Structures in the Jackass Lakes pluton–host-rock system, central Sierra Nevada, California, and inferred mid-Cretaceous Farallon–North America plate kinematics

2018 ◽  
Vol 130 (11-12) ◽  
pp. 1940-1958
Author(s):  
Ryan J. Krueger ◽  
Aaron S. Yoshinobu
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Host Rock ◽  
Rock System ◽  
Plate Kinematics

scholarly journals A crucial geologic test of Late Jurassic exotic collision versus endemic re-accretion in the Klamath Mountains Province, western United States, with implications for the assembly of western North America

2021 ◽  
Author(s):  
Todd A. LaMaskin ◽  
Jonathan A. Rivas ◽  
David L. Barbeau ◽  
Joshua J. Schwartz ◽  
John A. Russell ◽  
...  
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Continental Margin ◽  
North American ◽  
Detrital Zircon ◽  
Late Jurassic ◽  
North American Plate ◽  
Klamath Mountains ◽  
Clastic Rocks ◽  
Plate Margin

Differing interpretations of geophysical and geologic data have led to debate regarding continent-scale plate configuration, subduction polarity, and timing of collisional events on the western North American plate margin in pre–mid-Cretaceous time. One set of models involves collision and accretion of far-traveled “exotic” terranes against the continental margin along a west-dipping subduction zone, whereas a second set of models involves long-lived, east-dipping subduction under the continental margin and a fringing or “endemic” origin for many Mesozoic terranes on the western North American plate margin. Here, we present new detrital zircon U-Pb ages from clastic rocks of the Rattlesnake Creek and Western Klamath terranes in the Klamath Mountains of northern California and southern Oregon that provide a test of these contrasting models. Our data show that portions of the Rattlesnake Creek terrane cover sequence (Salt Creek assemblage) are no older than ca. 170–161 Ma (Middle–early Late Jurassic) and contain 62–83% Precambrian detrital zircon grains. Turbidite sandstone samples of the Galice Formation are no older than ca. 158–153 Ma (middle Late Jurassic) and contain 15–55% Precambrian detrital zircon grains. Based on a comparison of our data to published magmatic and detrital ages representing provenance scenarios predicted by the exotic and endemic models (a crucial geologic test), we show that our samples were likely sourced from the previously accreted, older terranes of the Klamath Mountains and Sierra Nevada, as well as active-arc sources, with some degree of contribution from recycled sources in the continental interior. Our observations are inconsistent with paleogeographic reconstructions that are based on exotic, intra-oceanic arcs formed far offshore of North America. In contrast, the incorporation of recycled detritus from older terranes of the Klamath Mountains and Sierra Nevada, as well as North America, into the Rattlesnake Creek and Western Klamath terranes prior to Late Jurassic deformation adds substantial support to endemic models. Our results suggest that during long-lived, east-dipping subduction, the opening and subsequent closing of the marginal Galice/Josephine basin occurred as a result of in situ extension and subsequent contraction. Our results show that tectonic models invoking exotic, intra-oceanic archipelagos composed of Cordilleran arc terranes fail a crucial geologic test of the terranes’ proposed exotic origin and support the occurrence of east-dipping, pre–mid-Cretaceous subduction beneath the North American continental margin.

Penutian Languages

2018 ◽  
Author(s):  
Anthony P. Grant
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Current Knowledge ◽  
Language Family ◽  
Western North America

The Penutian language family, Penutian phylum, or better still, Penutian hypothesis is one of the largest genealogical linguistic groupings to have been proposed for western North America. It involves 16 families or isolates. Only a few of these families are demonstrably relatable to one another according to current knowledge and diachronic techniques. Sometimes Penutian is split by observers into groups of languages assumed to be interrelated, and this is done without assumptions that the groups themselves are interrelated. This article focuses on the Canadian and US languages in “Sapir’s Penutian,” the most commonly accepted version; the most southerly family within Penutian is thus held as Yokutsan of California’s Sierra Nevada. It discusses the subclassification of the so-called Penutian languages into families and smaller units; aspects of their phonology, morphosyntax, and contact histories; and issues in their revitalization and the potential reconstruction of Proto-Penutian.

Mountain Climates of North America

2000 ◽  
Author(s):  
C. David Whiteman
Keyword(s):  
United States ◽  
North America ◽  
Sierra Nevada ◽  
Rocky Mountains ◽  
Climatic Conditions ◽  
Cascade Range ◽  
Coast Range ◽  
Alaska Range ◽  
Mountain Ranges ◽  
The Pacific

The basic climatic characteristics of the major mountain ranges in the United States—the Appalachians, the Coast Range, the Alaska Range, the Cascade Range, the Sierra Nevada, and the Rocky Mountains—can be described in terms of the four factors discussed in chapter 1. The mountains of North America extend latitudinally all the way from the Arctic Circle (66.5°N) to the tropic of Cancer (23.5°N) (figure 2.1). There are significant differences in day length and angle of solar radiation over this latitude belt that result in large seasonal and diurnal differences in the weather from north to south. Elevations in the contiguous United States extend from below sea level at Death Valley to over 14,000 ft (4270 m) in the Cascade Range, the Sierra Nevada, and the Rocky Mountains. Several prominent peaks along the Coast Range in Alaska and Canada (e.g., Mount St. Elias and Mount Logan) reach elevations above 18,000 ft (5486 m). Denali (20,320 ft or 6194 m) in the Alaska Range is the highest peak in North America. The highest peak in the Canadian Rockies is Mt. Robson, with an elevation of 12,972 ft (3954 m). The climates of the Coast Range, the Cascade Range, and the Sierra Nevada, all near the Pacific Ocean, are primarily maritime. The Appalachian Mountains of the eastern United States are subject to a maritime influence from the Atlantic Ocean and the Gulf of Mexico, but they are also affected by the prevailing westerly winds that bring continental climatic conditions. Only the climate of the Rocky Mountains, far from both the Pacific and Atlantic Oceans, is primarily continental. Each of the mountain ranges is influenced by regional circulations. For example, the Appalachians are exposed to the warm, moist winds brought northward by the Bermuda-Azores High and to the influence of the Gulf Stream. Similarly, the Coast Range feels the impact of the Pacific High, the Aleutian low, and the Japanese Current. A mountain range, depending on its size, shape, orientation, and location relative to air mass source regions, can itself affect the regional climate by acting as a barrier to regional flows.

Middle Miocene through Pliocene North American Vegetational History: 16.3-1.6 Ma

1999 ◽  
Author(s):  
Alan Graham
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
North American ◽  
Middle Miocene ◽  
Middle Eocene ◽  
Alaska Range ◽  
Seasonally Dry ◽  
Middle Latitudes ◽  
The North ◽  
Dry Climates

During the Middle Miocene through the Pliocene the Appalachian Mountains underwent continued erosion and approached modern elevations. The Rocky Mountains had undergone uplift to half or more of their present elevation during the Late Cretaceous to Middle Eocene Laramide Revolution; after a lull during the Middle Eocene through the Early Miocene, there was increased tectonic activity beginning ~12 Ma and especially between 7 and 4 Ma. Locally some highlands may have approached or attained modern elevations. The increasingly high mountains and plateaus of Asia and North America deflected the major air streams southward, bringing colder polar air into the middle latitudes of North America. An extensive Antarctic ice sheet further cooled ocean waters and contributed to the spread of seasonally dry climates. The elimination of most of the Asian exotics from the North American flora dates to the Late Miocene-Pliocene as a result of a decline in summer rainfall. The Sierra Nevada attained about two-thirds of their present elevation within the past 10 Ma. They were appreciably elevated at ~5 Ma, stood at ~2100 m at 3 Ma, and have risen ~950 m since 3 Ma (Huber, 1981). The California Coast Ranges and Cascade Mountains attained significant heights by 3 Ma, and there was a rapid rise of the Alaska Range at ~6 Ma. Temperatures increased between ~18 and 16 Ma. In the absence of major plate reorganization and intense volcanic activity and with increased erosion from continued replacement of the dense evergreen forest by deciduous forest and shrubland (increasing albedo), atmospheric CO2 concentration decreased and a sharp lowering of temperature occurred in the Middle Miocene between 15 and 10 Ma. Eolian dust deposits increased in the Late Cenozoic, suggesting greater aridity (Rea et al., 1985). This is supported by kaolinite records from North Atlantic deep sea sediments (Chamley, 1979). At ~4.8~4.9 Ma global cooling and a marine regression of ~40~50 m combined to isolate the Mediterranean Basin from the ocean and to concentrate large volumes of salt as water evaporated. The biota was destroyed, giving rise to the term Messinian salinity crisis.

Caves as a key habitat for rare and endemic species of the west coast of North America: a taxonomic revision of the spider genus Oaphantes (Araneae: Linyphiidae)

Zootaxa ◽  
2020 ◽  
Vol 4819 (2) ◽  
pp. 349-363
Author(s):  
P. PAQUIN ◽  
N. DUPÉRRÉ ◽  
D.J. BUCKLE ◽  
D. UBICK
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Endemic Species ◽  
West Coast ◽  
Taxonomic Revision ◽  
The West ◽  
Southern Limit ◽  
Climatic Variations ◽  
The North ◽  
Sierra Nevada Mountains

The genus Oaphantes is known from the West Coast of North America. Here we revise the genus which now includes three species, two of which are new: O. cryophilus n. sp. and O. prometheus n. sp. All Members of the genus Oaphantes show affinities for cave habitats. Oaphantes pallidulus is known from caves of the Coast Ranges of California and also from epigean records. Oaphantes cryophilus n. sp. is restricted to caves in the southern limit of its distribution in the Sierra Nevada Mountains of California, but in the north it is known from epigean records in Oregon, Washington and British Columbia. Oaphantes prometheus n. sp. is an eyeless troglobite endemic to a single cave in the Sierra Nevada of California. The distribution and relationships of the three species suggest an evolutive scenario likely due to climatic variations and affinities for colder conditions.

Systematics, phylogeny and zoogeography of genus Yoraperla (Plecoptera: Peltoperlidae)

1994 ◽  
Vol 25 (3) ◽  
pp. 241-273 ◽  
Author(s):  
Bill P. Stark ◽  
C. Riley Nelson
Keyword(s):  
New Species ◽  
North America ◽  
Sierra Nevada ◽  
East Asian ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Japanese Species ◽  
Asian Clade ◽  
Three New Species ◽  
American Clade

AbstractYoraperla Ricker, 1952 is revised and 4 nearctic and 3 oriental species are recognized. Three new species, X siletz, Y. han and Y. uchidai, are described and Y. nigrisoma (Banks, 1948) is removed from the synonymy of Y. brevis (Banks, 1907). Phylogenetic and zoogeographic analyses support the hypothesis of two disjunct clades isolated by an increase in sea level in the Bering Straits. The east Asian clade is consistently resolved with the two Korean species Y. han and Y. uchidai forming a sister group relationship apart from the Japanese species Y. uenoi, while resolution of the western North American clade is less secure. Yoraperla probably arose in the Sierra Nevada of North America and migrated to east Asia along an inland route including the Rocky Mts. Future collection and conservation suggestions are given.

Millennial-scale variations in western Sierra Nevada precipitation during the last glacial cycle MIS 4/3 transition

2014 ◽  
Vol 82 (1) ◽  
pp. 236-248 ◽  
Author(s):  
Jessica L. Oster ◽  
Isabel P. Montañez ◽  
Regina Mertz-Kraus ◽  
Warren D. Sharp ◽  
Greg M. Stock ◽  
...  
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Western Slope ◽  
Western North America ◽  
Glacial Cycle ◽  
Climatic Response ◽  
Last Glacial ◽  
Mis 3 ◽  
Heinrich Event ◽  
The Last Glacial

AbstractDansgaard–Oeschger (D–O) cycles had far-reaching effects on Northern Hemisphere and tropical climate systems during the last glacial period, yet the climatic response to D–O cycles in western North America is controversial, especially prior to 55 ka. We document changes in precipitation along the western slope of the central Sierra Nevada during early Marine Oxygen Isotope Stages (MIS) 3 and 4 (55–67 ka) from a U-series dated speleothem record from McLean's Cave. The timing of our multi-proxy geochemical dataset is coeval with D–O interstadials (15–18) and stadials, including Heinrich Event 6. The McLean's Cave stalagmite indicates warmer and drier conditions during Greenland interstadials (GISs 15–18), signified by elevated δ18O, δ13C, reflectance, and trace element concentrations, and less radiogenic 87Sr/86Sr. Our record extends evidence of a strong linkage between high-latitude warming and reduced precipitation in western North America to early MIS 3 and MIS 4. This record shows that the linkage persists in diverse global climate states, and documents the nature of the climatic response in central California to Heinrich Event 6.

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