I am a geochemist and petrologist and I have a broad interest in the application of (micro-) analytical tools to study the geochemistry of different geological environments. In particular, my major research interests are the Earth’s geodynamic evolution, differentiation processes in the Earth, and mafic-ultramafic layered intrusions and associated Ni-Cu-PGE mineralisation. I use a multidisciplinary approach combining geochemical and thermodynamic modelling and a wide variety of analytical tools in geochemistry. My research interests are analytically intensive and focus on the measurement of a number of radiogenic (Sr, U, Pb, Hf and Os) and stable (O, B) isotopes. Furthermore, I am interested in developing and employing in situ techniques utilising laser ablation ICP-MS in order to measure the chemical and isotopic composition of small quantities of material with a high degree of spatial resolution.

In my PhD project I investigate the thermal and chemical evolution of crustal rocks during the assembly of the supercontinent Gondwana. The Neoproterozoic breakup of the Rodinia supercontinent and assembly of Gondwana is arguably one of the most important events concerning geodynamics, palaeoclimatic changes, and development of biologic diversity on Earth. Amalgamation of continental lithosphere into supercontinents is linked to periods of extreme metamorphic conditions that induce extensive partial melting of the crust. Heat sources responsible for these conditions are contentious and mostly elevated radioactive heat production or increased mantle heat input are discussed. My research focuses on a Neoproterozoic orogen marked by a series of granitic plutons and anatectic units that formed during West Gondwana assembly. The present day exposure makes different crustal levels accessible which offers the opportunity to study the thermal evolution during orogenesis. I used zircon geochronology coupled with Lu-Hf isotopes to identify distinct terranes and accretionary events as well as to trace crustal reworking during continental collision.

Garnet records both the conditions and the timing of its growth, which can be linked to ages, durations, and rates of specific Earth processes. While the thermodynamics that control pressure-temperature-composition conditions of garnet growth are well constrained, garnet chronology is restricted to tedious lab work. We developed an analytical routine to date low-U garnet to decipher tectonometamorphic processes and conditions. I combined thermodynamic modelling with in situ U-Pb dating techniques to reconstruct the metamorphic evolution of the studied terranes. The results show two separate terranes that collided and underwent contemporaneous crustal thickening during which one section stayed relatively cold whereas the other underwent partial melting. This observation reflects the compositional control of different rock types on the vertical distribution of heat producing elements. Whereas tonalites and their differentiated products allowed stabilization of a thick crust in one terrane, a higher heat flow of the other terrane induced by larger concentration of heat producing elements through passive margin material input led to partial melting. This suggests that radioactive heat production seems to be an effective cause for crustal melting during supercontinent assembly.

PUBLICATIONS

 Peer-reviewed articles

 Schannor, M., Lana, C., Nicoli, G., Gerdes, A., Cutts, K., Hecht, L. – Reconstructing the metamorphic evolution of the Araçuaí orogen (SE Brazil) using in situ U–Pb garnet dating and P–T modelling. Journal of Metamorphic Geology (submitted)

Schannor, M., Lana, C., Fonseca, M. (2018) São Francisco – Congo craton break-up delimited by U-Pb-Hf isotopes and trace-elements of zircons in metasediments of the Araçuaí belt. Geoscience Frontiers in press

Schannor, M., Veksler I., Hecht, L., Harris, C., Romer, R.L., Manyeruke, T. (2018) Small-scale Sr and O isotope variations through the UG2 in the eastern Bushveld Complex: the role of crustal fluids. Chemical Geology 485, 100–112

Albert, C., Lana, C., Gerdes, A., Schannor, M., Narduzzi, F., Queiroga, G. (2018) Archean magmatic-hydrothermal fluid evolution in the Quadrilátero Ferrífero (SE Brazil) documented by B isotopes (LA MC-ICPMS) in tourmaline. Chemical Geology 481, 95–109

Nicoli, G., Thomassot, E., Schannor, M., Vezinet, A., Jovovic, I. (2018) Constraining a Precambrian Wilson Cycle lifespan: an example from the ca. 1.8 Ga Nagssugtoqidian Orogen, southeastern Greenland. Lithos 296–299, 1–16

Gauert, C., Schannor, M., Hecht, L., Reinholz, U. and Radke, M. (2016) A Comparison of In Situ Analytical Methods for Trace Element Measurement in Gold Samples from Various South African Gold Deposits. Geostandards and Geoanalytical Research 40(2), 267–289

Veksler, I.V., Reid, D.L., Dulski, P., Keiding, J.K., Schannor, M., Hecht, L. and Trumbull, R.B. (2015) Electrochemical Processes in a Crystal Mush: Cyclic Units in the Upper Critical Zone of the Bushveld Complex, South Africa. Journal of Petrology 56(6), 1229–1250

 

Articles in preparation

Schannor, M., Lana, C., Mazoz, A., Narduzzi, F. and Fonseca, M. – Reworked Paleoproterozoic sources for Cordilleran-type Neoproterozoic granitoids from the Araçuaí orogen (SE Brazil): Constraints from Hf isotope zircon composition.

Albert, C., Schannor, M., Lobato, L.M., Dos Santos, J., and Lana, C. – Constraints on fluid sources in orogenic gold deposits in the Quadrilátero Ferrífero (Brazil) from tourmaline chemical and boron isotope composition.

Selected conference presentations

 Schannor, M., Veksler, I.V., Hecht, L., Harris, C., Romer R., Manyeruke, T.D., (2018) Small-scale Sr and O isotope variations through the UG2 in the eastern Bushveld Complex: the role of crustal fluids. 13th International Platinum Symposium, Polokwane, South Africa (invited)

 Schannor, M., Lana, C., Fonseca, M., Alkmim, F. (2017) São Francisco–Congo craton breakup: clues from U-Pb-Hf of detrital zircons in Neoproterozoic metasediments of the Araçuaí belt (SE Brazil). Goldschmidt Conference Paris

Schannor, M., Hecht, L., Veksler, I.V., Manyeruke, T.D., Romer R. (2014) Variation in plagioclase chemical and isotopic composition in the UCZ of the Eastern Bushveld Complex, South Africa. 21st General Meeting of the International Mineralogical Association (IMA2014), Johannesburg

 

 
 

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