Science Opportunities - Basic Research Opportunities in Earth Science - page 44

on much smaller samples than was previously possible. New methods of
age interpolation (e.g., based on periodic orbital forcing functions), data
integration, and quantification of gap effects and diachrony in
geochronological datums are leading to significant refinements of the
geological time scale. The increased temporal acuity offers the
opportunity to test the plausibility of mechanisms proposed for major
events seen in the rock and fossil records, such as the end-Permian mass
extinction.
• Comprehensive studies of past and present environments, combined with
numerical simulations and “meta-analyses” of diverse data sets, are
dramatically improving our insight into the quality of the geological
record. New methods for estimating the completeness of sedimentary
successions and evaluating hiatuses ( Figure 2.8 ) are leading to
improvements in the sampling and analysis of the rock and fossil records,
and field and laboratory studies are leading to a greater understanding of
the processes of selective modification and preservation of the geologic
record.
In addition to new tools, advances in geobiology depend on new field
studies of regions and key stratigraphic intervals, phylogenetic and systematic
analyses of key groups, and reevaluation and organization of existing data
archived in museums, written records, and electronic media. These investigations
yield vital new information on the geography, environmental and evolutionary
context, age, and composition of biotas and on the deployment of evolutionary
lineages in time and space.
Science Goals and Challenges
Recent advances in relevant technologies and capabilities have set the stage
for significant progress in understanding the role of biological processes in
geosystems, the evolution of life on Earth, and the factors that have shaped the
current and past biospheres. Fundamental new knowledge at the interface of the
biological and Earth sciences is anticipated in the following broad areas:
• the interrelationship among organisms, biological processes, and the
fundamental physical and chemical properties of the Critical Zone;
• the extent to which geological processes, such as weathering and mineral
precipitation, are mediated by biological processes, and the mechanisms
by which this mediation occurs;
• the ways in which biogeochemical cycles operate and are controlled or
modulated by physical, chemical, and biological processes;
• the role of physical factors, including rare events, in structuring and
changing the composition and organization of biological communities;