Denali-Yukon, Domain 9

2007 ◽  
Author(s):  
Earl B. Alexander ◽  
Roger G. Coleman ◽  
Todd Keeler-Wolfe ◽  
Susan P. Harrison
Keyword(s):  
British Columbia ◽  
North America ◽  
Yukon Territory ◽  
Ultramafic Rocks ◽  
Mean Annual Precipitation ◽  
Alaska Range ◽  
Coast Mountains ◽  
Denali Fault ◽  
Ice Caps ◽  
Mountain Glaciers

The Denali-Yukon domain occupies a broad arc that, in general, follows the path of the Denali Fault along the Alaska Range and southwestward into the Yukon Territory. An ophiolite in the northwestern corner of British Columbia that is northeast of the projected Denali fault is included in this locality. A projection of the Denali fault system southwestward from the Alaska Range passes through the southwestern part of the Ahklun Mountains physiographic province, as the province was defined by Wahrhaftig (1965), to Kuskokwim Bay between the mouth of the Kuskowim River and Cape Newenham. Three mafic–ultramafic complexes on the southwestern edge of the Ahklun Mountains province are included in this domain. Glaciers covered this entire domain during the Pleistocene, and mountain glaciers and ice caps are still present at the higher elevations. Permafrost is currently discontinuous. The highest mountain in North America (Mt. McKinley, 6194 m) is in the Alaska Range, but the ultramafic rocks are all at much lower elevations. The climate is very cold throughout the domain, with severe winters and short summers. The mean annual precipitation ranges from 45 to150 cm in the Ahklun Mountains, from 30 to 60 cm in the Alaska Range, and from 30 to 75 cm, or more, in the Atlin area of northwestern British Columbia, which is in the rain shadow of the Coast Mountains. The greatest precipitation is during summers, from June or July to September or October. The frostfree period is on the order of 60–90 days, or shorter, but it may be longer in some of the Atlin area of British Columbia. Localities 9-1 through 9-3 are from Cape Newenham northeastward in the Ahklun Mountains. The ultramafic rocks in the Cape Newenham area were accreted to North America by north directed thrust faults during the Late Triassic and Middle Jurassic time. Localities 9-4 through 9-7 are in the Alaska Range. Locality 9-8 is along a projection of the Denali fault to the eastern edge of the Coast Ranges in British Columbia.

Late Holocene glacial activity in Manatee Valley, southern Coast Mountains, British Columbia, Canada

2011 ◽  
Vol 48 (3) ◽  
pp. 603-618 ◽  
Author(s):  
Lindsey Koehler ◽  
Dan J. Smith
Keyword(s):  
British Columbia ◽  
Late Holocene ◽  
18Th Century ◽  
Ice Age ◽  
Coast Mountains ◽  
Mountain Glaciers ◽  
Subsequent Episode ◽  
Glacial Expansion ◽  
Insight Into ◽  
Lichen Growth

The dendroglaciologic and lichenometric research methodologies employed in this study provide a perspective of glaciological conditions from 5 ka to present in a remote headwater area of the British Columbia Coast Mountains. Since Holocene ice fronts of four glaciers at this site periodically extended below treeline, previous glacier advances overrode and buried forests beneath till deposits. This study suggests that glaciers were expanding into standing forests at 4.76 and 3.78 ka. Following glacier expansion at 3.78 ka, a period of recession ensued when glaciers withdrew upvalley long enough for the development of deep pedogenic surfaces and the growth of trees exceeding 300 years. Investigations at Beluga and Manatee glaciers benchmark a subsequent episode of significant glacial expansion at 2.42 ka referred to as the “Manatee Advance”. This advance has regional correlatives and is distinguished from the Tiedemann Advance at Manatee Glacier by documentation of substantive ice front retreat between the two episodes. Examination of Little Ice Age (LIA) deposits in the study area allowed for presentation and application of a revised Rhizocarpon spp. lichen growth curve. Lichenometric surveys of lateral moraines associated with Beluga, Manatee, and Oluk glaciers provided limited insight into their early LIA behaviour but record advances during the 15th and 16th centuries. Locally, glaciers achieved their maximum LIA size prior to an early to mid 18th century moraine-building event. This reconstruction of Holocene glacial history offers insights consistent with the emerging record of glacier activity described for other southern British Columbia Coast Mountain glaciers.

The biology of Canadian weeds. 128. Leucanthemum vulgare Lam.

2004 ◽  
Vol 84 (1) ◽  
pp. 343-363 ◽  
Author(s):  
David R. Clements ◽  
Dan E. Cole ◽  
Jane King ◽  
Alec McClay
Keyword(s):  
British Columbia ◽  
North America ◽  
Yukon Territory ◽  
Perennial Herb ◽  
Old Fields ◽  
Western Canada ◽  
Far North ◽  
Pasture Quality ◽  
Ray Florets ◽  
Noxious Weed

Leucanthemum vulgare Lam. (Asteraceae), known as ox-eye daisy, is a familiar perennial herb with white ray florets and yellow disc florets. It commonly inhabits roadside ver ges, pastures and old fields from Newfoundland to British Columbia, and also as far north as the Yukon Territory. Introduced from Europe, L. vulgare was well established in North America by 1800. The Canadian distribution of L. vulgare has expanded in many areas recently, particularly in western Canada. It can form dense populations that may reduce diversity of natural vegetation or pasture quality, and also serves as a host and reservoir for several species of polyphagous gall-forming Meloidogyne nematodes that feed on crops. It is considered a noxious weed under provincial legislation in Quebec, Manitoba, Alberta and British Columbia, as well as under the Canada Seeds Act. Control efforts are sometimes complicated by difficulties in distinguishing ox-eye daisy from some forms of the commercially available Shasta daisy ( L. × superbum).

Anastrophyllum assimile and Marsupella revoluta, new to the interior of North America

1977 ◽  
Vol 55 (19) ◽  
pp. 2479-2484 ◽  
Author(s):  
Diana G. Horton
Keyword(s):  
British Columbia ◽  
North America ◽  
Northwest Territories ◽  
North American ◽  
Yukon Territory ◽  
The Arctic ◽  
Devon Island ◽  
New Localities ◽  
Central Eastern ◽  
Coastal British Columbia

Anastrophyllum assimile (Mitt.) Steph. and Marsupella revoluta (Nees) Lindb. are reported from the Keele Peak area, central-eastern Yukon Territory, Canada, and M. revoluta is also reported from Devon Island, Northwest Territories, Canada. These new localities extend a pattern of disjunct occurrences throughout the known range of both species, which further support the hypothesis of their relictual status. However, collections of A. assimile from coastal British Columbia and the Alexander Archipelago, Alaska, are indicative of strong oceanic affinities of North American populations of this species. Also, the arctic and alpine localities at which either A. assimile or M. revoluta might be expected to occur in the interior of Alaska and the Yukon are limited in number as both species invariably occur in association with siliceous substrates.

Gulf of Alaska, Domain 8

2007 ◽  
Author(s):  
Earl B. Alexander ◽  
Roger G. Coleman ◽  
Todd Keeler-Wolfe ◽  
Susan P. Harrison
Keyword(s):  
Sea Level ◽  
Gulf Of Alaska ◽  
Ultramafic Rocks ◽  
Mean Annual Precipitation ◽  
Kenai Peninsula ◽  
Ice Caps ◽  
The North ◽  
Kodiak Island ◽  
North Side ◽  
Frost Free Period

The Gulf of Alaska domain extends eastward from Kodiak Island across the Kenai Peninsula, around the Chugach Mountains, and beyond Tonsina, curves southward across the glacier-covered St. Elias Mountains. The southeastern segment of the domain is west of the Canadian Coastal Mountains and includes the coastline and islands in southeastern Alaska. Ultramafic rocks occur sporadically in this region from British Columbia northwestward through southeastern Alaska and around the Gulf of Alaska to the Kenai Peninsula. Most of this domain is mountainous, especially in areas where there are ultramafic rocks. Elevations range from sea level to >5000 m, although ultramafic rocks are not found at the highest elevations. This area was glaciated during the Pleistocene. Many glaciers persist at the higher elevations, and some descend to sea level. The present climate ranges from cold to very cold and from humid to very humid, or perhumid. Mean annual precipitation ranges from 30 or 40 cm on the north side and west end of the Chugach Mountains, to >400 cm along the coast around Prince William Sound and in southeastern Alaska. Southeastern Alaska is a humid-to-perhumid area with dense forests at lower elevations that grade upward into alpine areas. The north side of the Chugach Mountains is drier, but still humid. Precipitation exceeds evapotranspiration in all months of every year. The frost-free period ranges from no more than a few days or weeks at the higher elevations to about 220 days in sheltered areas near sea level in southeasern Alaska. Some of the highest snowfall in North America is in this domain, and ice caps persist in some of the higher mountains with many glaciers flowing into the sea. Serpentine rocks of the Gulf of Alaska domain occur in both ophiolites and in concentric bodies, and some are from the roots of volcanic arcs complexes. West of the Chatham Straight fault, a discontinuous belt of ultramafic bodies extends for >1600 km from Kodiak Island across the Kenai Peninsula, and around the Chugach Range, arching southward as far as Baranof Island (Burns 1985).

Dendroglaciological evidence for Holocene glacial advances in the Todd Icefield area, northern British Columbia Coast Mountains

2008 ◽  
Vol 45 (1) ◽  
pp. 83-98 ◽  
Author(s):  
Scott I Jackson ◽  
Sarah C Laxton ◽  
Dan J Smith
Keyword(s):  
British Columbia ◽  
North America ◽  
Late Holocene ◽  
Ice Age ◽  
Abies Lasiocarpa ◽  
Two Phase ◽  
Increment Core ◽  
Coast Mountains ◽  
First Millennium ◽  
Subfossil Wood

Accelerated glacial recession and downwasting in Pacific North America is exposing land surfaces and features buried by glacial advances that, in many locations, predate the recent Little Ice Age (LIA). Dendrochronologic analyses of increment core samples from living trees (Abies lasiocarpa, Tsuga mertensiana) and samples of subfossil wood collected in the Todd Icefield area, Boundary Ranges, British Columbia Coast Mountains, provide the basis for a dendroglaciological and radiocarbon-based reconstruction of late Holocene glacier activity. Five intervals of glacier expansion were recorded by trees killed or buried by advancing glaciers: (1) an advance prior to ~3000 14C years BP; (2) an advance at ~3000 14C years BP that coincides with the regional Tiedemann advance; (3) an unattributed advance at 2300 14C years BP; (4) a two-phase advance at ~1700 and ~1450 14C years BP that corresponds with the regional First Millennium advance; (5) an advance with three phases of expansion that began prior to ~750 14C BP and is consistent with the regional early LIA interval and a two-phase interval of late LIA expansion culminating after ~240 and 100 years BP. This chronology of late Holocene glaciation matches that emerging from similar investigations in the coastal cordillera of Pacific North America and provides additional support for the regional significance of both the Tiedemann and the First Millennium advances.

scholarly journals Oligocene-Neogene lithospheric-scale reactivation of Mesozoic terrane accretionary structures in the Alaska Range suture zone, southern Alaska, USA: Comment

2021 ◽  
Author(s):  
Grant Lowey
Keyword(s):  
Suture Zone ◽  
Ultramafic Rocks ◽  
Metamorphic Rocks ◽  
Geologic Mapping ◽  
Alaska Range ◽  
Denali Fault ◽  
South Central ◽  
Ultramafic Complex ◽  
History Of ◽  
Ultramafic Intrusion

Waldien et al. (2021) present new bedrock geologic mapping, U-Pb geochronology, and 40Ar/39Ar thermochronology from the eastern Alaska Range in south-central Alaska to determine the burial and exhumation history of metamorphic rocks associated with the Alaska Range suture zone, interpret the history of faults responsible for the burial and exhumation of the metamorphic rocks, and speculate on the relative importance of the Alaska Range suture zone and related structures during Cenozoic reactivation. They also propose that ultramafic rocks in their Ann Creek map area in south-central Alaska (herein referred to as the “Ann Creek ultramafic complex”) correlate with the Pyroxenite Creek ultramafic complex in southwestern Yukon, and that this correlation is “consistent with other estimates of >400 km” of offset on the Denali fault. However, despite Waldien et al.’s (2021) claim that the purportedly offset ultramafic rocks are “similar” and that characteristics of the Ann Creek ultramafic complex “make a strong case” for a faulted portion of an Alaska-type ultramafic intrusion, their paper gives short shrift in describing the Pyroxenite Creek ultramafic complex and in discussing previous estimates of displacement on the Denali fault. In Addition, Waldien et al. (2021) are either unaware of or ignore several key references of the Pyroxenite Creek ultramafic complex and estimates of displacement on the Denali fault. As a result, Waldien et al.’s (2021) claim of a “correlation” between allegedly offset ultramafic rocks is suspect, and their reference to “other estimates of >400 km” of offset on the Denali fault is incorrect, or at the very least misleading.

NEWLY RECOGNIZED HOLARCTIC AND INTRODUCED PLANT BUGS IN NORTH AMERICA (HETEROPTERA: MIRIDAE)

1998 ◽  
Vol 130 (3) ◽  
pp. 267-283 ◽  
Author(s):  
Michael D. Schwartz ◽  
G.G.E. Scudder
Keyword(s):  
British Columbia ◽  
North America ◽  
Northwest Territories ◽  
North American ◽  
Washington State ◽  
Yukon Territory ◽  
Lygus Rugulipennis

AbstractThe first North American records forDeraeocoris punctulatus(Fallén),Labopidea artemisiae(Sahlberg), andLabopidea bermaniKerzhner indicate that the species are naturally Holarctic.Lygus rugulipennisPoppius is now considered naturally Holarctic after specimens ofLygus perplexusStanger from Alaska, Yukon Territory, and Northwest Territories are correctly identified asL.rugulipennis. Additional North American localities forLabopidea discolor(Sahlberg) support the contention that the species is naturally Holarctic. Collections ofOrthotylus ochrotrichusFieber from Royal Oak, British Columbia, andMalacocoris chlorizansPanzer from British Columbia and Washington state suggest that these species are adventive to North America. Diagnoses are provided to distinguish all the taxa from other North American congeners. A key to the northern Nearctic species ofLabopideais given.

scholarly journals Distribution of Surging Glaciers in Western North America

1969 ◽  
Vol 8 (53) ◽  
pp. 229-240 ◽  
Author(s):  
Austin Post
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Cascade Range ◽  
Western North America ◽  
Geothermal Heat ◽  
Alaska Range ◽  
Coast Mountains ◽  
Glacier Bay ◽  
Olympic Mountains ◽  
Restricted Distribution

In western North America 204 surging glaciers have been identified by aerial photographic observations. These glaciers exhibit either intense crevassing and rapid ice displacements during surges or distinctive surface features which have resulted from past surges. Distribution of these unusual glaciers is not random throughout the glacierized areas, as they occur only in the Alaska Range, eastern Wrangell Mountains, eastern Chugach Mountains, Icefield Ranges, and the St Elias Mountains near Yakutat and Glacier Bay. No surging glaciers have been identified in the Brooks Range, Kenai Mountains, west and central Chugach Mountains, west and central Wrangell Mountains, Coast Mountains, Rocky Mountains, Cascade Range, Olympic Mountains, or Sierra Nevada. No definite reason for this restricted distribution is apparent. Surging glaciers are found in maritime to continental and temperate to subpolar environments. Practically all physical forms of glaciers are represented. The restricted distribution does not relate to topography, bedrock type, altitude, orientation, or size of glacier. Some surging glaciers are associated with fault-related valleys, but neither recent faulting nor earthquakes have initiated surge activity. Possible causes for the limited distribution of surges are unusual bedrock roughness or permeability in certain areas, anomalously high ground-water temperatures, and/or abnormal geothermal heat flow.

The taxonomy and distribution of rare or uncommon species of Albatrellus in western North America

1997 ◽  
Vol 75 (2) ◽  
pp. 261-273 ◽  
Author(s):  
J. Ginns
Keyword(s):  
British Columbia ◽  
New Mexico ◽  
North America ◽  
Key Words ◽  
Northwest Territories ◽  
Yukon Territory ◽  
Western North America ◽  
General Locality

Habitat data, although sparse, and occurrence are summarized for nine rare or uncommon species of Albatrellus. Significant range extensions are Albatrellus avellaneus in British Columbia, Oregon, and Washington, Albatrellus caeruleoporus in California, British Columbia, Oregon, and Washington, Albatrellus dispansus in Washington, Albatrellus ellisii in Colorado, Oregon, Washington, and Wyoming, Albatrellus flettii in Alaska, Alberta, northern British Columbia, Idaho, New Mexico, and Wyoming, Albatrellus subrubescens in Alberta, California, Northwest Territories, and Washington, Albatrellus syringae in North America (Alaska, Alberta, British Columbia, and Yukon Territory). Three additional collections of Albatrellus skamanius bring the total known collections of the species to four; all are from the same general locality. A key to the western species, emphasizing features of fresh basidiomes, is included. The basidiome features of these species are supplemented with data from additional collections. Spore sizes in several species are more critically defined. Amyloidity occurred in basidiospores and (or) hyphae of A. avellaneus, Albatrellus affin. cristatus, A. ellisii, A. flettii, A. skamanius, and A. subrubescens. Key words: systematics, ecology, Basidiomycetes, conservation, biodiversity, fungi.

scholarly journals Distribution of Surging Glaciers in Western North America

1969 ◽  
Vol 8 (53) ◽  
pp. 229-240 ◽  
Author(s):  
Austin Post
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Cascade Range ◽  
Western North America ◽  
Geothermal Heat ◽  
Alaska Range ◽  
Coast Mountains ◽  
Glacier Bay ◽  
Olympic Mountains ◽  
Restricted Distribution

In western North America 204 surging glaciers have been identified by aerial photographic observations. These glaciers exhibit either intense crevassing and rapid ice displacements during surges or distinctive surface features which have resulted from past surges. Distribution of these unusual glaciers is not random throughout the glacierized areas, as they occur only in the Alaska Range, eastern Wrangell Mountains, eastern Chugach Mountains, Icefield Ranges, and the St Elias Mountains near Yakutat and Glacier Bay. No surging glaciers have been identified in the Brooks Range, Kenai Mountains, west and central Chugach Mountains, west and central Wrangell Mountains, Coast Mountains, Rocky Mountains, Cascade Range, Olympic Mountains, or Sierra Nevada. No definite reason for this restricted distribution is apparent. Surging glaciers are found in maritime to continental and temperate to subpolar environments. Practically all physical forms of glaciers are represented. The restricted distribution does not relate to topography, bedrock type, altitude, orientation, or size of glacier. Some surging glaciers are associated with fault-related valleys, but neither recent faulting nor earthquakes have initiated surge activity. Possible causes for the limited distribution of surges are unusual bedrock roughness or permeability in certain areas, anomalously high ground-water temperatures, and/or abnormal geothermal heat flow.

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