Geodynamics and Basin Studies

Tectonic significance and origin of different serpentinite types in the Alpine-Apennine orogenic wedge of eastern Elba, Italy

This Master's project was designed for Andrea Oliva Kjemperud who started her Master's program in Earth Sciences, UiB, in the fall semester 2023. The Master's project is given by the research group Geodynamics and basin studies.

Main content

Project description
Orogenic wedges juxtapose tectonic units that originated far from each other, but tracing these back to their origins is often difficult. On Elba Island, Italy, apparently different types of serpentinites are closely juxtaposed and are associated with different types of sedimentary rocks. The different serpentinite occurrences are linked to distal Jurassic-Cretaceous deep sea sediments on the one hand and much younger Oligocene foredeep sedimentary rocks on the other. The former are preliminarily interpreted as serpentinites that originated as the result of ultra-slow spreading in an abyssal setting, whilst the latter are thought to result from a younger contractional subduction-exhumation setting. Serpentinitisation of the ultramafic protolith would have happened at the sea floor in the former case and in the mantle
wedge in the latter.

In order to better constrain the petrology of these differing mantle rocks, a comparative petrological investigation of the apparently differing serpentinite types will be conducted. The focus will be on petrology of the relict phases, including spinel, olivine and pyroxenes. The Cr-# of spinel will point to the differing origins of the serpentinites, abyssal sea floor vs. mantle wedge. In addition, a qualitative textural analyses of the serpentinites will be undertaken to further distinguish between serpentinites that originate in extensional vs. contractional settings. The petrological analyses will be conducted in collaboration with Prof. Wolfgang Bach, Univ. of Bremen, Germany.

Figure 1

Geological map of parts of eastern Elba, which shows the closely juxtaposed serpentinite bands in the orogenic wedge of eastern Elba,

after Jacobs et al. (2018)

Proposed course plan during the master's degree (60 ECTS):

Field- lab- and analysis work:
Participation in the field course to Elba, GEOV252
Microprobe analyses at Univ. of Bremen