50 results on '"Fuchs, Margret C."'
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2. How can agile sensing improve recycling stream characterisation and monitoring for e-waste? - news from the HELIOS lab
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Fuchs, Margret C., primary, Lorenz, Sandra, additional, Madriz Diaz, Yuleika C., additional, Abend, Titus, additional, Shaik Fareedh, Junaidh, additional, de Lima Ribeiro, Andrea, additional, Arbash, Elias, additional, Rasti, Behnood, additional, Beyer, Jan, additional, Röder, Christian, additional, Schüler, Nadine, additional, Dornich, Kay, additional, Heitmann, Johannes, additional, and Gloaguen, Richard, additional
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- 2023
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3. The abanico plot: Visualising chronometric data with individual standard errors
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Dietze, Michael, Kreutzer, Sebastian, Burow, Christoph, Fuchs, Margret C., Fischer, Manfred, and Schmidt, Christoph
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- 2016
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4. Multi-Sensor Characterization for an Improved Identification of Polymers in WEEE Recycling
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de Lima Ribeiro, Andréa, primary, Fuchs, Margret C., additional, Lorenz, Sandra, additional, Röder, Christian, additional, Heitmann, Johannes, additional, and Gloaguen, Richard, additional
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- 2023
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5. Data processing in luminescence dating analysis: An exemplary workflow using the R package ‘Luminescence’
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Fuchs, Margret C., Kreutzer, Sebastian, Burow, Christoph, Dietze, Michael, Fischer, Manfred, Schmidt, Christoph, and Fuchs, Markus
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- 2015
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6. Exploring the potential of luminescence methods for dating Alpine rock glaciers
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Fuchs, Margret C., Böhlert, Ralph, Krbetschek, Matthias, Preusser, Frank, and Egli, Markus
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- 2013
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7. sandbox – creating and analysing synthetic sediment sections with R
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Dietze, Michael, primary, Kreutzer, Sebastian, additional, Fuchs, Margret C., additional, and Meszner, Sascha, additional
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- 2022
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8. Multisensor characterization of WEEE polymers: spectral fingerprints for the recycling industry
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de Lima Ribeiro, Andréa, primary, Fuchs, Margret C., additional, Lorenz, Sandra, additional, Röder, Christian, additional, Madriz, Yuleika, additional, Herrmann, Erik, additional, Gloaguen, Richard, additional, and Heitmann, Johannes, additional
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- 2022
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9. sandbox – Creating and Analysing Synthetic Sediment Sections with R
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Dietze, Michael, primary, Kreutzer, Sebastian, additional, Fuchs, Margret C., additional, and Meszner, Sascha, additional
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- 2021
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10. Supplementary material to "sandbox – Creating and Analysing Synthetic Sediment Sections with R"
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Dietze, Michael, primary, Kreutzer, Sebastian, additional, Fuchs, Margret C., additional, and Meszner, Sascha, additional
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- 2021
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11. Book of Abstracts - vDEUQUA2021
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Abadi, Mehrdad, Abbasi, Hamidreza, Abd El-Raouf, Amr, Abdulkarim, Mubarak, Adolph, Marie-Luise, Aeschbach, Werner, Akçar, Naki, Amini, Hamideh, Andreev, Andrej, Anselmetti, Flavio S., Aumaître, Georges, Avendaño Villeda, Diana, Bartz, Melanie, Baumhauer, Roland, Bazarradnaa, Enkhtuya, Bebiolka, Anke, Behling, Hermann, Benkaddour, Abdelfattah, Binot, Franz, Birlo, Stella, Bittner, Lucas, Bliedtner, Marcel, Bolland, Alexander, Bork, Hans-Rudolf, Bouaziz, Moncef, Bourlès, Didier, Brauer, Achim, Breuer, Sonja, Bromm, Tobias, Buechi, Marius W., Burghardt, Diana, Busch, Robert, Caballero, Margarita, Carr, Andrew S., Chapkanski, Stoil, Christl, Marcus, Cosac, Marian, Dal Corso, Marta, Daniel, Thomas, Dar, Reyaz, Dave, Aditi Krishna, De Jonge, Cindy, Deplazes, Gaudenz, Dietze, Elisabeth, Dietze, Michael, Dietzel, Martin, Dreibrodt, Stefan, Drysdale, Russell, du Plessis, Nadia, Dubois, Nathalie, Duller, Geoff, Duttmann, Rainer, Duval, Mathieu, Döhlert-Albani, Norman, Egli, Markus, Einwögerer, Thomas, Elbracht, Jörg, Enters, Dirk, Enzel, Yehouda, Ertlen, Damien, Farkas, Beáta, Fattahi, Morteza, Faust, Dominik, Faybishenko, Boris, Feistmantl, Nina, Fernandez, Philippe, Ferrier, Catherine, Fiedler, Sabine, Fischer, Birgit, Fischer, Peter, Fitzsimmons, Kathryn, Fletcher, William, Frechen, Manfred, Fuchs, Margret C., Fuchs, Markus, Fuelling, Alexander, Fábián, Szabolcs, Fülling, Alexander, Garbe, Philipp, Gebhardt, Catalina, Gegg, Lukas, Geis, Anna-Lena, Geitner, Clemens, Ghanbarian, Behzad, Gianotti, Franco, Gil Romera, Graciela, Glaser, Bruno, Glückler, Ramesh, Gresina, Fruzsina, Grootes, Pieter Meiert, Guadelli, Aleta, Guadelli, Jean-Luc, Guérin, Guillaume, Haas, Jean Nicolas, Haberzettl, Torsten, Hambach, Ulrich, Hardt, Jacob, Hein, Michael, Heinrich, Hartmut, Heinrich, Susann, Herzschuh, Ulrike, Heydari, Maryam, Hildebrandt, Dominic, Hirschmann, Philip, Hofmann, Felix Martin, Hofmann, Robert, Hogrefe, Ines, Huang, Jyh-Jaan Steven, Hunt, Allen, Händel, Marc, Ivy-Ochs, Susan, Jary, Zdzisław, Jeanneret, Pilar, Jöris, Olaf, Kalicki, Tomasz, Kamleitner, Sarah, Karaschewski, Jasmin, Keddadouche, Karim, Kehl, Martin, Kern, Zoltán, Kertscher, Cathleen, Khatooni, Darvish, Khosravichenar, Azra, Kipfer, Rolf, Kirchner, André, Kirleis, Wiebke, Klaes, Björn, Knitter, Daniel, Kolb, Thomas, Konstantinovski Puntos, Cyryl, Kreienbrink, Frauke, Kreutzer, Sebastian, Kulongoski, Justin, Laag, Christian, Labahn, Jakob, Lachner, Johannes, Lak, Razyeh, Lamb, Henry F., Lampe, Reinhard, Lang, Jörg, Lange-Athinodorou, Eva, Lauer, Tobias, Leanni, Laetitia, Leblanc, Jean-Claude, Lee, An-Sheng, Lehmkuhl, Frank, Lempe, Bernhard, Lerch, Marcel, Liou, Sofia Ya Hsuan, Lisa, Lenka, Liu, Zuorui, Lomax, Johanna, Lorenz, Sebastian, Lozano García, Socorro, Madarász, Balázs, Madritsch, Herfried, Maier, Andreas, Mangelsdorf, Kai, Markovic, Slobodan, Martinez Abarca, Luis Rodrigo, Marx, Samuel, May, Jan-Hendrik, Mayr, Christoph, Meister, Julia, Merchel, Silke, Meszner, Sascha, Meyer, Juliane, Mikdad, Abdeslam, Milevski, Ivica, Mir, Jehangeer, Mischke, Steffen, Mohammadi, Ali, Monegato, Giovanni, Moreiras, Stella, Mueller, Daniela, Muratoreanu, George, Müller, Daniela, Müller, Johannes, Nadeau, Marie-Josée, Nett, Janina, Neugebauer, Ina, Ng, Jessica, Nill, Leon, Nir, Nadav, Ohlendorf, Christian, Opp, Christian, Orgeira, Maria, Ortega Guerrero, Beatriz, Pasda, Clemens, Pasda, Kerstin, Penkman, Kirsty, Peric, Zoran, Pichat, Sylvain, Piller, Werner, Polgar, Irene, Prendergast, Amy, Preusser, Frank, Prud'homme, Charlotte, Pötter, Stephan, Quick, Lynne J., Rambeau, Claire, Reichert, Markus, Reimann, Tony, Reiss, Lilian, Roettig, Christopher-Bastian, Rolf, Christian, Russell, James, Ruszkiczay-Rüdiger, Zsófia, Ryzner, Kamila, Sahakyan, Lilit, Salazar, Gary, Salomon, Ferréol, Sardar Abadi, Mehrdad, Sarı, Selma, Scardia, Giancarlo, Schiestl, Robert, Schimmelpfennig, Irene, Schirmer, Wolfgang, Schmidt, Christoph, Schmidt, Johannes, Schmitt, Laurent, Schneider, Birgit, Schulte, Philipp, Schulze, Tabea, Schunke, Torsten, Schwab, Markus J., Schwahn, Lea, Schwamborn, Georg, Schwark, Lorenz, Schäfer, Dieter, Schütt, Brigitta, Seltzer, Alan, Selzer, Johnnes, Severinghaus, Jeffrey, Shah, Rayees, Simon, Ulrich, Sirakov, Nikolay, Sirakova, Svoboda, Sontag-González, Mariana, Sprafke, Tobias, Stahlschmidt, Mareike, Stauber, Theresa, Steier, Peter, Steiner, Martin, Stojakowits, Philipp, Strobel, Paul, Stroessner, Kathrin, Struck, Julian, Stute, Martin, Stutzriemer, Marika, Stäuble, Harald, Szidat, Sönke, Taneva, Stanimira, Tanner, David, ASTER, Team, Temovski, Marjan, Tinapp, Christian, Tjallingii, Rik, Trappe, Julian, Tylmann, Wojciech, Ulfers, Arne, Ullmann, Tobias, Urban, Brigitte, van Meer, Mike, Varga, György, Veres, Daniel, Verstraeten, Gert, Videiko, Michail, Vinnepand, Mathias, Vockenhuber, Christof, Vogel, Hendrik, Voigt, Silke, von Suchodoletz, Hans, Vött, Andreas, Weiß, Marcel, Werther, Lukas, Wolf, Daniel, Wonik, Thomas, Wrozyna, Claudia, Wunderlich, Tina, Zech, Michael, Zech, Roland, Zeeden, Christian, Zielhofer, Christoph, Zolitschka, Bernd, Zöller, Ludwig, Żurek, Krzysztof, von Suchodoletz, Hans, Dietze, Elisabeth, Dietze, Michael, Meister, Julia, Wrozyna, Claudia, Zeeden, Christian, Kreutzer, Sebastian, and Hildebrandt, Dominic
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Quaternary ,Conference abstracts ,Geoscience - Abstract
Collection of conference abstracts presented at the vDEUQUA2021 (2021-09-30 to 2021-09-01), the virtual meeting of the German Quaternary Association (DEUQUA).
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- 2021
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12. Optically stimulated luminescence dating of fluvioglacial (sandur) sediments from north-eastern Germany
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Lüthgens, Christopher, Krbetschek, Matthias, Böse, Margot, and Fuchs, Margret C.
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- 2010
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13. The mystery of Bunge Land (New Siberian Archipelago): implications for its formation based on palaeoenvironmental records, geomorphology, and remote sensing
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Schirrmeister, Lutz, Grosse, Guido, Kunitsky, Viktor V., Fuchs, Margret C., Krbetschek, Matthias, Andreev, Andrei A., Herzschuh, Ulrike, Babyi, Olga, Siegert, Christine, Meyer, Hanno, Derevyagin, Alexander Y., and Wetterich, Sebastian
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- 2010
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14. A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification
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Fuchs, Margret C., primary, Beyer, Jan, additional, Lorenz, Sandra, additional, Sharma, Suchinder, additional, Renno, Axel D., additional, Heitmann, Johannes, additional, and Gloaguen, Richard, additional
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- 2021
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15. Tectonic and climatic forcing on the Panj river system during the Quaternary
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Fuchs, Margret C., Gloaguen, Richard, and Pohl, Eric
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- 2013
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16. Sandbox – Creating and Analysing Synthetic Sediment Sections with R
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Dietze , Michael, Kreutzer , Sebastian, and Fuchs , Margret C.
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Geoscientific concepts and hypotheses are usually formulated based on empirical data from the field or the laboratory (induction). After translation into models they can be applied to case study scenarios (deduction). However, the other way around – expressing hypotheses explicitly by models and test these by empiric data – is a rarely touched trail. There are several models tailored to investigate the boundary conditions and processes that generate, mobilise, route and eventually deposit sediment in a landscape. Thereby, the last part, sediment deposition, is usually omitted. Essentially, there is no model that explicitly focuses on mapping out the characteristics of sedimentary deposits – the material that is used by many disciplines to reconstruct landscape evolution. The R package sandbox is a model framework that allows creating and analysing virtual sediment sections for exploratory, explanatory, forecasting and inverse research questions. sandbox is a probabilistic and rule-based model framework for a wide range of possible applications. It has been advanced and linked to another model to allow the full work flow of modelling luminescence measurements. This contribution introduces news about recent developments and shows a set of applications.
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- 2021
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17. A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification
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Fuchs, Margret C., primary, Beyer, Jan, additional, Lorenz, Sandra, additional, Sharma, Suchinder, additional, Renno, Axel D., additional, Heitmann, Johannes, additional, and Gloaguen, Richard, additional
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- 2020
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18. Laser-induced fluorescence (LiF) spectroscopy for detecting REE cross-contaminations in the Smithsonian rare-earth element phosphate standards
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Fuchs, Margret C., primary, Beyer, Jan, additional, Lorenz, Sandra, additional, Sharma, Suchinder K., additional, Renno, Axel D., additional, Heitmann, Johannes, additional, and Gloaguen, Richard, additional
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- 2020
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19. Multi-method dating of ancient permafrost of the Batagay megaslump, East Siberia
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Wetterich, Sebastian, primary, Murton, Julian B., additional, Toms, Phillip, additional, Wood, Jamie, additional, Blinov, Alexander, additional, Opel, Thomas, additional, Fuchs, Margret C., additional, Merchel, Silke, additional, Rugel, Georg, additional, Gärtner, Andreas, additional, and Savvinov, Grigoriy, additional
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- 2020
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20. Multisensor characterization of WEEE polymers: spectral fingerprints for the recycling industry
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Schelkens, Peter, Kozacki, Tomasz, de Lima Ribeiro, Andréa, Fuchs, Margret C., Lorenz, Sandra, Röder, Christian, Madriz, Yuleika, Herrmann, Erik, Gloaguen, Richard, and Heitmann, Johannes
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- 2022
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21. Ice Complex formation on Bol’shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka
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Wetterich, Sebastian, Rudaya, Natalia, Kuznetsov, Vladislav, Maksimov, Fedor, Opel, Thomas, Meyer, Hanno, Günther, Frank, Bobrov, Anatoly, Raschke, Elena, Zimmermann, Heike, Strauss, Jens, Starikova, Anna, Fuchs, Margret C., Schirrmeister, Lutz, Wetterich, Sebastian, Rudaya, Natalia, Kuznetsov, Vladislav, Maksimov, Fedor, Opel, Thomas, Meyer, Hanno, Günther, Frank, Bobrov, Anatoly, Raschke, Elena, Zimmermann, Heike, Strauss, Jens, Starikova, Anna, Fuchs, Margret C., and Schirrmeister, Lutz
- Abstract
Late Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol’shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the MIS 7a-c Interglacial. The preservation of the ice-rich Yukagir IC proves its resilience to Last Interglacial and lateglacial-Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3 and MIS 2 ages exposed on Bol’shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveals grassshrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. Ice Complex data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.
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- 2019
22. A sensor network for non-invasive identification of semiconductors
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Berghmans, Francis, Zergioti, Ioanna, de Lima Ribeiro, Andréa, Röder, Christian, Fuchs, Margret C., Heitmann, Johannes, and Gloaguen, Richard
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- 2024
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23. Tectonic and climatic forcing on the rivers in Pamir
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Fuchs, Margret C. and Gloaguen, Richard
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- 2013
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24. A spectral library for laser-induced fluorescence analysis as a tool for rare earth element identification.
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Fuchs, Margret C., Beyer, Jan, Lorenz, Sandra, Sharma, Suchinder, Renno, Axel D., Heitmann, Johannes, and Gloaguen, Richard
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FLUORIMETRY , *LASER-induced fluorescence , *IDENTIFICATION - Abstract
With the recurring interest on rare-earth elements (REE), laser-induced fluorescence (LiF) may provide a powerful tool for their rapid and accurate identification at different stages along their value chain. Applications to natural materials such as rocks could complement the spectroscopy-based toolkit for innovative, non-invasive exploration technologies. However, the diagnostic assignment of detected emission lines to individual REE remains challenging, because of the complex composition of natural rocks in which they can be found. The resulting mixed spectra and the large amount of data generated demand for automated approaches of data evaluation, especially in mapping applications such as drill core scanning. LiF reference data provide the solution for robust REE identification, yet they usually remain in the form of tables of published emission lines. We show that a complete reference spectra library could open manifold options for innovative automated analysis. We present a library of high-resolution LiF reference spectra using the Smithsonian rare-earth phosphate standards for electron microprobe analysis.We employ three standard laser wavelengths (325 nm, 442 nm, 532 nm) to record representative spectra in the UV-visible to near-infrared spectral range (340-1080 nm). Excitation at all three laser wavelengths yielded characteristic spectra with distinct REE-related emission lines for EuPO4, TbPO4, DyPO4 and YbPO4. In the other samples, the high-energy excitation at 325 nm caused unspecific, broadband defect emissions. Here, lower energy laser excitation showed successful for suppressing non-REE-related emission. At 442 nm excitation, REE-reference spectra depict the diagnostic emission lines of PrPO4, SmPO4 and ErPO4. For NdPO4 and HoPO4 most efficient excitation was achieved with 532 nm. Our results emphasise on the possibility of selective REE excitation by changing the excitation wavelength according to the suitable conditions for individual REEs. Our reference spectra provide a database for transparent and reproducible evaluation of REE-bearing rocks. The LiF spectral library is available at https://zenodo.org/ and the registered DOI: http://doi.org/10.5281/zenodo.4054606 (Fuchs et al., 2020). It gives access to traceable data for manifold further studies on comparison of emission line positions, emission line intensity ratios and splitting into emission line sub-levels or can be used as reference or training data for automated approaches of component assignment. [ABSTRACT FROM AUTHOR]
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- 2020
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25. Feldspar flotation as a quartz-purification method in cosmogenic nuclide dating: A case study of fluvial sediments from the Pamir
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Sulaymonova, Vasila A., primary, Fuchs, Margret C., additional, Gloaguen, Richard, additional, Möckel, Robert, additional, Merchel, Silke, additional, Rudolph, Martin, additional, and Krbetschek, Matthias R., additional
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- 2018
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26. Yedoma Ice Complex of the Buor Khaya Peninsula (southern Laptev Sea)
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Schirrmeister, Lutz, Schwamborn, Georg, Overduin, Pier Paul, Strauss, Jens, Fuchs, Margret C., Grigoriev, Mikhail, Yakshina, Irina, Rethemeyer, Janet, Dietze, Elisabeth, Wetterich, Sebastian, Schirrmeister, Lutz, Schwamborn, Georg, Overduin, Pier Paul, Strauss, Jens, Fuchs, Margret C., Grigoriev, Mikhail, Yakshina, Irina, Rethemeyer, Janet, Dietze, Elisabeth, and Wetterich, Sebastian
- Abstract
The composition of perennially frozen deposits holds information on the palaeo-environment during and following deposition. In this study, we investigate late Pleistocene permafrost at the western coast of the Buor Khaya Peninsula in the south-central Laptev Sea (Siberia), namely the prominent eastern Siberian Yedoma Ice Complex (IC). Two Yedoma IC exposures and one drill core were studied for cryolithological (i.e. ice and sediment features), geochemical, and geochronological parameters. Borehole temperatures were measured for 3 years to capture the current thermal state of permafrost. The studied sequences were composed of ice-oversaturated silts and fine-grained sands with considerable amounts of organic matter (0.2 to 24 wt %). Syngenetic ice wedges intersect the frozen deposits. The deposition of the Yedoma IC, as revealed by radiocarbon dates of sedimentary organic matter, took place between 54.1 and 30.1 kyr BP. Continued Yedoma IC deposition until about 14.7 kyr BP is shown by dates from organic matter preserved in ice-wedge ice. For the lowermost and oldest Yedoma IC part, infrared-stimulated luminescence dates on feldspar show deposition ages between 51.1 +/- 4.9 and 44.2 +/- 3.6 kyr BP. End-member modelling was applied to grain-size-distribution data to determined sedimentation processes during Yedoma IC formation. Three to five robust end-members were detected within Yedoma IC deposits, which we interpret as different modes of primary and reworked unconfined alluvial slope and fan deposition as well as of localized eolian and fluvial sediment, which is overprinted by in situ frost weathering. The cryolithological inventory of the Yedoma IC preserved on the Buor Khaya Peninsula is closely related to the results of other IC studies, for example, to the west on the Bykovsky Peninsula, where formation time (mainly during the late Pleistocene marine isotope stages (MIS) 3 interstadial) and formation conditions were similar. Local freezing conditions on Buor K
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- 2017
27. Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)
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Opel, Thomas, Wetterich, Sebastian, Meyer, Hanno, Dereviagin, Alexander Y., Fuchs, Margret C., Schirrmeister, Lutz, Opel, Thomas, Wetterich, Sebastian, Meyer, Hanno, Dereviagin, Alexander Y., Fuchs, Margret C., and Schirrmeister, Lutz
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To reconstruct palaeoclimate and palaeoenvironmental conditions in the northeast Siberian Arctic, we studied late Quaternary permafrost at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared-stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst-lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during Marine Isotope Stage (MIS) 5. Ground-ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as a proxy for past winter climate conditions covers about 200 000 years and is supplemented by stable isotopes of pore and segregated ice which reflect annual climate conditions overprinted by freezing processes. Our ice-wedge stable-isotope data indicate substantial variations in northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between glacial and interglacial times but also over the last millennia to centuries. Stable isotope values of ice complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during MIS5c and by Holocene ice-wedge stable isotopes. Modern ice-wedge stable isotopes are most enriched and testify to the recent winter warming in the Arctic. Hence, ice-wedge-based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost
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- 2017
28. Ice Complex chronologies and environments in western Beringia
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Wetterich, Sebastian, Tumskoy, Vladimir, Rudaya, Natalia, Andreev, Andreev, Kuznetsov, Vladislav, Fuchs, Margret C., Schwamborn, Georg, Opel, Thomas, Meyer, Hanno, and Schirrmeister, Lutz
- Abstract
Polygon tundra with tundra-steppe vegetation cover and growing syngenetic ice-wedge nets evolved during stadial and interstadial periods of the late Quaternary in non-glaciated Beringia. The depositional relict of such environments is called Ice Complex (IC; ледовый комплекс [ledovyi kompleks] in Russian) permafrost. The IC archives preserve information of past periglacial and climate landscape conditions of mid- and late Pleistocene Beringian environments. In certain locations of the East Siberian Arctic, IC remnants of different age and extent are known. While using IC deposits as archives of palaeo-landscape and palaeo-environmental dynamics, summer and winter conditions over large time-scales are detectable. Commonly applied summer proxy include palaeontological proxy such as pollen, plant macrofossils, insect fossils and, most prominent, mammal fossils of the Mammoth fauna, while geochemical and stable isotope properties of ground ice allow for insights into freezing and winter conditions. IC chronologies are challenging because the deposition and post-sedimentary preservation of ice-rich permafrost are triggered by palaeo-relief settings and related processes as well as by the intensity of thermokarst. This complicates geochronological interpretations, as representatives of consecutive late Quaternary periods may be found at laterally different positions and altitudes in coastal and riverine exposures. Shifts between permafrost aggradation and degradation over time frequently cause gaps in sequences. Furthermore, numerical dating of IC mainly includes different approaches such as radiocarbon (14C) dating of organic material, infrared and optically-stimulated luminescence (IRSL, OSL) dating on feldspar and quartz grains, radioisotope disequilibria of thorium-230 to uranium-234 (230Th/U) dating of peat, and chlorine-36 to chloride ratios (36Cl/Cl) of ground ice. The application of various geochronologic methods to cover the age intervals of certain IC deposits implies that different permafrost components (organic, mineralic, ice) as well as different geochemical and physical properties have to be employed. At the southern coast of Bol'shoy Lyakhovsky Island at least four distinct IC strata were previously described and dated, which cover among the longest time interval of late Quaternary terrestrial permafrost deposition in East Siberia; starting about 200 kyr ago. With this contribution we seek to present and discuss our current understanding of IC chronologies preserved on the New Siberian Archipelago including MIS2 Yedoma (Sartan) IC, MIS3 Yedoma (Molotkov) IC, MIS5 Buchchagy IC, and MIS7a Yukagir IC. Geocryological and palaeo-environmental proxy data highlight past periglacial landscape and deposition processes to deduce past climate conditions and Beringian palaeo-ecological settings and dynamics.
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- 2016
29. Late Quaternary records from the Chatanika River valley near Fairbanks (Alaska)
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Schirrmeister, Lutz, Meyer, Hanno, Andreev, Andreev, Wetterich, Sebastian, Kienast, Frank, Bobrov, Anatoly, Fuchs, Margret C., Sierralta, Melanie, and Herzschuh, Ulrike
- Abstract
Perennially-frozen deposits are considered as excellent paleoenvironmental archives similar to lacustrine, deep marine, and glacier records because of the long-term and good preservation of fossil records under stable permafrost conditions. A permafrost tunnel in the Vault Creek Valley (Chatanika River Valley, near Fairbanks) exposes a sequence of frozen deposits and ground ice that provides a comprehensive set of proxies to reconstruct the late Quaternary environmental history of Interior Alaska. The multi-proxy approach includes different dating techniques (radiocarbon-accelerator mass spectrometry [AMS 14C], optically stimulated luminescence [OSL], thorium/uranium radioisotope disequilibria [230Th/U]), as well as methods of sedimentology, paleoecology, hydrochemistry, and stable isotope geochemistry of ground ice. The studied sequence consists of 36-m-thick late Quaternary deposits above schistose bedrock. Main portions of the sequence accumulated during the early and middle Wisconsin periods. The lowermost unit A consists of about 9-m-thick ice-bonded fluvial gravels with sand and peat lenses. A late Sangamon (MIS 5a) age of unit A is assumed. Spruce forest with birch, larch, and some shrubby alder dominated the vegetation. High presence of Sphagnum spores and Cyperaceae pollen points to mires in the Vault Creek Valley. The overlying unit B consists of 10-m-thick alternating fluvial gravels, loess-like silt, and sand layers, penetrated by small ice wedges. OSL dates support a stadial early Wisconsin (MIS 4) age of unit B. Pollen and plant macrofossil data point to spruce forests with some birch interspersed with wetlands around the site. The following unit C is composed of 15-m-thick ice-rich loess-like and organic-rich silt with fossil bones and large ice wedges. Unit C formed during the interstadial mid-Wisconsin (MIS 3) and stadial late Wisconsin (MIS 2) as indicated by radiocarbon ages. Post-depositional slope processes significantly deformed both, ground ice and sediments of unit C. Pollen data show that spruce forests and wetlands dominated the area. The macrofossil remains of Picea, Larix, and Alnus incana ssp. tenuifolia also prove the existence of boreal coniferous forests during the mid-Wisconsin interstadial, which were replaced by treeless tundra-steppe vegetation during the late Wisconsin stadial. Unit C is discordantly overlain by the 2-m-thick late Holocene deposits of unit D. The pollen record of unit D indicates boreal forest vegetation similar to the modern one. The permafrost record from the Vault Creek tunnel reflects more than 90 ka of periglacial landscape dynamics triggered by fluvial and eolian accumulation, and formation of ice-wedge polygons and post-depositional deformation by slope processes. The record represents a typical Wisconsin valley-bottom facies in Central Alaska.
- Published
- 2016
30. Late Quaternary accretion and decline of syngenetic ice-rich permafrost
- Author
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Wetterich, Sebastian, Strauss, Jens, Fuchs, Margret C., and Schirrmeister, Lutz
- Abstract
The region of perennially frozen ground constitutes one quarter of the northern hemisphere landmass. Negative annual mean air temperatures and ground freezing periods exceeding ground thaw periods are the prerequisites for downward freezing of loose deposits and bedrock in non-glaciated regions. Hence, permafrost distribution and thickness on Earth are closely related to late Quaternary climate variations and ecosystem modifications. Generally, glacial stages are expected to promote permafrost accretion and ground ice formation in accumulating sediments,whereas interglacial stages lead to intense permafrost thaw and ground-ice melt. Deep freezing synchronous with ongoing sedimentation is termed as syngenetic while epigenetic freezing occurs in pre-existing deposits. Typical landforms of syngenetic permafrost are ice-wedge polygons of past tundra environments. Ice-rich silty and/or peaty deposits intersected by large ice wedges (up to several decameters in height and meters in with) build-up unique Ice Complex (IC) strata, which are aligned to mid- and late Pleistocene stadial and interstadial stages. The most prominent example for such formations is the Yedoma IC of MIS 3 interstadial age. Increasing air and ground temperatures during warm stages disturbed the thermal equilibrium at the upper permafrost boundary and subsequently led to permafrost thaw, ground-ice melt and surface subsidence. Typical permafrost degradation processes are thermokarst and thermo-erosion that result in large lake-filled basins (up to kilometers in diameter) and valley structures, respectively. The modern periglacial surface in Alaskan and East Siberian lowlands preserves Yedoma IC remnants in uplands and hills next to widely-distributed thermokarst basins since lateglacial and Holocene warming affected up to 70% of the original IC distribution on an area of more than 1,000,000 km2. The overarching climate-driven pattern of cold-stage IC permafrost accretion and warm-stage IC permafrost degradation provides, however, only a first-order approximation in understanding past permafrost dynamics. Beside long-term freezing conditions also thin snow cover and winter precipitation were required to create ice-rich permafrost such as Yedoma IC. Its dynamics are furthermore altered by on-site conditions in water supply, relief and vegetation, which promote either aggradation or degradation processes. For example, current climate warming certainly enables large-scale permafrost thaw and widespread thermokarst. But, ice-wedge growth and permafrost accretion occurs in places after local disturbance such as thermokarst lake drainage causing a change from lacustrine to palustrine environments. Repeated occupation of thermokarst basins by lakes is commonly described as thaw-lake cycle although hereditary structures, i.e. pre-existing basins promote the lacustrine refill and highlight the path-dependence of thermokarst processes and the importance of the paleo-relief. Traces of periglacial landforms preserved in permafrost deposits are indicative of the interplay between past climate and landscape settings. Besides climate control on-site periglacial morphology, hydrology and vegetation alter permafrost regimes, and are to be taken into account when interpreting late Quaternary permafrost chronologies. In summary, the completeness of certain vertical permafrost sequences depends (1) on paleo-relief that defined past accumulation and (thermo-)erosion areas, and (2) on overprints of degradation periods that erased older formations.
- Published
- 2016
31. Exploratory data analysis using the R package 'Luminescence' - Towards data mining in OSL applications
- Author
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Burow, Christoph, Zens, Jörg, Kreutzer, Sebastian, Dietze, Michael, Fuchs, Margret C., Fischer, Manfred, Schmidt, Christoph, and Brückner, Helmut
- Published
- 2016
- Full Text
- View/download PDF
32. Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)
- Author
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Opel, Thomas, primary, Wetterich, Sebastian, additional, Meyer, Hanno, additional, Dereviagin, Alexander Y., additional, Fuchs, Margret C., additional, and Schirrmeister, Lutz, additional
- Published
- 2017
- Full Text
- View/download PDF
33. Yedoma Ice Complex of the Buor Khaya Peninsula (southern Laptev Sea)
- Author
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Schirrmeister, Lutz, primary, Schwamborn, Georg, additional, Overduin, Pier Paul, additional, Strauss, Jens, additional, Fuchs, Margret C., additional, Grigoriev, Mikhail, additional, Yakshina, Irina, additional, Rethemeyer, Janet, additional, Dietze, Elisabeth, additional, and Wetterich, Sebastian, additional
- Published
- 2017
- Full Text
- View/download PDF
34. Yedoma Ice Complex of the Buor Khaya Peninsula (southern Laptev Sea)
- Author
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Schirrmeister, Lutz, primary, Schwamborn, Georg, additional, Overduin, Pier Paul, additional, Strauss, Jens, additional, Fuchs, Margret C., additional, Grigoriev, Mikhail, additional, Yakshina, Irina, additional, Rethemeyer, Janet, additional, Dietze, Elisabeth, additional, and Wetterich, Sebastian, additional
- Published
- 2016
- Full Text
- View/download PDF
35. Supplementary material to "Yedoma Ice Complex of the Buor Khaya Peninsula (southern Laptev Sea)"
- Author
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Schirrmeister, Lutz, primary, Schwamborn, Georg, additional, Overduin, Pier Paul, additional, Strauss, Jens, additional, Fuchs, Margret C., additional, Grigoriev, Mikhail, additional, Yakshina, Irina, additional, Rethemeyer, Janet, additional, Dietze, Elisabeth, additional, and Wetterich, Sebastian, additional
- Published
- 2016
- Full Text
- View/download PDF
36. Emission spectroscopy for the identification of rare earth elements using laser-induced photoluminescence
- Author
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Fuchs, Margret C., primary, Gloaguen, Richard, additional, Beyer, Jan, additional, Jakob, Sandra, additional, and Heitman, Johannes, additional
- Published
- 2016
- Full Text
- View/download PDF
37. Introducing an R package for luminescence dating analysis
- Author
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Sebastian Kreutzer, Christoph Schmidt, Fuchs, Margret C., Michael Dietze, Manfred Fischer, Markus Fuchs, Department of Geography, Justus-Liebig- University, Justus-Liebig-Universität Gießen (JLU), Geographical Institute, Geomorphology, University of Bayreuth, Universität Bayreuth, Institute for Geography, University of Cologne, Universität zu Köln, Institute for Geology [Freiberg] ( Institut für Geologie [Freiberg]), Technishe Universität Bergakademie Freiberg (TU Bergakademie Freiberg), Institute of Geography, TU Dresden, and Technische Universität Dresden = Dresden University of Technology (TU Dresden)
- Subjects
[STAT.AP]Statistics [stat]/Applications [stat.AP] ,curve fitting ,luminescence dating ,radial plot ,LM-OSL - Abstract
International audience; _____________________________________________________________________________________________ Abstract For routine luminescence dating applications the commonly used Risø readers are bundled with analysis software, such as Viewer or Analyst. These software solutions are appropriate for most of the regular dating and publication jobs, and enable assessment of luminescence characteristics and provide basic statistical data treatment. However, for further statistical analysis and data treatments, this software may reach its limits. In such cases, open programming languages are a more appropriate approach. Here, we present the R package 'Luminescence' for a more flexible handling of luminescence data and related plotting purposes, using the statistical programming language R. The R language as well as the package and the source code are provided under the General Public License (GPL) conditions and are available for free. The basic functionality of the package is described along with three application examples. This package is not an alternative to the existing software (Analyst, Viewer) but may provide a collection of additional tools to analyse luminescence data and serve as a platform for further contributions.
- Published
- 2012
38. Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces
- Author
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Fuchs, Margret C., Gloaguen, Richard, Krbetschek, Matthias R., Szulc, Adam, Fuchs, Margret C., Gloaguen, Richard, Krbetschek, Matthias R., and Szulc, Adam
- Abstract
Calculated incision rates along the Panj, the main river of the Pamir, are used to investigate any influence by tectonics or climate on the architecture of the river. The depositional ages of Panj River terraces were calculated using optically stimulated luminescence (OSL) dating of terrace sand. Fluvial incision rates were generated by integrating the terrace depositional ages with accurate kinematic GPS measurements of terrace heights above the modern Panj. We investigated 16 terraces along the Panj at the western Pamir margin and one terrace from the Vakhsh River to the north of the Pamir. The results reveal brief periods of fluvial deposition over the past 26 kyr. The oldest Panj terrace depositional ages coincide with early MIS 2 and MIS 2/1 glaciations on the Pamir Plateau. Younger terrace ages have no apparent link with glacial cycles. Terraces with varying heights above the modern Panj at different localities yielded similar depositional ages. This suggests that local conditions have determined fluvial incision rates. Combining all of the terrace measurements, the average incision rate of the Panj over the last 26 kyr has been ~ 5.6 mm/yr. A high mean incision rate of ~ 7.3 mm/yr was calculated from terraces where the Panj has cut a steep-sided valley through the Shakhdara dome. Significantly lower incision rates (~ 2–3 mm/yr) were calculated from terraces where the Panj flows along the southern boundaries of the Shakhdara and Yazgulom domes. At those localities, graded segments of the Panj River profile and increased valley widths are indicative of local base levels. Downstream of the Yazgulom dome, river incision rates are generally lower (~ 4–5 mm/yr) than the Panj average. However, there is one exception where higher incision rates (~ 6 mm/yr) were calculated upstream of the Darvaz Fault Zone, a major tectonic feature that forms the western boundary of the Pamir. The Vakhsh River terrace to the north of the Pamir yielded a lower incision rate (~ 3 mm/yr)
- Published
- 2014
39. Data processing in luminescence dating analysis: An exemplary workflow using the R package 'Luminescence'
- Author
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Fuchs, Margret C., Kreutzer, Sebastian, Burow, Christoph, Dietze, Michael, Fischer, Manfred, Schmidt, Christoph, Fuchs, Markus, Fuchs, Margret C., Kreutzer, Sebastian, Burow, Christoph, Dietze, Michael, Fischer, Manfred, Schmidt, Christoph, and Fuchs, Markus
- Abstract
The first version of the R package ‘Luminescence’ was released and published in 2012. Since then, the package has been continuously improved by implementing further measurement protocols, adding age models, and extending functions. In geoscientific applications, luminescence dating requires a series of data processing procedures. A comprehensive and replicate analysis of luminescence data using the R package ‘Luminescence’, therefore, suggests combining selected functions. With this contribution, we provide a practical example of a workflow from reading measurement data to age modelling. The exemplary data processing routine is applied to an OSL data set of a fluvial sediment sample from the Pamir Mountains.
- Published
- 2014
40. Holocene sediment dynamics in the vicinity of a roman battle field near Osnabrueck (NW-Germany)
- Author
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Bussmann, Jens, Stele, Andreas, Härtling, Joachim W., Zielhofer, Christoph, Fuchs, Margret C., Bussmann, Jens, Stele, Andreas, Härtling, Joachim W., Zielhofer, Christoph, and Fuchs, Margret C.
- Abstract
The interpretation of the Holocene sediment dynamics at Mount Kalkriese in the Wiehengebirge mountains (northwestern Germany) shows that the onset and the extent of human land use corresponds well with most colluvial archives in Central European loess regions: The onset of soil erosion in the Wiehengebirge mountains started during the Early Neolithic period. For the Bronze Age, erosion and colluviation are documented as well. A considerable increase of soil erosion with correlated reworking of colluvial sediments was found since Roman times, indicated by the burial of Germanic artifacts of Roman Age at the toe-slopes. Unfortunately, no absolute ages exist for the post roman period. However, in analogy to other sites it can be assumed that highest erosion rates occurred during the Middle Ages. This study also shows typical problems when using the soilscape model for calculating the sediment budget: since truncated soil profifi les are used to model eroded volumes, only minimum soil erosion is mapped. This can lead to a considerable discrepancy between eroded and accumulated volumes. Therefore, we have to assume that soil erosion at the plateau and in upslope areas at Mount Kalkriese was much higher than predicted by the soilscape model. In addition, extensive anthropogenic accumulation soils (Plaggen soils) were deposited in the downslope areas, thereby increasing the discrepancy between erosion and accumulation volumes. The combination of mapping erosion and accumulation with augerings and trenches, calculation of the mass balance by GIS, relative and absolute dating and geophysical evidence provides a powerful tool in landscape interpretation. Due to the small number of numerical ages, the landscape model at Mount Kalkriese has to be considered preliminary.
- Published
- 2014
41. Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait).
- Author
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Wetterich, Sebastian, Meyer, Hanno, Schirrmeister, Lutz, Opel, Thomas, Dereviagin, Alexander Yu., and Fuchs, Margret C.
- Abstract
To reconstruct palaeoclimate and palaeonvironmental conditions in the Northeast Siberian Arctic, we studied late Quaternary permafrost deposits at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during the Marine Isotope Stage (MIS) 5. Ground ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as proxy for past winter climate conditions covers the last about 200 thousand years and is supplemented by texture-ice stable isotopes which contain annual climate conditions overprinted by freezing processes. Our ice wedge stable-water isotope data indicate substantial variations in Northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between Glacial and Interglacial but also over the last millennia to decades. Stable isotope values of Ice Complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during the MIS5c and by Holocene ice-wedge stable-isotopes. Modern ice-wedge stable isotopes are most enriched and testify the recent winter warming in the Arctic. Hence, ice-wedge based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost and allow for distinguishing between seasonal trends of past climate dynamics. Future progress in ice-wedge dating and an improved temporal resolution of ice-wedge derived climate information may help to fully explore the palaeoclimatic potential of ice wedges. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces
- Author
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Fuchs, Margret C., primary, Gloaguen, Richard, additional, Krbetschek, Matthias, additional, and Szulc, Adam, additional
- Published
- 2014
- Full Text
- View/download PDF
43. Holocene Sediment Dynamics in the Vicinity of a Roman battlefield near Osnabrück (NW-Germany)
- Author
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Bussmann, Jens, primary, Stele, Andreas, additional, Härtling, Joachim W., additional, Zielhofer, Christoph, additional, and Fuchs, Margret C., additional
- Published
- 2014
- Full Text
- View/download PDF
44. A practical guide to the R package Luminescence
- Author
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Dietze, Michael, Kreutzer, Sebastian, Fuchs, Margret C., Burow, Christoph, Fischer, Manfred, Schmidt, Christoph, Dietze, Michael, Kreutzer, Sebastian, Fuchs, Margret C., Burow, Christoph, Fischer, Manfred, and Schmidt, Christoph
- Abstract
A practical guide for the R package 'Luminescence' is provided. An introduction on data types in R is given first, followed by a guideline on how to import, analyse and visualise typical SAR-OSL measurement data.
- Published
- 2013
45. Introducing an R package for luminescence dating analysis
- Author
-
Kreutzer, Sebastian, Schmidt, Christoph, Fuchs, Margret C., Dietze, Michael, Fischer, Manfred, Fuchs, Markus, Kreutzer, Sebastian, Schmidt, Christoph, Fuchs, Margret C., Dietze, Michael, Fischer, Manfred, and Fuchs, Markus
- Abstract
For routine luminescence dating applications the commonly used Risø readers are bundled with analysis software, such as Viewer or Analyst. These software solutions are appropriate for most of the regular dating and publication jobs, and enable assessment of luminescence characteristics and provide basic statistical data treatment. However, for further statistical analysis and data treatments, this software may reach its limits. In such cases, open programming languages are a more appropriate approach. Here, we present the R package ‘Luminescence’ for a more flexible handling of luminescence data and related plotting purposes, using the statistical programming language R. The R language as well as the package and the source code are provided under the General Public License (GPL) conditions and are available for free. The basic functionality of the package is described along with three application examples. This package is not an alternative to the existing software (Analyst, Viewer) but may provide a collection of additional tools to analyse luminescence data and serve as a platform for further contributions.
- Published
- 2012
46. Yedoma Ice Complex of the Buor Khaya Peninsula (southernLaptev Sea).
- Author
-
Schirrmeister, Lutz, Schwamborn, Georg, Overduin, Pier Paul, Strauss, Jens, Fuchs, Margret C., Grigoriev, Mikhail, Irina Yakshina, Rethemeyer, Janet, Dietze, Elisabeth, and Wetterich, Sebastian
- Subjects
PENINSULAS ,PERMAFROST ,SEDIMENTATION & deposition ,PALEOENVIRONMENTAL studies ,GEOLOGICAL time scales - Abstract
The composition of permafrost deposits holds information on the paleo-environment during and following deposition. Sampling natural exposures and drilling are two methods used to access permafrost archives. In this study, we combine both approaches at the western coast of the Buor Khaya Peninsula in the south-central Laptev Sea (Siberia) to study late Pleistocene permafrost; namely the Yedoma Ice Complex (IC), which is prominent across much of eastern Siberia. Two Yedoma IC exposures and one drill core were studied for cryolithological (i.e. ice and sediment features), geochemical, and geochronological parameters. Borehole temperatures were measured for three years to capture the current thermal state of permafrost. The studied sequences were composed of ice-oversaturated silts and fine-grained sands with considerable amounts of organic matter (0.2 to 24 wt%). Syngenetic ice wedges intersect the frozen deposits. The deposition of the Yedoma IC, as revealed by radiocarbon dates of sedimentary organic matter, took place between 54.1 and 30.1 kyr BP. Continued Yedoma IC deposition until about 14.7 kyr BP is shown by dates from organic matter preserved in ice-wedge ice. For the lowermost and oldest Yedoma IC part, infrared-stimulated luminescence dates on feldspar show deposition ages between 51.1 ± 4.9 and 44.2 ± 3.6 kyr BP. End-member modelling was applied to grain-size-distribution data to unmix sedimentation processes during Yedoma IC formation. Three to five statistical end-members were detected within Yedoma IC deposits of different ages, which we interpret as signals of alluvial, proluvial, and aeolian transport and redeposition as well as in-situ frost weathering in a polygonal tundra landscape. The study captures the internal variation of Yedoma IC characteristics and puts its local stratigraphy into regional scale. The cryolithological inventory of the Yedoma IC preserved on the Buor Khaya Peninsula is closely related to the results of other IC studies, for example, to the west on the Bykovsky Peninsula, where formation time (mainly during the late Pleistocene MIS 3 interstadial) and conditions were similar. Local freezing conditions on Buor Khaya, however, differed, and created solute-enriched (salty) and isotopically-light porewater pointing to deep active-layer and thaw-bulb freezing after deposition. Due to intense coastal erosion, the biogeochemical signature of the studied Yedoma IC represents the terrestrial end-member for, and is closely related to organic matter currently being deposited in the marine realm of the Laptev Sea shelf. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
47. Multisensor characterization of WEEE polymers: spectral fingerprints for the recycling industry.
- Author
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de Lima Ribeiro, Andréa, Fuchs, Margret C., Lorenz, Sandra, Röder, Christian, Madriz, Yuleika, Herrmann, Erik, Gloaguen, Richard, and Heitmann, Johannes
- Published
- 2022
- Full Text
- View/download PDF
48. A spectral library for Smithsonian rare-earth element phosphate standards using laser-induced fluorescence.
- Author
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Fuchs, Margret C., Beyer, Jan, Lorenz, Sandra, Sharma, Suchinder K., Renno, Axel D., Heitmann, Johannes, and Gloaguen, Richard
- Subjects
- *
LASER-induced fluorescence , *ELECTRON probe microanalysis , *PHOSPHATE minerals , *LIE detectors & detection , *RARE earth metals , *DATA libraries - Abstract
Innovation in raw material exploration relies on efficient and non-invasive technologies. Spectroscopy based methods have proven great potential to deliver instant and spatially continuous information on the composition of an investigated surface. Several studies successfully applied laser-induced fluorescence (LIF) for rare-earth element (REE) identification in natural rocks. However, the diagnostic assignment of detected emission lines remains a complex task, because of the highly variable composition of natural rocks. It needs a transfer of the profound knowledge from the field of applied physics and synthetic materials to the natural rock material under investigation. The evaluation of measured spectra and robust assignment of REEs requires reference data, yet usually based on tables of published emission lines, while data of complete reference spectra are not available.We present a library of reference spectra for all luminescent rare-earth elements using the Smithsonian rare-earth phosphate standards for electron microprobe analysis. We employ laser-induced fluorescence at three commonly used laser wavelengths (325 nm, 442 nm, 532 nm) to acquire reference spectra for REE phosphate minerals in the visible to near-infrared spectral range (350 – 1080 nm). Excitation at all three laser wavelengths yielded spectra with distinct REE-related emission lines for EuPO4, TbPO4, DyPO4 and YbPO4. Lower energy laser excitation at 442 nm showed successful especially for suppressing non-REE-related broadband defect emission. Resulting REE-reference spectra include those from PrPO4, SmPO4 and ErPO4. For NdPO4 and HoPO4 most efficient excitation was achieved with 532 nm. The diagnostic emission lines of GdPO4 lie outside the detection range and none of the three laser wavelengths was appropriate for TmPO4 excitation.Our results demonstrate the suitability of LIF for REE detection and especially the possibility of selective element excitation. Our reference spectra provide the full spectral information at high resolution (0.13nm) as a basis for an improved evaluation of REE-bearing natural rocks allowing for data analysis of emission line positions, emission line intensity ratios and splitting into emission line sub-levels. The spectral library data support the use of LIF for REE analysis in natural samples and its application in raw material exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2019
49. A practical guide to the R package Luminescence
- Author
-
Michael Dietze, Sebastian Kreutzer, Fuchs, Margret C., Christoph Burow, Manfred Fischer, Christoph Schmidt, Institute of Geography, TU Dresden, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Department of Geography, Justus-Liebig- University, Justus-Liebig-Universität Gießen (JLU), Institute for Geology [Freiberg] ( Institut für Geologie [Freiberg]), Technishe Universität Bergakademie Freiberg (TU Bergakademie Freiberg), Institute for Geography, University of Cologne, Universität zu Köln, Geographical Institute, Geomorphology, University of Bayreuth, and Universität Bayreuth
- Subjects
plotting ,[STAT.AP]Statistics [stat]/Applications [stat.AP] ,data analysis ,luminescence dating - Abstract
International audience; A practical guide for the R package 'Luminescence' is provided. An introduction on data types in R is given first, followed by a guideline on how to import, analyse and visualise typical SAR-OSL measurement data. Introduction Since the R package 'Luminescence' has been introduced by Kreutzer et al. (2012) the developer team is continuously asked for advice from the luminescence dating community. Such requests considerably help us to further improve the package and make the tools more efficient and user friendly. However, most of these queries are not directed to specific problems of the provided functions but rather on the usage of R and the package in general. Motivated by an e-mail conversation with Geoff Duller this contribution aims to provide an example-based, short practical guide to R and the package 'Luminescence'. First, we focus on properties and ways to index different sorts of data structures, which are essential for an efficient use of the R package 'Luminescence'. A second section describes processing steps for luminescence data, from importing a BIN-file to plotting a D e distribution. A third section comprises the examples in a comprehensive code section. Throughout the manuscript R calls or R related code snippets are typed in monospaced letters. In some cases, numerical and graphical output was truncated for illustrative reasons.
50. Exploring the potential of luminescence methods for dating Alpine rock glaciers
- Author
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Ralph Böhlert, Matthias Krbetschek, Markus Egli, Frank Preusser, Margret C. Fuchs, University of Zurich, and Fuchs, Margret C
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Thermoluminescence dating ,Landform ,Stratigraphy ,1901 Earth and Planetary Sciences (miscellaneous) ,Rock glacier ,Geology ,Permafrost ,01 natural sciences ,Paleontology ,10122 Institute of Geography ,Earth and Planetary Sciences (miscellaneous) ,910 Geography & travel ,1913 Stratigraphy ,Luminescence ,Geomorphology ,Quartz ,1907 Geology ,0105 earth and related environmental sciences - Abstract
Rock glaciers contain valuable information about the spatial and temporal distribution of permafrost. The wide distribution of these landforms in high mountains promotes them as useful archives for the deciphering of the environmental conditions during their formation and evolution. However, age constraints are needed to unravel the palaeoclimatic context of rock glaciers, but numerical dating is difficult. Here, we present a case study assessing the potential of luminescence techniques (OSL, IRSL) to date the inner sand-rich layer of active rock glaciers. We focus on the signal properties and the resetting of the signal prior to deposition by investigating single grains. While most quartz shows low signal intensities and problematic luminescence characteristics, K-feldspar exhibits much brighter and well-performing signals. Most signals from plagioclases do not show suitable properties. Luminescence signals far below saturation indicate distinct but differential bleaching. The finite mixture model was used to determine the prominent populations in the equivalent dose distributions. The luminescence ages represent travel times of grains since incorporation into the rock glacier and hence, minimum ages of rock glacier formation. Luminescence ages between 3 ka and 8 ka for three rock glaciers from the Upper Engadine and Albula region (Swiss Alps) agree well with independent age estimates from relative and semi-quantitative approaches. Therefore, luminescence seems to have the potential of revealing age constraints about processes related to the formation of rock glaciers, but further investigations are required for solving some of the problems remaining and reducing the dating uncertainties.
- Published
- 2013
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