Geobiology is a rapidly growing and truly interdisciplinary field at the interface between earth and life sciences, and mainstream research in geobiology involves microbes and microbial activities at all scales in different geological environments through time in Earth’s history. This research and its findings have strong implications for the evolution of life on the Earth and potentially in other planets.

The encompassing aim of the European Science Foundation Programm "Environments and Ecosystem Dynamics of the Eurasian Neogene (EEDEN), is the detailed analysis of the response of terrestrial ecosystems to environmental change through the integration of multidisciplinary studies focussing on some selected, already fairly well-known "high-resolution" time intervals in the Neogene of the Eurasian realm. These intervals are known to (a) include major changes in the composition of terrestrial communities, (b) portray large-scale palaeogeographical reorganizations and changes in overall environmental conditions in the terrestrial realm and (c) allow the establishment of high-resolution stratigraphic correlations with data and interpretations pertaining to regional and global aspects of the coeval development of marine environments. They cover (1) the latest Miocene to Early Pliocene (HRI 1:7-4 Ma ago), (2) the latest Middle Miocene to early Late Miocene (HRI 2: 12 - 8.5 Ma ago) and (3) the late Early to early Middle Miocene (HRI3: 17-14 Ma ago).

The research strategy of the EEDEN - programm was realized through three corresponding, internally comprehensive, but mutually complementary and overlapping programme components. These are the terrestrial database component, the time-stratigraphic / palaeogeographic component, and the palaeobiological component.

One of the fundamental components, the time-stratigraphic / palaeogeographic component, needs to incorporate the latest dates available to reconstruct the paleogeographic / palinstastic evolution of the Tethys / Mediterranean and the Paratethys realms and to incorporate all these results in a continous sequence paleogeographic maps. Such paleogeographic / palinstastic maps as they are published here are the base for the goals of the EEDEN programm to reconstruct the Environments and Ecosystem Dynamics of the Eurasian Neogene. This new paleogeographic atlas is the continuation of earlier works within the last decade presented by Dercourt et al. 1985, 1993, 2000; Hamor (Ed.) 1988; Kovac2002; Rogl 1998; Rogl & Steininger 1983,1984; Senes 1960; Steininger & Rogl 1982,1984; Steininger et al. 1985; Ziegler 1990.

We are grateful to the European Science Foundation and the Senckenbergische Naturforschende Gesellschaft, which have sponsored the publication of these paleogeographic maps within the EEDEN Programm.

Fritz F. Steininger

A crustal-scale ductile shear zone network in the Precambrian granulite-facies crust of Madagascar is examined to determine the nature of the connections between the mantle arid lower crust. Based on three independent data sets - field and satellite mapping, C- and O-isotope geochemistry and gravimetry - this crust is divided into three zones: (1) outside of shear zones; (2) minor shear zones that are <140 km long and 7 km wide; and (3) major shear zones mat are >350 km long (up to 1000 km) and 20-35 km wide. The mantle is uplifted by about 10 km beneath the major shear zones. The major shear zones are rooted in and are inferred to be controlled by the mantle; they directly tapped mantle-derived C02. The small-scale minor shear zones were controlled by crustal processes and focused crustally derived H20-rich±C02 fluids. The regular distribution of the shear zones on a crustal scale is in agreement with models of buckling of the continental lithosphere in a compressional context. The propagation of these mechanical instabilities promoted and channelled fluid flow. These major Pan-African shear zones thinned the crust and were reactivated during the subsequent drifting of Madagascar and opening of the Indian Ocean during Jurassic to Cretaceous times. They also controlled many of the brittle fault zones in the overlying sedimentary basins. Mantle-rooted large-scale shear zones are inferred to be a general feature of cratonic areas reactivated by shear zone systems.