Dans le cadre du Symposium CH-QUAT de cette année au Swiss Geoscience Meeting, il a été possible de soutenir les étudiants en Bachelor & Master, les doctorants et les postdocs en payant les frais de conférence et de voyage.
Ronald Lloren / PhD Thesis at the Departement of Earth Science / ETH Zürich, Switzerland and Eawag - Swiss Federal Institute of Aquatic Science and Technology / Duebendorf, Switzerland
Attending the 2018 LacCore Continental Scientific Drilling summer school at the University of Minnesota was a great opportunity for me to learn new coring techniques, sediment data analyses and management planning. My participation was made possible through the additional financial support from the Swiss Quaternary Science Society (CH-QUAT).
Before the summer school, my coring skills were only limited to gravity-, Uwetech- and piston-corers. It has broadened to Kullenberg gravity piston corer and freeze corer since then. In the 9-day comprehensive program, two components strongly captured my interest. One was the initial core description (ICD) in which we used the TMI (Tool for Microscopic Identification) using smear slides to characterize unconsolidated sediments. This tool provides information on past depositional environments including geochemistry, mineralogy, flora and fauna. The other session, which I believe was very beneficial for me, was the project planning and management aspect. After the summer school, I went directly to a fieldwork in Samoa for 2 weeks and what I learned from the said topic was immediately put into practice. Definitely valuable as well since I am slated again for another fieldwork in August 2019 to French Polynesia for my dissertation: where I will collect peat cores in order to investigate the influence of anthropogenic activities and climatological trends during the late Holocene in the South Pacific.
Moreover, the summer school was also a perfect venue to meet and work with other scientists, professors, and early-career scientists who are in the same field as mine. It was an opportunity to exchange ideas with them, learn about their current research, and gain insights on how to improve my own research. It was not just coring sediment samples and meeting new scientists, but it was also an opportunity to market what we do to young kids, to ignite their curiosity in Earth Science studies. A day was allotted to market our work and practice communication science in a nearby town and showcased what we do to everyone especially to young kids.
I have gained immense knowledge after attending this summer school. Something I can bring back and share to my home country, the Philippines. It has equipped me with the cutting-edge techniques and innovations in sediment-coring analyses and market my science.
EAWAG - Department Surface Waters Research & Management
Tanja Frei / Master's Thesis at the Departement of Earth Science / ETH Zürich, Switzerland
10Be Surface Exposure Dating and reconstruction of the glacial retreat in the Debant Valley (Eastern Alps), Austria in the Lateglacial and Holocene
Supervisors: PD Dr. Susan Ivy-Ochs, Dr. Jürgen Reitner
The Debant Valley in the Schober Group mountains in the eastern Alps offers an astonishing record of glacial and periglacial deposits reaching from the Lateglacial to the Holocene. This unique archive south of the Alpine main chain offers the opportunity to decipher the Alpine-wide discussed Lateglacial-Holocene-transition based on sedimentary and morphological evidence and supported by surface exposure dating using 10Be.
In June 2018, I spent two weeks in the Debant Valley geomorphologically mapping the area upvalley from the Lienzer Hütte. Sediment profiles were studied, the sediment described and the (peri)glacial landforms recognised and recorded. The mapped landforms are the basis for the paleoglacial reconstruction of the glacial stadials that will be done in a second step within my master thesis. The aim of the cosmogenic 10Be exposure dating is to place a temporal framework on glacier retreat and re-advance history from the late Lateglacial to the Little Ice Age. Samples were taken in a 4-day field campaign in early October 2018.
The support of CH-QUAT allowed me to carry out a 2-week field campaign in June 2018, where I mapped the valley.
Sibyl Rebmann / Master’s Thesis at the Institute of Geological Sciences /
A geotechnical safety analysis in aggregate mining
Supervisor: PD Dr. Naki Akçar
Excavation of unconsolidated sediments as aggregate material inhibits special importance in mining safety. Although the sediments are quarried without blasting, the geomechanical response of the sediment package to the unloading through excavation and to the loading determines the stability of the system. Therefore, the planning and management of the aggregate production in gravel pits require continuous assessment, and thus, geotechnical safety analysis. The goal of this Master’s thesis is to analyze the safety of aggregate mining in a gravel pit in the northern Alpine Foreland (Iff AG, Niederbipp). Two specific areas in the pit are investigated: (i) the lower gravel layer, which shows stability issues upon excavation of the overlying moraine material and (ii) the western wall, where instability occurs in particular subsequently to rainy days, when a stream is provoked. The survey of these sources of problems consists of fieldwork, laboratory work, modeling and interpretation. Geological mapping (with support of GIS) in addition to geotechnical experiments in the field build the basis to achieve this goal. Furthermore, undisturbed samples are analyzed in the laboratory. Geomechanical parameters of the sediments are used to understand how they deform, yield, flow and fail during and after the excavation, as well as to determine a safety factor based on the failure criteria, frictional sliding, time dependent strength and (in)stability.
The support of CH-QUAT allowed me to finish the field work concerning the issue (i). Samples were collected and analyzed in the laboratory according to the Unified Soil Classification System. Also, infiltration tests, the sand replacement method and the dynamic as well as the static plate load test were executed in the gravel pit. I am very grateful for the support of my supervisor Naki Akçar and of Franziska Nyffeneger (Berner Fachhochschule) as well as the financial support provided by CH-QUAT.
Catharina Dieleman / Exogene Geology /
University of Bern
Glaciers overrode the northern Alpine Foreland at least 13 times during the Quaternary (the past 2.6 million years). The imprints of these advances can be found within sediment packages covering Mesozoic bedrock or Tertiary Molasse. These packages are divided, based on their morphostratigraphy and topography, into four distinct units: Höhere Deckenschotter (HDS), Tiefere Deckenschotter (TDS), Hochterrasse (HT) and Niederterrasse (NT). For a long time, they were correlated with the Günz (with HDS), Mindel (with TDS), Riss (with HT) and Würm (with NT) glaciations after Penck and Brückner (1909). These units show a reversed stratigraphic relationship. This means that deposits at a higher elevation are considered to be older than deposits at a lower elevation.
The Swiss Deckenschotter represent the oldest Quaternary units in the northern Alpine Foreland and are characterised by a succession of glaciofluvial gravel beds with intercalated glacial and/or overbank deposits. A significant phase of incision separates HDS from TDS. HDS and TDS deposits were recently dated using depth-profile and isochron-burial dating techniques. The analysis of cosmogenic nuclides 10Be as well as 26Al yielded ages of ca. 2 Ma for HDS and ca. 1 Ma for TDS deposits. At Irchel, the oldest Deckenschotter deposits in the northern Alpine Foreland are found. The established chronology shows that 1 Ma old deposits are located at the same elevation as around 2 Ma old ones. Therefore, how far can we explain the recently reconstructed chronology with the “same elevation means same age” approach?
In this study, we focus on the new Deckenschotter sites as well as revisiting previously studied ones in order to produce knowledge on: (1) the timing of Early and Middle Pleistocene glaciations in the Alps; (2) patterns of erosion; and (3) the landscape evolution in the Northern Alpine Foreland. Therefore, at each study site sedimentological analyses of the deposits will be applied which allows the identification of the provenance, the transport mechanism as well as the depositional environment. The timing will be reconstructed applying isochron-burial dating using in-situ produced cosmogenic 10Be and 26Al.
I would like to thank the CH-QUAT for supporting my participation to AGAQ (Arbeitsgruppe Alpenvorland – Quartär), which took place May10th-12th 2018 in Bad Waldsee, Southern Germany. During this meeting, I had the opportunity to get in touch with researchers from Germany, Austria and Switzerland and whose focus is on the Quaternary of the northern Alpine Foreland. I enjoyed presenting my research and talking about it with different people and exchanging knowledge concerning various techniques used in Quaternary sciences, as well as the Quaternary geology of the northern Alpine Foreland.
Sarah Lo Russo / Masterarbeit am Departement Umweltwissenschaften / Integrative Prähistorische und Naturwissenschaftliche Archäologie, Universität Basel, Schweiz
Dank der Unterstützung von CH-Quat konnte ich am diesjährigen Workshop of Archaeological Soil Micromorphology vom 1. bis 3. August in Brüssel teilnehmen. Die Teilnahme ermöglichte mir in kürzester Zeit einen Einblick in Projekte und Fragestellungen aus unterschiedlichen Epochen und geografischen Räumen sowie mit verschiedenen Forschungsschwerpunkten zu gewinnen. Waren mir bisher die breiten Einsatzmöglichkeiten der Mikromorphologie theoretisch bekannt, so habe ich diese nun praktisch kennen gelernt. Die Posterpräsentation sowie die Teilnahme am Workshop ganz allgemein ermöglichte es mir ausserdem ausgewählte Proben meiner Masterarbeit mit mehreren Experten*innen zu diskutieren. Mehrere meiner Fragestellungen konnte ich sodann gezielter beziehungsweise differenzierter angehen.
Dies ist das Abstract des in Brüssel präsentierten Posters:
The Mithraeum at Kempraten (Rapperswil-Jona, Switzerland) – First results of a geoarchaeological study
Sarah Lo Russo, Christine Pümpin, Regula Ackermann, Martin Schindler, Philippe Rentzel
An area of 1100 m2 was archaeologically examined in 2015/16 in advance of a new construction project at Kempraten (municipality of Rapperswil-Jona, Canton St.Gallen CH). Besides three Roman lime kilns, the excavations also unexpectedly uncovered a mithraeum.
The site is located on the north-western edge of the vicus, a short distance from the presumed course of the road and right on the shoreline of Lake Zurich. After the lime kilns had become defunct, the mithraeum was built on a rocky terrace situated slightly above the lake level. At this point in the investigation three construction phases can be distinguished, of which the sacred building existed from the advanced stages of the 3rd century to at least the turn of the 5th century. Whilst the two first phases ended in a conflagration, it has not yet been possible to pinpoint the reasons why the mithraeum was eventually abandoned.
The excavation strategy and specific field methods employed were developed in collaboration with various experts (archaeologists, archaeobiologists, geoarchaeologists, geologists, numismatists) specifically for the purpose of excavating the mithraeum. A rich assemblage of finds and samples were recovered from inside the building using a fine grid to allow for an analysis of both the vertical and horizontal stratigraphy.
The main goal of the interdisciplinary analysis project will be to reconstruct as closely as possible the ritual practices and the design of the building using the finds and their distribution patterns in combination with the features. Micromorphological examinations are being undertaken with the aim of reconstructing the interior of the building and the processes that took place during phases of use, destruction and alteration. Some questions such as the detection of probable fillings of hollow floors, the degree of bioturbation or the origin of the charcoal (ritual fire or conflagration) have been considered. The poster focusses on the first results of some micromorphological samples analysed for a master thesis.
Sarah Lo Russo
IPNA, Universität Basel