MACROSTRAT: TOWARDS A COMMON DATA INFRASTRUCTURE TO SUPPORT DEEP TIME EARTH SYSTEMS SCIENCE

The emergence over the past several decades of numerous geochemical proxies for biogeochemical cycling, geochronology, and physical environmental and biological change has transformed deep time research. Because these proxies are extracted from rocks and sediments, studies employing them often focus on the assembly of high-resolution records from stratigraphic sections and cores, sampled individually or across a limited geographic region and small portion of the geologic column. Data from such studies are then often made available through the published literature or, with ever greater frequency, via online data repositories, such as those maintained by IEDA. Synthetic compilations of proxy data, which aim to reconstruct long-term, secular changes or to test global hypotheses that require large data sets, are derived by extracting data and geological age estimates from distributed sources. Most such data compilations are, as a result, static resources that are difficult to assess, update with new age and environmental constraints, or integrate with other data sets. Here, we describe Macrostrat (http://macrostrat.org), which provides a basic, but also comprehensive, spatial and temporal quantitative description of rocks and sediments in the upper crust and their reconstructed paleogeographic positions (via GPlates). Macrostrat serves as a scaffolding upon which all data extracted from the geological record can, at least in principle, be be stored and related. This geologic record-focused approach to data integration allows the constraints provided by, for example, geochronological measurements to be automatically propagated into other related but independent records, such as fossil occurrence data in the Paleobiology Database (http://paleobiodb.org). Macrostrat also provides quantitative and comparatively high resolution constraints on the fluxes of biogeochemically sensitive elements into and out of the sedimentary reservoir and on the evolution of Earth’s surface environment in both space and time.