Organization and Reorganization of Rivers and Sediment Routing Through Time: Examples from the Gulf of Mexico Mississippi System, Geologic Past to Near Future

Mike Blum | Department of Geology | University of Kansas
11:30 am
Thursday, December 7, 2017 | TELUS Convention Centre, MacLeod Hall C/D

Please note: The cut-off date for ticket sales is
1:00 pm, four business days before event [Friday, December 01, 2017].
Each CSPG Technical Luncheon is 1 APEGA PDH credit.

The northern Gulf of Mexico (GoM) margin is dominated by the Mississippi River sediment-dispersal system.  Mississippi source terrain stretches from the Rocky Mountains in the western US to the Appalachian Cordillera in the east.  Sediment from this vast area is routed through the tributary system and main stem for ~5000 km to the well-known alluvial-deltaic plain of south Louisiana and the deep-water basin-floor fan.  However, integration of a continental-scale Mississippi drainage is a Late Neocene phenomenon, and sediment routing to the GoM has changed significantly over time.  This presentation illustrates large-scale change in drainage, sediment routing, and sediment storage for the Mississippi system at 3 different time scales: (a) the last 200 Myrs, where tectonic and geodynamic processes dominate, (b) the last 200 Kyrs, where Milankovitch climate and sea-level changes dominate, and (C) the 200-yr period of the 20th and 21st centuries when human activities have fundamentally altered the sediment routing and dispersal system.

Phanerozoic drainage patterns in North America are becoming increasingly well-known through a large number of detrital zircon studies.  Following assembly of the late Paleozoic Appalachian Cordillera, much of North America drained generally west, then ultimately north to the Boreal Sea during the Late Jurassic and Early Cretaceous.  This period of sediment routing, which produced much of the Mesozoic succession of the Western Canada Sedimentary Basin, met its demise with development and eastward migration of the Western Cordillera and its associated foreland-basin system, and Late Cretaceous flooding of the Western Interior Seaway.  With withdrawal of the seaway, much of southern North America was then routed to the GoM, and an ancestral Mississippi was not likely present until the latest Cretaceous to early Paleocene.  By this time, the Mississippi system had extended headwards into the US continental interior, with tributaries that extended from the Great Plains to the Appalachians, and was routing sediment to a large alluvial-deltaic plain and basin-floor fan in the northern GoM.  However, the primary axis for GoM sediment input had its headwaters in the Western Cordillera, entered the GoM in what is now central Texas, and is now represented by the Paleocene-Early Eocene Wilcox Group of the GoM shelf and deep basin.

Mike Blum is the Scott and Carol Ritchie Distinguished Professor in Geology at the University of Kansas (KU).  Mike received his bachelors, masters and PhD from the University of Texas at Austin where he developed his research interests in fluvial, coastal, and shallow-marine depositional systems, stratigraphic signatures of tectonics, climate and sea-level change, and source-to-sink routing of sediments to deepwater systems.  Prior to joining KU, he was a Research Advisor at ExxonMobil Upstream Research in Houston from 2008-2014, where Calgary was his favorite place to visit and collaborate: his primary focus at ExxonMobil was on the development of quantitative and semi-quantitative source-to-sink concepts and models that would apply across exploration and production scales.  Before joining ExxonMobil, he was Harrison Professor in Geology and Geophysics at Louisiana State University, where he worked on evolution of the Mississippi valley and Gulf of Mexico shoreline.  His current research group is something of a blend of these previous academic and industry efforts, and includes projects in various parts of the Gulf of Mexico basin, the Mesozoic US Western Interior, the Lower Cretaceous of the Western Canada Sedimentary Basin, and the Neogene to modern Himalayan-sourced Ganges-Brahmaputra River system and the associated deepwater Bengal Fan.