scholarly journals Geochemical data for lake sediments in the Superior Province of Manitoba (NTS 53-E, 53-L and 53-M)

2017 ◽  
Author(s):  
M W McCurdy ◽  
C O Böhm ◽  
S D Anderson ◽  
M S Gauthier ◽  
S D Amor
Keyword(s):  
Lake Sediments ◽  
Geochemical Data ◽  
Superior Province

Stratigraphy and sedimentary process in a closed-basin lake in Central Italy during the Anthropocene

2021 ◽  
Author(s):  
Paola Gravina ◽  
Beatrice Moroni ◽  
Riccardo Vivani ◽  
Alessandro Ludovisi ◽  
Roberta Selvaggi ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Level ◽  
Lake Sediments ◽  
Biological Effects ◽  
Central Italy ◽  
Geochemical Data ◽  
Climate Variations ◽  
Sedimentary Process ◽  
Climatic Fluctuations ◽  
Precipitation Processes

<p>Shallow and closed lakes are affected by meteorological and climate variations and are especially sensitive to the change in their hydrological balance. In central Italy, there is the fourth-largest lake of the country, the Trasimeno Lake, whose water level has undergone various fluctuations over the centuries with alternation of flood and drought periods because of its shallow depth and the absence of natural outflows [1].</p><p>Sediment archives are used as information records to study chemical, physical, and biological environmental variations and changes in the hydrological budget driven by climatic fluctuations, but this is particularly complicated in shallow lakes due to the multiple perturbative phenomena. A robust study depends on the ability to obtain valid high-resolution geochemical data from lake sediments.</p><p>We conducted high-resolution geochemical analysis on three sediment cores about 1 meter long each, collected in Lake Trasimeno. We sectioned at 1  or 2 cm interval, which provided a detailed characterization of the significant changes in lacustrine processes that occurred in the basin during the Anthropocene (~last 150 years) [2], combining quantitative chemical (ICP-OES) and semi-quantitative (XRD and SEM) investigations. Geochemical variables are used as paleolimnological proxies to reconstruct past lake events that occurred within the water column. In particular, we report the study of the endogenic precipitates characteristic of the Trasimeno sediments, whose precipitation processes have been influenced by water fluctuations and anthropogenic impacts.</p><p>Given the strong presence of water fluctuations, the investigation period was divided into three distinct phases related to the lake's hydrometric state and characterized by sedimentary compounds of different nature. The endogenic carbonate compounds of calcite (commonly present in the Trasimeno sediments) contain a different Mg percentage during the different hydrometric phases. The lake sediments are particularly rich in Mg-calcite due to both water level changes and biological effects. Moreover, co-precipitation of non-crystalline Ca-P compounds (e.g., apatite type) has been detected during a hydrometric phase characterized by high microorganisms activity. Precipitation processes were triggered in Trasimeno by the growth of nutrient discharge into the lake (since the 1970s) and are currently studied for their importance in controlling eutrophication phenomena.</p><p>In conclusion, our findings show that rapid lake responses to water fluctuations and climate variations were transcribed within the sedimentary stratigraphic archives, which underlines their value and high quality in paleoenvironmental and paleohydrological reconstruction.</p><p>References:</p><p>[1] Frondini, Dragoni, Morgantini, Donnini, Cardellini, Caliro, Melillo, and Chiodini (2019). An En-dorheic Lake in a Changing Climate: Geochemical Investigations at Lake Trasimeno (Italy).Water, 11(7):1319.</p><p> [2] Gaino, E., Scoccia, F., Piersanti, S., Rebora, M., Bellucci, L. G., and Ludovisi, A. (2012). Spiculerecords of Ephydatia fluviatilis as a proxy for hydrological and environmental changes inthe shallow Lake Trasimeno (Umbria, Italy). Hydrobiologia, 679(1):139–153.</p>

scholarly journals A late Quaternary record of eolian silt deposition in a maar lake, St. Michael Island, western Alaska

2003 ◽  
Vol 60 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Daniel R. Muhs ◽  
Thomas A. Ager ◽  
Josh Been ◽  
J. Platt Bradbury ◽  
Walter E. Dean
Keyword(s):  
Lake Sediments ◽  
Late Quaternary ◽  
Geochemical Data ◽  
Unexpected Finding ◽  
The Holocene ◽  
Tundra Vegetation ◽  
Shrub Tundra ◽  
Loess Deposition ◽  
Maar Lake ◽  
Glacial Time

AbstractRecent stratigraphic studies in central Alaska have yielded the unexpected finding that there is little evidence for full-glacial (late Wisconsin) loess deposition. Because the loess record of western Alaska is poorly exposed and not well known, we analyzed a core from Zagoskin Lake, a maar lake on St. Michael Island, to determine if a full-glacial eolian record could be found in that region. Particle size and geochemical data indicate that the mineral fraction of the lake sediments is not derived from the local basalt and is probably eolian. Silt deposition took place from at least the latter part of the mid-Wisconsin interstadial period through the Holocene, based on radiocarbon dating. Based on the locations of likely loess sources, eolian silt in western Alaska was probably deflated by northeasterly winds from glaciofluvial sediments. If last-glacial winds that deposited loess were indeed from the northeast, this reconstruction is in conflict with a model-derived reconstruction of paleowinds in Alaska. Mass accumulation rates in Zagoskin Lake were higher during the Pleistocene than during the Holocene. In addition, more eolian sediment is recorded in the lake sediments than as loess on the adjacent landscape. The thinner loess record on land may be due to the sparse, herb tundra vegetation that dominated the landscape in full-glacial time. Herb tundra would have been an inefficient loess trap compared to forest or even shrub tundra due to its low roughness height. The lack of abundant, full-glacial, eolian silt deposition in the loess stratigraphic record of central Alaska may be due, therefore, to a mimimal ability of the landscape to trap loess, rather than a lack of available eolian sediment.

scholarly journals Geochemical data for lake sediments and surface waters, Abitau Lake area, Northwest Territories (NTS 75-B)

2016 ◽  
Author(s):  
M W McCurdy ◽  
S J Pehrsson ◽  
H Falck ◽  
S J A Day ◽  
J E Campbell
Keyword(s):  
Lake Sediments ◽  
Northwest Territories ◽  
Surface Waters ◽  
Geochemical Data ◽  
Lake Area

Geophysical correlations in the Ungava Bay area

2002 ◽  
Vol 39 (5) ◽  
pp. 625-637 ◽  
Author(s):  
E Bourlon ◽  
J C Mareschal ◽  
W R Roest ◽  
H Telmat
Keyword(s):  
Linear Trend ◽  
Shear Zones ◽  
Magnetic Fabric ◽  
Magnetic Data ◽  
Geochemical Data ◽  
Superior Province ◽  
Baffin Island ◽  
Gravity Gradients ◽  
Core Zone ◽  
The Way

We used gravity and magnetic data to extend geological features across Ungava Bay and Hudson Strait, from northern Quebec and Labrador to Baffin Island. Tectonic domains identified on land were extended offshore by visual inspection of the potential fields. The boundaries identified on colour shaded relief maps were drawn on the original marine magnetic profiles to verify the robustness of the conclusions. Our interpretation in Ungava Bay remains speculative but gives some insight into the architecture of the northeastern Canadian Shield. Onshore, where trends are well marked, the magnetic fabric of the Superior Province reappears east of the New Quebec Orogen in the western core zone. Geochronology and geochemical data also suggest the affinity of the western core zone with the Superior Province. On the gravity map, the New Quebec Orogen appears to vanish offshore. A major trend in magnetic and gravity gradients can be followed offshore possibly as far north as Hudson Strait. It has been identified as the extension of the George River and Moonbase shear zones. The De Pas Batholith is associated with a linear trend west of this shear zone. To the east, several features appear distinctly in the magnetic map. A narrow northwest-trending anomaly can be followed from Quebec all the way to Baffin Island. On land, this feature marks the western limit of the Lake Harbour Group. Two wide north-trending bands that can be followed from the Torngat Orogen all the way to Baffin Island are interpreted as the extensions of the Lac Lomier Complex and Tasiuyak Domain.

Pickle Lake revisited: New structural, geochronological and geochemical constraints on greenstone belt assembly, western Superior Province, Canada

2006 ◽  
Vol 43 (7) ◽  
pp. 821-847 ◽  
Author(s):  
M D Young ◽  
V McNicoll ◽  
H Helmstaedt ◽  
T Skulski ◽  
J A Percival
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Tholeiitic Basalt ◽  
Pyroclastic Flows ◽  
Iron Formation ◽  
Geochemical Data ◽  
Superior Province ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Two Samples

New field work, U–Pb ages, geochemical data, and Sm–Nd isotopic analyses have established the timing and determined the nature of volcanism, deformation, and tectonic assembly of the Pickle Lake greenstone belt in the Uchi subprovince of the western Superior Province of the Canadian Shield. The >2860 Ma Pickle Crow assemblage has been redefined to include the former Northern Pickle assemblage on the basis of stratigraphic continuity and similar volcanic geochemistry between the two units across a previously inferred fault contact. The Pickle Crow assemblage consists of tholeiitic basalt with thin, but laterally extensive, oxide-facies iron formation overlain by alkalic basalts and minor calc-alkaline andesites to dacites with primitive Nd isotopic compositions (εNd2.89 Ga = +2.1 to +2.4) suggestive of deposition in a sediment-starved oceanic basin. The ~2 km thick ~2836 Ma Kaminiskag assemblage (former Woman assemblage) consists of tholeiitic basalt interbedded with intermediate and rare felsic pyroclastic flows with primitive Nd isotopic compositions (εNd2.836 Ga = +2.4). Two samples of intermediate volcanic rocks interbedded with southeast-younging pillowed basalt, previously inferred to be part of the Pickle Crow assemblage, yielded U–Pb zircon ages of 2744 [Formula: see text] Ma and 2729 ± 3 Ma. These rocks are thus part of the younger Confederation assemblage, which consists of intercalated basalt and dacite (εNd2.74 Ga = +0.1 to +0.8) exhibiting diverse compositions probably reflecting eruption in a continental margin arc to back-arc setting. The contact between the Confederation and Kaminiskag assemblages is assumed to be a fault. The greenstone belt is intruded by late syn- to posttectonic plutons including the composite quartz dioritic to gabbroic July Falls stock with a new U–Pb zircon age of 2749 [Formula: see text] Ma, and the ~2741 to 2740 Ma trondhjemitic to granodioritic Ochig Lake pluton and Pickle Lake stock, as well as the ~2697 to 2716 Ma Hooker–Burkoski stock. The earliest recognized deformation (D1) is recorded by a local bedding-parallel foliation in the Pickle Crow assemblage. This foliation is truncated by the ~2735 Ma Albany quartz–feldspar porphyry dyke and is not recognized in the volcanic rocks of the Confederation assemblage. The early deformation event is attributed to overturning of the Pickle Crow assemblage prior to deposition of the ~2744 to 2729 Ma Confederation assemblage. Subsequent deformation and development of a regionally penetrative planar fabric (S2) postdates ~2729 Ma volcanism, pre-dates the intrusion of the ca. <2716 Ma Hooker–Burkoski stock and is host to gold mineralization.

Searching for weather in varves: use of ultra-high-resolution scanning techniques to reconstruct seasonal meteorological conditions

2021 ◽  
Author(s):  
Paul Zander ◽  
Maurycy Żarczyński ◽  
Wojciech Tylmann ◽  
Shauna-kay Rainford ◽  
Martin Grosjean
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Lake Sediments ◽  
Predictive Power ◽  
Accumulation Rate ◽  
Meteorological Data ◽  
Meteorological Conditions ◽  
Additive Models ◽  
Geochemical Data ◽  
Formation Processes

&lt;p&gt;Varved lake sediments are recognized as valuable archives of paleoclimatic information due to their precise chronological control. However, paleoclimate reconstructions based on the composition of biochemical varves are relatively rare (Zolitschka et al., 2015). We applied novel high-resolution scanning techniques to the varved sediments of Lake &amp;#379;abi&amp;#324;skie, Poland to obtain spatially resolved geochemical data at a resolution of 60 &amp;#956;m covering the period 1966-2019. Relative abundances of elements were measured in resin-embedded sediment slabs using a Bruker M4 Tornado micro-XRF scanner. Chloropigments-&lt;em&gt;a&lt;/em&gt; and bacteriopheopigments-&lt;em&gt;a&lt;/em&gt; were measured on a wet sediment core using a Specim Hyperspectral core scanner (Butz et al., 2015). The high resolution of the scanning data, and the relatively thick well-preserved varves (average thickness = 6.4 mm), enables a close examination of seasonal scale sediment composition and varve formation processes. Time series of geochemical variables within each varve year were classified into 4 varve type groups based on the dissimilarity measure &amp;#968; for multivariate time series (Benito and Birks, 2020; Gordon and Birks, 1974). Based on a Multivariate Analysis Of Variance test, these groups of years experienced significant (p&lt;0.05) differences in seasonal meteorological conditions, particularly wind speed and temperature.&amp;#160; Additionally, a correlation analysis on mean annual geochemical values from the aforementioned scanning techniques and conventional CNS analysis, and seasonal meteorological data revealed significant (p&lt;0.05) correlations with windiness and temperature. Based on these relationships, we applied generalized additive models to predict spring and summer (MAMJJA) temperature and number of windy days (spring through fall), yielding models with significant predictive power. Based on model selection, the variables with the most predictive power for spring and summer temperature were Ti (negative correlation) and total C. The variables with the most predictive power for windiness were Si, sediment accumulation rate, and varve type. This study highlights the usefulness of high-resolution scanning techniques to improve our understanding of varve formation processes and relationships between varve composition and climate variables in biochemical varves.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Benito, B. M. and Birks, H. J. B.: distantia: an open&amp;#8208;source toolset to quantify dissimilarity between multivariate ecological time&amp;#8208;series, Ecography (Cop.)., 43(5), 660&amp;#8211;667, doi:10.1111/ecog.04895, 2020.&lt;/p&gt;&lt;p&gt;Butz, C., Grosjean, M., Fischer, D., Wunderle, S., Tylmann, W. and Rein, B.: Hyperspectral imaging spectroscopy: a promising method for the biogeochemical analysis of lake sediments, J. Appl. Remote Sens., 9(1), 096031, doi:10.1117/1.jrs.9.096031, 2015.&lt;/p&gt;&lt;p&gt;Gordon, A. D. and Birks, H. J. B.: Numerical methods in Quaternary palaeoecology: II. Comparison of pollen diagrams, New Phytol., 73(1), 221&amp;#8211;249, doi:10.1111/j.1469-8137.1974.tb04621.x, 1974.&lt;/p&gt;&lt;p&gt;Zolitschka, B., Francus, P., Ojala, A. E. K. and Schimmelmann, A.: Varves in lake sediments - a review, Quat. Sci. Rev., 117, 1&amp;#8211;41, doi:10.1016/j.quascirev.2015.03.019, 2015.&lt;/p&gt;

scholarly journals Evaluation of the Anthropogenic Metal Pollution at Osisko Lake: Sediments Characterization for Reclamation Purposes

2021 ◽  
Vol 11 (5) ◽  
pp. 2298
Author(s):  
Louise Darricau ◽  
Abdellatif Elghali ◽  
Patrick Martel ◽  
Mostafa Benzaazoua
Keyword(s):  
Lake Sediments ◽  
Chemical Species ◽  
Anthropogenic Pollution ◽  
Major Elements ◽  
Geochemical Data ◽  
Atmospheric Conditions ◽  
Lake Ecosystems ◽  
Sediment Samples ◽  
Geochemical Properties ◽  
High Concentrations

The anthropogenic pollution of lake ecosystems by human activities (e.g., mining industries) is recognized as a serious issue. The Osisko urban lake located in Rouyn-Noranda (Quebec, Canada) was used partially as a waste disposal facility for many decades, causing a heavy pollution. The main undertakings of this study are (i) assessing the mineralogical and geochemical properties of lake Osisko sediments, and (ii) studying the pollution that occurred within lake water due to the sediments’ reactivity. Water and sediments across the lake were collected in different sensitive locations. Within the sediment samples, two parts were distinguished: a small layer of black vase over grey sediments. The black vase resembled organic matter while the gray sediment seemed close to clean lake sediments. The collected samples were characterized for their physical (particle size distribution, specific gravity and specific surface area), chemical (minor and major elements as well as total sulfur and carbon) and mineralogical (X-ray diffraction and scanning electron microscope) properties. Additionally, the reactivity of sediments was studied using weathering cells to quantify chemical species leaching and their releasing rates. The results showed that the vase was the only contaminated part with high concentrations of sulfur and metals such as copper, zinc and iron. Geochemical data showed that the composite sample and the vase potentially cause contaminated acid drainage if they are exposed to atmospheric conditions. Indeed, the pH values of the leachates from both samples were between 4 and 6, while those corresponding to sediments remained around circumneutral values. Quantitatively, the contaminant release from the tested samples was variable. Indeed, the Fe cumulative concentrations were around 200, 80 and 20 mg/kg for the vase, composite and sediment samples, respectively. Similarly, the Zn cumulative concentrations were around 4500, 4200, and below the detection limit for vase, composite and sediment samples, respectively. The same tendency was observed for Cu, S, and Fe. Thus, sediments within Osisko lake present a risk for water contamination if they are resuspended or dredged out of the lake. Consequently, they should be stabilized before their disposal. The samples’ high Cu contents also offer the possibility of their reprocessing.

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