Journal
EARTH-SCIENCE REVIEWS
Volume 185, Issue -, Pages 974-1003Publisher
ELSEVIER
DOI: 10.1016/j.earscirev.2018.08.011
Keywords
Rouse Formation; Solute evolution; Tidal rhythmite; Streptochilus; Brackish water fauna
Categories
Funding
- Geological Society of America's Limnogeology Division's Kerry Kelts Research Award
- U.S. Geological Survey
- National Science Foundation [NSF-EAR1545998]
- University of Arizona's Maxwell Short Scholarship
- Division Of Earth Sciences
- Directorate For Geosciences [1545998] Funding Source: National Science Foundation
Ask authors/readers for more resources
Brackish marine and brackish continental environments are fundamentally different from a compositional perspective. Brackish water is often defined as having salinity lower than that of standard seawater but higher than that of freshwater, but less regard is given to the origin of the salts involved. The simple dilution of standard seawater by freshwater in a coastal or estuarine setting constitutes a brackish environment, but so do lakes where continental fresh water is impounded and becomes more saline through a variety of solute evolution pathways. The range of potential compositions of brackish lake water is diverse and includes water with sea-water-like compositions. Isolated brackish lake environments located hundreds of kilometers inland can evolve towards sodium chloride-dominated, low alkalinity environments that mimic the composition of brackish seawater environments. These types of lakes can harbor a variety of continentally invasive but typically marine organisms, including but not limited to algae, foraminifers, mollusks, diatoms, and crustaceans. Distinguishing brackish marine from brackish lake environments in the geologic record can be difficult. In this paper, the enigmatic late Miocene and early Pliocene southern Bouse Formation of southern Arizona and California, USA, considered by many to represent a marine transgression along the lower Colorado River corridor, is discussed within a broad framework that incorporates hydrochemical, biogeographical, and species niche concepts. A brackish lake interpretation provides a powerful platform that can comprehensively account for the enigmatic mixed marine and continental fossil assemblage and possible tidal rhythmites that feature prominently in the southern Souse Formation controversy. A review of the broader regional (paleo)environmental context for the southern Bouse supports a sodium chloride-dominated, low alkalinity, mildly brackish (10-5 ppt) Colorado River-fed lake depositional environment that was populated by an intriguing but predictable array of euryhaline, opportunistic, and continentally invasive marginal marine organisms.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available