Subsurface Data in the Lower Colorado River Corridor and Its Implications for Tectonic Models of Basin Evolution Within the Palo Verde and Parker Valleys

Cassidy, Colleen E.; Crow, Ryan S.; House, P. Kyle; Thacker, Jacob O.; Beard, Les P.; Cohen, Andrew S.; Pearthree, P.A.; Howard, Keith A.

doi:10.1130/abs/2018rm-314097

Cited by 6 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The extent and geometry of subsurface Bouse Formation have been investigated in several stages by drilling (Metzger, 1968;, and is currently under comprehensive investigation and synthesis by the U.S. Geological Survey (e.g., Cassidy et al, 2018). Structure contours for the base of Bouse Formation (Fig.…”

Section: ■ ■ Geologic Settingmentioning

confidence: 99%

Post–12 Ma deformation in the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation

et al. 2019

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: ■ ■ Geologic Settingmentioning

confidence: 99%

Post–12 Ma deformation in the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…above results, supplemented with data from test well 36bbb, which penetrated 90 m of sediment including 52 m of the Bouse Formation siliciclastic member (Fig. 2; Metzger et al, 1973;Cassidy et al, 2018;Cohen et al, 2019). The cross section is displayed at 5× vertical exaggeration to permit visualization of key stratigraphic relations in thin geologic units.…”

Section: Research Papermentioning

confidence: 89%

“…9, 11), but its thickness appears to decrease into deeper parts of the basin as indicated by observations that it is consistently <5 m thick where encountered in subsurface wells throughout the Blythe Basin (Metzger et al, 1973). Although the base of the Bouse Formation was not penetrated in well 36bbb, regional isopach analyses suggest that the basal carbonate member likely is <50 m below the bottom of the well (24 m below sea level) (Turak, 2000;Cassidy et al, 2018;Crow et al, 2018Crow et al, , 2019b. Thus, the available constraints indicate a basin architecture characterized by gentle basinward bedding dips adjacent to high-angle faults at the basin margins, with bedding dips decreasing to subhorizontal in the basin center beneath the modern Colorado River (Figs.…”

Section: Research Papermentioning

confidence: 97%

“…Deposits of the Bouse Formation and Bullhead Alluvium have subsided or been faulted down in the central Blythe Basin (Fig. 12; Metzger et al, 1973;Howard et al, 2015;Cassidy et al, 2018;Cohen et al, 2019;Crow et al, 2019b), suggesting that structures in the Blythe Basin were active during late Miocene to Pliocene time. Direct evidence for syn-and post-Bouse faulting in the Blythe Basin includes basin-bounding faults such as the Lost Trigo fault mapped along the eastern margin of the basin (Metzger et al, 1973;San Diego Gas and Electric Company, 1976;Menges and Pearthree, 1983;Sherrod and Tosdal, 1991;Richard, 1993;this study).…”

Section: Structural Controls On Basin Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

Tectonostratigraphic record of late Miocene–early Pliocene transtensional faulting in the Eastern California shear zone, southwestern USA

et al. 2021

Self Cite

View full text Add to dashboard Cite

The Eastern California shear zone (ECSZ; southwestern USA) accommodates ~20%–25% of Pacific–North America relative plate motion east of the San Andreas fault, yet little is known about its early tectonic evolution. This paper presents a detailed stratigraphic and structural analysis of the uppermost Miocene to lower Pliocene Bouse Formation in the southern Blythe Basin, lower Colorado River valley, where gently dipping and faulted strata provide a record of deformation in the paleo-ECSZ. In the western Trigo Mountains, splaying strands of the Lost Trigo fault zone include a west-dipping normal fault that cuts the Bouse Formation and a steeply NE-dipping oblique dextral-normal fault where an anomalously thick (~140 m) section of Bouse Formation siliciclastic deposits filled a local fault-controlled depocenter. Systematic basinward thickening and stratal wedge geometries in the western Trigo and southeastern Palo Verde Mountains, on opposite sides of the Colorado River valley, record basinward tilting during deposition of the Bouse Formation. We conclude that the southern Blythe Basin formed as a broad transtensional sag basin in a diffuse releasing stepover between the dextral Laguna fault system in the south and the Cibola and Big Maria fault zones in the north. A palinspastic reconstruction at 5 Ma shows that the southern Blythe Basin was part of a diffuse regional network of linked right-stepping dextral, normal, and oblique-slip faults related to Pacific–North America plate boundary dextral shear. Diffuse transtensional strain linked northward to the Stateline fault system, eastern Garlock fault, and Walker Lane, and southward to the Gulf of California shear zone, which initiated ca. 7–9 Ma, implying a similar age of inception for the paleo-ECSZ.

show abstract

“…The Bouse Formation includes a thin, laterally extensive basal carbonate member overlain by a siliciclastic member that represents the oldest deposits of the early Colorado River (Dorsey et al, 2018). The siliciclastic member thickens to >200 m beneath the modern Colorado River floodplain (Metzger et al, 1973;Cassidy et al, 2018;Crow et al, 2019;Cohen et al, 2019) and pinches out to zero thickness at the basin margins (Figs. 3,4).…”

Section: Overviewmentioning

confidence: 99%

Early Pliocene Marine Transgression into the Lower Colorado River Valley, Southwestern USA, by Re-Flooding of a Former Tidal Strait

Dorsey¹,

Braga²,

Gardner³

et al. 2022

Preprint

View full text Add to dashboard Cite

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.

show abstract

Subsurface Data in the Lower Colorado River Corridor and Its Implications for Tectonic Models of Basin Evolution Within the Palo Verde and Parker Valleys

Cited by 6 publications

References 0 publications

Post–12 Ma deformation in the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation

Post–12 Ma deformation in the lower Colorado River corridor, southwestern USA: Implications for diffuse transtension and the Bouse Formation

Tectonostratigraphic record of late Miocene–early Pliocene transtensional faulting in the Eastern California shear zone, southwestern USA

Early Pliocene Marine Transgression into the Lower Colorado River Valley, Southwestern USA, by Re-Flooding of a Former Tidal Strait

Contact Info

Product

Resources

About