Paper No. 3
Presentation Time: 8:45 AM

MAJOR ADVANCES IN SILICICLASTIC SEDIMENTARY GEOLOGY, 1960-2012: PROCESSES, DEPOSITIONAL SYSTEMS AND STRATIGRAPHY


STEEL, Ron, Geological Sciences, University of Texas at Austin, Austin, TX 78702, rsteel@jsg.utexas.edu

There was a new focus on ‘processes’ within sedimentary geology from the 1960s. It was initially driven by alluvial-channel and flow-regime experiments, but led to the concept of facies succession for all depositional environments and eventually, on the larger scale, to a new stratigraphy in which base-level change was the key ingredient. Systematic study of modern environments led to a marked improvement in our knowledge of alluvial to deepwater sedimentary systems, and how they are linked. New access to seismic data, especially on shelf margins and deep marine environments, was critical for further great changes in our understanding of marine processes and basin-scale products. Integration of new knowledge on rates and time scales in tectonics, climate dynamics and sea-level change has been important for gleaning the signals of these drivers from the accumulated sedimentary successions. Current research, not least from geomorphic and stratigraphic experiments, is suggesting that autogenic responses in stratigraphy are more common and occur on longer time scales than formerly thought, and will cause a rethink in sequence stratigraphy.