Paleozoic tectonic domains of Nevada: An interpretive discussion to accompany the geologic map of Nevada

Abstract

The Paleozoic geologic history of Nevada can be viewed in terms of tectonic domains derived from the newly interpreted digital geologic map of Nevada. These domains reveal that Paleozoic tectonic events were shaped by complex interactions between the continental margin in Nevada and accreted terranes outboard of the margin. Ten domains are described. They include lower Paleozoic domains based on paleogeographic facies, the Carbonate Shelf, Slope and Basin domains; the Nolan Belt domain, a structurally complex domain that includes Precambrian and lower Paleozoic slope and basin facies rocks; the Dutch Flat domain, an Upper Devonian feldspathic sandstone of exotic origin; an Upper Devonian to Lower Pennsylvanian siliciclastic Foreland basin domain resting conformably over the Shelf domain; the Pennsylvanian and Permian siliciclastic and carbonate Antler Overlap domain, which sits unconformably over all of the older domains; the Golconda domain of deformed upper Paleozoic oceanic, carbonate and siliciclastic rocks, which is faulted over the Antler Overlap domain; the upper Paleozoic and Mesozoic volcaniclastic Black Rock-Jackson domain; and numerous carbonate, siliciclastic, and volcaniclastic Mesozoic terranes and assemblages that were either accreted to the margin or deposited unconformably over previously accreted Paleozoic terranes. Interpretations of these domains defi ne multiple, distinct, lower Paleozoic tectonic environments. They suggest that the "Antler Orogeny" can be reinterpreted as a sequence of tectonic events involving deformation of the margin and the accretion of multiple terranes to the margin over an extended period from the Late Devonian to the Early Pennsylvanian in a complex transpressive tectonic regime. Some of the accreted terranes contain rocks unlike those from the adjacent margin or other terranes and suggest they are far traveled. A change in the plate boundary confi guration in the Middle Pennsylvanian led to the development of a new margin that refl ected the effects of a new plate boundary farther to the west. Accretion to the margin of upper Paleozoic oceanic terranes at the close of the Paleozoic redefi ned the margin once again as it changed from a transpressive accretion regime to a true backarc plate tectonic setting in the Mesozoic. East-vergent and west-vergent, thickskinned thrusting and exhumation coupled with signifi cant translation of components of Mesozoic and older terranes rearranged the Paleozoic rocks of the shelf and earlier accreted terranes during Jurassic and Cretaceous time. Viewing the geologic history of the region in the context of terrane accretion provides new insight into the complex processes that shaped the continental margin of western North America.

Three‐Dimensional Evolution of the Early Paleozoic Western Laurentian Margin: New Insights From Detrital Zircon U‐Pb Geochronology and Hf Isotope Geochemistry of the Harmony Formation of Nevada

“…Subsequently, more extensive U‐Pb analyses of detrital zircons led to the proposal that the Harmony A originated in central or southern Laurentia, and the Harmony B was derived from northern Laurentia (Gehrels, Dickinson, Riley, et al, ) (Figure ). Later workers suggested that the Harmony Formation was an exotic accreted terrane, based on the absence of local source terranes (Jones‐Crafford, ; Ketner et al, ).…”

Geometry of the Neoproterozoic and Paleozoic rift margin of western Laurentia: Implications for mineral deposit settings

“…Across the Great Basin of eastern Nevada and western Utah, Neoproterozoic-Devonian geologic features are characterized by the great width and thickness of north-striking miogeoclinal facies belts of the carbonate platform shelf and the Antler allochthon slope and basin (Stewart, 1980(Stewart, , 1991Turner et al, 1989;Poole et al, 1992;Cook, 2005;Crafford, 2008). This segment is also characterized by minor episodes of alkalic magmatism (Turner et al, 1989), underlying zones of both extended and intact Laurentian basement, and the presence of probable rotated crustal fault blocks at depth (Tosdal et al, 2000;Crafford and Grauch, 2002) that were reactivated during the Devonian (Emsbo et al, 1999;Morrow and Sandberg, 2008).…”

The Inskip Formation, the Harmony Formation, and the Havallah sequence of Northwestern Nevada — An interrelated Paleozoic assemblage in the home of the Sonoma orogeny

“…These authors state that some of the forms "***suggest a paleogeographic relationship with northwestern Canada***" and other areas extremely remote from Nevada. This information led McCollum and McCollum (1989) to the conclusion that the Antler orogeny was "a transpressional orogen within a transcurrent fault system" and it tends to confirm the conclusion of Ketner and others (2005) and Crafford (2008), based entirely on other data, that the provenance of Cambrian limestone olistoliths, as well as arkosic clasts of the Harmony Formation, was an exotic terrane transported tectonically to Nevada from northwestern Canada. Olistostromes bearing large clasts of limestone were not identified in the Inskip Formation.…”