Geodynamics of the Polar Regions

Department of Geosciences

Interrelations of tectonic deformation and surface erosion with West Antarctic Ice Sheet dynamics

PhD Project of Max Zundel

West Antarctica, and particularly the Amundsen Sea area, hosts glaciers with the most pronounced mass losses of the whole continent. Complete collapse of the West Antarctic Ice Sheet would result in a global sea level rise of 3 to 5 m. Apart from climatic and oceanographic changes, ice sheets are influenced by the tectonic and structural history as well as by heat flow patterns of the underlying bedrock. This project plan aims for a better understanding of the long-term geodynamic and paleo-topographic evolution of the Amundsen Sea area, of its heat flow distribution, and of its glacial thinning and retreat history. This will be achieved by applying a combination of geophysical methods, thermochronology, and surface exposure dating. Combining these data sets will provide information on spatial and temporal correlations of geodynamic activity, heat flow patterns, and ice sheet evolution. In more general terms, this project will contribute to a better understanding of relations between lithospheric processes, surface processes, and glacial dynamics. The project is based on Polarstern expedition XXX/3 in February-March 2015. During this expedition, the shallow drilling MeBo device will be deployed, enabling the first drilling campaign in the Amundsen Sea. Cored material will include basement rocks and clastic sediments presumably covering the time from the Cretaceous to the present, offering a unique opportunity for studying the evolution of the Amundsen Sea area.

This project is carried out in cooperation with Dr. Karsten Gohl (AWI Bremerhaven) and Dr. Norbert Kaul (University of Bremen).

Investigating the influence of sediment transport on (U-Th-Sm)/He thermochronology

PhD Project of Ruben Rosenkranz

(U-Th)/He analysis on detrital grains is highly interesting for studying exhumation histories of mountain belts, because it provides a paleo-record of thermal processes close to the surface. One of the reasons why it is not routinely applied yet is because of the uncertainties related to grain abrasion during sediment transport. This study aims to investigate and quantify this abrasion effect and to find strategies for applying He analysis on detrital grains.


Routinely, apatite (U-Th)/He data are corrected according to grain size and morphology to adjust for He loss from alpha ejection at the grain margins (Farley et al., 1996). The He depleted outer part of the grain may be mechanically abraded during sediment transport. If this is the case, alpha-ejection correction would lead to overcorrection and thus to He dates which are too old. Because of the different diffusion profiles, the effect of abrasion during sediment transport may be different for slowly cooled rocks as compared to rapidly cooled rocks.

Research strategy and methodology

In a first step, we will sample river sands from Himalayan source areas with relatively well-defined and suitable age patterns. These samples will be dated by He thermochronology using conventional alpha correction. Comparison with detrital age patterns with the hinterland age distribution will give evidence on the amount of age bias resulting from grain abrasion during sediment transport. In a second step, we will mechanically abrade apatites and zircons of the same samples using a Krogh-type cell in the laboratory (Krogh, 1982). For grains which are unzoned and rapidly cooled, laboratory abrasion should do away with the need of applying alpha correction (Spiegel et al., 2009). This approach would provide a solution for circumnavigating the uncertainties on how much alpha correction is appropriate for grains partially or fully abraded during sediment transport. On the other hand, due to the different He diffusion profiles, laboratory abrasion of slowly cooled grains may lead to "too-old" He dates. This effect will also be tested in our study. Potential grain zonations will be checked by scanning electron microscopy and LA-ICPMS profiles. In a third step, we will apply our approach to older sandstones deposited in the geological past.

The project is part of the Marie Curie Initial Training Network iTECC.
For further information see or

Investigating the influence of pore water on the (U-Th-Sm)/He system

PhD Project of Mohammad Sohi

Apatite (U-Th-Sm)/He (AHe) thermochronology is sensitive to a temperature range between ~85 to 40°C (Wolf et al. 1998) and thus records geodynamic processes of the near-surface shallow crust. One of the main methodological obstacles still to overcome is that the AHe system sometimes produces erroneously old dates contradicting other radiogenic dating systems and/or independent geological evidence (e.g., Green et al., 2006). Some of these apparently erroneous dates could be related to radiation damage enhancing He retentivity in apatite (e.g., Flowers, 2009), or to He implantation (Spiegel et al., 2009). These approaches, however, cannot sufficiently explain the strongly aberrant, though partly replicating AHe dates, which are partly even older than the formation ages of their magmatic host rocks. Accordingly, some mechanism for introducing extraneous He into apatite must exist which has not yet been investigated. For this study, we pursue two different goals:

  • We will test the hypothesis that He contained in pore water of rocks affects the AHe system. Two different mechanisms may then explain the erroneously old AHe dates
    • He from pore water may be transferred into apatite before the system is closed, thus violating the basic assumption of zero He concentration before system closure, and
    • elevated He concentrations at the grain boundaries would be in contradiction with the basic diffusion equation underlying the calculation of AHe dates.

  • For being able to measure its composition we need to directly extract pore water from the rock under closed system conditions. For this we will test the selFrag high voltage pulsed power equipment, which is currently refined for applications in ground water research. This part of the study will be designated to optimizing technical procedures for pore water extraction in close cooperation with the selFrag AG in Switzerland, who will be associated partner. Pore water analyses obtained through the selFrag equipment will be compared to a second set of analyses based on traditional indirect extraction methods as described by, e.g., Osenbrück et al. (1998), in cooperation with the Department of Environmental Physics at Bremen University (cooperation partner Dr. Jürgen Sültenfuß).


No studies exist so far that link pore water composition to AHe thermochronology. However, studies from groundwater research describe high He content of pore waters and its interactions with the host minerals: For sediment derived from old crustal rocks the release of radiogenic He into the groundwater is up to 300 times higher than can be supported by the in situ decay of U and Th (Solomon et al., 1996). For shale samples pore waters may contain more He than the host minerals altogether (Tolstikhin et al., 2005). The same authors describe quartz from sandstones of the Swiss Molasse Basin, which contains excessive He migrated into it from surrounding pore waters. Generally, pore water volumes reach from ~1% for crystalline basement to 10 to 15% for sedimentary rocks. Accordingly, considering pore water composition may be particularly important when investigating sedimentary sections, as proposed for this initial training network.

Research strategy and methodology

Samples will be taken from sedimentary sections and hinterland source rocks investigated for this network. For comparison, we will also study samples from the Indian craton, since cratonic rocks are the most problematic for AHe dating. From these rocks, pore water will be extracted by the selFrag and by traditional procedures, and analysed for 4He-concentration, 3He/4He ratio, and Ne/He ratio. The latter values give evidence on He provenance and atmospheric contamination. From the same samples, apatite will be dated by AHe thermochronology. We will then
  • compare pore water compositions obtained from selFrag and from traditional extraction methods,
  • related pore water compositions to results of AHe dating, and
  • test whether high He concentrations in pore water correlate with lithology, deposition ages, or grain size of the host rock.

The project is part of the Marie Curie Initial Training Network iTECC.
For further information see or

Long term structural development and landscape evolution of eastern Dronning Maud Land, and implications for the geological evolution of the Weddell Sea region

PhD Projects of Nicole Lucka and Antonia Ruppel

This project deals with the geodynamic evolution of Sør Rondane/ eastern Dronning Maud Land (DML) and is based on the expedition "GEA II" in 2011/12, and subsequent isototpe-geochemical and thermochronological research. Sør Rondane is located at a key position where the still unknown suture between East and West Gondwana is presumed to pass through DML. It also occupies a crucial position at the Karoo-Maud Plume between Antarctica, Africa/ Madagascar and India/ Sri Lanka, and therefore represents a key locus for our understanding of the Gondwana breakup history, the opening of the South Atlantic Ocean, and the establishment of the present plate configuration. Structural mapping, isotope geochemistry and geochronology (U-Pb SHRIMP and LA-ICP-MS, Ar-Ar) will be used to gain a better knowledge on the geodynamic evolution of the basement rocks and to detect the position of the E-W-Gondwana suture. Thermochronological methods (fission track/ FT and (U-Th-Sm)/He) and structural analyses of brittle fault zones will be applied to investigate the Phanerozoic shallow crustal dynamics of eastern DML. The regional paleo-isotherm pattern will provide constraints on the geological/ paleogeographic setting of DML within Gondwana, the Gondwana breakup history and regional passive margin evolution, and the long-term landscape and climate evolution of DML within the Antarctic continent. Moreover, the subglacial geology will be investigated by an aerogeophysical survey in combination with ground-geophysical studies in order to trace rock units and tectonic structures on a regional scale.

This project is carried out in cooperation with Dr. Andreas Läufer and Dr. Detlev Damaske (both BGR Hannover) and Prof. Joachim Jacobs (University of Bergen, Norway).


Sources and Sinks of Pliocene erosion: Investigating the latest-stage exhumation history of the Alps

Ph.D. Projects of Simon Elfert & Wolfgang Reiter (finished in 2014 and 2013, respectively)

The Alps as well as many other Cenozoic orogens experienced an approximately threefold increase of sediment deposition rates during the last ~5 Ma. The reasons for this increase are controversially discussed in the literature since more than a decade. The goal of this project is to improve our understanding of timing, rates, and changes of denudation during the late-stage evolution of the Central and Western Alps. Tracking regional differences in the timing of denudation events may answer the question whether Pliocene enhanced erosion was dominantly climatically or tectonically controlled. We try to achieve our goals by a combination of detrital thermochronology on Alpine-derived debris deposited in circum-Alpine basins (Rhine, Rhone, and Bresse-Graben) and high-resolution thermochronology on key areas of the Alpine source regions (Lepontine Dome and Aar Massif).

This project was part of the EUROCORE Program Topo Europe, Collaborative Research Project Thermo Europe: Coupled climatic / tectonic forcing of European topography revealed through thermochronometry.

Cooperation partners are Maria Laura Balestrieri, University of Florence, Onno Oncken & Charlotte Cederbom, GFZ Potsdam, Peter van der Beek, University of Grenoble, Sean Willett, ETH Zurich, Paul Andriessen, University of Amsterdam, Piotr Krzywiec, University of Warsaw.

Coupling of lithosphere dynamics, surface processes and ice sheet evolution — constraints from Marie Byrd Land, West Antarctica

Ph.D. Project Julia Lindow, finished in 2014

West Antarctica combines one of the largest active rift systems with one of the largest ice sheets on earth. Complete melting of the West Antarctic ice sheet would result in a global sea level rise of ~5 m. Understanding ice sheet dynamics is of major importance for predicting future deglaciation processes in Antarctica. Generally, it is assumed that the geodynamic activity of Western Antarctica as the "cradle" of the West Antarctic ice sheet exerts a strong influence on ice sheet dynamics, but coupling and feedback mechanisms are poorly understood. Also, information on both, the geodynamic evolution of West Antarctica and on long-term changes of its ice sheet is scarce. Our project aims to apply geophysical and thermochronological methods for unravelling the geodynamic evolution of Marie Byrd Land (West Antarctica) in terms of crustal structure, exhumation and erosion rates, fault activities, and (paleo-) geothermal gradient. Furthermore, we will use cosmogenic nuclide analysis for reconstructing thinning rates and glacial retreat in Marie Byrd Land. The combination of both data sets will provide information on spatial and temporal correlations of geodynamic activity and ice sheet evolution. This will contribute to our understanding of interrelations between lithospheric processes, surface processes, and ice sheet dynamics, thus providing benchmarks for future deglaciation models.

Project in cooperation with Karsten Gohl (Alfred-Wegener Institute, Bremerhaven) and Joanne Johnson (British Antarctic Survey)

The influence on climate and tectonics on uplift and denudation of the Terra Nova Bay region (Transantarctic Mountains)

Ph.D. Project Jannis Prenzel, finished in 2014

The Terra Nova Bay region forms a segment of the Transantarctic Mountains (TAM) in the western Ross Sea that is characterized by extreme landscape contrasts. There, a high Alpine coastal morphology developed in immediate vicinity to high-elevated inland plateaus and deep, structurally defined glacial troughs. Structural geology, geomorphological observations and sampling of basement and cover rocks in this region during the expedition BGR GANOVEX X (2009/10) will provide the ground truth for the subsequent application of thermochronological techniques (fission track and (U-Th-Sm)/He analyses). Based on these data and thermal history modelling, the regional uplift and denudation history of the Terra Nova Bay region will be constrained with the four main topics:

  • the evolution of t a Cretaceous "Victoria Basin" on the continental crust of SE Australia and the western Ross Sea,

  • the diachronous rifting processes across the two escarpments of Pacific passive margin and West Antarctic rift shoulder /TAM,

  • timing and amount of the final denudation of the TAM since the Eocene / Oligocene, and

  • quantification and explanation of development of landscape contrasts within the Terra Nova Bay region resulting from the interplay between climate, tectonics and lithology. This aspect also comprises implications for the long-term climate evolution on the margin of the East Antarctic Craton.

Project in cooperation with Andreas Läufer (Federal Institute for Geosciences and Natural Resources (BGR)

Cooling and denudation history of Spitsbergen, and inferences for tectonics, climate and long-term landscape evolution

Ph.D. Project Nina Dörr, finished in 2012

This project is a research cooperation between the University of Bremen, the Federal Institute for Geosciences and Natural Resources (BGR), and other partners. The project applies apatite fission track (FT) and (U-Th-Sm)/He thermochronology, clay mineral and vitrinite reflectance analysis for reconstructing the thermal history of basement rocks and sedimentary cover. The principle aim of this research is to investigate the Phanerozoic crustal dynamics of northern and central Spitsbergen, its implications on the opening of the Atlantic and consequences on regional long-term climate evolution. Four specific objectives are:

  • Passive margin evolution of Svalbard

  • Late Mesozoic and Cenozoic regional tectonic history

  • Thermal evolution of the Central Tertiary Basin

  • Coupling of Neogene climate change and tectonics, and long-term landscape evolution.

Contact Info

Prof. Dr. Cornelia Spiegel-Behnke

Tel.: +49 421 218-65280
Fax.: +49 421 218-65309

Universität Bremen
FB5 - Geowissenschaften
Klagenfurter Str. 2
28359 Bremen