A MODEST PROPOSAL TO IMPROVE SEDIMENTARY-PETROLOGY DATA COLLECTION AND PRESENTATION

A common application of sedimentary-petrology principles in integrated geological studies is inference of plate-tectonic setting or other provenance features from quantitative analysis of sand composition. Successful inference derives from a knowledge base of the empirical relationship between certain sand compositions and certain provenance variables in modern and ancient systems. Maximizing success in inferential reasoning, while also minimizing time and effort, leads most researchers to consider only a subset of the sediments generated by the environment they wish to reconstruct, usually medium sand. Another increasingly common application of sedimentary-petrology principles in integrated study is the deduction of petrophysical properties, for example porosity and permeability, of subsurface sedimentary deposits. Pores are environmentally and economically important, because they can host hydrocarbons, consumable water, or contaminants. How fast or easily the contents move depends on pore characteristics. The pores' character depends on the nature of the sediments. Indirect geophysical tools for examining the subsurface are relatively fast and cheap, but they do not measure the desired values very well. Direct observation by coring is very expensive. We can reason deductively about the relationship between sediment character and petrophysical properties based on empirical relationships and conceptual models. The knowledge base that supports inference about provenance is widely used for deduction of petrophysical properties, but it is particularly inadequate for that task because it relies mostly on a subset of sediments. Sedimentary petrologists, especially researchers in modern systems whose primary goal is to support inference about tectonic-setting, can help the entire community by taking a few simple steps when collecting and reporting data: (1) collect and report quantitative textural data; (2) provide compositional information about all grain sizes; (3) provide all data in the rawest possible form. Providing abundant and raw data, in the publication itself or in some readily accessible data repository, ensures that researchers with diverse needs will benefit from work done for other purposes. Cooperation from publishers is vital to create and maintain data access.