Clay mineral distributions in and around the Mississippi River watershed and Northern Gulf of Mexico: sources and transport patterns

Abstract

International audienceMaps of the distributions of the four major clay minerals (smectite, illite, kaolinite and chlorite) in and around the Mississippi River drainage basin and in the Northern Gulf of Mexico have been produced using newly acquired data from erodible/alluvial terrestrial sediments and marine surface sediments, as well as from previously published data. East of the Rockies, North America can be divided into four, large, clay-mineral provinces: (1) the north-western Mississippi River watershed (smectite rich), (2) the Great Lakes area and eastern Mississippi River watershed (illite and chlorite rich), (3) the south-eastern United States (kaolinite rich) and (4) the Brazos River and south-western Mississippi River watersheds (illite and kaolinite rich). The clay mineral distributions in surface sediments of the present-day Gulf of Mexico are strongly influenced by three main factors: (1) by relative fluvial contributions: the Mississippi River delivers the bulk of the clay input to the Northern Gulf of Mexico whereas the Apalachicola, Mobile, Brazos and Rio Grande rivers inputs have more local influences; (2) by differential settling of various clay mineral species, which is identified for the first time in Northern Gulf of Mexico sediments; and (3) by oceanic current transport: the Gulf of Mexico surface and subsurface circulation distributes the clay-rich sediments from river mouth sources throughout the Northern Gulf of Mexico

Changes in precipitation regimes over North America during the Holocene as recorded by mineralogy and geochemistry of Gulf of Mexico sediments

“…The letters S, I, C and K (standing for smectite, illite, chlorite and kaolinite, respectively) indicate areas where the bedrock/soils contain a clay mineral assemblage markedly dominated by one clay species. Note that the Mississippi River receives main discharges from the Missouri (NW) + Ohio (NE) rivers system, which drains almost half of the conterminous USA (e.g., Sionneau et al, 2008). GOM: Gulf of Mexico, LC: Loop Current.…”

“…1b): (1) the northwestern Mississippi and Missouri rivers watershed is characterized by high smectite content (S N 50%, I b 30%, K b 20%, C b 14%), (2) the northeastern province mainly delivering illite and chlorite (S b 20%, I N 30%, K b 25%, C N 12%), (3) the kaolinite-rich southeastern part of the United States (S b 30%, I b 20%, K N 30%, C b 28%), and (4) the Brazos River and southwestern Mississippi River watersheds is dominated by illite and kaolinite (S b 40%, I N 30%, K N 20%, C b 8%). More details on the clay mineral distributions in and around Mississippi River watershed are discussed by Sionneau et al (2008). The letters S, I, C and K denote smectite, illite, chlorite and kaolinite, respectively.…”

Sediments of the Gulf of Mexico

“…The deep-sea mud that is dominated by clay minerals shows that the most abundant species of clay mineral is smectite. Illite is the next most abundant (Sionneau et al 2008). Chlorite and kaolinite are the minor clay mineral species.…”

Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

“…In spite of the broad knowledge that river systems and drainage basins have changed significantly since the LGM (Upham, 1883;Bell, 1889;Clayton and Moran, 1982;Dyke and Prest, 1987;Wright, 1987;Teller, 1990a, b;Marshall and Clarke, 1999;Patterson, 1997Patterson, , 1998Licciardi et al, 1999;Overeem et al, 2005;Tarasov and Peltier, 2006;Wickert, 2014;Ullman et al, 2014;Margold et al, 2014;Ullman et al, 2015;Margold et al, 2015), many studies do not include any clear picture of drainage basin evolution. This results in representations of the modern drainage network wholly or partially in place of glacial-stage drainage basins (e.g., Blum et al, 2000;Sionneau et al, 2008;Montero-Serrano et al, 2009;Sionneau et al, 2010;Kujau et al, 2010;Lewis and Teller, 2006;Tripsanas et al, 2007Tripsanas et al, , 2014Rittenour et al, 2003Rittenour et al, , 2005Rittenour et al, , 2007Knox, 2007) that help to propagate a lack of consciousness about the continental-scale hydrologic changes that occurred, even in cases when the study acknowledges in the text that past drainage pathways were different. The best current Cenozoic history of Mississippi River drainage does not attempt to place its northern drainage basin boundary during the Pleistocene (Galloway et al, 2011).…”