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by K. Lambeck, R. Sabadini and E. B08Chi Viscosity is one of the
important material properties of the Earth, controlling tectonic
and dynamic processes such as mantle convection, isostasy, and
glacial rebound. Yet it remains a poorly resolved parameter and
basic questions such as whether the planet's response to loading is
linear or non-linear, or what are its depth and lateral variations
remain uncertain. Part of the answer to such questions lies in
laboratory observations of the rheology of terrestrial materials.
But the extrapolation of such measurements from the laboratory
environment to the geological environment is a hazardous and vexing
undertaking, for neither the time scales nor the strain rates
characterizing the geological processes can be reproduced in the
laboratory. General rules for this extrapolation are that if
deformation is observed in the laboratory at a particular
temperature, deformation in geological environments will occur at a
much reduced temperature, and that if at laboratory strain rates a
particular deformation mechanism dominates over all others, the
relative importance of possible mechanisms may be quite different
at the geologically encountered strain rates. Hence experimental
results are little more than guidelines as to how the Earth may
respond to forces on long time scales.
The geodynamic evolution of the Mediterranean region has been often
described as a puzzling problem' because of the complex space-time
distribution of tectonic events. The gathering of new constraining
information and frequent changes of data and ideas among the
scientists working on this topic seems to be the most suitable
approach to the above problem. This volume reports the most
significant results of geological, geophysical, seismological,
volcanological, paleomagnetic studies and the geodynamic syntheses
presented, and discussed. Special attention is devoted to regions,
such as the Aegean--Anatolian and central Mediterranean, which
played a crucial role in the evolution of the whole Mediterranean
area. A considerable improvement in the understanding of the
post-Tortonian deformation pattern of the Tyrrhenian--Apennine
system has been achieved by recent geological and geophysical
investigations. The geodynamic implications of the data presently
available might provide important insights into the evolution of
continental collision zones, where shortening processes may also
involve lateral extrusion of crustal wedges and consumption of
continental-like lithosphere. The main uncertainties which still
surround the relative motion between Africa and Eurasia in the
Mediterranean region are also pointed out. The arguments reported
in this volume are mainly addressed to research scientists and
advanced students of the earth sciences. (abstract) This volume
reports information about the evolutionary history and the present
structural-tectonic setting of the Mediterranean region, which has
been presented and discussed during a meeting on Recent Evolution
and Seismicity of the Mediterranean Region', held in Erice (Italy)
in September 1992. Recent results of geological, geophysical,
seismological, volcanological and paleomagnetic studies are
described. The geodynamic implications of the presently available
data set might provide important insights into the evolution of
continental collision zones, where shortening processes may also
involve lateral extrusion of crustal wedges and consumption of
continental-like lithosphere.
The geodynamic evolution of the Mediterranean region has been often
described as a puzzling problem' because of the complex space-time
distribution of tectonic events. The gathering of new constraining
information and frequent changes of data and ideas among the
scientists working on this topic seems to be the most suitable
approach to the above problem. This volume reports the most
significant results of geological, geophysical, seismological,
volcanological, paleomagnetic studies and the geodynamic syntheses
presented, and discussed. Special attention is devoted to regions,
such as the Aegean--Anatolian and central Mediterranean, which
played a crucial role in the evolution of the whole Mediterranean
area. A considerable improvement in the understanding of the
post-Tortonian deformation pattern of the Tyrrhenian--Apennine
system has been achieved by recent geological and geophysical
investigations. The geodynamic implications of the data presently
available might provide important insights into the evolution of
continental collision zones, where shortening processes may also
involve lateral extrusion of crustal wedges and consumption of
continental-like lithosphere. The main uncertainties which still
surround the relative motion between Africa and Eurasia in the
Mediterranean region are also pointed out. The arguments reported
in this volume are mainly addressed to research scientists and
advanced students of the earth sciences. (abstract) This volume
reports information about the evolutionary history and the present
structural-tectonic setting of the Mediterranean region, which has
been presented and discussed during a meeting on Recent Evolution
and Seismicity of the Mediterranean Region', held in Erice (Italy)
in September 1992. Recent results of geological, geophysical,
seismological, volcanological and paleomagnetic studies are
described. The geodynamic implications of the presently available
data set might provide important insights into the evolution of
continental collision zones, where shortening processes may also
involve lateral extrusion of crustal wedges and consumption of
continental-like lithosphere.
by K. Lambeck, R. Sabadini and E. B08Chi Viscosity is one of the
important material properties of the Earth, controlling tectonic
and dynamic processes such as mantle convection, isostasy, and
glacial rebound. Yet it remains a poorly resolved parameter and
basic questions such as whether the planet's response to loading is
linear or non-linear, or what are its depth and lateral variations
remain uncertain. Part of the answer to such questions lies in
laboratory observations of the rheology of terrestrial materials.
But the extrapolation of such measurements from the laboratory
environment to the geological environment is a hazardous and vexing
undertaking, for neither the time scales nor the strain rates
characterizing the geological processes can be reproduced in the
laboratory. General rules for this extrapolation are that if
deformation is observed in the laboratory at a particular
temperature, deformation in geological environments will occur at a
much reduced temperature, and that if at laboratory strain rates a
particular deformation mechanism dominates over all others, the
relative importance of possible mechanisms may be quite different
at the geologically encountered strain rates. Hence experimental
results are little more than guidelines as to how the Earth may
respond to forces on long time scales.
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