Suitability of calibrated X-ray fluorescence core scanning for environmental geochemical characterisation of heterogeneous sediment cores

2020 ◽  
pp. 104824
Author(s):  
Tatiana Goldberg ◽  
Rick Hennekam ◽  
Laura Wasch ◽  
Gert-Jan Reichart ◽  
Oliver Rach ◽  
...  
Keyword(s):  
Sediment Cores ◽  
X Ray

scholarly journals A new device to mount portable energy-dispersive X-ray fluorescence spectrometers (p-ED-XRF) for semi-continuous analyses of split (sediment) cores and solid samples

2017 ◽  
Vol 6 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Philipp Hoelzmann ◽  
Torsten Klein ◽  
Frank Kutz ◽  
Brigitta Schütt
Keyword(s):  
Spatial Resolution ◽  
Atlantic Coast ◽  
Sediment Cores ◽  
Ccd Camera ◽  
Energy Dispersive ◽  
Solid Samples ◽  
Industrial Property ◽  
X Ray ◽  
New Device ◽  
Sample Chamber

Abstract. Portable energy-dispersive X-ray fluorescence spectrometers (p-ED-XRF) have become increasingly popular in sedimentary laboratories to quantify the chemical composition of a range of materials such as sediments, soils, solid samples, and artefacts. Here, we introduce a low-cost, clearly arranged unit that functions as a sample chamber (German industrial property rights no. 20 2014 106 048.0) for p-ED-XRF devices to facilitate economic, non-destructive, fast, and semi-continuous analysis of (sediment) cores or other solid samples. The spatial resolution of the measurements is limited to the specifications of the applied p-ED-XRF device – in our case a Thermo Scientific Niton XL3t p-ED-XRF spectrometer with a maximum spatial resolution of 0.3 cm and equipped with a charge-coupled device (CCD) camera to document the measurement spot. We demonstrate the strength of combining p-ED-XRF analyses with this new sample chamber to identify Holocene facies changes (e.g. marine vs. terrestrial sedimentary facies) using a sediment core from an estuarine environment in the context of a geoarchaeological investigation at the Atlantic coast of southern Spain.

Using X-ray fluorescence core scanning to assess acid sulfate soils

Soil Research ◽  
2014 ◽  
Vol 52 (8) ◽  
pp. 760 ◽  
Author(s):  
Ulrike Proske ◽  
Henk Heijnis ◽  
Patricia Gadd
Keyword(s):  
Chemical Elements ◽  
Sediment Cores ◽  
Cost Effective ◽  
Transitional Zone ◽  
Initial Assessment ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
X Ray ◽  
Effective Manner ◽  
Sulfate Soils

During the formation of acid sulfate soils (ASS), several chemical elements in the sediment are mobilised. These elements are removed from the sediment or become enriched as precipitates in distinct horizons. The stratigraphic depth in which these precipitates accumulate is element-specific and is located either within the oxidised or in a transitional zone between the oxidised and the reduced zone. Aim of this study is to demonstrate how X-ray fluorescence core scanning, together with detailed sediment descriptions, can be used to perform an initial assessment of these different zones in ASS in a fast and cost-effective manner. We measured the chemical element signatures of K, Fe, Pb, Sr, Zn, Ni, Y, Mn and Ca in two sediment cores from Western Australia where ASS are suspected to occur. The oxidised zone in both cores is characterised by the occurrence of jarosite, which is indicated by pale straw yellow mottling and synchronous peaks in Fe/Ti, K/Ti, Pb/Ti and Sr/Ti, and of other secondary Fe-oxides, which are indicated by reddish mottling and synchronous peaks in Fe/Ti and Pb/Ti. The transition zone into reduced material is marked by synchronous peaks in Zn/Ti, Ni/Ti, Y/Ti and Mn/Ti. Based on these characteristic signatures, we broadly estimated the depth of the oxidised and the transitional zone at both sites.

A late Holocene Record of sediment dynamics obtained from Lake Altaussee (Salzkammergut, Austria). 

2021 ◽  
Author(s):  
Jasper Moernaut ◽  
Sebastian Wagner ◽  
Julia Rechenmacher ◽  
Markus Fiebig ◽  
Marcel Ortler ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Mass Movement ◽  
Sediment Dynamics ◽  
Coastal Sediments ◽  
Coarse Grained ◽  
Lake Basin ◽  
Stratigraphic Correlation ◽  
X Ray ◽  
The University ◽  
Subbottom Profiling

<p>Sedimentary records in inner-Alpine lakes typically show a rich history of changes in sediment dynamics and the occurrence of various geohazards. Lake Altaussee (712 m asl; 2.4 x 1.0 km; max. 72 m deep) is a dimictic, moderately-sized glacigenic lake located in the Northern Calcareous Alps. Currently, it has no major river inflow and most water input comes from several subaqueous springs, forming large and deep craters (max. 60 m diameter and 22 m deep) on the lake bottom. Since 2019, a wide suite of investigations (hydrogeology, microplastics, hydroacoustics, geomorphology, sedimentology) started under the framework of the Walter Munk Foundation for the Oceans (WMFO) and the University of Natural Resources and Life Sciences (BOKU) Vienna. In 2020, the University of Innsbruck (UIBK) became a project partner to undertake joint research on its sedimentary infill.</p><p>We present preliminary results from lacustrine morphological mapping of high-resolution multibeam bathymetry (Kongsberg EM2040), seismic-stratigraphic analysis of subbottom profiling data (Innomar SES-2000 and Kongsberg GEOPULSE), and sedimentological/geochemical analysis on 22 short cores (60-170 cm long). Stratigraphic correlation between the 22 cores is based on visual detection of marker layers in Multi-Sensor Core Logging (MSCL), X-Ray CT and X-ray fluorescence (XRF) core scanning data.</p><p>The sediment cores mainly exhibit slowly-accumulating organic-rich sediments, typical for lake systems that lack significant fluvial sediment input. One unit of finely-laminated clastic carbonate-rich sedimentation can be traced back to an episode in which a major creek −draining an area of active salt mining− was flowing into the western part of the lake. In medieval times, this creek was artificially diverted and depositional conditions in the lake returned to organic-rich sedimentation. </p><p>The hydroacoustic data show a scattered pattern of large-scale blocks up to 50-70 m diameter in the eastern half of the lake basin. This suggests the occurrence of one or more large gravitational mass movements, which potentially originated at the steep rock slopes at the northern and eastern end of the lake. A megaturbidite (>1-2 m thick) can be traced over the entire basin floor in both subbottom profiling data and sediment cores, and directly overlies the blocks in the deep basin. Isopach mapping of this megaturbidite hints at sediment transport from both the eastern and western slopes, which we interpret to have occurred as the results of a mass-movement induced impulse wave that eroded coastal sediments at the opposite side of the lake and transported these to the deeper basin. On the shallower western plateau, the presence of an outstanding coarse-grained stratigraphic unit with an erosive base further supports this hypothesis, as it is stratigraphically coeval to the megaturbidite. Biogenic gas accumulation at the base of the megaturbidite prevents further penetration on the subbottom profiles, but some acoustic windows visualize up to 15 m of infill.</p><p>Upcoming research involves the establishment of <sup>14</sup>C-based age-depth models, the acquisition of single-channel airgun seismics to visualize the entire infill of the lake through the gas blanket, and long piston coring to investigate the sediment dynamics and geohazards recorded in the Holocene sedimentary infill.</p>

The Sedimentary Record of the 2018 Anchorage Earthquake in Eklutna Lake, Alaska: Calibrating the Lacustrine Seismograph

2019 ◽  
Vol 91 (1) ◽  
pp. 126-141 ◽  
Author(s):  
Maarten Van Daele ◽  
Peter J. Haeussler ◽  
Robert C. Witter ◽  
Nore Praet ◽  
Marc De Batist
Keyword(s):  
Sediment Cores ◽  
Turbidity Currents ◽  
Lake Surface ◽  
Local Site Effects ◽  
X Ray ◽  
Local Site ◽  
South Central ◽  
Proglacial Lakes ◽  
X Ray Computed ◽  
Recent Earthquakes

Abstract The 30 November 2018 Mw 7.1 Anchorage earthquake caused modified Mercalli intensities of V¼ to V½ at Eklutna Lake (south central Alaska). A few hours after the earthquake, a “dirt streak” was observed on the lake surface, followed by a peak in sediment turbidity values (∼80 times normal) at a drinking water facility, which receives water from the lake through a pipe. These observations hint toward turbidity currents triggered by the earthquake in Eklutna Lake. Here, we study 32 short sediment cores retrieved from across Eklutna Lake and observe a millimeter‐to‐centimeter scale turbidite that can be confidently attributed to the 2018 earthquake in all coring locations. X‐ray computed tomography, grain‐size, and color‐spectral analyses of the turbidite show that it shares physical characteristics with the turbidite generated by the 1964 Mw 9.2 Great Alaska earthquake, while it is considerably different from turbidites caused by historical floods. The 2018 turbidite reaches its largest thickness in the inflow‐proximal basin, but when compared to the 1964 turbidite and thereby canceling out local site effects, it is relatively thick in the inflow‐distal sub‐basin. The latter was exposed to stronger shaking during the 2018 earthquake, and this relative thickness trend may therefore be attributed to shaking intensity and gives an indication of the location of the earthquake epicenter relative to the basin axis. Furthermore, in contrast to the 1964 turbidite, which was sourced from both deltas and hemipelagic slopes, the 2018 turbidite was sourced from deltas only, as evidenced by its distribution. These results confirm that while it is generally accepted that shaking intensities of ≥VI are needed to trigger turbidity currents from hemipelagic slopes, intensities as low as V¼ can be sufficient to trigger turbidity currents from deltaic slopes. Our results show that proglacial lakes can sensitively record differences in shaking intensity and that investigating deposits from recent earthquakes is crucial to calibrate the lacustrine seismograph.

A Regional Stratigraphic Isochron (ca. 8000 14C yr B.P.) from Final Deglaciation of Hudson Strait

1996 ◽  
Vol 46 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Michael W. Kerwin
Keyword(s):  
Sediment Cores ◽  
Laurentide Ice Sheet ◽  
Time Interval ◽  
Hudson Bay ◽  
Baffin Island ◽  
Clay Layer ◽  
X Ray ◽  
Northern Margin ◽  
Group A ◽  
Glaciomarine Sediments

Sedimentologic, rock-magnetic, and X-ray fluorescence data from two marine sediment cores in Hudson Strait suggest that a red, hematite-rich clay layer was deposited throughout the strait during the final collapse of the Laurentide Ice Sheet in the vicinity of northern Hudson Bay and western Hudson Strait. This layer, which can be recognized by its reddish-pink color (10YR6/2 to 5YR4/2) and relatively high-hematite proportions (low magnetic susceptibility and magnetite-to-hematite ratio), is dated from 8000 to 7900 14C yr B.P. at both ends of the strait. The Dubawnt Group, a Proterozoic bedrock unit in northern Hudson Bay, is the most likely source of this stratigraphic isochron. In eastern Hudson strait, the recognition of this red unit and other distal glaciomarine sediments from 8400 to 7900 14C yr B.P. indicates that little sediment from the nearby Labrador Dome reached eastern Hudson Strait during this 500-yr interval. This time interval immediately postdates the Noble Inlet advance, a northward flow of Labrador ice across eastern Hudson Strait onto southern Baffin Island from ca. 8900 to 8400 14C yr B.P. One explanation for the lack of Labrador sediments is that the northern margin of the Labrador dome was cold-based for up to 500 yr following the Noble Inlet advance.

scholarly journals Facies characterisation of sediments from the East Frisian Wadden Sea (Germany): new insights from down-core scanning techniques

2021 ◽  
Vol 100 ◽  
Author(s):  
An-Sheng Lee ◽  
Dirk Enters ◽  
Jürgen Titschack ◽  
Bernd Zolitschka
Keyword(s):  
Wadden Sea ◽  
Biological Activities ◽  
Sediment Cores ◽  
Biological Information ◽  
High Temporal Resolution ◽  
X Ray ◽  
Facies Classification ◽  
Depositional Processes ◽  
Fundamental Information ◽  
Facies Types

Abstract Sediment facies provide fundamental information to interpret palaeoenvironments, climatic variation, archaeological aspects and natural resource potentials since they are summary products of depositional processes, environmental conditions and biological activities for a given time and location. The conventional method of facies discrimination relies on macroscopic and/or microscopic determination of sediment structures combined with basic physical, chemical and biological information. It is a qualitative measure, depending on observer-dependent sedimentological descriptions, which cannot be reanalysed readily by further studies. Quantitative laboratory measurements can overcome this disadvantage, but are in need of large sample numbers and/or high temporal resolution, and are time-, labour- and cost-intensive. In order to facilitate an observer-independent and efficient method of facies classification, our study evaluates the potential of combining four non-destructive down-core scanning techniques: magnetic susceptibility (MS), X-ray computed tomography (CT), X-ray fluorescence (XRF) and digital photography. These techniques were applied on selected sections of sediment cores recovered around the island of Norderney (East Frisian Wadden Sea, Germany). We process and integrate the acquired scanning measurements of XRF elemental intensities, represented by principal components, MS, CT density and lightness of eight sediment facies previously recognised by conventional facies analysis: moraine, eolian/fluvial, soil, peat, lagoonal, sand flat, channel fill and beach-foreshore. A novel type of density plot is introduced to visualise the digitised sediment information that allows an observer-independent differentiation of these facies types. Thus, the presented methodology provides the first step towards automated supervised facies classification with the potential to reproduce human assessments in a fully reproducible and quantitative manner.

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