scholarly journals Review and analysis of the age and origin of the Pliocene Bouse Formation, lower Colorado River Valley, southwestern USA

Geosphere ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 444-459 ◽  
Author(s):  
Jon E. Spencer ◽  
P. Jonathan Patchett ◽  
Philip A. Pearthree ◽  
P. Kyle House ◽  
Andrei M. Sarna-Wojcicki ◽  
...  
2021 ◽  
Author(s):  
Rebecca Dorsey ◽  
Juan Carlos Braga Alarcón ◽  
Kevin Gardner ◽  
Brennan O'Connell

Marine straits and seaways are known to host a wide range of sedimentary processes and products, but the role of marine connections in the development of large river systems remains little studied. This study explores a hypothesis that shallow marine waters flooded the lower Colorado River valley at ~ 5 Ma along a fault-controlled former tidal straight, soon after the river was first integrated to the northern Gulf of California. The upper bioclastic member of the southern Bouse Formation provides a critical test of this hypothesis. The upper bioclastic member contains wave ripple-laminated bioclastic grainstone with minor red mudstone, pebbly grainstone with HCS-like stratification and symmetrical gravelly ripples, and calcareous-matrix conglomerate. Fossils include upward-branching segmented coralline-like red algae with no known modern relatives but confirmed as marine calcareous algae, echinoid spines, barnacles, shallow marine foraminifers, clams, and serpulid worm tubes. These results provide evidence for deposition in a shallow marine bay or estuary seaward of the transgressive backstepping Colorado River delta. Tsunamis generated by seismic and meteorologic sources likely produced the HCS-like and wave-ripple cross-bedding in poorly-sorted gravelly grainstone. Marine waters inundated a former tidal strait within a fault-bounded tectonic lowland that connected the lower Colorado River to the Gulf of California. Delta backstepping and transgression resulted from a decrease in sediment output due to sediment trapping in upstream basins and relative sea-level rise produced by regional tectonic subsidence.


2019 ◽  
Author(s):  
Rebecca J. Dorsey ◽  
◽  
Juan Carlos Braga ◽  
Kevin Gardner ◽  
Kristin McDougall ◽  
...  

1992 ◽  
Vol 23 (1) ◽  
pp. 117-118
Author(s):  
P.J. Casselton

2019 ◽  
Vol 61 (4) ◽  
pp. 863-879
Author(s):  
Dennis V. Johnson ◽  
Jane C. MacKnight

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 111-135
Author(s):  
Jacob O. Thacker ◽  
Karl E. Karlstrom ◽  
Laura J. Crossey ◽  
Ryan S. Crow ◽  
Colleen E. Cassidy ◽  
...  

Abstract Structural evidence presented here documents that deformation was ongoing within the lower Colorado River corridor (southwestern USA) during and after the latest Miocene Epoch, postdating large-magnitude extension and metamorphic core complex formation. Geometric and kinematic data collected on faults in key geologic units constrain the timing of deformation in relation to the age of the Bouse Formation, a unit that records the first arrival and integration of the Colorado River. North-south–striking extensional, NW-SE–striking oblique dextral, NE-SW–striking oblique sinistral, and east-west–striking contractional faults and related structures are observed to deform pre– (>6 Ma), syn– (6–4.8 Ma), and post–Bouse Formation (<4.8 Ma) strata. Fault displacements are typically at the centimeter to meter scale, and locally exhibit 10-m-scale displacements. Bouse Formation basalt carbonate locally exhibits outcrop-scale (tens of meters) syndepositional dips of 30°–90°, draped over and encrusted upon paleotopography, and has a basin-wide vertical distribution of as much as 500 m. We argue that part of this vertical distribution of Bouse Formation deposits represents syn- and post-Bouse deformation that enhanced north-south–trending depocenters due to combined tectonic and isostatic subsidence in a regional fault kinematic framework of east-west diffuse extension within an overall strain field of dextral transtension. Here we (1) characterize post-detachment tectonism within the corridor, (2) show that diffuse tectonism is cumulatively significant and likely modified original elevations of Bouse Formation outcrops, and (3) demonstrate that this tectonism may have played a role in the integration history of the lower Colorado River. We suggest a model whereby intracontinental transtension took place in a several hundred kilometers-wide area inboard of the San Andreas fault within a diffuse Pacific–North America plate margin since the latest Miocene.


Ecology ◽  
1980 ◽  
Vol 61 (6) ◽  
pp. 1402-1411 ◽  
Author(s):  
Jake Rice ◽  
Bertin W. Anderson ◽  
Robert D. Ohmart

Geosphere ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 473-473
Author(s):  
Jacob O. Thacker ◽  
Karl E. Karlstrom ◽  
Laura J. Crossey ◽  
Ryan S. Crow ◽  
Colleen E. Cassidy ◽  
...  

2015 ◽  
Vol 7 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Daniel P. Collins ◽  
Blake A. Grisham ◽  
Courtenay M. Conring ◽  
Jeffrey M. Knetter ◽  
Warren C. Conway ◽  
...  

Abstract Population delineation throughout the annual life cycle for migratory birds is needed to formulate regional and national management and conservation strategies. Despite being well studied continentally, connectivity of sandhill crane Grus canadensis populations throughout the western portion of their North American range remains poorly described. Our objectives were to 1) use global positioning system satellite transmitter terminals to identify summer distributions for the Lower Colorado River Valley Population of greater sandhill cranes Grus canadensis tabida and 2) determine whether intermingling occurs among any of the western greater sandhill crane populations: Rocky Mountain Population, Lower Colorado River Valley Population, and Central Valley Population. Capture and marking occurred during winter and summer on private lands in California and Idaho as well as on two National Wildlife Refuges: Cibola and Sonny Bono Salton Sea National Wildlife Refuges. A majority of marked greater sandhill cranes summered in what is established Lower Colorado River Valley Population breeding areas in northeastern Nevada and southwestern Idaho. A handful of greater sandhill cranes summered outside of traditional breeding areas in west-central Idaho around Cascade Reservoir near Donnelly and Cascade, Idaho. For example, a greater sandhill crane colt captured near Donnelly in July 2014 survived to winter migration and moved south to areas associated with the Rocky Mountain Population. The integration of the greater sandhill crane colt captured near Donnelly provides the first evidence of potential intermingling between the Lower Colorado River Population and Rocky Mountain Population. We suggest continued marking and banding efforts of all three western populations of greater sandhill cranes will accurately delineate population boundaries and connectivity and inform management decisions for the three populations.


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