Our general research interests focus on understanding the origin and evolution of the continental crust through the application of geochemical techniques. Study of the dynamics of orogenic cycles through a combination of geochronology, metamorphic petrology and structural geology. The chemistry of rocks contains information on a substantial part of the Earth's history and evolution. The goal of our research is to unravel the history of our favorite planet by studying the distribution and abundance of chemical elements and isotopes. In particular we are very interested to understand the processes that led to the formation of the Earth and its subsequent modification to a chemically differentiated planet. These modifications are an essential prerequisite for the formation and diversification of live on Earth and also form the basis of our evolved and technology oriented civilization. We try to find answers to our questions by analyzing rocks, minerals and meteorites for their content of certain elements, the isotope composition of some of these elements and the distribution of the elements among the minerals in the rocks. Of great importance and interest to us are the isotope composition of elements that are produced by natural radioactive decay, because they contain essential information on the parameter time. These elements include Sr, Nd, and Pb. By analyzing the isotopes of these elements it is possible for us to obtain absolute ages for important geologic events. In addition we use these isotopes to understand the dynamics of our planet by determining the rates of geologic processes. We use the chemical information obtained in the laboratory to interpret the rocks and whole geologic units we study in the field. For the chemical analyses we use all the analytical equipment available in our department (electron microprobe, XRF, INAA, XRD.....) but in particular our mass spectrometers.