The Sedimentary Record of ‘Complexity’

Abstract:

At short timescales (i.e. 10^-4 to 10² yrs) the linkage between system forcing, response, and product can be measured and quantified at the field and laboratory scale. Even so, the general consensus is that this tripartite relationship is non-linear and complex. At long timescales (i.e. 10²-10⁷ yrs) the relationship between forcing and response is less certain (since we are not around long enough to observe and measure it) but the sedimentary record (the ‘product’) provides measurable, although fragmentary, information. Given this, what does/can the sedimentary record realistically offer Earth Scientists with regards to past system forcing, response, and state? Conversely the sedimentary record might be thought of as the final, ordered state(?) of time-integrated complex behaviour. The main issues from a stratigraphic perspective are: How do we recognise complex behaviour in the sedimentary record? At what temporal and spatial scales must we consider? What do we measure? How do we measure it? Using outcrop, laboratory and numerical datasets we will address some of these issues and then discuss the applicability and limitations of the sedimentary record. As a final point, if we truly want to understand the sedimentary record then much more could be done to integrate sedimentary product with the known system forcing and response (i.e. laboratory experiments, numerical experiments and real world process-product analysis). Such a workflow should ensure that an appropriate theory is designed that can be directly applied to the outcrop sedimentary record.