scholarly journals Antipodean fugitive terranes in southern Laurentia: How Proterozoic Australia built the American West

Lithosphere ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 551-559 ◽  
Author(s):  
G.M. Gibson ◽  
D.C. Champion
Keyword(s):  
North America ◽  
American West ◽  
Ocean Basin ◽  
Backarc Basin ◽  
Left Behind ◽  
Marginal Sea ◽  
Depleted Mantle ◽  
Rodinia Supercontinent ◽  
Laurentian Margin ◽  
Archean Basement

Abstract Paleoproterozoic arc and backarc assemblages accreted to the south Laurentian margin between 1800 Ma and 1600 Ma, and previously thought to be indigenous to North America, more likely represent fragments of a dismembered marginal sea developed outboard of the formerly opposing Australian-Antarctic plate. Fugitive elements of this arc-backarc system in North America share a common geological record with their left-behind Australia-Antarctic counterparts, including discrete peaks in tectonic and/or magmatic activity at 1780 Ma, 1760 Ma, 1740 Ma, 1710–1705 Ma, 1690–1670 Ma, 1650 Ma, and 1620 Ma. Subduction rollback, ocean basin closure, and the arrival of Laurentia at the Australian-Antarctic convergent margin first led to arc-continent collision at 1650–1640 Ma and then continent-continent collision by 1620 Ma as the last vestiges of the backarc basin collapsed. Collision induced obduction and transfer of the arc and more outboard parts of the Australian-Antarctic backarc basin onto the Laurentian margin, where they remained following later breakup of the Neoproterozoic Rodinia supercontinent. North American felsic rocks generally yield Nd depleted mantle model ages consistent with arc and backarc assemblages built on early Paleoproterozoic Australian crust as opposed to older Archean basement making up the now underlying Wyoming and Superior cratons.

Synopsis of late Palaeozoic and Mesozoic terrane accretion within the Cordillera of western North America

1990 ◽  
Vol 331 (1620) ◽  
pp. 479-486 ◽  
Keyword(s):  
North America ◽  
Western North America ◽  
Island Arcs ◽  
Multidisciplinary Research ◽  
The West ◽  
Marginal Sea ◽  
Faunal Diversity ◽  
Cordilleran Margin ◽  
Terrane Accretion ◽  
Faunal Studies

Establishing the paleogeographic origin of most of the terranes within the Cordillera remains an ellusive goal; despite more than 10 years of multidisciplinary research, the home port of any major terrane has not been identified unequivocally. Even most continental fragments that show affinities to North America cannot be repositioned confidently along the Cordilleran margin, and some continental fragments (e.g. Chulita) probably are not North American in origin. Cordilleran oceanic terranes, including island arcs, seamounts, off-ridge islands, and scraps of ocean basins, are especially difficult to reposition because Panthalassa has been destroyed. Faunal studies with emphasis on palaeobiogeographic affinities are the most useful, particularly when coupled with analyses of faunal diversity and endemism. Such studies suggest that some terranes previously thought to have formed near the Cordillerran margin were situated thousands of kilometres to the west, and were separated from the continent by broad ocean basins, rather than by a narrow marginal sea.

Early Contact and Migration

2017 ◽  
Author(s):  
Sue Fawn Chung
Keyword(s):  
North America ◽  
West Coast ◽  
American West ◽  
Chinese Immigrants ◽  
The West ◽  
Value Differences ◽  
Chain Migration ◽  
Coastal Cities ◽  
New Frontier ◽  
And Migration

This chapter focuses on the early contact between Chinese and Americans, the lumber trade, the Chinese immigration to the American West, the recruitment of workers to North America, chain migration, and the importance of early Chinese organizations. It examines why and how the Chinese first came to the American West, what kinds of organizations they established, how they were recruited for work, and what they contributed to the building of the new frontier. It also considers how trade between the West Coast and China, and especially the latter's eastern coastal cities, developed and shows that most Chinese immigrants harbored the “American dream” and thus came voluntarily to the American West. Finally, it discusses some of the factors that worked against the Chinese's acculturation and assimilation, including, language and value differences.

The Epic Journey of Achilles

Ramus ◽  
1976 ◽  
Vol 5 (1) ◽  
pp. 1-17
Author(s):  
William R. Nethercut
Keyword(s):  
North America ◽  
Joseph Campbell ◽  
Left Behind ◽  
The World ◽  
The Many ◽  
Common Sequence

Folk sagas, and epics, develop around a common sequence. A hero is isolated from his society, he enters a land of mystery, is tested by a confrontation with some dread power, he undergoes a symbolic death, and experiences a life-enhancing return to those he left behind. At the end, he is reinstated into the world of men. Joseph Campbell documents the ubiquity of this progression in Asia, Africa, North America, and Europe.The most prominent fact which seems to contradict the above order in the Iliad is the absence of any land of fantasy into which Achilles travels, and, along with this omission, the absence too of any weird or supernatural being against whom the hero must contend. We may even say that their is no real journey that the hero undertakes, for the action of the story lies consistently around Troy. Achilles appears static: he sits in a perfectly ordinary tent. However, this turn of the usual plot achieves something new: it allows Homer to suggest Achilles as an inwardly existing personality, whose mental estrangement is all the more clearly defined by the physical continuities about him. Unlike Odysseus and the many wandering heroes who get blown off course, lose their way in the woods, or who are kidnapped on their wedding nights, Achilles is within reach. Yet he remains apart.

Lower–Middle Ordovician stratigraphy of North-East Greenland

2002 ◽  
pp. 117-125 ◽  
Author(s):  
Svend Stouge ◽  
W. Douglas Boyce ◽  
Jørgen L. Christiansen ◽  
David A.T. Harper ◽  
Ian Knight
Keyword(s):  
Passive Margin ◽  
East Greenland ◽  
Middle Ordovician ◽  
North East ◽  
Upper Proterozoic ◽  
Iapetus Ocean ◽  
Rodinia Supercontinent ◽  
Lower Palaeozoic ◽  
Early Palaeozoic ◽  
Laurentian Margin

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stouge, S., Boyce, W. D., Christiansen, J. L., Harper, D. A., & Knight, I. (2002). Lower–Middle Ordovician stratigraphy of North-East Greenland. Geology of Greenland Survey Bulletin, 191, 117-125. https://doi.org/10.34194/ggub.v191.5138 _______________ The Upper Proterozoic (Riphean) to Lower Palaeozoic succession in North-East Greenland is exposed in a broad N–S-trending belt in the fjord region between 71°38´ and 74°25´N (Fig. 1). The succession comprises mainly marine sediments accumulated during the later stages of the break-up of the Rodinia supercontinent, the subsequent opening of the Iapetus Ocean and formation of the passive margin along the edge of the Laurentian palaeocontinent. Investigations of the sedimentary succession were initiated on Ella Ø in the summer of 2000 as part of a project to investigate the development of the Laurentian margin facing the Iapetus Ocean in the Early Palaeozoic, when studies of the uppermost formations of the Riphean Eleonore Bay Supergroup to the Lower Ordovician Antiklinalbugt Formation on Ella Ø were undertaken (Stouge et al. 2001). Ella Ø was revisited during the summer of 2001, with the focus on the Ordovician formations. In addition, investigations were undertaken in the Albert Heim Bjerge area where the uppermost part of the Ordovician succession is preserved (Fig. 1).

A Laurentian margin subduction perspective: Geodynamic constraints from phase equilibria modeling of barroisite greenstones, northern USA Appalachians

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2587-2605
Author(s):  
I.W. Honsberger ◽  
J. Laird ◽  
J.E. Johnson
Keyword(s):  
Phase Equilibria ◽  
Continental Margin ◽  
Volcanic Rocks ◽  
Oceanic Lithosphere ◽  
Ocean Basin ◽  
Iapetus Ocean ◽  
Continental Arc ◽  
Slab Tear ◽  
Shallow Subduction ◽  
Laurentian Margin

Abstract Phase equilibria modeling of sodic-calcic amphibole-epidote assemblages in greenstones in the northern Appalachians, USA, is compatible with relatively shallow subduction of the early Paleozoic Laurentian margin along the Laurentia-Gondwana suture zone during closure of a portion of the Iapetus Ocean basin. Pseudosection and isopleth calculations demonstrate that peak metamorphic conditions ranged between 0.65 GPa, 480 °C and 0.85 GPa, 495 °C down-dip along the subducted Laurentian continental margin between ∼20 km and ∼30 km depth. Quantitative petrological data are explained in the context of an Early Ordovician geodynamic model involving shallow subduction of relatively young, warm, and buoyant Laurentian margin continental-oceanic lithosphere and Iapetus Ocean crust beneath a relatively warm and wet peri-Gondwanan continental arc. A relatively warm subduction zone setting may have contributed to the formation of a thin, ductile metasedimentary rock-rich channel between the down-going Laurentian slab and the overriding continental arc. This accretionary channel accommodated metamorphism and tectonization of continental margin sediments and mafic volcanic rocks (greenstones) of the Laurentian margin and provided a pathway for exhumation of serpentinite slivers and rare eclogite blocks. Restricted asthenospheric flow in the forearc mantle wedge provides one explanation for the lack of ophiolites and absence of a well-preserved ultra-high-pressure terrane in central and northern Vermont. Exhumation of the subducted portion of the Laurentian margin may have been temperature triggered due to increased asthenospheric flow following a slab tear at relatively shallow depths.

scholarly journals An elongate hadrosaurid forelimb with biological traces informs the biogeography of the Lambeosaurinae

2020 ◽  
pp. 1-9
Author(s):  
Chase Doran Brownstein ◽  
Immanuel Bissell
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Cretaceous ◽  
North American ◽  
American West ◽  
Atlantic Coastal Plain ◽  
Western Interior Seaway ◽  
Terrestrial Vertebrates ◽  
Both Bones ◽  
Atlantic Coastal

Abstract Although the fossil record of the Late Cretaceous eastern North American landmass Appalachia is poor compared to that from the American West, it includes material from surprisingly aberrant terrestrial vertebrates that may represent relictual forms persisting in relative isolation until the end of the Mesozoic. One intriguing question is to what extent eastern and western North American faunas interspersed following the closure of the Western Interior Seaway during the Maastrichtian Stage of the Late Cretaceous ca. 70 Ma. Isolated remains from the Atlantic Coastal Plain in New Jersey have been preliminarily identified as the bones of crested lambeosaurine hadrosaurids, a derived clade known from the Cretaceous of Asia, western North America, and Europe, but have not been formally described. We describe the partial forelimb of a large hadrosaurid from the late Maastrichtian New Egypt Formation of New Jersey. The ulna preserves multiple deep scores identifiable as shark feeding marks, and both bones show ovoid and circular marks attributable to invertebrates. This forelimb is very similar to another partial antebrachium from the same area that shows evidence of septic arthritis. Both these specimens and a complete humerus from the same unit are closely comparable to the lower forelimbs of lambeosaurines among hadrosaurid dinosaurs. Although the absence of lambeosaurine synapomorphies observable on the New Egypt Formation forelimbs precludes their definite referral to Lambeosaurinae, they show that a morphotype of large hadrosauromorph with distinctly elongate forelimbs existed in the latest Maastrichtian of eastern North America and allow for a revision of the latest Cretaceous biogeography of crested herbivorous dinosaurs.

Mediating Judaism: Mind, Body, Spirit, and Contemporary North American Jewish Fiction

AJS Review ◽  
2006 ◽  
Vol 30 (2) ◽  
pp. 231-253
Author(s):  
Sara R. Horowitz
Keyword(s):  
Twentieth Century ◽  
North America ◽  
North American ◽  
Traditional Practices ◽  
Jewish Literature ◽  
Women Novelists ◽  
Left Behind ◽  
American Jewish ◽  
Jewish Immigrants ◽  
Canadian Culture

That Jewish literature in North America is an altogether secular venue has long been regarded as a truism among many influential literary scholars. Indeed, for much of the twentieth century, the fiction of Jewish immigrants and their progeny wrote its way into American and Canadian culture through narratives that captured the process of acculturation by distancing itself from Jewish traditional practices, construed mockingly or nostalgically as relics of a European life left behind, a wellspring of historical or textual memories that oppress or elevate. The few departures from this trend—fiction that represents Judaic ritual and experience sympathetically, with complexity and depth—are exceptions that prove the rule: Chaim Potok’s novels, for example, beginning in the late 1960s and continuing through the close of the twentieth century, and a handful of women novelists negotiating Jewish feminism in stories and novels of the 1980s and 1990s.

Nineteenth-Century Arrow Wounds and Perceptions of Prehistoric Warfare

2005 ◽  
Vol 70 (1) ◽  
pp. 144-156 ◽  
Author(s):  
George R. Milner
Keyword(s):  
Nineteenth Century ◽  
North America ◽  
Papua New Guinea ◽  
American West ◽  
Intergroup Conflict ◽  
Eastern North America ◽  
Indian Wars ◽  
Bone Damage ◽  
The World ◽  
Ways Of Life

In recent years, prehistoric warfare has increasingly attracted the attention of archaeologists in North America, much like other parts of the world. Skeletons with several forms of trauma, including arrow wounds, are often used as evidence of intergroup conflict, although opinion is divided over what these casualties might mean in terms of the effect of warfare on everyday life. Information on 191 patients from the nineteenth-century Indian Wars in the American West indicates that only about one in three arrows damaged bone, and as many as one-half of wounded lived for months or years following their injuries. Arrow wound distributions vary among Indian Wars cases, modern Papua New Guinea patients, and prehistoric skeletons from eastern North America, in large part because of differences in how fighting was conducted. Despite arguments to the contrary, it is reasonable to infer that even low percentages of archaeological skeletons with distinctive conflict-related bone damage indicate that warfare must have had a perceptible impact on ways of life.

scholarly journals Aerial Photogrammetry in the American West: Documenting the Construction of Cattle Water Tanks by Texas Cowboys

Heritage ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1899-1911
Author(s):  
Stance Hurst ◽  
Eileen Johnson ◽  
Doug Cunningham ◽  
Glenn Fernandez-Cespedes
Keyword(s):  
Surface Water ◽  
Cultural Heritage ◽  
Unmanned Aerial Vehicle ◽  
Similar Pattern ◽  
American West ◽  
Left Behind ◽  
Aerial Photogrammetry ◽  
Aerial Vehicle ◽  
Water Tanks ◽  
Land Changes

Aerial photogrammetry is increasingly being used to discover, document, and interpret the cultural heritage of landscapes. Information on the constructed cultural heritage left behind by the first cattle ranchers in the American West is being lost as the land is transformed and modified, and stewardship of the land changes across generations. An unmanned aerial vehicle (UAV) has been used in this research to record and interpret two surface water cattle tanks constructed by Texas cowboys in the mid-1880s. Similar size rocks have been used and placed in a similar pattern across the walls of both tanks. This similarity suggests both tanks were constructed at the same time. This research also demonstrates that UAV photogrammetry can be used to rapidly record and analyze the constructed cultural heritage of American West cowboys.

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