FIELD TRIPS
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A number of pre- and post-meeting field trips are being offered. All trips begin and end in Nipigon. Most of the stops are road-accessible and involve minimal walking. The Rossport Transect trip is being offered twice due to anticipated high demand and limited spaces.
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Tuesday, May 24 & Wednesday, May 25 (overnight in Geraldton area Tuesday night)
Leaders: Mark Smyk & Tom Hart (OGS) and Phil Fralick (Lakehead University)
This two-day trip will investigate supracrustal rocks of the Neoarchean Beardmore-Geraldton greenstone belt which forms the southern margin of the Wabigoon Subprovince east of Lake Nipigon. The belt produced over 4 million ounces of gold from a number of high-grade mines. Several gold occurrences will be visited and described in a structural, alteration and tectonic context.
Wednesday, May 25
Leader: Peter Barnett (OGS)
This trip will follow the Highway 11 corridor from Lake Superior at Nipigon north to Lake Nipigon near Beardmore, featuring varied aspects of Quaternary deposits and associated Archean and Proterozoic bedrock features and geomorphology. Deltaic features associated with the Pijitiwabik Canyon spillway, lacustrine rhythmites, aeolian deposits and tills will be described.
Wednesday, May 25
Leaders: Peter Hollings and Phil Fralick (Lakehead University)
The offshore islands in Lake Superior near Rossport provide a 6 km transect from Archean basement through to Mesoproterozoic. This trip will feature the following stratigraphic units: Neoarchean granitoids; Paleoproterozoic Animikie Group sedimentary rocks; Mesoproterozoic Sibley Group sedimentary rocks; and Mesoproterozoic, Midcontinent Rift-related Osler group volcanic rocks.
Please note that this trip is dependent on weather and lake conditions. In lieu of this trip, an alternate trip to the former Winston Lake copper-zinc mine will be offered.
Saturday, May 28
Leaders: Mark Smyk (OGS) and Steve Kissin (Lakehead University)
The Quetico Subprovince near Nipigon displays a gradation from greenschist-facies, clastic metasedimentary rocks near the boundary with the Wabigoon Subprovince to the north, to upper amphibolite-facies, metasedimentary migmatites and derived leucogranite, peraluminous granite and pegmatites characteristic of its core zone near its southern margin. This trip will feature representative metamorphic and granitoid rocks and structures therein, as well as rare element (Li, Be, Nb, Ta)-bearing pegmatites of the Lake Jean Group.
Saturday, May 28
Leader: Tom Hart (OGS)
This trip follows recent mapping conducted by the OGS as part of the Lake Nipigon Region Geoscience Initiative, which incorporated geological, geochemical and geophysical surveys to better understand the Nipigon Basin. The area is underlain by Neoarchean metasedimentary and granitoid rocks of the Quetico Subprovince, overlain by Mesoproterozoic Sibley Group sedimentary rocks and mafic to ultramafic intrusive rocks related to the Midcontinent Rift.
Saturday, May 28
Leaders: Peter Hollings and Phil Fralick (Lakehead University)
(see description above)
Photo Captions
Click on any photo for full size image.
Trip (1) - Geology and gold mineralization of the Beardmore-Geraldton greenstone belt
 Pillowed basalt flows, Poplar Lodge, Lake Nipigon |
 Close-up of pillowed basalt flows, Poplar Lodge, Lake Nipigon (Notebook is 18 cm long) |
 Deformed oxide-facies banded iron formation (BIF) below MacLeod-Cockshutt Mine headframe, near Geraldton. The BIF is the up-dip projection of a gold-bearing, sulphidized BIF-hosted ore zone. |
 Deformed conglomerate within the Barton Bay Deformation Zone close to the Consolidated Mosher Mine, near Geraldton. Less-competent clasts have been elongated and folded. |
 Phyllonitic supracrustal rocks associated with the Paint Lake Fault Zone, Missing Link gold property, Lapierre Township. This regional transcurrent fault forms the northern boundary of the Beardmore-Geraldton belt. |
Trip (2) - Quaternary Geology of the Beardmore – Nipigon area
 Ice climber on diabase palisades at the northern end of Pijitiwabik Canyon. This canyon served as a major glacial spillway from Orient Bay (Lake Nipigon), shown in the background. |
 Longitudinal sand dune cut by High Hill Harbour Road, near Lake Nipigon west of Beardmore. The dune is part of a coastal dune field created by prevailing onshore winds (right to left in photo) and abundant sand supply. |
 Thin-bedded rhythmites (varves) overlying till at the Sand River Mine 16 Zone, near Beardmore. The clay/silt couplets are related to glacial Lake Kelvin (now Lake Nipigon). |
 Roche moutonee island in Lake Helen, north of Nipigon. Ice flow from right to left. |
Trip (3/6) - A Stratigraphic Transect Across the Northern Flank of the Midcontinent Rift near Rossport (I)
 Ropy flow top (pahoehoe) in basalt of the Osler Group, Wilson Island, Lake Superior. |
 Archean granite exposed on the shore of Lake Superior near Rossport, where it is unconformably overlain by the Paleoproterozoic Gunflint Formation. Overlying Proterozoic rocks on the offshore islands (on the horizon) dip gently towards Lake Superior and the center of the Midcontinent Rift (to the left in the photograph). |
 Mafic dyke in Keweenawan Osler Group Basalts, Wilson Island. |
Trip (4) - Geology and Rare Element-bearing pegmatites of the Quetico Subprovince
 Massive, coarse-grained to pegmatitic granite of the Core Zone exposed on Highway 11 north of Nipigon. Note the large feldspar crystal (red box). |
 Folded metasedimentary migmatite of the Core Zone exposed on Highway 11 north of Nipigon. |
 Drusy spodumene crystals in narrow pegmatite dyke in leucogranite, Foster pegmatite, Lake Jean Group, northeast of Nipigon. Note channel cut and card for scale. |
Trip (5) - Geology of the Black Sturgeon Area
 Folded metasedimentary migmatite, Quetico Subprovince, Church Township. |
 Pegmatitic granite exposed in burned area below Proterozoic diabase sill, Church Township. |
 Aerial view, looking northwest, of the fault-bounded Black Sturgeon River valley. Archean granitoid rocks of the Quetico Subprovince (on right) are in fault-bounded contact with Mesoproterozoic Sibley Group sedimentary rocks and Keweenawan diabase sills (on left). |
 Large porphyoblasts of andalusite in metasedimentary schist, Quetico Subprovince, Church Township. |
