment a. The average flux was hence 61.8 μmol m−2 month−1 settled chlorophyll a+chlorophyllide a+pheopigment a (Table 1). It is worth noting that the replicate samples of the 40-m trap deviated strongly (coefficient of variation: 60.5%), whereas the coefficients of variation for the replicate samples in the traps
DOI: 10.1594/gfz.sddb.1067
title: Depth profiles of marker pigments from Bacillariophyceae plus Chrysophyceae (A), Chlorophyta (B), cyanobacterial picoplankton (C), Eustigmatophyceae, and Cryptophyta (D).

description: The traps were deployed for about 16 months. The respective regression equations and its coefficients of determination (r2) are reported in Table 5.In the 40-m trap, fucoxanthin was the dominant carotenoid (Table 1 and Fig. 3). Other pigments of Bacillariophyceae plus Chrysophyceae (chlorophyll c, diadinoxanthin, and diatoxanthin) as well as the cyanobacterial zeaxanthin also showed high sedimentation rates, whereas the chlorophyte chlorophyll b and lutein, as well as the cryptophyte alloxanthin, sedimented only in low amounts (Table 1 and Fig. 3). Abbreviations: Chl—chlorophyll, Fuco—fucoxanthin, Zea—zeaxanthin, β-car—β-carotene, Allo—alloxan
DOI: 10.1594/gfz.sddb.1068
title: Depth profiles of chlorophyll a/carbon ratio (Chla/C), chlorophyllide a/carbon ratio (Chlida/C), pheophorbide a/carbon ratio (Phbida/C), pheophytin a/carbon ratio (Pha/C), and pyropheophytin a/carbon ratio (PyroPha/C).

description: Fig. 4 visualises differences in the degradation between the organic compounds, chlorophylls, and carbon. The chlorophyll a/carbon ratio decreased with depth, indicating that organic carbon is more slowly degraded than chlorophyll a (Table 6 and Fig. 4), whereas the pheophytin a/carbon ratio and the pyropheophytin a/carbon ratio increased with the depth, indicating the formation of pheophytin and pyropheophytin with depth (Table 6 and Fig. 4). Best fits for the chlorophyllide a/carbon ratio and pheophorbide a/carbon ratio vs. depth were also linear regression models, but they were not significant (Fig. 4).
DOI: 10.1594/gfz.sddb.1069
title: Depth profiles of the contribution to total chlorophyll a+chlorophyllide a by Bacillariophyceae plus Chrysophyceae (BacChrys), Chlorophyta (Chloro), and cyanobacterial picoplankton (Cyano).

description: Calculations were based on factors established for 89 water samples across Lake Baikal in July 2001 (see text). The traps were deployed for about 16 months and the core top spanned c. 7 years (see text).According to the contribution to the chlorophyll a-model shown in Eq. (1), the chlorophyll a content in the water of the south basin in July 2001 was composed of 30% Bacillariophyceae plus Chrysophyceae, 44% Chlorophyta, and 26% cyanobacterial picoplankton. In the 40-m trap, in contrast, 87% of the chlorophyll a originated from Bacillariophyceae plus Chrysophyceae, 11% from Chlorophyta, and 2% from cyanobacterial picoplankton (Fig. 5). The percentage contribution did not change with the water depth, as the same composition was found in the deepest traps (Fig. 5).