scholarly journals Palynology of two sections of Late Quaternary sediments from the Porcupine River, Yukon Territory

1974 ◽  
Author(s):  
S Lichti-Federovich
Keyword(s):  
Late Quaternary ◽  
Yukon Territory ◽  
Quaternary Sediments

Palynology of six sections of Late Quaternary sediments from the Old Crow River, Yukon Territory

1973 ◽  
Vol 51 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Sigrid Lichti-Federovich
Keyword(s):  
Late Quaternary ◽  
Yukon Territory ◽  
Quaternary Sediments ◽  
Pollen Assemblage ◽  
Alluvial Deposits ◽  
Pollen Stratigraphy ◽  
Tundra Vegetation ◽  
Pollen Diagrams ◽  
Shrub Tundra ◽  
Basin Fill

The Old Crow Plain, northern Yukon Territory, Canada, is a large flat lowland consisting of basin-fill sediments of Late Quaternary age. The modern Arctic treeline passes across the northern tip of the lowland, and much of the vegetation consists of tundra and shrub tundra, with scattered groves of spruce mainly on alluvial deposits. Steep scarps have been exposed by the downcutting of the Old Crow River in these basin-fill sediments, and good exposures of Late Quaternary sediments are available for investigation. Samples from six of these exposures were analyzed for pollen. Although many parts of the sections were barren, it has been possible to derive pollen diagrams with discrete pollen zones for the six sections, and four pollen assemblage types have been identified. Their occurrence in the stratigraphie sequence suggests the following pattern of pollen stratigraphy: the lowermost sedimentary units, probably deposited early in the interstadial following an Early Wisconsin glaciation, are of pollen assemblage types III (Glumiflorae–herb) or IV (Betula–herb), both indicative of tundra vegetation; the middle levels of the sediment show, consistently, pollen spectra of type II (Picea–Betula–Glumiflorae–herb), indicating forest groves with tundra, quite similar to the modern vegetation. The sediment underlying the Upper Glaciolacustrine Unit (correlative, according to Hughes (1969), with the Classical Wisconsin Stadial) yields pollen assemblage type III (Glumiflorae–herb), which is interpreted as indicating a rich and varied tundra. These vegetation reconstructions are consonant with a tentative palaeoclimatic interpretation in terms of a tripartite interstadial climate showing severe tundra climate – milder forest or forest–tundra climate – severe tundra climate. Two of the sections have incomplete pollen stratigraphy for the uppermost postglacial silts and peats. They suggest that vegetation similar to the present day became established in the Old Crow Plain in mid-postglacial time.

OSL ages and origin of Late Quaternary sediments in the North Transdanubian Hills (Hungary): timing of neotectonic activity

2010 ◽  
Vol 222 (1-2) ◽  
pp. 209-220 ◽  
Author(s):  
Edit Thamó-Bozsó ◽  
Árpád Magyari ◽  
Balázs Musitz ◽  
Attila Nagy
Keyword(s):  
Late Quaternary ◽  
Quaternary Sediments ◽  
Neotectonic Activity ◽  
The North

Chronology and stratigraphy of Late Quaternary sediments in the Konya Basin, Turkey: Results from the KOPAL Project

1999 ◽  
Vol 18 (4-5) ◽  
pp. 611-630 ◽  
Author(s):  
N. Roberts ◽  
S. Black ◽  
P. Boyer ◽  
W.J. Eastwood ◽  
H.I. Griffiths ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Quaternary Sediments ◽  
Konya Basin

Electron Microprobe Correlation of Tephra Layers from Eastern Mediterranean Abyssal Sediments and the Island of Santorini

1980 ◽  
Vol 13 (2) ◽  
pp. 160-171 ◽  
Author(s):  
Alan N. Federman ◽  
Steven N. Carey
Keyword(s):  
Major Element ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Explosive Eruptions ◽  
Volcanic Complex ◽  
Quaternary Sediments ◽  
Additional Layer ◽  
Oxygen Isotope Stratigraphy ◽  
Tephra Layers ◽  
Isotope Stratigraphy

AbstractFive widespread tephra layers are found in late Quaternary sediments (0–130,000 yr B.P.) of the Eastern Mediterranean Sea. These layers have been correlated among abyssal cores and to their respective terrestrial sources by electron-probe microanalysis of glass and pumice shards. Major element variations are sufficient to discriminate unambiguously between the five major layers. Oxygen isotope stratigraphy in one of the cores studied was used to data four of the five layers. Two of the widespread layers are derived from explosive eruptions of the Santorini volcanic complex: the Minoan Ash (3370 yr B.P.) and the Acrotiri Ignimbrite (18,000 yr B.P.). An additional layer, found in one core only, is most likely correlated to the Middle Pumice Series of Santorini (approximately 100,000 yr B.P.). Two layers are correlated to deposits on the islands of Yali and Kos and date to 31,000 and 120,000 yr B.P., respectively. One layer originated from the Neapolitan area of Italy 38,000 yr B.P.

Multiple ash layers in late Quaternary sediments from the Central Indian Basin

2016 ◽  
Vol 316 ◽  
pp. 85-100 ◽  
Author(s):  
M.B.L. Mascarenhas-Pereira ◽  
B. Nagender Nath ◽  
S.D. Iyer ◽  
D.V. Borole ◽  
G. Parthiban ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Quaternary Sediments ◽  
Central Indian Basin

Emmons Lake Volcanic Center, Alaska Peninsula: source of the Late Wisconsin Dawson tephra, Yukon Territory, Canada

2003 ◽  
Vol 40 (7) ◽  
pp. 925-936 ◽  
Author(s):  
Margaret T Mangan ◽  
Christopher F Waythomas ◽  
Thomas P Miller ◽  
Frank A Trusdell
Keyword(s):  
Compositional Data ◽  
Late Quaternary ◽  
Yukon Territory ◽  
Volcanic Center ◽  
Pyroclastic Deposits ◽  
Alaska Peninsula ◽  
Aleutian Arc ◽  
Pumice Flow ◽  
North And South ◽  
The Bering Sea

The Emmons Lake Volcanic Center on the Alaska Peninsula of southwestern Alaska is the site of at least two rhyolitic caldera-forming eruptions (C1 and C2) of late Quaternary age that are possibly the largest of the numerous caldera-forming eruptions known in the Aleutian arc. The deposits produced by these eruptions are widespread (eruptive volumes of >50 km3 each), and their association with Quaternary glacial and eolian deposits on the Alaska Peninsula and elsewhere in Alaska and northwestern Canada enhances the likelihood of establishing geochronological control on Quaternary stratigraphic records in this region. The pyroclastic deposits associated with the second caldera-forming eruption (C2) consist of loose, granular, airfall and pumice-flow deposits that extend for tens of kilometres beyond Emmons Lake caldera, reaching both the Bering Sea and Pacific Ocean coastlines north and south of the caldera. Geochronological and compositional data on C2 deposits indicate a correlation with the Dawson tephra, a 24 000 14C BP (27 000 calibrated years BP), widespread bed of silicic ash found in loess deposits in west-central Yukon Territory, Canada. The correlation clearly establishes the Dawson tephra as the time-stratigraphic marker of the last glacial maximum.

U-series dating on late Quaternary sediments from Balikun Lake

1998 ◽  
Vol 43 (17) ◽  
pp. 1434-1441 ◽  
Author(s):  
Jiaqi Liu ◽  
Zhibang Ma
Keyword(s):  
Late Quaternary ◽  
Quaternary Sediments
Sign in / Sign up

Export Citation Format

Share Document