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History of Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin

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History of Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin History of Cenozoic North American drainage basin evolution, sediment yield, and accumulation in the Gulf of Mexico basin William E. Galloway1, Timothy L. Whiteaker2, and Patricia Ganey-Curry1 1Institute for Geophysics, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758-4445, USA 2Center for Research in Water Resources, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758-4445, USA ABSTRACT INTRODUCTION a synthesis of North American drainage basin evolution. Since that effort, several advances The Cenozoic fi ll of the Gulf of Mexico The Gulf of Mexico (GOM) originated as a in our understanding both of North American basin contains a continuous record of sedi- small ocean basin created by seafl oor spreading Cenozoic history (source) and of the GOM ment supply from the North American con- in the Middle Jurassic through Early Cretaceous. depositional record (sink) combine to cre- tinental interior for the past 65 million years. By the end of the Mesozoic, mixed carbonate ate the opportunity for a more accurate and Regional mapping of unit thickness and and clastic sedimentation had constructed a detailed synthesis. paleogeography for 18 depositional episodes northern basin margin characterized by a broad (1) New synthesis papers have elucidated the defi nes patterns of shifting entry points of coastal plain and shelf fronted by a well-defi ned regional history and timing of Cenozoic deposi- continental fl uvial systems and quantifi es shelf edge and continental slope (Galloway, tion and erosion within the continental interior the total volume of sediment supplied dur- 2008). However, clastic sediment supply rates (Holm, 2001; Raynolds, 2002; Flores, 2003; ing each episode. Eight fl uvio-deltaic axes were low, in part because of the high global sea Cather, 2004; Sewall and Sloan, 2006; Cather are present: the Rio Bravo, Rio Grande, levels that characterized the Cretaceous and in et al., 2008; Chapin, 2008; Smith et al., 2008; Guadalupe, Colorado, Houston-Brazos, Red, part because the Gulf basin was insulated from Davis et al., 2009; Lawton et al., 2009). Mississippi, and Tennessee axes. Sediment sediment derived from the active Laramide fore- (2) Regional tectonic syntheses have pro- volume was calculated from digitized hand- land uplands by the intervening foreland basin vided quantitative information about the timing contoured unit thickness maps using a geo- seaway that extended from Canada to northern and location of volcanic activity, uplift, and ero- graphic information system (GIS) algorithm New Mexico. Beginning in the late Paleocene, sional unroofi ng of source uplands (McMillan to sum volumes within polygons bounding large volumes of terrigenous clastic sediment et al., 2002; Chapin et al., 2004a; Kelley and interpreted North American river contribu- began to enter the basin from continental North Chapin, 2004; McMillan et al., 2006; McDow- tion. General age-dependent compaction fac- America, constructing large fl uvial/deltaic ell, 2007; Eaton, 2008; Flowers et al., 2008; tors were used to convert calculated volume systems along an extensive, prograding con- Cather et al., 2009; Fan and Dettman, 2009). to total grain volume. Values for rate of sup- tinental margin (Galloway, 2008). Along this (3) Deep petroleum exploration drilling and ply range from >150 km to <10 km3/Ma. margin, loading of stretched continental crust seismic data acquisition on the GOM continen- Paleogeographic maps for eleven Cenozoic caused broad fl exural down warping, creating tal slope and abyssal plain has resolved the cor- time intervals display the evolving matrix of accommodation space for an inboard apron relation of seismic sequences of the deep basin elevated source areas, intracontinental sedi- of coalesced alluvial plain deposits, forming with basin margin depositional episodes (e.g., ment repositories, known and inferred drain- the upper coastal plain (Galloway, 1981). This Combellas-Bigott and Galloway, 2005; Radov- age elements, and depositional fl uvial/deltaic apron merged basinward with a mosaic of delta ich et al., 2007). depocenters along the northern Gulf of Mexico plain and shore-zone systems that together con- (4) Regional seismic depth sections have basin margin. Patterns of sediment supply in structed the lower coastal plain. Seaward and provided thickness information where well time and space record the complex interplay beneath the prograding lower coastal plain suc- control is lacking, allowing construction basin- of intracontinental tectonism, climate change, cession, a prism of continental slope deposits, wide isopach contour maps that can be used for and drainage basin evolution. Five tectono- 5–10 km thick, infi lled the deep basin (Gal- volumetric calculations (Galloway et al., 2000; climatic eras are differentiated: Paleocene late loway, 2008). Basinal deposits, also several Galloway, 2002). Laramide era; early to middle Eocene ter- kilometers thick, derived from the northern (5) Ongoing mapping of GOM genetic minal Laramide era; middle Cenozoic (Late continental margin lap out against the Yucatan sequences incorporating new well, seismic, and Eocene–Early Miocene) dry, volcanogenic Platform to the south and the Florida Platform published information has continued to enhance era; middle Neogene (Middle–Late Miocene) to the east and mix with sediments of the eastern paleogeographic map detail for Cenozoic depo- arid, extensional era; and late Neogene (Plio– Mexican continental slope to the west. sitional episodes (Galloway et al., 2000; Gallo- Pleistocene) monsoonal, epeirogenic uplift era. Galloway (2005b) spliced the depositional way, 2008). Through most of the Cenozoic, three to four record of the northern GOM to the interpreted The combination of information from these independent continental-scale drainage basins regional tectonic, climatic, and geomorphic diverse resources offers the opportunity to have supplied sediment to the Gulf of Mexico. history of the continental interior to produce update, quantify, and signifi cantly enhance Geosphere; August 2011; v. 7; no. 4; p. 938–973; doi:10.1130/GES00647.1; 20 fi gures; 3 tables; 1 appendix fi gure; 2 appendix tables. 938 For permission to copy, contact [email protected] © 2011 Geological Society of America Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/7/4/938/3340555/938.pdf by guest on 02 October 2021 Cenozoic North American drainage basin evolution paleogeographic resolution of the 65 Ma Ceno- of burial and degree of compaction) derived GOM continental platform associated with the zoic history of this continental scale source–sink for similar volume calculations in the Atlan- Late Paleocene Thermal Maximum at ca. 55 Ma couple. That is the objective of this paper. tic margin by Pazzaglia and Brandon (1996) (Zachos et al., 2008), Wilcox deposition termi- were used to recalculate total volumes of solids nated with the long-lived Upper Wilcox depos- Volume and Volume Rate of (grain volume) for each sequence. These gen- ode. Further reduction in sediment supply to Sediment Supply eralized porosity values attempt to account for ~25 km3/Ma was accompanied by long-term ret- the greater compaction of older (and thus more rogradation of the central GOM coastal systems Following the stratigraphic framework of deeply buried) sediments relative to younger and early Eocene sediment starvation of the pre- Galloway et al. (2000), GOM Cenozoic strata (shallower) sediments. They are not lithology viously active abyssal fan systems (Galloway were divided into 18 chronologically signifi cant specifi c, and subsume the variable mix of sand- et al., 2000; Zarra, 2007). Carroll et al. (2006) depositional episodes (deposodes) for mapping stone and mudstone. They are approximations document a comparable decrease in sediment and volumetric analysis (Fig. 1). Each deposode that improve fi nal grain volume estimates. supply and corresponding evolution from over- was a signifi cant period of sediment supply and fi lled Paleocene to underfi lled lacustrine Eocene continental margin growth. Each is recorded in Results deposition in the northern basins of the Western the deposits of regionally correlative genetic Interior. They attribute the observed decrease to sequences (Galloway, 1989; Catuneanu et al., Results of volumetric calculations are sum- removal of easily eroded Cretaceous foreland 2009) that are bounded by major transgres- marized in Table 1. Of most interest is the basin clastics and exposure of granitic cores of sive beds and contained maximum fl ooding grain volume rate column. This value esti- Laramide uplifts. surfaces. These fl ooding events punctuated the mates the average rate that solid mineral mat- For nearly ten million years, encompassing dominantly progradational history of the con- ter was deposited in the basin during each of much of the Middle Eocene, sediment sup- tinental platform on the northern basin margin. 14 differentiated geologic time intervals (Liu ply to the northern GOM was extremely low. For purposes of this analysis, the relatively high- and Galloway, 1997). Extreme time spans of Only thin coastal and shelf facies prograded frequency deposodes of the Plio-Pleistocene 1 and 10.6 Ma likely accentuate and subdue, onto the northern shelf platform of the GOM. are grouped into two composite deposodes of respectively, calculated values. However, the Extensive condensed intervals, including 2–3 Ma duration. This makes them more com- other 12 time steps cluster between 3 and the glauconitic Weches and
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