Tectonic influence on Cenozoic mammal richness and sedimentation history of the Basin and Range, western North America

AbstractThe genus Eudasyphora Townsend 1911 is resurrected from junior synonymy and recognized with the genera Dasyphora Robineau-Desvoidy 1830 and Pyrellia Robineau-Desvoidy 1830. Rypellia Malloch 1932 is a subgenus of Eudasyphora, but Dasypyrellia Lobanov 1976 is reported as synonym novum. A key to the species of Eudasyphora is presented. Two new species are described: E. cordilleriana n. sp. from western North America, and E. canadiana n. sp. from northern North America. The phylogenetic and biogeographic analysis led to the following conclusions: Eudasyphora became separated from its sister genus Pyrellia before the beginning of the Pleistocene glaciations. The Rypellia line evolved further in the Oriental Region, whereas the Eudasyphora s. str. line developed in the Holarctic Region. Speciation in both subgenera is correlated with the history of the forest vegetation during the Pleistocene.

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AN ASSESSMENT OF LATE PLEISTOCENE TO MIDDLE HOLOCENE LAKE LEVEL FLUCTUATIONS IN SURPRISE VALLEY, CALIFORNIA

10.31237/osf.io/9hefc ◽

2018 ◽

Author(s):

Daniel Enrique Ibarra

Keyword(s):

United States ◽

North America ◽

Late Pleistocene ◽

General Circulation ◽

Lake Level ◽

Basin And Range ◽

Future Climate ◽

Western United States ◽

Western North America ◽

Ocean General Circulation

Knowledge of Earth’s climate history and sensitivity, combined with modeling past and future climate, are central to informing policy decisions regarding future climate change. The hydrologic response to future warming scenarios due to increased anthropogenic CO2 emissions remains uncertain. Freshwater availability in the arid western United States is projected to decrease in availability as increased agricultural, urban and industrial uses continue to stress supplies. Motivated by the potential for dramatic future hydrologic changes, studies recording the abrupt transitions between different equilibrium states of natural past climate variability shed light on our understanding of the modern climate system.The presence of pluvial lakes in the Basin and Range Province, in the western United States, during the late Pleistocene (40 to 10 ka) indicates far greater moisture availability during the Pleistocene glacials. This study investigates the timing and magnitude of the most recent pluvial lake cycle that filled Surprise Valley, California using geophysical, geochemical and geochronologic tools. Spanning 31.2 to 4.6 ka, this new lake level record places the highest lake level, at 180 meters above present day playa, at 13.9 ± 1.2 ka. This age appears to be nearly synchronous with highstands of Lake Lahontan to the south and the Chewaucan Basin to the north. Additionally, most of the Basin and Range lake highstands, including Lake Surprise, follow peaks in precipitation minus evapotranspiration (P-ET) by 8-10 kyr. By compiling a diverse set of paleoclimate data available for western North America, I found that the timing and geographic distribution of lake highstands is inconsistent with increased precipitation in response to shifting westerly winds, the current model for the genesis of large lakes in western North America. Rather, lakes levels are more strongly correlated with changes in summer insolation, suggesting that lake highstands were likely facilitated by colder temperatures and increased humidity due to the presence of continental ice sheets and increased atmospheric convergence. I compared the constraints from lake and soil-based records to Atmosphere-Ocean General Circulation Model simulations from the Paleoclimate Model Intercomparison Project 2. Based on model-proxy intercomparison, the Atmosphere-Ocean General Circulation Models, the same models used to also assess future climatic changes, poorly predict hydrologic quantities for the Last Glacial Maximum.

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PENROSE MEDAL: CONTINENTAL PLATE TECTONICS AND SOME LONG-STANDING CONTROVERSIES SURROUNDING THE TECTONIC HISTORY OF WESTERN NORTH AMERICA

10.1130/abs/2019am-332694 ◽

2019 ◽

Author(s):

Tanya M. Atwater ◽

Keyword(s):

North America ◽

Plate Tectonics ◽

Western North America ◽

Continental Plate ◽

Tectonic History ◽

History Of

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Evolutionary history of New World ticks of the genus Dermacentor (Ixodida: Ixodidae), and the origin of D. variabilis

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blz063 ◽

2019 ◽

Vol 127 (4) ◽

pp. 863-875 ◽

Cited By ~ 2

Author(s):

Paula Lado ◽

Hans Klompen

Keyword(s):

North America ◽

Evolutionary History ◽

New World ◽

Dermacentor Variabilis ◽

Eastern North America ◽

Western North America ◽

Land Bridge ◽

Phylogenetic Reconstructions ◽

History Of ◽

Migration Event

Abstract This study integrates biogeographical and phylogenetic data to determine the evolutionary history of the New World Dermacentor, and the origin of D. variabilis. The phylogenetic reconstructions presented here strongly support the hypothesis of an Afrotropical origin for Dermacentor, with later dispersal to Eurasia and the Nearctic. Phylogenetic and biogeographical data suggest that the genus reached the New World through the Beringia land bridge, from south-east Asia. The monophyly of the genus is supported, and most of the New World Dermacentor species appear as monophyletic. Dermacentor occidentals constitutes the sister lineage of D. variabilis, and the latter is subdivided into two well-supported clades: an eastern and a western clade. The western clade is genetically more variable than the eastern. The genus Dermacentor probably originated in Africa, and dispersed to the Palearctic and then to the New World through the Beringian route. Dermacentor variabilis appears to have originated in western North America, and then dispersed to eastern North America, probably in a single migration event.

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Upper mantle structure in the Basin and Range province, western North America, from the apparent velocities of S waves

Bulletin of the Seismological Society of America ◽

10.1785/bssa0590041653 ◽

1969 ◽

Vol 59 (4) ◽

pp. 1653-1665

Author(s):

Robert L. Kovach ◽

Russell Robinson

Keyword(s):

North America ◽

Wave Velocity ◽

Velocity Gradient ◽

Upper Mantle ◽

Shear Velocity ◽

Basin And Range ◽

P Wave ◽

Western North America ◽

Basin And Range Province ◽

S Waves

Abstract The variation of shear velocity with depth in the upper mantle for the Basin and Range province of western North America has been studied with direct measurements of dT/dΔ for S waves in the distance range 14° < Δ < 40°. Three orthogonal components of digital data were used and onset times were determined using the product of the horizontal radial and vertical components of motion and particle motion diagrams. A linear LRSM array in Arizona was used for the measurement of dT/dΔ. An S-wave velocity distribution is derived, compatible with P-wave velocity models for the same region. The derived model consists of a thin lid zone of shear velocity 4.5 km/sec overlying a low-velocity zone and a change in velocity gradient at a depth of 160 km. Two regions of high-velocity gradient are located at depths beginning at 360 km and 620 km.

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Plate tectonic history of the northeast Pacific and western North America

The Eastern Pacific Ocean and Hawaii ◽

10.1130/dnag-gna-n.21 ◽

2015 ◽

pp. 21-72 ◽

Cited By ~ 95

Author(s):

Tanya Atwater

Keyword(s):

North America ◽

Plate Tectonic ◽

Western North America ◽

Northeast Pacific ◽

Tectonic History ◽

History Of

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Illuminating the lack of consensus among descriptions of earth history data in the North American deserts: A resource for biologists

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133310363991 ◽

2010 ◽

Vol 34 (4) ◽

pp. 419-441 ◽

Cited By ~ 59

Author(s):

Joseph S. Wilson ◽

James P. Pitts

Keyword(s):

North America ◽

North American ◽

Western North America ◽

Mountain Building ◽

History Data ◽

Earth History ◽

The North ◽

Robust Model ◽

History Of ◽

Geomorphological Evolution

Understanding the timing of mountain building and desert formation events in western North America is crucial to understanding the evolutionary history of the diverse arid-adapted biota that is found there. While many different, often conflicting descriptions exist regarding geobiotic change in western North America, little work has been done to synthesize these various viewpoints. In this paper we present several case studies that illustrate the differences in the various explanations, based on geological and paleobiological data, detailing mountain uplift and desertification in western North America. The majority of the descriptions detailing mountain building in this area fall into two major periods of uplift, the Laramide uplift (∼70—50 Ma) and the Neogene uplift (∼15—2 Ma), yet it remains unclear which of these events was responsible for the formation of the modern mountains. Like the descriptions of mountain building, various accounts exist detailing the timing of desert formation. Some authors suggest that the deserts existed as far back as 15 Ma while others propose that desert formation occurred as recently as 10,000 years ago. Based on this review of the literature, we suggest that the data on Cenozoic geomorphological evolution of the North American desert landscape is still too coarse and filled with gaps to allow for the development of a robust model of landscape evolution. Instead, this work demonstrates the need for biologists studying the North American biota to realize just how problematic some of the earth history data and models are so that they can build this uncertainty into biogeographic reconstructions.

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