Trial Lecture and Thesis Defense - Mats Molén

Master of Science Mats Molén will hold the Trial Lecture and Thesis Defense for the Dr. Philos degree in Science on Tuesday, October 6, 2026.

Trial Lecture

The Trial Lecture will take place 10:15 - 11:15.

The title of the Trial Lecture is:

« Major Transformations in Earth’s History: Geological Evidence, Processes, and Chronology »

Thesis Defense

The Thesis Defense will take place 12:15 - 15:00.

The title of the thesis is:

« Glacial or mass flow deposits? Diamictites in critical discussion »

Abstract

For more than 150 years, characteristics of geologic features claimed to be evidence for pre-Pleistocene glaciations have been debated. Proxies and more detailed descriptions emerging from advancements of geologic science in recent decades, in understanding how features generated by mainly glacial and mass flow processes have originated, have been used in the field and also have been reviewed. Detailed studies of data offered in support of pre-Pleistocene glaciations have led to revisions that involve environments of mass movements. Similarities and differences between Quaternary glaciogenic and mass movement features are examined, and have provided a more systematic methodology for analysing the origins of more ancient deposits. Analyses and evaluation of data are from a) Quaternary glaciogenic sediments, b) formations which have been assigned to pre-Pleistocene glaciations, and c) formations with comparable features associated with mass movements (and occasionally tectonics). Multiple proxies are assembled to develop correct interpretations of ancient strata. The aim is not per se to reinterpret specific formations and past climate changes, but to enable data to be evaluated using a broader and more inclusive conceptual framework.

In summary, regularly occurring pre-Pleistocene features interpreted to be glaciogenic, have often been shown to have few or no Quaternary glaciogenic equivalents. These same features commonly form by sediment gravity flows or other non-glacial processes, which may have led to misinterpretations of ancient deposits. These features include, for example, environmental affinity of fossils, grading, bedding, fabrics, size and appearance of erratics, polished and striated clasts and surfaces (“pavements”), dropstones, and surface microtextures. Recent decades of progress in research relating to glacial and sediment gravity flow processes have resulted in proposals by geologists, based on more detailed field data, more often of an origin by mass movements and tectonism than glaciation. The most coherent data of this thesis, i.e., appearances of features produced by glaciation, sediment gravity flows and a few other geological processes, are summarized in a Diamict Origin Table which can be used as a starting point for future field research of environments of mixed origins.

Evaluation Committee

• 1st Opponent: Professor Jan A. Piotrowski, Department of Geoscience, Aarhus University, Denmark.
• 2nd Opponent: Professor Emeritus Jutta Winsemann, Institute of Earth System Sciences, Leibniz University Hannover, Germany.
• Internal member and leader of the committee: Professor Sten-Andreas Grundvåg, Department for Geoscience, UiT, Norway.

Streaming

The Trial Lecture and Thesis Defense will be streamed via Panopto:

Trial Lecture (10:15 - 11:15)
Watch the Trial Lecture

Thesis Defense (12:15 - 15:00)
Watch the Thesis Defense

Thesis

The thesis is available in Munin:

View the thesis in Munin