A Late Pleistocene plant-bearing deposit in Currie Township, near Matheson, Ontario

1979 ◽  
Vol 16 (5) ◽  
pp. 1130-1136 ◽  
Author(s):  
W. E. Brereton ◽  
J. A. Elson
Keyword(s):  
River Basin ◽  
Late Pleistocene ◽  
Glacial Lake ◽  
Fossil Plants ◽  
Fossil Plant ◽  
James Bay ◽  
Plant Detritus ◽  
Lake Ojibway ◽  
Moose River ◽  
James Bay Lowlands

Two overburden test holes drilled to bedrock in Currie Township, southwest of Matheson, Ontario, penetrated stratified beds containing fossil plant detritus resting on an oxidized substrate, which are between two till sheets underlying glacial Lake Ojibway-Barlow varved clays. The fossil plants, chiefly mosses, represent an environment that is common in the region today, and are radiocarbon dated (GSC-2148) as older than 37000 years. The interglacial deposit is tentatively correlated with the Missinaibi Formation in the Moose River basin of the James Bay lowlands, probably of Sangamon age.

Radiocarbon dates on peat and tree remains from James Bay area, subarctic Quebec

1979 ◽  
Vol 9 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Late Glacial ◽  
Glacial Lake ◽  
Before Present ◽  
James Bay ◽  
Radiocarbon Dates ◽  
Bay Area ◽  
Lake Ojibway ◽  
James Bay Lowlands

14C dates on peat and tree remains from the southern part of James Bay Lowlands, subarctic Quebec, indicate that forests and peatland conditions began at least 1000 years after the deglaciation of the area. Inception of forest and organic deposition in bogs varies within the main geological events of the late-glacial and postglacial times in the area: the drainage of glacial Lake Ojibway, the Tyrrell Sea transgression, and the emergence. The oldest age recorded for the beginning of peat deposition is 6890 ± 120 years before present (BP) at an elevation of 240 m and the youngest age is 3830 ± 120 years BP at an elevation of 60 m. A delay ranging from 400 to 900 years between forest occupation and the establishment of bog conditions is recorded.

Palynological evidence for recycling of Upper Devonian into Lower Cretaceous of the Moose River Basin, James Bay Lowland, Ontario

1982 ◽  
Vol 19 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Jocelyne A. Legault ◽  
Geoffrey Norris
Keyword(s):  
River Basin ◽  
Lower Cretaceous ◽  
Drill Hole ◽  
Upper Devonian ◽  
James Bay ◽  
Conductivity Anomaly ◽  
Multiple Recycling ◽  
Moose River

Cored drill hole on a high electromagnetic conductivity anomaly near the Onakawana lignite field penetrated 50.3 m of Pleistocene, Cretaceous, and Devonian strata. Spore–pollen floras from the Cretaceous interval indicate an early middle Albian age and a correlation with the lower part of the Mattagami Formation. Spores, acritarchs, and tasmanitids from the Devonian interval indicate that the upper part of the Long Rapids Formation is marine and is Frasnian–Famennian in age. Multiple recycling events are documented between the Devonian and Cretaceous and between the Cretaceous and Pleistocene, provenances being local near the margins of the basin.

Organochlorine Contaminants in Headwater Peatlands, and Selected Estuary Sites of the Moose River

1986 ◽  
Vol 21 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Robert C. McCrea ◽  
Greg M. Wickware
Keyword(s):  
Atmospheric Deposition ◽  
Organochlorine Pesticides ◽  
River Basin ◽  
Vascular Plants ◽  
Typha Latifolia ◽  
Coastal Marshes ◽  
Surficial Sediments ◽  
Organochlorine Contaminants ◽  
Hexachlorocyclohexane Isomers ◽  
Moose River

Abstract Peatland waters of the Moose River basin, as well as surficial sediments and vascular plants of the estuary were sampled in 1982. Elevated levels of PCBs were found at all five peatland sites; concentrations ranged from 28 to 65 ng/L. Of the seventeen organochlorine pesticides investigated, the hexachlorocyclohexane isomers (a-and y-BHC) were the most prominent with total BHC concentrations ranging from 1.5 to 13.7 ng/L. The presence of these contaminants in ombrotrophic bogs indicated that there was atmospheric deposition of organochlorine contaminants in the basin. Analyses of surficial sediments, collected from tidal flats and coastal marshes, showed that PCBs and organochlorine pesticides were not present. Samples of Triglochin maritima L. seed heads and Typha latifolia L. roots were also free of PCBs.

scholarly journals Simulation and Assessment of Future Glacial Lake Outburst Floods in the Poiqu River Basin, Central Himalayas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1376
Author(s):  
Taigang Zhang ◽  
Weicai Wang ◽  
Tanguang Gao ◽  
Baosheng An
Keyword(s):  
River Basin ◽  
Hazard Assessment ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Central Himalayas ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Social And Economic Development ◽  
Glacial Lake Outburst Flood

A glacial lake outburst flood (GLOF) is a typical glacier-related hazard in high mountain regions. In recent decades, glacial lakes in the Himalayas have expanded rapidly due to climate warming and glacial retreat. Some of these lakes are unstable, and may suddenly burst under different triggering factors, thus draining large amounts of water and impacting downstream social and economic development. Glacial lakes in the Poiqu River basin, Central Himalayas, have attracted great attention since GLOFs originating there could have a transboundary impact on both China and Nepal, as occurred during the Cirenmaco GLOF in 1981 and the Gongbatongshaco GLOF in 2016. Based on previous studies of this basin, we selected seven very high-risk moraine-dammed lakes (Gangxico, Galongco, Jialongco, Cirenmaco, Taraco, Beihu, and Cawuqudenco) to simulate GLOF propagation at different drainage percentage scenarios (i.e., 25%, 50%, 75%, and 100%), and to conduct hazard assessment. The results show that, when any glacial lake is drained completely or partly, most of the floods will enter Nepal after raging in China, and will continue to cause damage. In summary, 57.5 km of roads, 754 buildings, 3.3 km2 of farmland, and 25 bridges are at risk of damage due to GLOFs. The potentially inundated area within the Chinese part of the Poiqu River basin exceeds 45 km2. Due to the destructive impacts of GLOFs on downstream areas, appropriate and effective measures should be implemented to adapt to GLOF risk. We finally present a paradigm for conducting hazard assessment and risk management. It uses only freely available data and thus is easy to apply.

scholarly journals Assessing Climate Change Trends and Their Relationships with Alpine Vegetation and Surface Water Dynamics in the Everest Region, Nepal

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 987
Author(s):  
Mana Raj Rai ◽  
Amnat Chidthaisong ◽  
Chaiwat Ekkawatpanit ◽  
Pariwate Varnakovida
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
River Basin ◽  
Climate Impacts ◽  
Glacial Lake ◽  
Annual Precipitation ◽  
Series Data ◽  
Lake Area ◽  
Alpine Vegetation ◽  
Koshi River Basin

The Himalayas, especially the Everest region, are highly sensitive to climate change. Although there are research works on this region related to cryospheric work, the ecological understandings of the alpine zone and climate impacts are limited. This study aimed to assess the changes in surface water including glacier lake and streamflow and the spatial and temporal changes in alpine vegetation and examine their relationships with climatic factors (temperature and precipitation) during 1995–2019 in the Everest region and the Dudh Koshi river basin. In this study, Landsat time-series data, European Commission’s Joint Research Center (JRC) surface water data, ECMWF Reanalysis 5th Generation (ERA5) reanalysis temperature data, and meteorological station data were used. It was found that the glacial lake area and volume are expanding at the rates of 0.0676 and 0.0198 km3/year, respectively; the average annual streamflow is decreasing at the rate of 2.73 m3/s/year. Similarly, the alpine vegetation greening as indicated by normalized difference vegetation index (NDVI) is increasing at the rate of 0.00352 units/year. On the other hand, the annual mean temperature shows an increasing trend of 0.0329 °C/year, and the annual precipitation also shows a significant negative monotonic trend. It was also found that annual NDVI is significantly correlated with annual temperature. Likewise, the glacial lake area expansion is strongly correlated with annual minimum temperature and annual precipitation. Overall, we found a significant alteration in the alpine ecosystem of the Everest region that could impact on the water–energy–food nexus of the Dudh Koshi river basin.

A Carved Stone from D'Arcy, Saskatchewan

1940 ◽  
Vol 5 (4) ◽  
pp. 334-335
Author(s):  
Vladimar Alfred Vigfusson
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Glacial Lake ◽  
Bering Strait ◽  
The North ◽  
Gravel Pit ◽  
North Bank ◽  
The Town

In recent years, the attention of some archaeologists has been directed to the Canadian Northwest with the expectation of finding some evidence or indication of the early migrations of man on this continent. That man reached North America by Bering Strait from Asia, is generally accepted, but the theory that the migrations took place in late Pleistocene times and by way of an open corridor between the Keewatin ice and the Rockies, requires confirmation. It is significant that Folsom and Yuma points from Saskatchewan, described by E. B. Howard, were found mainly in areas bordering the ancient glacial Lake Regina.As a further contribution to this problem, it seems desirable to present a brief description of a carved stone relic found in gravel in central Saskatchewan about three years ago.The stone was found about seven miles southeast of the town of D'Arcy in a gravel pit located on Sec. 9, Tp. 28, Rge. 18, W. 3rd Meridian, on the north bank of a ravine running east into Bad Lake.

A fossil record of land plant origins from charophyte algae

Science ◽  
2021 ◽  
Vol 373 (6556) ◽  
pp. 792-796 ◽  
Author(s):  
Paul K. Strother ◽  
Clinton Foster
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Land Plant ◽  
Fossil Plants ◽  
Fossil Plant ◽  
Molecular Phylogenetic ◽  
History Of ◽  
Time Gap ◽  
Evolutionary Continuity

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma).

Distribution of fungi in a Triassic fern stem

2017 ◽  
Vol 108 (4) ◽  
pp. 387-398 ◽  
Author(s):  
Carla J. Harper ◽  
Jean Galtier ◽  
Thomas N. Taylor ◽  
Edith L. Taylor ◽  
Ronny Rößler ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Host Response ◽  
Host Tissue ◽  
Tissue Preservation ◽  
Fossil Plants ◽  
Fossil Plant ◽  
Distribution Maps ◽  
Different Types ◽  
Fungal Distribution ◽  
Fungal Associations

ABSTRACTDocumented evidence of fungi associated with Mesozoic ferns is exceedingly rare. Three different types of fungal remains occur in a portion of a small, permineralised fern stem of uncertain systematic affinities from the Triassic of Germany. Exquisite preservation of all internal tissues made it possible to map the spatial distribution of the fungi in several longitudinal and transverse sections. Narrow, intracellular hyphae extend through the entire cortex, while wide hyphae are concentrated in the cortical intercellular system adjacent to the stele and leaf traces. Hyphal swellings occur in the phloem and adjacent cortex, while moniliform hyphae (or chains of conidia) are present exclusively in parenchyma adjacent to the stele. No host response is recognisable, but host tissue preservation suggests that the fern was alive during fungal colonisation. The highest concentration of fungal remains occurs close to the stele and leaf traces, suggesting that the fungi either utilised the vascular tissues as an infection/colonisation pathway or extracted nutrients from these tissues. This study presents the first depiction of fungal distribution throughout a larger portion of a fossil plant. Although distribution maps are useful tools in assessing fungal associations in relatively small, fossil plants, preparing similar maps for larger and more complex fossils would certainly be difficult and extremely arduous.

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