AG Petrology of the Ocean Crust Room 5160 Department of Geosciences University of Bremen Klagenfurter Straße 4 28359 Bremen Germany Phone: +49 421 218 65136 Fax: +49 421 218 65429 > Email: bieseler@uni-bremen.de

Research

Metasomatic rocks from the Oman Ophiolite allow crucial insights into the dynamic evolution of the Oman Ophiolite from spreading to metasomatic reactions during obduction to present-day serpentinization and carbonation. Some metasomatic rocks are believed to have formed during high-temperature reactions between ocean crust and seawater-derived fluids (diopsidites, nephrites, epidosites). In fact, the occurrence of these lithologies has been given considerable significance in developing models for cooling of the ocean crust. A primary goal of studies in the Oman Ophiolite is to understand how present-day serpentinization affects carbon reaction pathways in the system. Serpentinization is widespread in the mantle section of the Oman Ophiolite, but little is known about when and at what temperatures and pressures serpentinization took place. In this regard, metasomatized gabbro dikes in the mantle section (rodingites) are of considerable interest, because they form during serpentinization and have great potential for providing information on pT conditions, fluid composition, and timing of serpentinization.

Expeditions

• 14.02. - 25.02.2011: Field work in the Oman Ophiolite Complex
• 22.02. - 13.03.2013: Field work in the Oman Ophiolite Complex
• 09.02. - 23.02.2015: Field work in the Oman Ophiolite Complex

During the field trip to the Oman Ophiolite Complex we sampled metasomatic dykes and veins crosscutting the upper mantle sections next to the mantle crust transition. Petrographic and geochemical analyses provided new insights and were used to develop thermodynamic reaction path models to simulate water rock interactions. The results offer an oppertunity to understand the conditions and history of fluid through fast-spreading oceanic crust and processes forming hydrothermally overprinted rocks

Scientific career

• 2006 - 2009: B.Sc. Geosciences at the University of Bremen
  • 2009: Bachelor thesis: "Untersuchung der Mineralparagenesen metamorph überprägter Gesteine der Pearya Basement Terranes im Vergleich zum nordkanadischen Kraton"
• 2009 - 2012: M.Sc. Geosciences at the University of Bremen
  • 2012: Master thesis: "On the formation of diopsidite dykes in the mantle-crust transition of the Oman Ophiolite"
• 2012 - present: Ph.D. student at the research group "Petrology of the Ocean Crust" at the University of Bremen

Publications

• Bieseler B, Diehl A, Jöns N, Lucassen F, Bach W (2018): Constraints on cooling of the lower ocean crust from epidote veins in the Wadi Gideah section, Oman Ophiolite. Geochemistry, Geophysics, Geosystems 19(11), 4195-4217.
  | doi:10.1029/2018GC007679 |

Conference Abstracts

• Bieseler B, Diehl A, Jöns N, Bach W (2017): Constraints on cooling of the lower ocean crust from epidote veins in the Wadi Gideah section, Oman Ophiolite. GeoBremen 2017, Bremen, Germany (Poster).
• Bieseler B, Diehl A, Jöns N, Bach W (2015): Constraints on cooling of the lower ocean crust from epidote veins in the Wadi Gideah section, Oman Ophiolite. Joint IODP/ICDP Colloquium, Bonn, Germany (Poster).