Biography

since 2009

Postdoctoral Research Assistant, Institute of Earth and Environmental Science, University of Potsdam

2008

Dr. phil. nat. in Mineralogy/Geochemistry - University of Frankfurt

2003

Diploma Geology/Paleontology - University of Münster

Research

• Lu-Hf geochronology of garnets from HP and UHP rocks. The Lu-Hf isotope system has become a powerful tool to date garnet bearing (or other high Lu/Hf minerals) assemblages in metamorphic rocks from high-pressure and ultrahigh-pressure orogens. Because e.g. garnet quickly incorporates lutetium during initial garnet growth, concentrating it in the cores of individual grains, it is possible to constrain the timing of garnet growth, and possibly also a (near-)peak HP/UHP event.

In my current research I focus on UHP eclogites from the Dabie-Sulu orogenic belt, China, and the punctuated and rapid garnet growth events in these rocks distinguished by Lu-Hf garnet geochronology.

• U-Pb zircon chronology by LA-ICPMS. U-Pb dating is a well developed geochronological tool to date accessory phases like zircon, sphene, rutile, etc. With the development of in-situ methods using laser ablation inductively coupled plasma mass spectrometry it has become increasingly usefull to date e.g. metamorphic zircons with more than one growth zone (i.e. inherited magmatic cores with concentric overgrowths) with a spacial resolution as low as ~20µm.
  

• Trace element distribution and fractionation in minerals during HP and UHP metamorphism. What do zoning patterns of certain trace elements in minerals tell us about its growth and evolution? Does this information help us to better interpret e.g. Lu-Hf ages of garnets? We often observe trace element zoning patterns (e.g. heavy HREE enrichment in garnet cores) while at the same time major elements are homogeneously distributed.

In our research group we focus on the question as to how these patterns are developed, and why they can be preserved even after HT and HP to UHP metamorphism.

Teaching

• Trace Element Geochemistry and Radiogenic Isotope Geology.

• Analytical Techniques in Mineralogy and Geochemistry.

Publications

Journal articles

Schmidt, A., Mezger, K., O'Brien, P.J. (2011): The time of eclogite formation in the ultrahigh-pressure rocks of the Sulu terrane: constraints from Lu-Hf garnet geochronology. Lithos vol. 125, p.743-756

A. P. Willner, A. Gerdes, H.-J. Massonne, A. Schmidt, M. Sudo, S. Thomson, G. Vujovich, (2010), The geodynamics of collision of a microplate (“Chilenia”) in Devonian times  deduced by the pressure-temperature-time evolution within part of a collisional belt (Guarguaráz Complex, W-Argentina), Contribution to Mineralogy and Petrology, Volume 162, Number 2, pp. 303-327 (DOI: 10.1007/s00410-010-0598-8)

Schmidt, A., Weyer, S.; John, T., Brey, G.P., (2009), HFSE systematics of rutile-bearing eclogites: New insights into subduction zone processes and implications for the Earth's HFSE budget, Geochimica et Cosmochimica Acta, v. 73, pp 455-468

Schmidt, A., Weyer, S., Mezger, K., Scherer, E., Xiao, Y., Hoefs, J., Brey, G.P., (2008), Rapid eclogitisation of the Dabie-Sulu UHP terrane: Constraints from Lu-Hf garnet geochronology. Earth Planet Science Letters, v. 273, pp 203-213

Conference abstracts:

A. Schmidt; M. Konrad-Schmolke; P.J. O'Brien, (2011), Growth- and post-growth behavior of major and trace elements in garnets, a case study, Mineralogical Magazine, Vol. 75 (3), pp.1818

A. Schmidt; K. Mezger; P. J. O'Brien, (2010), Linking Lu-Hf geochronology and garnet chemistry in eclogites of the Sulu UHP terrane, China. Implications for punctuated garnet growth events and interpretation of element zoning patterns regarding geochronology, Eos Trans. AGU

A. Schmidt, S. Weyer, T. John, G.P. Brey (2008) Nb/Ta systematics of orogenic eclogites, Geochimica et Cosmochimica Acta vol 72, Issue 12, Supplement 1, p.A833

A. Schmidt, S. Weyer, Y. Xiao, J. Hoefs, G.P. Brey (2007) Lu-Hf geochronology of eclogites from the Dabie-Sulu terrane: Constraints on the timing of eclogite-facies metamorphism, Geochimica et Cosmochmica Acta vol 71, Issue 15, Supplement 1, p.A894

Schmidt, A.; Weyer, S.; Xiao, Y.; Hoefs, J.; Brey; G.P. (2006), Lu-Hf Garnet Geochronology of Eclogites from the Dabie Orogenic Belt, Eastern China, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract T41C-1583

Schmidt, A.; Weyer, S.; Brey G.P. (2006) BSE reservoirs: Insights from Nb/Ta of rutile-bearing eclogites, Geochimica et Cosmochimica Acta Supplement, v. 70, iss. 18, p. 562

A. Schmidt, S. Weyer, G.P. Brey. (2005) High Field Strength Elements in rutile-bearing eclogites: Implications for crust-mantle evolution. Berichte der Deutschen Mineralogischen Gesellschaft, Beih. Z. Eur. J. Mineral. Vol. 17, No.1

A. Schmidt, R. Anand, S. Balakrishnan, K. Mezger. (2003) Evolution of the Archean Hutti-Maski schist belt, Eastern Dharwar Craton, South India. Berichte der Deutschen Mineralogischen Gesellschaft, Beih. Z. Eur. J. Mineral. Vol. 15, No.1

PhD thesis:

Schmidt, A. (2008) High Field Strength Element systematics and Lu-Hf & Sm-Nd garnet geochronology of orogenic eclogites. Goethe-Universität Frankfurt

Diploma thesis:

Schmidt, A. (2003) Geochemie und Geochronologie des archaischen Hutti-Maski Grünsteingürtels, Eastern Dharwar Craton, Karnataka, Süd-Indien. WWU Münster