Quaternary History of Northern Cumberland Peninsula, East Baffin Island, N.W.T., Canada Part VI: Preliminary Lichen Growth Curve for Rhizocarpon geographicum

1972 ◽  
Vol 83 (4) ◽  
pp. 1133 ◽  
Author(s):  
G. H. MILLER ◽  
J. T. ANDREWS
Keyword(s):  
Growth Curve ◽  
Baffin Island ◽  
Rhizocarpon Geographicum ◽  
History Of ◽  
Quaternary History ◽  
Lichen Growth

scholarly journals Recent Glacial History of an Alpine Area in the Colorado Front Range, U.S.A.: I. Establishing a Lichen-Growth Curve

1967 ◽  
Vol 6 (48) ◽  
pp. 817-832 ◽  
Author(s):  
James B. Benedict
Keyword(s):  
Growth Curve ◽  
Average Rate ◽  
Colorado Front Range ◽  
Ground Moraine ◽  
Front Range ◽  
Exposure Age ◽  
Rhizocarpon Geographicum ◽  
Valley Glacier ◽  
History Of ◽  
Lichen Growth

A lichen-growth curve has been developed for dating Recent glacial and periglacial deposits in the Indian Peaks area of the Colorado Front Range.Rhizocarpon geographicumwas selected for the study because of its long life span and consistent size-age relationship. The species grows at different rates in different micro-environments, with moisture, stability of substrate and length of snow-free growing season having the greatest effect. Growth rates were determined indirectly, by measuring the maximum diameters of circular or nearly circular thalli growing on surfaces of known exposure age. Measurements were made on 24 historically dated surfaces, ranging in age from 25 to 69 yr., and on three radiocarbon-dated surfaces, including (1) mudflow levees younger than 180 yr., (2) a rock wall built by prehistoric Indians about 970 yr. ago, and (3) ground moraine deposited by a retreating valley glacier about 2,460 radiocarbon years ago.R. geographicurrzgrows very rapidly (14. mm./100 yr.) during the First 100 yr. of its life. Growth then slows to an average rate of 3.3 mm./100 yr. The completed growth curve is believed to be suitable for dating deposits at least as old as 3,000 yr.

scholarly journals Recent Glacial History of an Alpine Area in the Colorado Front Range, U.S.A.: I. Establishing a Lichen-Growth Curve

1967 ◽  
Vol 6 (48) ◽  
pp. 817-832 ◽  
Author(s):  
James B. Benedict
Keyword(s):  
Growth Curve ◽  
Average Rate ◽  
Colorado Front Range ◽  
Ground Moraine ◽  
Front Range ◽  
Exposure Age ◽  
Rhizocarpon Geographicum ◽  
Valley Glacier ◽  
History Of ◽  
Lichen Growth

A lichen-growth curve has been developed for dating Recent glacial and periglacial deposits in the Indian Peaks area of the Colorado Front Range. Rhizocarpon geographicum was selected for the study because of its long life span and consistent size-age relationship. The species grows at different rates in different micro-environments, with moisture, stability of substrate and length of snow-free growing season having the greatest effect. Growth rates were determined indirectly, by measuring the maximum diameters of circular or nearly circular thalli growing on surfaces of known exposure age. Measurements were made on 24 historically dated surfaces, ranging in age from 25 to 69 yr., and on three radiocarbon-dated surfaces, including (1) mudflow levees younger than 180 yr., (2) a rock wall built by prehistoric Indians about 970 yr. ago, and (3) ground moraine deposited by a retreating valley glacier about 2,460 radiocarbon years ago. R. geographicurrz grows very rapidly (14. mm./100 yr.) during the First 100 yr. of its life. Growth then slows to an average rate of 3.3 mm./100 yr. The completed growth curve is believed to be suitable for dating deposits at least as old as 3,000 yr.

scholarly journals Holocene Glacier Fluctuations in the Torngat Mountains, Northern Labrador

2007 ◽  
Vol 37 (2) ◽  
pp. 211-216 ◽  
Author(s):  
William D. McCoy
Keyword(s):  
Growth Curve ◽  
Local Area ◽  
Baffin Island ◽  
Relative Age ◽  
Glacier Fluctuations ◽  
Glacier Recession ◽  
Rhizocarpon Geographicum ◽  
Lichen Growth

ABSTRACT Lichen measurements and other relative-age data were collected from deposits of several cirque glaciers in the Torngat Mountains of northern Labrador. Lichen growth stations were established, but no lichen-growth curve has yet been determined for the local area. However, moraines can be correlated between valleys on the basis of the largest diameter thallus of Rhizocarpon geographicum sensu lato combined with other relative-age data. These data suggest several discrete periods of Holocene glacier recession. If the R. geographicum s. I. growth curve established for the northern Cumberland Peninsula of Baffin Island (MILLER, 1975) is valid for similar environments in the Torngat Mountains, then glacier recession occurred < 150, 400, 550-750, 950, ≥ 1850, > 1850, ≥ 2800, > 2800, ≥ 4000, and > > 4000 yr BP. The latest three periods of glacier recession may correlate with periods of glacier recession on the Cumberland Peninsula of Baffin Island.

The Quaternary History of Northern Cumberland Peninsula, Baffin Island, N.W.T. Part I: The Late- and Neoglacial Deposits of the Akudlermuit and Boas Glaciers

1972 ◽  
Vol 9 (4) ◽  
pp. 403-414 ◽  
Author(s):  
P. Carrara ◽  
J. T. Andrews
Keyword(s):  
Ice Cores ◽  
Equilibrium Line ◽  
Baffin Island ◽  
The South ◽  
Lichen Cover ◽  
History Of ◽  
Quaternary History

Moraines of local glaciers predating the Neoglacial occur in sections of northern Cumberland Peninsula. A study of these deposits is reported for the area between the heads of Quajon and Narpaing Fiords. A chronology is developed based on lichenometry, percent of lichen cover, and the weathering of boulders and pebbles. Initial dating is done by lichenometry and dates older than about 6000 BP are attempted by establishing rates of weathering. About 12 500 BP glaciers existed in both south- and north-facing corries with an equilibrium line at 850 m a.s.1. During the next 5000 years the south-facing glaciers retreated and disappeared. About 7000 BP, moraines were deposited in front of the Akuldermnit and Boas glaciers— these moraines are no longer ice-cored. The equilibrium line lay between 850 and 975 m a.s.1. A 'warm' interval followed and the ice cores melted. This was followed by an early Neoglacial advance, dated about 3800 BP for the period of moraine stabilization; after a 2000 year interval four younger readvances are recorded. All Neoglacial moraines are ice-cored. During the last few decades the equilibrium line has risen.

The Quaternary History of the Northern Cumberland Peninsula, Baffin Island, N.W.T. Part III: The Late Glacial Deposits of Sulung and Itidlirn Valleys and Adjacent Parts of the Maktak-Narpaing Trough

1972 ◽  
Vol 9 (4) ◽  
pp. 366-374 ◽  
Author(s):  
R. E. Dugdale
Keyword(s):  
Cross Correlation ◽  
Phase 1 ◽  
Late Glacial ◽  
Lateral Moraine ◽  
Baffin Island ◽  
Phase 3 ◽  
Outlet Glacier ◽  
Valley Glacier ◽  
History Of ◽  
Quaternary History

Four moraine systems are recognized within the area. The oldest was deposited at the margin of a major outlet glacier about 600 m a.s.1 Local corrie glaciers in the Sulung and Itidlirn Valleys show three and two moraine systems respectively, which in part have over-ridden the lateral moraine. Studies of the degree of boulder weathering and the rounding of pebble edges on the four units allows cross-correlation between Itidlirn and Sulung Valleys. Weathering ratios are used to tentatively date the moraines as follows: lateral moraine of the outlet valley glacier, 43 000± years old; Phase 1 corrie moraine in Sulung Valley 35 000± years old; Phase 2 corrie moraines 23 000± years old and the youngest corrie moraines (Phase 3) 12 500± years old, as determined from weathering studies in adjacent valleys.

Late Quaternary history of colluvial deposition and erosion in hollows, central California Coast Ranges

1990 ◽  
Vol 102 (7) ◽  
pp. 969-982 ◽  
Author(s):  
STEVEN L. RENEAU ◽  
WILLIAM E. DIETRICH ◽  
DOUGLAS J. DONAHUE ◽  
A. J. TIMOTHY JULL ◽  
MEYER RUBIN
Keyword(s):  
Late Quaternary ◽  
California Coast ◽  
Central California ◽  
History Of ◽  
Quaternary History ◽  
Coast Ranges ◽  
California Coast Ranges

scholarly journals Plio-Quaternary history of the Turkish coastal zone of the Enez-Evros Delta: NE Aegean Sea

2001 ◽  
Vol 2 (2) ◽  
pp. 95 ◽  
Author(s):  
B. ALPAR
Keyword(s):  
Late Pleistocene ◽  
Sand Dunes ◽  
Aegean Sea ◽  
Interglacial Period ◽  
Shelf Area ◽  
Sea Level Changes ◽  
Seismic Profiles ◽  
Alluvial Deposits ◽  
History Of ◽  
Quaternary History

The Enez-Evros Delta, NE Aegean Sea, is located in one the most important wetlands in the world with its sandy offshore islands, abandoned channel mouths, sand-dunes, shoals, marshlands, saline lagoons and saltpans. It comprises very well developed sedimentary units and a prodelta lying on an older submarine delta. The present day elevations of the middle-late Pleistocene marine terraces indicate a regional tectonic uplift in the area. Due to lack of geophysical and bore hole data and partly due to its strategic position, the structural and stratigraphic features of the submarine extension of the delta are not known in detail. In this paper, Plio-Quaternary history of this delta and its submarine part on the Turkish shelf was explored by using high-resolution shallow reflection seismic profiles. The delta is formed by the alluvial deposits of the Enez-Evros River and shaped by their interaction with the sea. It takes place in front of a large and protected ancient bay which was filled rapidly over millennia. The sediments in the plateau off the river are principally pro-deltaic with muddy areas near the river mouths changing to muddy sand further out. The sea-level changes in Plio-Quaternary were characterised by three different seismic stratigraphic units on the folded Miocene limestone basement. In the late Pleistocene, the shelf area over an Upper Miocene basement was flooded during the Riss-Würm interglacial period, exposed in the Würm glacial stage, and flooded once again during the Holocene transgression.

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