Unanswered questions in deep carbon science

Prof. Robert M. Hazen

Carnegie Institution of Washington

Many fundamental unanswered questions remain regarding the physical, chemical, and biological behavior of carbon-bearing systems at depths greater than a few hundred meters. Recent results from field, experimental and theoretical studies point to the need for a new broadly interdisciplinary effort to understand deep carbon reservoirs and fluxes, the extent of possible deep abiotic organic synthesis, and the nature and extent of the deep biosphere. The Deep Carbon Observatory is a new international organization devoted to the study of these unanswered questions (see http://dco.ciw.edu). Recent findings underscore the need for a focus on deep carbon science. In particular, experimental discoveries of high-P-T organic synthesis from inorganic precursors, observations of complex interactions between organic molecules and minerals, field evidence for significant outgassing of C-O-H-N volatiles, recognition of extensive deep microbial ecosystems, and new experimental measurements and theoretical models of carbon sources and sinks demand a careful reappraisal of deep carbon.