THE STATUS OF PARASITES OF THE APPLE MAGGOT, RHAGOLETIS POMONELLA (DIPTERA: TEPHRITIDAE), IN ONTARIO

1971 ◽  
Vol 103 (4) ◽  
pp. 507-512 ◽  
Author(s):  
L. G. Monteith
Keyword(s):  
Lake Ontario ◽  
Rhagoletis Pomonella ◽  
Southern Ontario ◽  
Niagara Escarpment ◽  
The Status

AbstractOpius melleus Gah. and O. lectus Gah. were the only parasites of Rhagoletis pomonella (Walsh) found in southern Ontario during a 4-year survey. The parasites were found only in the Niagara Region on the slope of the Niagara Escarpment and between it and Lake Ontario. The population of parasites was low though they appeared to be well adapted to attack R. pomonella. They were found in, or adjoining, unsprayed sites where there was shrubby growth under the trees infested by R. pomonella.

On the origin of the Oak Ridges Moraine, southern Ontario

1985 ◽  
Vol 22 (2) ◽  
pp. 300-303 ◽  
Author(s):  
L. J. Chapman
Keyword(s):  
Lake Ontario ◽  
Glacial Lake ◽  
Stream Channel ◽  
Outlet Channel ◽  
Southern Ontario ◽  
Oak Ridges Moraine ◽  
Standing Water ◽  
Niagara Escarpment

Widespread occurrences of stratified silt and clay have been found under the surface sands on the crest of the Oak Ridges Moraine between Stouffville and Pontypool, Ontario. It is suggested that the most likely explanation for the submergence of that part of the moraine is that the Lake Ontario ice lobe was still overriding the Niagara Escarpment at the time, holding standing water in the area between the southern and northern ice lobes and the escarpment. A stream channel over the escarpment, extending from northeast of Cheltenham to Acton and beyond, may have served as the outlet. This sill is high enough to have held water over the above-mentioned silts and clays. It is of interest that this outlet channel led eventually to glacial Lake Whittlesey, indicating a correlation.

Trend surface analysis of major late Wisconsinan till sheets, Brantford–Woodstock area, southern Ontario

1978 ◽  
Vol 15 (6) ◽  
pp. 1025-1036 ◽  
Author(s):  
W. R. Cowan
Keyword(s):  
Strong Relationship ◽  
High Energy ◽  
Field Observations ◽  
Trend Surface Analysis ◽  
Southern Ontario ◽  
Niagara Escarpment ◽  
Regional Trends ◽  
Grade Material ◽  
Late Wisconsinan ◽  
Relationship Of

Linear and quadratic trend surfaces were computed for textural, carbonate, clast, and heavy mineral properties of the Catfish Creek (Nissouri Stadial), Port Stanley (Port Bruce Stadial), Tavistock (Port Bruce Stadial), and Wentworth (Port Huron Stadial) tills.Catfish Creek Till pebble grade material provided trend surfaces reflecting the underlying bedrock. However, an overall lack of regional trends in Catfish Creek Till is consistent with field observations that indicate remarkable uniformity for this till over several hundred square kilometres, a phenomenon that is believed to reflect the high energy of this ice sheet. Carbonates in Port Stanley Till were found to increase from east to west as the Silurian–Devonian contact was crossed. Tavistock Till was found to have increasing sand content and decreasing silt content from northwest to southeast owing to incorporation of underlying glaciofluvial sediments; pebble trends reflect the underlying bedrock for the most part. Wentworth Till trend surfaces for carbonates and pebbles show high dolomite near the Niagara Escarpment to the east and northeast with a dilution of dolomite and influx of limestone to the southwest.The strong relationship of the trend surfaces to substrate materials indicates the basal nature of the tills and the local origin of most glacial deposits. Pebble lithologies provide much information about local bedrock and drift prospectors should give close consideration to coarse fragments.

Watershed derived nutrients for Lake Ontario inflows: Model calibration considering typical land operations in Southern Ontario

2015 ◽  
Vol 41 (4) ◽  
pp. 1037-1051 ◽  
Author(s):  
Masoud Asadzadeh ◽  
Luis Leon ◽  
Craig McCrimmon ◽  
Wanhong Yang ◽  
Yongbo Liu ◽  
...  
Keyword(s):  
Model Calibration ◽  
Lake Ontario ◽  
Southern Ontario

scholarly journals Geological framework of the Laurentian trough aquifer system, southern Ontario

2018 ◽  
Vol 55 (7) ◽  
pp. 677-708 ◽  
Author(s):  
David R. Sharpe ◽  
André J.-M. Pugin ◽  
Hazen A.J. Russell
Keyword(s):  
Lake Ontario ◽  
Water Levels ◽  
Coarse Grained ◽  
Oak Ridges Moraine ◽  
Aquifer System ◽  
Fine Grained ◽  
Niagara Escarpment ◽  
Base Level ◽  
Glacial Periods ◽  
East West

The Laurentian trough (LT), a depression >100 km long, >3000 km2 in area, and 100 m deep at the base of the Niagara Escarpment, extends from within Georgian Bay to Lake Ontario. It has a complex erosional history and is filled and buried by up to 200 m of interglacial and glacial sediment. The primary depression fronts a cuesta landscape and is attributed to differential erosion by fluvial, glacial, and glaciofluvial processes, exposing Ordovician rocks along the Canadian Shield margin. The fill succession includes sediments from the last two glacial periods (Illinoian, Wisconsinan) and the intervening interglacial time (Sangamonian), a poorly dated succession with at least three regional unconformities. A subaerial (interglacial, Don Formation) unconformity relates to low base level mainly preserved in lows of the LT, succeeded by a long period of rising water levels and glaciolacustrine conditions as ice advanced into the Lake Ontario basin. A second unconformity, within the Thorncliffe Formation, is the result of rapid channel erosion to bedrock, forming an ∼north–south network filled with coarse-grained glaciofluvial, transitional to fine-grained glaciolacustrine subaqueous fan sediment. The overlying drumlinized Newmarket Till, up to 50 m thick, is a distinct regional unit with a planar to undulating base. A third unconformity event eroded Newmarket Till, locally truncating it and underlying sediment to bedrock. Three younger sediment packages, Oak Ridges Moraine (channel and ridge sediment), Halton, and glaciolacustrine overlie this erosion surface. Significant regional aquifers are hosted within the LT. Upper Thorncliffe Formation sediments, north–south glaciofluvial channel–fan aquifers, are protected by overlying mud and Newmarket Till aquitards. Similarly, Oak Ridges Moraine sediments comprise a north–south array of glaciofluvial channel–fans and east–west fan aquifers, locally covered by silt–clay rhythmite and till aquitards.

Revised stratigraphy of the middle Simcoe Group (Ordovician, upper Sandbian–Katian) in its type area: an integrated approach

2020 ◽  
Vol 57 (1) ◽  
pp. 184-198 ◽  
Author(s):  
Timothy R. Paton ◽  
Carlton E. Brett
Keyword(s):  
New York ◽  
Integrated Approach ◽  
Early 20Th Century ◽  
Upper Ordovician ◽  
Southern Ontario ◽  
Lower Member ◽  
Type Area ◽  
Central United States ◽  
The Status ◽  
Uppermost Portion

The Upper Ordovician Bobcaygeon Formation of southern Ontario is a widespread unit that spans the Sandbian–Katian stage boundary and contains exceptionally preserved invertebrate fossil assemblages, including the famed ‘Kirkfield echinoderm fauna.’ However, the precise correlation of this interval remains poorly understood. This paper presents new data on high-resolution sequence and carbon isotope chemostratigraphy of the Bobcaygeon interval based on new quarry exposures and introduces refined definitions of unit boundaries based on allostratigraphic criteria. Sequence, chemo-, and biostratigraphic evidence indicate that the Bobcaygeon Formation represents a composite unit as it encompasses a major erosional unconformity. The Coboconk and Kirkfield formations, described in the early 20th century, were merged into a single unit, the Bobcaygeon, out of concern that the original lithostratigraphic divisions would be conflated with biostratigraphic zones of the same names. However, these biostratigraphic zones are no longer favoured, and the lower member of the Bobcaygeon is here elevated again to the status of formation (Coboconk Formation) and represents the uppermost portion of the Sandbian M4 sequence. The middle and upper members of the Bobcaygeon, herein reassigned to the Kirkfield Formation, represent the upper Sandbian to lower Katian M5A and M5B sequences recognized widely in the eastern and central United States. The term Bobcaygeon is retained and elevated to the rank of subgroup. The Kirkfield Formation is divided into three members and contacts are refined, placing a 1–2 m transgressive grainstone at the base of each sequence. These units are correlated with equivalent strata of New York and the Cincinnati Arch.

A Comparison of Urbanization Effects on Stream Benthic Macroinvertebrates and Water Chemistry in an Urban and an Urbanizing Basin in Southern Ontario, Canada

2010 ◽  
Vol 45 (3) ◽  
pp. 327-341 ◽  
Author(s):  
Normand L. Bazinet ◽  
Beth M. Gilbert ◽  
Angela M. Wallace
Keyword(s):  
Land Cover ◽  
Urban Development ◽  
Correspondence Analysis ◽  
Lake Ontario ◽  
Urban Land ◽  
Biotic Index ◽  
Southern Ontario ◽  
Urban Land Cover ◽  
Linear Relationships ◽  
Lake Simcoe

Abstract Benthic invertebrate communities were compared in several watersheds within an urban basin and an urbanizing basin in southern Ontario, Canada. The urban watersheds of the Lake Ontario basin and the urbanizing watersheds within the Lake Simcoe basin share similar geologies, soils, and climates, but differ in the stage of urban development within these two basins. Correspondence analysis showed that invertebrate populations formed distinct groups split between these two basins owing to intense urban development in the Lake Ontario watersheds versus the agricultural nature of the Lake Simcoe basin. Canonical correspondence analysis ordinations indicated that the major environmental gradients were related to urban land cover (imperviousness), chloride, nitrates and stream order factors. Urban land cover and chloride were most strongly associated with the first axis. The typical logarithmic relationship between urban land cover and benthos found in other studies was not evident in this study. Rather, 9 of the 12 metrics tested had significant linear relationships with urban land cover. The Hilsenhoff Family Biotic Index and percent Oligochaeta metrics showed the strongest positive linear relationships with urban land cover. Pollution sensitive groups (Ephemeroptera, Plecoptera, and Trichoptera) along with richness and diversity measures decreased with increasing urbanization.

The Seismicity of the Western Lake Ontario Area: Results from the Southern Ontario Seismic Network (SOSN), 1992-2001

2002 ◽  
Vol 73 (4) ◽  
pp. 534-551 ◽  
Author(s):  
R. F. Mereu ◽  
H. W. Asmis ◽  
B. Dunn ◽  
J. Brunet ◽  
D. Eaton ◽  
...  
Keyword(s):  
Lake Ontario ◽  
Seismic Network ◽  
Southern Ontario ◽  
Western Lake
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