Neoglacial history of the Stikine–Iskut area, northern Coast Mountains, British Columbia

1987 ◽  
Vol 24 (7) ◽  
pp. 1294-1301 ◽  
Author(s):  
J. M. Ryder
Keyword(s):  
British Columbia ◽  
Aerial Photograph ◽  
Northern Coast ◽  
Historical Records ◽  
Radiocarbon Dates ◽  
Coast Mountains ◽  
Low Level ◽  
The Past ◽  
History Of ◽  
Late Nineteenth

Information about Neoglacial features was obtained from aerial photograph interpretation, observations during low-level flights, ground checking, and historical records. Terminal moraines at Great, Flood, and Mud glaciers date from the late seventeenth to early eighteenth centuries, and recessional moraines at these glaciers and terminal moraines at glaciers farther east date from the late nineteenth to early twentieth centuries. These late Neoglacial terminal moraines appear, in general, to mark the greatest post-Pleistocene extent of the glaciers. Radiocarbon dates from overridden trees and soil indicate that 500–600 14C years BP glaciers were considerably more extensive than they are at present and were advancing. Preservation of a 3800 14C year old caribou antler in a snowbank that is now rapidly shrinking suggests that climate has been relatively cool and moist for the past four millennia.

scholarly journals Late Cretaceous to Paleocene Tectonometamorphic Evolution of the Blanchard River Assemblage, Southwest Yukon: New Insight into the Terminal Accretion of Insular Terranes in the Northern Cordillera

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Lianna Vice ◽  
H. Daniel Gibson ◽  
Steve Israel
Keyword(s):  
British Columbia ◽  
Late Cretaceous ◽  
Amphibolite Facies ◽  
Contact Metamorphism ◽  
Northern Coast ◽  
Coast Mountains ◽  
Tectonic Events ◽  
Western Cordillera ◽  
History Of ◽  
Northwestern North America

Abstract The Intermontane-Insular terrane boundary stretches over 2000 kilometers from British Columbia to Alaska in the western Cordillera. Juxtaposed between these terranes is a series of Jura-Cretaceous basinal and arc assemblages that record a complicated and contested tectonic evolution related to the Mesozoic-Paleocene accretionary history of northwestern North America. In southwest Yukon, west-verging thrust faults facilitated structural stacking of the Yukon-Tanana terrane over these basinal assemblages, including the Early Cretaceous Blanchard River assemblage. These previously undated compressional structures are thought to be related to the final collapse of the Jura-Cretaceous basins and the tectonic burial of the Blanchard River assemblage resulting in amphibolite facies metamorphism. New in situ U-Th-Pb monazite ages record at least three tectonic events: (1) the tectonic burial of the Blanchard River assemblage to amphibolite facies conditions between 83 and 76 Ma; (2) peak burial was followed by regional exhumation at ca. 70-68 Ma; and (3) intense heating and ca. 63-61 Ma low-pressure contact metamorphism attributed to the intrusion of the voluminous Ruby Range suite, which is part of the northern Coast Mountains batholith. The tectonometamorphic evolution recorded in the Blanchard River assemblage can be correlated to tectonism within southwest Yukon and along the length of the Insular-Intermontane boundary from western British Columbia through southwestern Yukon and Alaska. In southwest Yukon, these results suggest an asymmetric final collapse of Jura-Cretaceous basins during the Late Cretaceous, which relates to the terminal accretion of the Insular terranes as they moved northward.

The sedimentary record and Neoglacial history of Tide Lake, northwestern British Columbia

1992 ◽  
Vol 29 (11) ◽  
pp. 2383-2396 ◽  
Author(s):  
John J. Clague ◽  
William H. Mathews
Keyword(s):  
Twentieth Century ◽  
British Columbia ◽  
Ice Age ◽  
Second Phase ◽  
Northern Coast ◽  
Coast Mountains ◽  
Fine Sediments ◽  
Early Twentieth Century ◽  
Outburst Floods ◽  
History Of

Tide Lake was the largest glacier-dammed lake in British Columbia before its demise in the early twentieth century. Situated in the northern Coast Mountains, the lake was impounded by Frank Mackie Glacier and its Neoglacial end moraine. A study of Tide Lake has provided information on styles of glaciolacustrine sedimentation and the chronology of the Neoglacial interval.Much of the sediment underlying the floor of Tide Lake was transported by subglacial and proglacial meltwater streams flowing from nearby glaciers. During the last phase of the lake, large subaqueous fans were built in front of Berendon and Frank Mackie glaciers, and deltas formed on the east side of the basin. Rhythmically bedded fine sediments, which cover much of the lake floor but are almost completely lacking on the slopes above, were deposited from underflows originating on deltas and subaqueous fans and by fallout from interflows and overflows.Three major and one minor lake phases are recognized from stratigraphic, geomorphic, radiocarbon, and dendrochronological data: the earliest phase is undated, but older than 3000 BP (1300 B.C.); the second phase has yielded radiocarbon ages of 2600–2700 BP (800–1000 B.C.); a third, minor phase, during which Tide Lake was restricted to the northern part of the basin, began before 1600 BP (A.D. 350–550) and probably ended a few hundred years later; the last phase may have begun as early as 1000 BP (A.D. 1000–1150), peaked in the seventeenth century, and ended in the early twentieth century. During each of the four phases, Tide Lake fluctuated in a complex fashion and at times was empty. The second phase corresponds to a widely recognized middle Neoglacial advance in western North America; the last phase is coincident with the Little Ice Age. Outburst floods from Tide Lake in the nineteenth and early twentieth centuries devastated Bowser River valley as far downstream as Bowser Lake. The last of the floods occurred around A.D. 1930 when the Frank Mackie moraine was breached and the lake emptied for the last time.

Advance of the Late Wisconsin Cordilleran Ice Sheet in Southern British Columbia Since 22,000 Yr B.P.

1980 ◽  
Vol 13 (3) ◽  
pp. 322-326 ◽  
Author(s):  
J. J. Clague ◽  
J. E. Armstrong ◽  
W. H. Mathews
Keyword(s):  
British Columbia ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Major Advance ◽  
Radiocarbon Dates ◽  
Coast Mountains ◽  
Growth History ◽  
Glacier Ice ◽  
History Of ◽  
Cordilleran Ice Sheet

AbstractRadiocarbon dates from critical stratigraphic localities in southern British Columbia indicate that the growth history of the late Wisconsin Cordilleran Ice Sheet was different from that of most of the Laurentide Ice Sheet to the east. Much of southern British Columbia remained free of ice until after about 19,000 to 20,000 yr ago; only adjacent to the Coast Mountains is there a record of lowland glacier tongues in the interval 22,000 to 20,000 yr B.P. A major advance to the climax of late Wisconsin Cordilleran glacier ice in the northern States was not begun until after about 18,000 yr B.P. in the southwest of British Columbia and after about 17,500 yr B.P. in the southeast. The rate of glacier growth must have been very rapid in the two to three millennia prior to the climax, which has been dated in western Washington at shortly after 15,000 yr B.P.

Introduction

2018 ◽  
Author(s):  
Nurit Yaari
Keyword(s):  
Nineteenth Century ◽  
Eastern Europe ◽  
The Political ◽  
Late Nineteenth Century ◽  
Jewish Culture ◽  
The Past ◽  
Future State ◽  
History Of ◽  
Late Nineteenth ◽  
State Of Israel

This chapter examines the lack of continuous tradition of the art of the theatre in the history of Jewish culture. Theatre as art and institution was forbidden for Jews during most of their history, and although there were plays written in different times and places during the past centuries, no tradition of theatre evolved in Jewish culture until the middle of the nineteenth century. In view of this absence, the author discusses the genesis of Jewish theatre in Eastern Europe and in Eretz-Yisrael (The Land of Israel) since the late nineteenth century, encouraged by the Jewish Enlightenment movement, the emergence of Jewish nationalism, and the rebirth of Hebrew as a language of everyday life. Finally, the chapter traces the development of parallel strands of theatre that preceded the Israeli theatre and shadowed the emergence of the political infrastructure of the future State of Israel.

Past and recent biodiversity profiling in ancient Lake Chalco Mexico by a metagenomics analysis

2021 ◽  
Author(s):  
Bárbara Moguel ◽  
Liseth Pérez ◽  
Luis David Alcaraz ◽  
Socorro Lozano-García ◽  
Luis Herrera-Estrella ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Environmental Dna ◽  
Radiocarbon Dates ◽  
The Past ◽  
Mexican Volcanic Belt ◽  
History Of ◽  
High Throughput Dna Sequencing ◽  
High Altitude Lake ◽  
Taxonomic Groups ◽  
The Relationship

<p>For decades, paleoecological studies in lake sediments have focused on reconstructing the environments of the past and explaining phenomena linked to climatic variations. Recent advances in high-throughput DNA sequencing have allowed access to environmental DNA (eDNA) and ancient sedimentary DNA (sedaDNA) as a new and efficient proxy for past and present biodiversity. The basin of Mexico (BM) is located in the central part of the Trans-Mexican Volcanic Belt at 2,200 m a.s.l.; with the southern portion harboring the Chalco sub-basin. Lake Chalco is one of the last remaining natural aquatic ecosystems within the ever-expanding urban area surrounding Mexico City. The paleoenvironmental history of this lake has been previously characterized using sedimentological and geochemical proxies, as well as preserved microfossils (diatoms, pollen) with a temporal framework based on multiple radiocarbon dates. However, information for the remaining taxonomic groups and metabolic pathways remained unexplored. Here, we present the first metagenomics-based study for the Holocene in a high-altitude lake in Central Mexico –Lake Chalco. We explored the relationship between the lake’s paleoenvironmental condition and estimations of taxonomic and metabolic profiles across the sedimentary sequence (2.5 meters long). Multiple biological and abiotic variables revealed three main environmental phases: 1) a cool freshwater lake (FW1: 11,500-11,000 cal years BP), 2) a warm hyposaline lake (HS2: 11,000-6,000 cal years BP), and 3) a temperate, subsaline lake (SS3, <6,000 cal years BP). We describe the structure of the microbiota community and taxonomy richness turnover in the three Holocene paleoenvironmental phases. During the past 12 000 years BP the most abundant domains in Lake Chalco sediments were Bacteria, followed by Archaea, and Eukarya (36,722 genera). The analysis of functional proteins showed high biodiversity with a total of 27,636,243 proteins identified, but it was only possible to annotate 3,227,398 of them. Also, we identified several genes associated with some relevant pathways, such as methanogenesis. Altogether, this study allowed us to reconstruct the natural history of lake Chalco and its surroundings.</p>

The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.)

1996 ◽  
Vol 70 (2) ◽  
pp. 280-293 ◽  
Author(s):  
Desmond Collins
Keyword(s):  
British Columbia ◽  
Sea Cucumber ◽  
Great Difficulty ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
The Past ◽  
History Of ◽  
The Many ◽  
Life On Earth ◽  
Mistaken Identification

The remarkable “evolution” of the reconstructions of Anomalocaris, the extraordinary predator from the 515 million year old Middle Cambrian Burgess Shale of British Columbia, reflects the dramatic changes in our interpretation of early animal life on Earth over the past 100 years. Beginning in 1892 with a claw identified as the abdomen and tail of a phyllocarid crustacean, parts of Anomalocaris have been described variously as a jellyfish, a sea-cucumber, a polychaete worm, a composite of a jellyfish and sponge, or have been attached to other arthropods as appendages. Charles D. Walcott collected complete specimens of Anomalocaris nathorsti between 1911 and 1917, and a Geological Survey of Canada party collected an almost complete specimen of Anomalocaris canadensis in 1966 or 1967, but neither species was adequately described until 1985. At that time they were interpreted by Whittington and Briggs to be representatives of “a hitherto unknown phylum.”Here, using recently collected specimens, the two species are newly reconstructed and described in the genera Anomalocaris and Laggania, and interpreted to be members of an extinct arthropod class, Dinocarida, and order Radiodonta, new to science. The long history of inaccurate reconstruction and mistaken identification of Anomalocaris and Laggania exemplifies our great difficulty in visualizing and classifying, from fossil remains, the many Cambrian animals with no apparent living descendants.

The Southern Levant and the Ancient Near Eastern Canon

2020 ◽  
pp. 45-65
Author(s):  
Rachel Hallote
Keyword(s):  
Twentieth Century ◽  
Small Scale ◽  
Past Century ◽  
Southern Levant ◽  
Near Eastern ◽  
The Past ◽  
The Bible ◽  
Biblical Narratives ◽  
History Of ◽  
Late Nineteenth

When the artistic canon of the Southern Levant coalesced in the late nineteenth and early twentieth centuries, scholars thought of the region, then Ottoman Palestine, as the locus of the Bible. The small-scale nature of the archaeological finds as well as their relative dearth reinforced a reliance on biblical narratives as a framework for understanding the culture of the region. Moreover, early scholarship did not recognize the complex regionalism of the Southern Levant or the diversity of its populations. Consequently, the artistic canon that developed did not represent the historical and archaeological realities of the region. This chapter examines the history of how the artistic canon of the Southern Levant formed over the past century of scholarship, why various scholars of the early and middle twentieth century included particular items in the canon, and why these now entrenched representations may or may not be helpful to the discipline’s future.

Glacier fluctuations during the past millennium in Garibaldi Provincial Park, southern Coast Mountains, British Columbia

2007 ◽  
Vol 44 (9) ◽  
pp. 1215-1233 ◽  
Author(s):  
Johannes Koch ◽  
John J Clague ◽  
Gerald D Osborn
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Ice Age ◽  
Southern Coast ◽  
Coast Mountains ◽  
The Past ◽  
Glacier Fluctuations ◽  
Garibaldi Provincial Park ◽  
Provincial Park ◽  
Past Millennium

The Little Ice Age glacier history in Garibaldi Provincial Park (southern Coast Mountains, British Columbia) was reconstructed using geomorphic mapping, radiocarbon ages on fossil wood in glacier forefields, dendrochronology, and lichenometry. The Little Ice Age began in the 11th century. Glaciers reached their first maximum of the past millennium in the 12th century. They were only slightly more extensive than today in the 13th century, but advanced at least twice in the 14th and 15th centuries to near their maximum Little Ice Age positions. Glaciers probably fluctuated around these advanced positions from the 15th century to the beginning of the 18th century. They achieved their greatest extent between A.D. 1690 and 1720. Moraines were deposited at positions beyond present-day ice limits throughout the 19th and early 20th centuries. Glacier fluctuations appear to be synchronous throughout Garibaldi Park. This chronology agrees well with similar records from other mountain ranges and with reconstructed Northern Hemisphere temperature series, indicating global forcing of glacier fluctuations in the past millennium. It also corresponds with sunspot minima, indicating that solar irradiance plays an important role in late Holocene climate change.

Toleration and the Cromwellian Protectorate

1984 ◽  
Vol 21 ◽  
pp. 199-233 ◽  
Author(s):  
Blair Worden
Keyword(s):  
Nineteenth Century ◽  
Religious Toleration ◽  
Moral Foundations ◽  
The Past ◽  
History Of ◽  
The Subject ◽  
Late Nineteenth

Toleration is a Victorian subject, a monument to Victorian liberalism. ‘To us who have been educated in the nineteenth century’, proclaimed F. A. Inderwick in his book on the Interregnum, ‘any declaration inconsistent with religious toleration would be abhorrent and inadmissible’. His sentiment would not have seemed controversial to a generation raised on such best-selling works as Buckle’s History of Civilisation in England and Lecky’s History of the Rise and Influence of the Spirit of Rationalism. It may be that the Victorians, enquiring into the origins of the toleration which they had achieved, were prone to congratulate the past on becoming more like the present. Yet in the late nineteenth and early twentieth centuries, when interest in the subject was perhaps at its peak, we can also detect, in the statements on toleration of a Creighton or a Figgis, a fear that the present might become more like the past: that materialism and religious indifference might destroy the moral foundations of toleration, and foster a new barbarism which would persecute Christians afresh.

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