Mid and late holocene diatoms from ?Water Supply Lake?, Baffin Island, N.W.T., Canada

1991 ◽  
Vol 6 (3) ◽  
Author(s):  
AlexanderP. Wolfe
Keyword(s):  
Water Supply ◽  
Late Holocene ◽  
Baffin Island

Late Holocene Glacier Fluctuations and Vegetation Changes at Maktak Fiord, Baffin Island, N.W.T., Canada

1976 ◽  
Vol 8 (4) ◽  
pp. 343 ◽  
Author(s):  
G. S. Boulton ◽  
J. H. Dickson ◽  
H. Nichols ◽  
M. Nichols ◽  
S. K. Short
Keyword(s):  
Late Holocene ◽  
Vegetation Changes ◽  
Baffin Island ◽  
Glacier Fluctuations

Spatial patterns of modern diatom distribution and multiple paleolimnological records from a small arctic lake on Baffin Island, Arctic Canada

1996 ◽  
Vol 74 (3) ◽  
pp. 435-449 ◽  
Author(s):  
Alexander P. Wolfe
Keyword(s):  
Late Holocene ◽  
Baffin Island ◽  
Diatom Assemblages ◽  
Arctic Canada ◽  
Habitat Specificity ◽  
Radiocarbon Dates ◽  
Numerous Species ◽  
Sediment Reworking ◽  
Clear Differentiation ◽  
Lake Ontogeny

The assumption that within-lake, deep-water sedimentary diatom assemblages are relatively uniform and that a single core is sufficient to depict lake ontogeny was tested for a small tarn on the southwestern Cumberland Peninsula of Baffin Island, Northwest Territories. Diatom transport and deposition were evaluated through analyses of periphytic, planktonic, and epipelic habitats. Diatom stratigraphies of four cores were used to test whether or not trends are comparable in different regions of the lake and throughout the Holocene. Among 12 surface-sediment stations, diatom distributions were alternately highly equitable or variable. Valves of evenly distributed genera (Aulacoseira and Achnanthes) are mixed in the water column prior to deposition. This is supported by plankton tow and periphyton samples, which were respectively dominated by Aulacoseira distans (and varieties) and Achnanthes altaica. Conversely, frequencies of several benthic taxa (e.g., Pinnularia biceps, species of Eunotia) varied up to 30% between stations, in patterns unrelated to water depth, and reflecting habitat specificity and minimal transport prior to burial. Of the four cores (38.0–95.5 cm), analysis of the two longest revealed three distinct zones: (i) a zone dominated by species of Fragilaria (> 9000 BP); (ii) a zone containing benthic acidophilic diatoms indicating natural acidification (9000–7000 BP); and (iii) a zone characterized by numerous species of Aulacoseira ranging from the mid to late Holocene. Clear differentiation of the lower two zones was impossible in the shorter cores, and radiocarbon dates suggest that sediment reworking truncated the earliest records of organic sedimentation at these sites. Correspondence analysis facilitated comparisons of the diatom stratigraphies and enabled the evaluation of core reproducibility. Central cores preserve the most useful paleolimnological records in this environment. Keywords: diatoms, paleolimnology, Arctic Canada, Baffin Island.

scholarly journals Holocene Environmental Change in the Frobisher Bay Area, Baffin Island, N.W.T.: Deglaciation, Emergence, and the Sequence of Vegetation and Climate

2007 ◽  
Vol 39 (2) ◽  
pp. 151-162 ◽  
Author(s):  
J. D. Jacobs ◽  
W. N. Mode ◽  
C. A. Squires ◽  
G. H. Miller
Keyword(s):  
Late Holocene ◽  
Late Glacial ◽  
Pollen Record ◽  
Baffin Island ◽  
Bay Area ◽  
Modern Pollen ◽  
Moist Environment ◽  
Organic Fractions ◽  
Late Glacial And Holocene ◽  
Inland Ice

ABSTRACT The late-glacial and Holocene paleoenvironmental sequence for the Frobisher Bay area is outlined using glacial, sea level, and palynological evidence. A rapid retreat of ice from the late Foxe glacial maximum in the lower part of the bay after 11,000 BP was followed by a series of stillstands or minor readvances between ca. 8500 and 7000 BP and possibly later, before the final disappearance of the inland ice centred near Amadjuak Lake. Lithostratigraphy of three buried organic sections which together represent deposition occurring over the period from 5500 to 400 BP indicates a change from a relatively warm, moist environment before 5500 BP to neoglacial conditions, with the coldest phases centred around 5000, 2700, 1200 BP and probably sometime after 400 radiocarbon years BP. As evidenced by peat growth and pollen data, milder, wetter conditions prevailed from 4500 to 3000 BP and again from ca. 2600 to 1800 BP. Peat growth and soil organic fractions point to lesser mild intervals ca. 900 BP and 400 BP, but these are not apparent in the pollen assemblage. The pollen record does not extend to the last four centuries; however, lichenometric studies of neoglacial moraines by DOWDESWELL (1984) show that the maximum late Holocene advance of glaciers in the area occurred within the last century. Modern pollen samples indicate that the present vegetation of the inner Frobisher Bay area is comparable to that of the milder intervals of the late Holocene.

Neoglacial ice expansion and late Holocene cold-based ice cap dynamics on Cumberland Peninsula, Baffin Island, Arctic Canada

2014 ◽  
Vol 91 ◽  
pp. 242-256 ◽  
Author(s):  
Annina Margreth ◽  
Arthur S. Dyke ◽  
John C. Gosse ◽  
Alice M. Telka
Keyword(s):  
Late Holocene ◽  
Baffin Island ◽  
Arctic Canada ◽  
Ice Cap

scholarly journals Palynology of six middle and late Holocene peat sections, Baffin Island

2011 ◽  
Vol 34 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Susan K. Short ◽  
John T. Andrews
Keyword(s):  
Late Holocene ◽  
High Arctic ◽  
Baffin Island ◽  
Canadian High Arctic ◽  
Shrub Willow ◽  
Pollen Diagrams ◽  
Pollen Rain ◽  
Middle And Late Holocene

Palynological investigations were undertaken at six sites on the northern Cumberland Peninsula, Baffin Island. Pollen assemblages from the Canadian High Arctic are rare, and the purpose of this paper is to expand this record. Twelve pollen diagrams from the six sites are presented. They suggest that over the last 1000 years, the pollen rain has been dominated by pollen of the gra-minoid group. This contrasts with earlier pollen assemblages between 2500 and 2000 years BP and between 5000 and 4000 BP which were typically more diverse and included significant quantities of heath and shrub (willow) pollen. A pronounced willow peak is evident on the diagrams and dates from ca. 2500 BP.

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

Sign in / Sign up

Export Citation Format

Share Document