Neotectonic framework of the north-central Alaska Range foothills

AbstractPowder X-ray and optical data have been recorded for a sample of exceptionally rare earth-poor eudialyte (Na12(Ca, REE)6(Fe2+,Mn,Mg)3Zr3(Zr,Nb)x[Si9O27−y(OH)y]2[Si3O9]2(C1,F)z, with x = 0. 1–0.9, y = 1–3 and z = 0.7–1.4) from a pegmatitic vein associated with the peralkaline Windy Fork granite in the north–central Alaska range. The eudialyte is uniaxial positive with ω= 1.6062(2), ε= 1.6138 (3) and microprobe analyses indicate that the sum of REE + Yis less than 0.1 weight percent. Refined unit cell dimensions are: a = 14.2572(4), c = 30.1338(27), Dx= 2.67, F30= 128 (0.006, 42), M20= 76. An indexed powder diffraction pattern is given.

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Effects of weather and parasitic insects on behavior and group dynamics of caribou of the Delta Herd, Alaska

Canadian Journal of Zoology ◽

10.1139/z97-793 ◽

1997 ◽

Vol 75 (10) ◽

pp. 1659-1670 ◽

Cited By ~ 47

Author(s):

Frank M. Mörschel ◽

David R. Klein

Keyword(s):

High Temperature ◽

Ambient Temperature ◽

Group Dynamics ◽

Rangifer Tarandus ◽

High Ambient Temperature ◽

Alaska Range ◽

North Central ◽

Insect Abundance ◽

Rates Of Change ◽

The North

The influence of weather and parasitic insects on the behavior and group dynamics of caribou (Rangifer tarandus) of the Delta Herd in the north-central Alaska Range was investigated. Data on weather, insect abundance, and caribou behavior were collected during summer in 1994 and 1995. High ambient temperature had the greatest influence on activity budgets and rates of change in activity of caribou. In the insect season, rates of activity changes and standing increased and feeding decreased with high temperature. Rates of activity changes and moving increased and feeding decreased with high temperature, even in the absence of insects. Caribou decreased feeding and increased standing in the presence of oestrid flies, and increased the rate of activity changes in the presence of mosquitoes and oestrid flies. Weather, especially high temperature, and parasitic insects, particularly oestrid flies, affected caribou mainly by decreasing foraging opportunities and increasing energy-expending activities.

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Canyon Creek: A Late Pleistocene Vertebrate Locality in Interior Alaska

Quaternary Research ◽

10.1016/0033-5894(81)90043-0 ◽

1981 ◽

Vol 16 (2) ◽

pp. 167-180 ◽

Cited By ~ 26

Author(s):

Florence R. Weber ◽

Thomas D. Hamilton ◽

David M. Hopkins ◽

Charles A. Repenning ◽

Herbert Haas

Keyword(s):

Late Holocene ◽

Mammuthus Primigenius ◽

Alaska Range ◽

North Central ◽

The North ◽

Subsequent Period ◽

Eolian Sand ◽

Wild Ass ◽

Fossil Bones ◽

Woolly Mammoth

AbstractThe Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000–17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf.O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode.

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