Travertines of the Bouse Formation

2016 desert symposium e Bouse Formation provides a sedimentary record of the rst arrival of the Colorado River, water and sediment, as it was integrated from the Colorado Plateau to the Gulf of California 5–6 Ma. is unit is generally thin (10–100s m) but widespread within basins in the lower Colorado River corridor that extend from Lake Mead to Yuma (Fig. 1). e basins are interpreted to have been previously internally drained areas that were integrated basin-to-basin by the Colorado River (e.g., Spencer et al., 2008; 2013), although marine/estuarine inundation has been proposed for the southern part of the corridor (e.g., Miller et al., 2014; McDougall and MirandaMartinez, 2014). e lower parts of the Bouse Formation are predominantly carbonates; the upper part (the interbedded unit) consists mainly of siliciclastic deposits, including Colorado River muds and sands. is paper focuses on the carbonate facies of the Bouse with a goal of understanding the di erent types and origins of Bouse carbonates. Dorsey et al. (this volume) describe three carbonate facies in the southernmost part of the corridor: (1) lower bioclastic limestone and minor tufa that are interpreted to represent highenergy shallow water (including tidal) environments; (2) a marl succession that is interpreted to record precipitated carbonate settling below wave base in a large body of water; and (3) an upper unit of fossil-rich calcarenite and conglomerate (Gootee et al., this volume) that overlies the other carbonate facies, mudstone, and cross-bedded Colorado River sandstone. Dorsey et al (this volume) interpret this upper unit as evidence of reinundation of an early Colorado River valley by a lake or estuary; Gootee et al (this volume) suggest that the upper unit is a mix of local tributary siliciclastic material and carbonate reworked from the lower two carbonate units as the water level in the valley receded. Travertines of the Bouse Formation