radar (InSAR)—are capable of mapping crustal deformation with
centimeter-level precision, paving the way for advances in earthquake
mechanics, volcano physics, and crustal rheology. Seismic
tomography can now image the subsurface with enough horizontal
resolution to observe how individual surface features are expressed at
depth. These remote-sensing techniques, in combination with field
mapping, deep continental drilling for in situ sampling and
experimentation, and advanced laboratory analysis of rocks brought up
from great depths, offer major opportunities to address basic questions
regarding the three-dimensional structure and composition of the
continents, the geologic record of continental formation and assembly,
and the physical processes in continental deformation zones. Targets
of this research include:
• mechanisms of active deformation, earthquake physics, coupling
between brittle and ductile deformations, and fault-system dynamics
and evolution,
• role of fluids in chemical, thermal, magmatic and mechanical
processes, deep circulation systems in hydrothermal areas and
sedimentary basins, and fluxes from the mantle,
• nature of the lower continental crust, its average composition and
fluid content, processes of formation and development, and role as a
mechanical decoupling layer, and
• deep structure of the continental lithosphere, its coupling to the
underlying mantle, and implications for Earth evolution.
5. Studies of the Earth’s deep interior, to define its structure,
composition, and state, and to understand the machinery of mantle
convection and the core dynamo. The quality and quantity of data are
expanding at an extraordinary rate in many related fields—
seismology, geomagnetic studies, geochemistry, and high-pressure
research. Increased computational speeds and high-bandwidth
networks have greatly facilitated the processing of very large data sets
and the realistic modeling of deep-interior dynamics. Laboratory
studies conducted at mantle and core conditions are now able to
provide constraints on the physical and chemical conditions essential
for the interpretation of numerical simulations. There are four primary
areas of investigation:
• complex time-dependent flow patterns of solid-state mantle
convection, which can be inferred by reconciling seismic
tomographic and geochemical data using high-resolution numerical
simulations,
• operation and interaction of mantle convection and the core dynamo
over Earth history, which can be studied through multidisciplinary
investigations of the core-mantle boundary,
EXECUTIVE SUMMARY
4
About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.
centimeter-level precision, paving the way for advances in earthquake
mechanics, volcano physics, and crustal rheology. Seismic
tomography can now image the subsurface with enough horizontal
resolution to observe how individual surface features are expressed at
depth. These remote-sensing techniques, in combination with field
mapping, deep continental drilling for in situ sampling and
experimentation, and advanced laboratory analysis of rocks brought up
from great depths, offer major opportunities to address basic questions
regarding the three-dimensional structure and composition of the
continents, the geologic record of continental formation and assembly,
and the physical processes in continental deformation zones. Targets
of this research include:
• mechanisms of active deformation, earthquake physics, coupling
between brittle and ductile deformations, and fault-system dynamics
and evolution,
• role of fluids in chemical, thermal, magmatic and mechanical
processes, deep circulation systems in hydrothermal areas and
sedimentary basins, and fluxes from the mantle,
• nature of the lower continental crust, its average composition and
fluid content, processes of formation and development, and role as a
mechanical decoupling layer, and
• deep structure of the continental lithosphere, its coupling to the
underlying mantle, and implications for Earth evolution.
5. Studies of the Earth’s deep interior, to define its structure,
composition, and state, and to understand the machinery of mantle
convection and the core dynamo. The quality and quantity of data are
expanding at an extraordinary rate in many related fields—
seismology, geomagnetic studies, geochemistry, and high-pressure
research. Increased computational speeds and high-bandwidth
networks have greatly facilitated the processing of very large data sets
and the realistic modeling of deep-interior dynamics. Laboratory
studies conducted at mantle and core conditions are now able to
provide constraints on the physical and chemical conditions essential
for the interpretation of numerical simulations. There are four primary
areas of investigation:
• complex time-dependent flow patterns of solid-state mantle
convection, which can be inferred by reconciling seismic
tomographic and geochemical data using high-resolution numerical
simulations,
• operation and interaction of mantle convection and the core dynamo
over Earth history, which can be studied through multidisciplinary
investigations of the core-mantle boundary,
EXECUTIVE SUMMARY
4
About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.