THE GREAT FIELD TRIP – GEOLOGY OF EASTERN CANADA
The Appalachian Province (Eastern Townships of Quebec and NW Maine); the Grenville Province (Montreal - Parc de la Verendrye and Sudbury to Barry); the Kenoran Province (Noranda, Timmins, Kirkland Lake); the Southern Province (Cobalt; River Valley; Sudbury; Cutler, Whitefish Falls); the Keweenawan (Batchawana Bay); and the Pleistocene of the Scarborough area of Toronto.
The following itinerary is based on a
two-week Spring field course I ran in the 1970-90’s for fourth year students in
the B.Sc geology programme at the University of Western Ontario, the aim of the
course being to study as much of the tectonic history of the Structural
Provinces of Eastern Canada as could be reasonably achieved in two weeks. This
time constraint usually meant that the Keweenawan or River Valley excursions could only be accomodated
through separate field trips held in the Spring or Fall. The
manuscript as displayed on this web page is "under construction" and will be
modified and added to as time permits. The outcrop locations are in the
process of being recorded in a Google Earth folder:
http://instruct.uwo.ca/earth-sci/fieldlog/Google_Earth/gft.kmz . Currently I have
few GPS UTM coordinates for the stops, but have now added a set of 6 stops,
including photographs, for the Ordovician 'Bulge Passage' sequence present at
the 'Centre de la Nature' in Laval/Montreal.
DAY 1. London to
Montreal
Leave London at 8.00 a.m.
En route to Toronto note red shales of the Queenston Fm below the Lower Silurian
Clinton/Cataract sandstones, shale and dolostone and the Lockport Dolostone of
the Niagra escarpment (after the Campbellville exit, before the Milton exit).
Stop 1. Guidebook - Geology of Eastern
Canada.
EXIT 380 AT Brimley Rd., South); CONTINUE FOR 8.5 KM. ALONG BRIMLEY TO BLUFFERS
PARK; THE BUS SHOULD ARRIVE BY 10.30 A.M.
The section at the Bluffers Park includes only the Scarborough sand and the
overlying Sunnybrook Till and associated mud units.
Lithofacies logs for the Sunnybrook 'Till' at Scarborough Bluffs,.
Dutch Church East side of the Seminary Road.
rippled sand to lam. mud turbidites sand with loading structures.
lam. sand - ripp. sand - lam. mud. massive sands with load structures.
lam. muds and rippled sands laminated muds and sands w. ripples
lam. muds with dropstones laminated muds
mud w. load structures
laminated muds. laminated muds with dropstones.
stratifed, resedimented diamictite stratified, resed diam.
w. flow nose at top w. gravels at the top.
lam. muds with dropstones (thin). massive diamictite, resedimented
massive diamictite. massive diamictite.
massive diamictite, interbedded w. massive diamictite, resedimented
underlying sands.
stratified, resedimented diamictite. laminated mud
w. clast conc. at the top.
Scarborough Sands, rippled at the top. Scarborough Sands, load
structures at bottom.
Notes:
The Scarborough Sand is a near shore lacustrine deposit rich in organic
matter, pollen, and beetles (cool climate). It has a high percentage of mica and red
garnet, and 'cut and fill' structures are present at Cathedral Bluffs. There is
an outcrop of
Scarborough sand at base of the hill, east side, which has very large slump balls and
cross laminated ripples.
The underlying Scarborough Silt was deposited in a lake drained by the Hudson
and Mohawk valleys. The silt is buff coloured and therefore oxidised. At its contact with
the overlying Sunnybrook till, cross laminations
in the Scarborough Sand are outlined by heavy mineral concentrations.
The Sunnybrook till overlying the Scarborough Sands is rich in dolomite clasts
and has garnets that are more purplish than those in the Scarborough sands. The
till is very clay rich and therefore thought to have picked up lake deposits
- the upper part, the Bloor Member, is laminated and is transitional to the
lower Thorncliffe sands. The Seminary till overlying the Lower Thorncliffe is a
clayey sand till with flat subrounded pebbles (basal till with shear layering).
It is more garnetiferous than the Sunnybrook. It is also poorer in dolomite but
richer in calcite clasts.
Eyles and Eyles (1983) claim that the diamictites are not tills because of :
1) the absence of major erosive contacts associated with lodgement and melt-out processes at an icebase-bed interface,
2) the presence within the diamicts of undisturbed lenses of starved ripples, loaded sand pillows and ripples, silt laminae, silt, clay and diamict intraclasts, and graded laminations of silt and clay deposited by turbidity currents,
3) the presence of interbedded and loaded basal contacts with underlying deltaic sands, and
4) loaded transitional and interbedded upper contacts with deltaic sands or laminated silty clays.
Nevertheless there is evidence of deformational disturbance at the Scarborough - Sunnyside contact of the Seminary section in the form of rotated slivers of high angle, heavy mineral banding, and the interleaving of sand and till.
Leave Scarborough (Highway 2 = Kingston Rd) at 11.15 a.m.
Lunch at McDonalds in Cobourg (first exit from 401).
Leave Cobourg at 2 p.m.
Stop 2.
Brockville , km. 696. Potsdam sandstone, outcrops on south side of the Highway
just beyond the overpass (see Clarke et al. p.8-10 for description of the
Potsdam).
The outcrop at Brockville seems to represent the transition of the Potsdam to the Beekmanstown. (See Bernstein, 1992, CJES, v. 29, p. 2677.) Lower units are bedded grey sandstones, some of which are calcareous, with hummocky cross bedded units and interlayered intertidal siltstones, overlain by bioturbated grey sandstones followed by bioturbated sandy dolomites. Note near the base a unit of broken storm deposit?' material with carbonate clasts. Sequence may represent deepening water with bioturbated sandstone formed below storm wave-base, or, alternatively, shallowing conditions with the dolomite deposition as a prelude to Sabkha formation. In this case, the bioturbated sandstone may reflect the development of a protective off-shore carbonate reef system, and it may be possible to find chicken wire texture (deposition of carbonate +\-sulphate from evaporitic waters passing through mud cracks). In this respect note the presence of calcite nodules as a possible replacement of sulphate? The Potsdam would in this case be equivalent to the Chateauguay facies of the Potsdam of the Montreal region (Nepean of Ontario, see Bernstein, 1992) -` shallow marine, intertidal, nearshore deposits; cross bedding less prominant than in the underlying fluvial red and grey sandstones of the Covey Hill facies. Note the absence of the Beekmantown and Chazy groups on the southwest side of the Frontenac axis; point out the presence of Trenton rocks at Manitoulin and at New Liskeard; initially the Frontenac axis marked the south-`west edge of a continental embayment accumulating shallow water sediments. The Chazy-`Beekmantown contact marks a phase of uplift (gibberulus -`hirundo - `LLanvirn) perhaps representing a temporary seizure along the slip zone at the time when continental margin slope-`and-`rise sediments began to enter the subduction zone. Subsequently, the continental margin began to subside (deposition of the St. Therese sandstone member of the Chazy) and by Trenton times subsidence was accompanied by a major phase of transgression as ocean closure entered its final stages.
Enter Montreal on Highway 40;
To get to the
University of Montreal:
go
South on 15; exit at 66 (Edouard Mont Petit, one way west) onto Decarie Blvd;
south two blocks then left onto Chemin Queen Mary; continue to Chemin Cote de
Neige; then left to Edouard Mont Petit.
(Note : at the Residences; first two digits of the key number refer to the
floor; the second three digits to the to the room).
If staying at
the Quality Inn, enter Montreal on route 40 and exit at 65 where 40 intersects
520 (Cote de liesse), and then to go west on Cote de Liesse.
Motel Ideal - exit 40 before Av. Jeunesse; stay at Motel Ideal on Av. before Rue
Sauriol and Rue Fleury. Jeunesse before Pont Viau; (the Motel Ideal in Pont Viau
is at north end of Blvd des Laurentides, east side of the road, before Rue St.
Martin.) Motel Ideal requires pre-payment or a credit card.
DAY 2 Montreal to Sherbrooke
(When ordering lunchs indicate that they are to be ready by 8.30 a.m.).
Follow Blvd Edouard Mont Petit west to Decarie Blvd; then north (turn right) to
Highway 40; east on 40 to exit 76 (Blvd Pie IX); north on Pie IX; cross Pont Pie
IX and exit at flyover junction with Bd de la Concorde; turn left to onto Blvd
de la Concorde and very soon after turn right onto Rue du Parc which leads to
the parking lot at the northwest end of the St. Vincent de Paul Nature Park.
If staying at the Motel Ideal in Pont Viau, go north on Lajeunesse to Rue Henri Bourassa,
turn right and continue to Avenue Papineau, get into centre lane and turn north
(left) onto route 19, cross Pont Papineau, and exit at Rue de la Concorde.
Travel east on Concorde and before reaching Highway 25 turn left onto Rue du Parc.
Continue north to the parking lot of the St. Vincent de Paul Nature Park (Centre
de la Nature).
Stop 1. ST. VINCENT DE PAUL Nature Park -
Chazy, Black River, and Trenton Groups (The following ammended description
is from the guide by Clark, T.H., Globensky, Y.,
and Hofmann, H., 1979, Stratigraphy, petrography, and sedimentology of the
Paleozoic of the Laurentian Platform. Geol. Assoc. Can. Fieldtrip A-7, 35p.).
The station letters and unit numbers are from this publication, the Google Earth
referenced stops have been added.
Stations A to D (stop 1 in the Google Earth gft.kmz file) along the west
shore of the artificial boating lake include cross bedded
calcarenites
(with
stylolitic shale seams) of the St. Martin facies
of the Laval Fm.. The calcarenites separated by are accumulations of
wave- or current transported shell debris on shallow banks. The
upper horizon is notable for containing abundant
orange-yellow dolomite 'clasts'. Stations E-J
(stop 2 in the Google Earth gft.kmz file) exposed along the park road to the
east of the lake are of
orange-weathering
dolomites, shales,
and sandy dolomites of the Pamelia Fm. (units 7 to 15).
The limestones at
stop 3A in the Google Earth gft.kmz file exhibit ripple marks, mud
cracks, breccias, phosphatic fragments, and oolitic limestones. The mud cracks mark the last
emergence above sea level of the Montreal area prior to the development of the
Lorraine exogeosynclinal basin.
At stations E to L, N (stop 3B
in the Google Earth gft.kmz file) occur fine grained limestones, mega-rippled oolites, and thin
shaly beds of the Lowville Fm. ( units 16-38). The presence of the colonial
tabulate coral Tetradium marks a return to deeper water conditions. The
limestones above the oolitic unit at stop 3B exhibit
storm hummocky cross beds indicating deposition above storm wave base.
Stations J to N (stop 3C in the Google Earth gft.kmz file) include fine grained
burrowed limestone layers (units 42,43) separated by a burrowed shaly layer.
They form the
two prominent horizons ledge at top of the cliff and mark the base
of the Leray Fm.. The bioturbation indicates that they are supratidal and lagoonal
sediments deposited in a storm protected environment behind a coral reef.
The
ledges (units 44-51) at stop 4 in the Google Earth gft.kmz file are made of fine to medium grained limestone with abundant
fossils
and
black chert nodules.
They may be reef
talus fan deposits. The overlying coarse calc-arenites of the
Deschambault Fm. may indicate foundering and a jump shoreward of reef development
followed by seaward growth of the reef.
Stations M,O,P,R contain thin bedded limestones of units 52-53 of the Ouareau Fm. (Monteregian
sill in Ouareau at M) and units 54-57
of the
Mile End Fm. A lithologic break
occurs at the top of unit 57 and is marked by the presence of a rusty -
weathering pyrite seam (best seen on the north side of the quarry); above the
pyrite seam occur thick bedded to massive, conglomeratic calcarenites of the
Deschambault Fm. and the overlying thinner calcarenites and shale interbeds of
the Montreal Fm. These rocks represent a return to deep water, open marine conditions supporting a
prolific benthic fauna.
Montreal to Sherbrooke
Travel south on route 25 crossing Pont Pie IX. Follow Boulevard Pie IX (route
125) to highway 40/25 and continue east on 40/25 and then south on 25, crossing
the St. Lawrence using the Lafontaine tunnel. There are good outcrops of the
Montreal Formation in road cuts before the tunnel. Upon exiting the tunnel take
highway 20 along the South shore of the St. Lawrence. Exit at the Pont
Champlain, pass under the bridge and take the Sherbrooke entrance onto Highway
10.
Stop 2. Km. 59 On the north
side of the highway are exposed red argillites of the Mawcook Fm of the Supposed
Lower Cambrian Shefford (Charny) Group of the Granby nappe.
Km. 68.6 (Autoroute des Cantons de l'Est) - Second outcrop after exit 68. Granby
Fm turbidites of the Shefford (Charny) Group. Thick graded units with large rip
up clasts; Bouma cycles. The rocks dip northwest and according to Slivitsky and
St Julien (1987) underlie the Mawcook argillites. Both units units constitute
the Granby nappe overlying the Drummondville olistostrome. Volcanic rocks of the
Montagne de Saint Anselme Fm ?? occur within the red argillites of the Sillery
Fm of the Chaudiere nappe at Notre Dame de Bon Conseil, northeast of
Drummondville).
Stop 3. Km 74 - Melange with irregular shaped blocks of quartzo-feldspathic rock. This unit is probably equivalent to the Middle Orodovician (graptolites) (Globensky, 1978) Drummondville wildflysch but is located between the quartzofeldspathic turbidites of the Charny and the lime turbidites of the Stanbridge nappe. Note the scaly nature of the cleavage and the highly sutured edges of some of the blocks, some of which show cross laminated ripples. This unit is not shown on the map of Slivitsky and St Julien.
Stop 4. Km 75.3 - Thin bedded lime turbidites of the Stanbridge Group (Charbonneau, 1980); graded beds seen at NW end of the outcrop; well developed pseudobedding; cleavage-pseudobedding folded by vertical folds; Stanbridge nappe; Lower to Mid Orovician according to Charbonneau (1980), quoted by Slivitzky, A. and St. Julien, P., (1987). The Granby, Drummondville and Stanbridge nappes overlie the deep water carbonate facies of the Middle Ordovician Bulstrode/Melbourne/Saint Sabine and Bourret Formations, all of which may be parallochthonous units.
Stop 5. Km 78 - black argillites, euxinic facies of the Stanbridge, with very thin carbonate seams; well developed steep cleavage; carbonate seams are microfolded. Suggestion of grading and flame structures indicating the rocks are inverted.
Stop 6. Frost Village (leave the autoroute at exit km 90 to Waterloo and turn right at junction with 112 towards Frost Village) - After 2.5 km, and about a half kilometre beyond Frost Village occur small but prominent road side exposures of blue-green metavolcanics of the Tibbit Hill forming the core of an anticline; tectonic fish (shear pods); high TiO2; crossite; vesicular on north side of the highway; green epidote patches. Mark late Proterozoic rifting episode (Coish et al. 1987). Very similar looking rocks to the Catoctin volcanics of the Southern Appalachians.
Stop 7. Road cut through a prominent hill about 4 km beyond Frost Village between Frost Village and South Stukely; quartz-sericite and carbonaceous black schists of the Oak Hill (Bonsecours Group) showing three phases of deformation; there appears to be carbonate beds in the black shales at the north-east end of the outcrop. The black shale - quartz-sericite schist contact may therefore be the equivalent of the Potsdam - Beekmanstown boundary. On the Slivitsky and St. Julien map the contact is shown to be between OH7 (Sweetsburgh slate) and OH4 (West Sutton Phyllite) but the calcareous units are more likely to be a continuation of the sliver of BM (Bulstrode and Melbourne calcareous graphitic slate) shown on the Slivitsky and St. Julien map along strike to the NE.
Stop 8. Caldwell sandstones (turbidites) below the Orford ophiolite complex; sandstones contain abundant detrital mica. Graded units with mud clasts, younging to the west, are discernable in the central east part of the outcrop. In the western part the turbidites are cut by an anastomosing shear system. The easternmost part of the outcrop is occupied by purple black shales. The relationship of the shales to the turbidites is not evident. The Caldwell at this locality may be a window of Charny equivalent turbidites separating nappes of the Oak Hill and the ophiolite belt. Since the Oak Hill is a more distal facies than the Caldwell, it is likely that the former was thrust over the latter, and that the Caldwell was subsequently thrust over the Oak Hill by out of sequence faulting.
Stop 9. Serpentinites and
altered mafic rocks including rodingite with pink veins of hydrogarnet.
Clinopyroxenites and gabbro at the east end of the outcrop. Slickensided
surfaces common in the serpentinite.
DAY 3. Sherbrooke to Thetford Mines via Asbestos.
Take highway 55 towards Windsor if travelling to Asbestos (Stops 00 and 0) or highway 112 if travelling direct to Disraeli.
Stop 00. Felsic tuffaceous rocks interlayerd with turbiditic sandstones and shales (trachyte of Cooke, SD5 of Slivitsky and St. Julien) on the Sherbrooke - Drummondville highway 55, 2 to 3 km SE of the Windsor exit.
Stop 0. Take highway 249 to
Asbestos. Climb Burbank Hill at the southwest end of the Asbestos pit just
before entering Asbestos. Ledges blasted out on the north side of teh hill are
composed of altered gabbro and diabase of the Asbestos ophiolite. On the south
side of the hill the gabbro is overlain by a spectacular boulder conglomerate
with large blocks of clinopyroxenite. Note: according to Hubert the conglomerate
is separated from the St. Daniel by a red mudstone.
Stop 1. Travel to St. Jaques from Disraeli
on highway 263. Turn around at St. Jaque and examine the Caldwell sandstones in
the road cuts on the east side of the road on the hill descending into St Jaques.
The outcrops exhibit the same type of anastomizing shear deformation found in
the Caldwell at Lake Orford.
Stop 2. Contact of mafic rocks of the
dynamothermal aureole and the serpentinite. Pseudomorphic chlorite after garnet
in outcrop at the NW end of the road cut, SW side of the road.
Stop 3. From Disraeli take the road to Lake St Francis and Saint Daniel. Pillow lava and sheeted diabase with one sided chills (see St-Julien, P. 1972. La tectonique appalachienne dans les cantons de l'Est de la province de Quebec. 24 ième Congrès géologique international; livret-guide de l'excursion B-21, 22p. Figure 6. Stop E4.)
Stop 4. Continue for about 3/4 mile cliff-side outcrops of what St.Julien mapped as gabbro and diorite. (Not marked as a stop on St. Julien's figure 6) These outcrops are of gabbro and sheeted diabase, and include both orange weathering boninitic and green weathering plagioclase-phyric basaltic sheets.
Stop 5. Trun right at the
junction with highway 267 to stop E3 on St. Julien's Figure 6. St. Daniel
olistostrome; sandstone, lime turbidite and felsic volcanic fragments; 'flysch
and chips'; debris flow.
(Extraneous note: mafic rocks mapped by Slivitsky and St. Julien as Caldwell
basic volcanics in the Caldwell section between Robertsonville and Ste Methode
(northeast of St. Daniel) are gabbros and dikes, and therefore more likely to be
tectonic slivers of the ophiolite.)
Stop 6. Return towards Thetford on highway 267. Leave 267 to take the short cut to Black Lake. At the junction with highway 112 There are exposures of Lake harzburgite, dunite, chromitite and asbestos; muscovite granite representing altered felsic intrusive material (see paper in CJES?).
Stop 7. Continue towards
Disraeli via Coleraine. Spectacular exposure of Coleraine Breccia in Coleraine
cemetry. Debris flows - matrix supported - in red silstones; contains clasts of
Caldwell schist, and of most ophiolite units; clast of pyroxenite at top and
rear of lower outcrop.
Stop 8. Leave cemetry onto 112. Return
towards Black Lake but make a left turn on highway to Saint Julien. Turn left
onto road to Lac East, and left again at the recreation area. Where you descend
a steep gradient about 1 km further on there are exposures of clinopyroxenite
veining dunite. 50 metres further on in a field to the left of the road there is
an exposure of Caldwell gritty sandstone with pinstripe cleavagae. Return on
foot towards the recreational area to examine the change of pyroxenite into into
gabbro. Leave the cars at the recreation area and climb the hill to the north
from the southwest side. There are poorly exposed and moss covered outcrops of
sheeted diabase at the top of the lower approaches to the steeper part of the
hill. Climbing the hill one passes from greenstones to red volcanic clast
bearing red mudstones, mudstones, debris flows similar to those of Coleraine in
red mudstones. The debris flow contain clasts of Caldwell-like schist.
Day 4 Thetford Mines to Sherbrooke via Riviere des
Plantes and Chain Lakes
Travel from Thetford mines via Robertsonville on 269 to St. Methode and on to
junction with 108. Turn north on 108 to Beauceville. Then NW on 171/73 about 7
km to Riviere des Plantes. (See Cousineau, P.A., 1990, The Riviere des Plantes
ophiolitic melange: tectonic setting and melange formation in the Quebec
Apalachians: Jour. Geol., v. 99, p. 81-96, Figure 2; Cousineau, P.A. 1986. Le
domaine oceanique entre Saint Camille de Bellechasse et Lac Frontière. Ministere
de l'Energie et des Ressources MB 86-25, 49 p.) Walk up the river to the first
rapids. On the way you will observe serpentine in contact with highly
metamorphosed paraconglomerates. Follow 171 to just south of St. George and just
south of Jersey Mills take 204 to Lac Megantic, 161 to Woburn, and Maine 27 to
Chain Lakes. Boil Mountain ophiolite includes Betts Cove type clinopyroxenites.
Coish, R.A., and Rogers, N.W., 1987, Geochemistry of the Boil Mountain
ophiolitic complex, northwest Maine, and tectonic implications: Contrib.
Mineral. Petrol., v. 97, p. 51-65.
Boudette, E. L.,, 1970, Pre-Silurian rocks in the BoundaryMountains
anticlinorium, northwestern Maine: N.E.I.G.C., Trip C, p. 1-21.
Stop 1. Outcrops just before the Highway
Camp. Meta clastic rocks exhibiting metamorphic fractal recrystallization
textures similar to those in Grenville rocks near Alban, Ontario.
Stop 2. Outcrops on sides of the road close to the Alder Stream - Chain of Ponds (Lakes) Township line north of the Sarampus Falls Picnic site. Chain Lakes diamictites with clasts of vein quartz and calc-silicate material. Next outcrop further south on the east side of the road clearly shows the clastic aspect of the rocks.
Stop 3. Continue south. Just after the Alders Stream - Jim Pond Township boundary occur outcrops on both sides of the road of clinopyroxenite, passing to the south into metagabbro. This is stop 5 in the Rangely Lakes Field Guide, p. C15
Stop 4. 1.8 miles further on
from stop 3 is a large road side cliff outcrop of highly stretched plagioclase-phyric
pillow lava.
Other stops are described on pages C16 to C18 in the 1970 Rangely Lakes Field
Guide.
12.1 Turn left on Jim Pond Camps access road
12.3 Bridge over North Branch Dead river. Bear left at intersection onto
lumbering road.
12.9 Intersection; bear left
16.4 Turn around as directed where the road is wide and its shoulders are dry
and level. Begin retracing route in the southerly direction.
16.6 Stop 6. Foliated granofels of the Chain
Lakes massif.
The granofels at Stop 6 is lithogically comparble to that seen in the previous
two stops. Here, however, foliation, oriented 060 ,75 SE, is strongly developed
and conspicuous. This foliation is believed attributable to shearing related to
either normal or strike-slip local faultingwhich gradually cuts out all the
mafic rocks in the complex to the east until the Attean Quartz Monzonite is in
direct contact with the massif on the east side of the Chain Lakes quadrangle
(fig 1).
17.1 Viles Pond Brook
17.2 Stop 7. Epidiorite-quartz diorite
autobreccia (unit 5b) of the ultamafic complex.
Rocks here are comparable to some of those seen at Stops 4 and 5, but evidence
for serpentinization is inconspicuous or serpentinite is lackingentirely. The
outcrop is a particularly good 3-D exposure of the unit. The epidiorite, as the
abundant fancies, is composed essentially of chloritized amphibole and
plagioclase. The epidiorite is cut by a boxwork of finergrained quartz diorite
veins and, rarely, quartz veins.Rare xenoliths of granofels of the complex may
be found in this unit which attests to the relative age of the sequences as does
the contact at Stop 44.6. The autobreccia lacks conspicuous deformation here,
but it is cut by several sets of fractures tending to brecciate parts of the
unit.
17.7 Roadside outcrop of epidiorite autobreccia.
18.2 Intrusive contact of the Attean Quartz Monzonite with the alpine complex is
concealed beneathPleistocene ground moraine.
18.3 Stop 8. Attean Quartz Monzonite.
Attean Quartz Monzonite crops out here as part ofa body about 3,000 feet thick
(fig. 1). The rock seen is composed of about equal amounts of quartz, altered
plagioclase, and potassium feldspar with 5 percent or less of altered mafic
accessory minerals; it is sheared, foliated, and epidote are conspicuous
alteration products.
18.8 Stop 9. Attean Quartz Monzonite.
Rock on the southeastern side of the pluton (fig.1) presents a textural contrast
to that seen at the previous stop. Quartz and some feldspar in the Attean here
is of the same grain size, but the bulk of the feldspar is more altered and
occurs as groundmass components. The Attean here is indicated to be structurally
beneath the volcanic rocks to the south by graded beds and pillowtop
observations, and its intrusive relationship with unit 2a is unequivocally
established.
19.0 Stop 10. Lower(?) Ordovician greenstone
with lapilli beds.
The greenstone here (unit 2a) is composed of amygdaloidal metabasalt with poorly
developed pillow structure which is interlayered with graywacke beds as much as
1 foot thick composed principally of lapilli, feldspar, and quartz. Pink to
brownish calcite composes the amygdules, and rare blue quartz clasts occur in
the lapilli beds. (Please do not hommer upon or remove these quartz clasts.)
Layering in this unit strikes 043 and dips abouut 78 NW. Grading and
crosslamination in the the lapilli beds indicates that the layering is slightly
overturned; the regional sequence faces southeast. the metamorphic grade is
indicated to be in the lower greenschist facies by a chlorite-albite-epidote
assemblage; no textures suggest that it was ever in the facies characterized by
higher temperature.
19.2 Stop 11. Metamorphosed quartz latite
volcanic rocks of the Lower (?) Ordovician sequence.
The greenstone at the last sop is stratigraphically overlain by metamoprhosed
lava (keratophyre), brecia, and ash flow of quartz latite composition (unit 2b);
the contact is sharply defined. The sequence of outcrops here here represents
nearly two-thirds of an unbroken section of felsic volcanic rocks which is about
2,000 feet thick. These volcanic rocks are part of a lenticle that extends on
regional strike from the northwestern ninth of Kennebago quadrangle through Stop
11 to the northeast for an unknown distance.
Here these volcanic rocks appear in perhaps their most spectacular accumulation.
They are part of an unbroken southeast-facing unit which, in contrast to the
lower boundary, grades well into overlying metagraywacke-iron formation and
greenstone units (units 2c and 2d). Interbeds of ferruginous chert and
quartz-rich graywacke increase in abundance toward the top of the unit and
finally predominate (unit 2c).
In unit 2c, thick quartz-rich graywacke beds are commonly associated with the
iron formation. These are not exposed in the section here but are observable in
the ridges on strike.
The metamorphic grade of rock at Stop 11 is compatible with that at Stop 10, and
indications are that rocks at both stops have had the same history of
pressure-temperature since deposition.
Return to transportation, remain on principal road, and retrace the route back
to Rte. 27.
Note: The following notes are added in the interest of continuity. Refer to
Boone and others (this volume, fig.1) for geology. Unscheduled stops may be
added, if interest and time permit, to elucidate the stratigraphic sequence in
Lower(?) Ordovician rocks.
Return to Sherbrooke via highway 212 to Cookshire and 108 to Lennoxville. It is
only a short diversion to turn north at Notre Dame du Bois to visit the
Observatory and/or Sanctuary at the top of the Mount Megantic (Devonian
granodiorite).
DAY 5. Sherbrooke - Ayers Cliff region
(Alain Tremblay - Guadeloupe fault shear zone exposed in stream near
East Angus, location marked on St. Julien map.
Sliver of Ascot granite in Ascot rhyolite, new road cuts on the Thetford road.
Pillow lava in Clergy retirement home, and sheared mafic lavas supposedly below
clastic units of the supposed Frontier - Beauceville sequence to be checked next
year. St. Daniel behind the Provigo on King Street. Exposure of mill rock in the
housing estate north of the Provigo stop. Exposure of polyfolded Ascot in the
woods beyond the SINTRA quarries.
Stop 1. Devonian Limestones of the St.
Francis Group of the Connecticut Valley - Gaspe Synclinorium at Lennoxville.
Outcrop is composed of limestone with thin shale interbeds; sheet dip is to the
east but axial plane of the most obvious fold system dips steeply to the west,
indicating the existence of the Gaspe-Connecticut synclinorium to the east. Some
isoclinal folds are clearly deformed cross beds and the more obvious isoclinal
folds may also be of slump origin. Nevertheless, there is a prominent lineation
on the bedding surfaces, which is transverse to the fold axis of the more
obvious fold structure.
Stop 2. Albert Mine. This stop is at the
first major cross roads on the road leading to Sherbrooke. On the south side of
the road is a unit of pin stripe F2 foliated (F1 is a very fine oblique
foliation; F3 is eeply plunging lineation) dacitic tuffs with some primary
layering involving chert or thin felsic flows and fragmental beds. The foliation
is largely parallel to the bedding but in places is oblique to bedding surfaces.
On the north side of the road is mafic chloritic schist in contact with felsic
sericitic schist, with massive sulphide along the contact. At the east end of
the outcrop occurs iron formation. (Visit this outcrop rather than the Albert
Mines dump).
Stop 3. Outcrop of pin-striped mineralized
felsic volcanic rock in suburban housing development on south side of the road
entering Sherbrooke.
Stop 4. Mafic volcanics, possibly stretched
pilows, of the Sherbrooke Quarry. These rocks (sample 1-6) contain according to
Tremblay .56 wt% TiO2 at 130 Cr. Boninitic rocks (sample 1-8) form outcrops of
the same unit further south (at corner of the road leading west to the tennis
courts and ski hill). Note mafic meta-phenocrysts; rock could be a pyroxene-phyric
basalt of the pigeonitic series. Emphasize the bimodal nature of the volcanism
and similarity in this respect to Tonga - Kermadec.
Stop 5. Mill rock outcrop at the Tennis club. Loose block near the top of the outcrop, with tear shaped fragments which are perhaps bombs; note the zoned nature of the bombs on the tennis court side of the outcrop; although most fragments are flattened as well as elongated, some fragments are not flattened. The flattening may therefore be a primary feature, in which case they are likely L-tectonites. Size variation possibly possibly defines cyclic units, tops towards downtown Sherbrooke.
Stop 6. Magog turbidites (turn right at the Ford Garage); examine cross-laminated ripples for sense of flow (perhaps axial); note that variation in bed thickness on the limbs of the St. Victor syncline indicates source derivation from the east.
Stop 7. Take highway 55 towards Drummondville and leave the highway exit at the very next exit Chemin St. Joseph. Circle clockwise around to the overpass and just before reaching the overpass examine the conglomeratic debris flows of unit M5 of Tremblay (Map MB 87-28)
Stop 8. Re-enter highway 55 and branch onto highway 10. East of where high10 passes beneath Chemin Duplessis there is a long exposure of the Frontier formation, and just before highway 10 joins highway 112 there are new exposures of unit A4 felsic volcanics and a sliver of supposedly intrusive granite. To examine these exposures the cars can be parked in a lay by on the north side of highway 10.
Stop 9. Continue for a few metres along 112 and then turn left onto Chemin Champigny. Follow this road to Chemin Duplessis, turn right, and then right again at the junction with highway 216. A half-kilometre further on there is a good outcrop on the east side of the road of course volcanoclastite with shale fragments of unit M2 (Etchemin?). Contine 1 - 2 km along 216 to examine outcrops of Beauceville. Turn around and drive towards Sherbrooke. Just past the junction with Chemin Duplessis on the west side of the road occur massive white weathering sandy volcanoclastites. Return south along Chemin Duplessis and turn right onto rue Papineau. On the right hand side as you climb the steep part of the hill just after the first sharp bend are highly deformed L-tectonite fragmental rocks supposedly of unit M1.
Stop 10. Take highway 216 to
St Catherine de Hatley (Katevale) and on to Ayers Cliff via Turnertown (or take
highway 10 and 55 to the Ayers Cliff exit.) Chromite grains in felsic volcanic
material in black shales occur ? Turn right onto highway 141 and then take 2nd
left 1.2 km after passing over highway 55. The Ayers Cliff quarry is on the left
a short distance (100 m) after the turn-off. In the quarry are mafic and felsic
volcanics structurally overlying the Bunker Hill psammites. Debris flow of black
shale and volcanic material, including chromite grains. Flow channels underlying
felsic tuffs; indicate sequence is younging to the east, confirming the
synclinal nature of the Ayers Cliff synform. High nickel values in white
weathering felsic tuff collected by Wayne Nesbitt. Next outcrop on highway 141
travelling towards Magog is of quartzose sandstone of the St. Daniel, whereas
the large outcrop on the northeast side of the road on the bend about a half km
further on is supposedly of Beauceville? M1.
Continue south on the road for about ? km and then turn left into a lane leading
to a cleared property with good oucrops of gritty Bunker Hill turbidites. BE
POLITE!
Stop 11. Return towards Ayers Cliff and take
Chemin Benoit which leads of the north entrance roadway to Highway 55. First
outcrops after crossing the stream are of Ayers Cliff proximal facies sandstones
and melange. Note quartz-rich nature of the clasts; all clasts seem to be
sandstone but some are gritty sandstones, others are finely bedded.
Stop 12. First outcrops
after crossing highway 55 are of chromite-bearing sandstone; deformed load
structures and three-phase polydeformation.
Take Chemin Bacon to Turnertown - Ayers Cliff road. Turn left towards Turnertown
and travel 1.4 km to outcrops on the NE side of the road at the bend just before
the stream and a large farm. The rocks contain clear evidence of a vertical
crenulation cleavage related to the regional distortion of the F1/F2 cleavage.
The rocks also show the low angle late cleavage.
Stop 13. Distal facies black shales; grading
in turbidites and bedding cleavage relationships indicate younging to southeast.
Bouma units not easily recognisable, but cleavage better developed in the finer
grained more argillaceous upper part of the graded units. On north side of the
highway at the northeast end, are good examples of highly flattened sulphides in
cleaved black shale. On the south side some outcrops display well developed
surfaces with silvery arsenopyrite.
Note small debris flow in the argillites
DAY 6 Sherbrooke to Mont Laurier.
READ Basu, A.R. and Pettingill, H.S., 1983. Origin and age of Adirondack
anorthosites re-evaluated with Nd isotopes. Geology, 11: 514.
Stop 1. Km 57 Exit to St. Anne des Lacs.
Faersundite.( this is not stop 1 in the Morin Anorthosite Guidebook but the same
description applies.)
Stop 2. On highway just beyond St Saveur des Monts. Garnet-rich jotunite with a few very large porphyroblasts of plagioclase. Small xenoliths also in evidence. Garnet indicates relatively high proportion of normative orthopyroxene.
Stop 3. Km 74.4 Anorthosite. Scattered oriented large phenocrysts; some patches of cumulate plagioclase with intercumulus opx. In next long outcrop, at its southeast end, the anorthosite is cut by a dike of gabbroic anorthosite. The anorthosite contains abundant intercumulus opx, is commonly discontinuously layered (schlieren), and contains large 'floating' xenoclasts, or clast aggegates, of plagioclase. At this stage of crystallisation, the anorthositic liquid has perhaps become dense enough to allow plagioclase flotation. In places the anorthosite exhibits rosette texture, with the rosettes being relatively opx-rich patches. The anorthosite seems to be a plagioclase cumulate containing irregular amounts of intercumulus orthopyroxene in patches which have been drawn out by magmatic flow into elongated schlieren. The rocks are not mechanically deformed and the flowage must have taken place prior to complete crystallization of the intercumulus material. Note absence of garnet. If the anorthosite is domed shaped the strain associated with diapiric movement must have largely been accomodated in the mangerites of the southern margin.
Stop 4a km 88.6 Exit from freeway; outcrops on the north side of the road two-thirds up the ramp. Good example of intercumulate textured anorthosite and of the presence of xenoliths, amphibole with albite rims, and amphibolite xenoliths.
Stop 4b. km 88.8 Gabbroic anorthosite cumulates. This stop is located on the north side of the freeway north of St. Agathe just beyond the overpass where the freeway merges with the old road out of St. Agathe. Leave the freeway and park on the east side of the overpass. Can see oriented opx-bearing cumulates. Crystallisation sequence is opx-plagioclase, perhaps reflecting the more mafic composition of the Ti and P rich jotunitic immiscible fraction. The south end of the outcrop contains a vein of ilmenite rich material.
Stop 5. mangerite (near sharp bend to right in the highway); note presence of xenoliths and the oriented K-feldspar laths (top of the outcrop); good illustration that plagioclase weathers more easily than K-feldspar. There is narrow shear zone cutting the mangerite on the north side of the outcrop. Otherwise the mangerite is not deformed. High quartz content suggests it is a farsundite, not mangerite.
Stop 6. mylonitic basement gneiss at Labelle; note sillimanite and strongly flattened quartz aggregates. Fabric seems to be S rather than L. The outcrop just beyond Rue de l'Eglise at the north end of town contains thin units of blastomylonite (see Wynne Edwards guide).
Stop 7. marbles, amph-opx migmatites; biotite-garnet restites; quartzite; opx in mobilizates. From top to bottom of the hill the rocks exposed are highly deformed garnet biotite restites and quartzofeldspathic gneisses. The mafic migmatites and marbles, although deformed, are annealed (the pegmatitic patches in mafic migmatite contain large crystals of opx), and the boundary of the Labelle shear zone is therefore likely at the bottom of the hill.
Stop 8. Basement gneiss, before Lacoste; quarry on southwest side of road. The gneisses have a marked linear fabric. They are cut by undeformed veins of granite. Pegmatite bodies are however deformed.
Stop 9. Tourmaline quartzites and diopside-bearing calc-silicate
schists.
Day 6 Mont Laurier to Sudbury
Leave 7 a.m. Follow highway 117 to Lac Gatineau (about 11 km); then
take highway 107, (beware, turnoff is not well marked!!), to Maniwaki (41 km).
Travel south on 107 to Kazabazua, then take 301 to Campbell's Bay. Turn left
onto 148 and then after about 10 km turn right back onto 301 to Portage du Fort;
bear right onto 653, crossing the Ottawa river, to connect with Ontario Highway
17 (lunch in Deep River).
OR
DAY 6. Mont Laurier to Noranda
Grand Remous Bridge mile 42.5.
Stop 1. Biotite gabbro mile 44.6 optional.
Stop 2. Many new road exposures of marble now exposed on this section of the
road just after entering the Parc /† de Verenderye. The 'snakes' outcrop was
removed during road construction. Good exposures of pegmatite in marble at Km
279.
Stop 3. Lac Fauchard mile 178.3 Biotite restites; optional.
Stop 4. Lac a la Veille km 289.5 charnokitic gneiss with amphibole and lesser
opx; recumbent folds.
Stop 5. Lac des Fourches km 306 Aphebian gneisses of Doig j).
Stop 6. Lac Roland km 314 migmatitic gneisses with clinopyroxenite tectonic fish
and single grains of amphibole rimmed cpx in gneiss.
Lunch at old runway.
Stop 7. km 408 garnet gneiss with garnet biotite restite patches; quarry on
corner, east side of road.
Stop 8. McLauren Lake km 443 First mylonite zones; picnic spot.
Stop 9. Lac a La Puce km 445.5 kyanite schists.
Stop 10. Dumagami; turn north on route 395 towards Preissac (Yellow sign marked
Allison Project). Outcrops of Kewagama; tuffs with elutriation (not Bouma)
grading. At the Dumagami pond, note the coarse grading; the presence of exotic
clasts of felsic plutonic material; at the northwest corner of the pond there
are possibly aluminosilicate blasts; behind the mill shed are sediments with
good deformed flames in reworked ? tuffaceous turbiditic sediments.
DAY 7 Noranda area.
From the Hotel take Murdoch St. to 9th St. and 9th to Palais. Turn
left and continue to the triple junction of Palais, Terminous Ouest, and
Principal. Go west on Terminous Ouest to Dallaire. Then left (south) onto
Quebec. Continue south to Granada.
Stop 1. Grenada Cemetery . Outcrop V-10, p. 177-179, fig. 90 of Dimroth and
Rocheleau, unit T2 of Goulet, 1978. Subvertical beds of graded sandstone and
pelitic interbeds. Sedimentation units are continuous at the scale of the
outcrop, although some beds are lenticular. Bed thickness varies from a few
millimetres to about 1.5 m with an average of about 25 cm. Sandstones usually
show the Bouma 'a' division, and parallel lamination and large scale oblique
lamination in sets of 15-20 cm is not uncommon. It is also possible to observe
convolute lamination, slump structures, and erosion channels. From these
outcrops it is possible to walk west to the core of the Grenada syncline.
Stop 2. Outcrop V-11, p. 179, Fig. 90, of Dimroth and Rocheleau, T1 of Goulet,
1978. 1.2 km south of Grenada, east side of the road. Petromict conglomerate
containing magnetite pebbles. It is a lenticular unit, 1000 m. thick, within the
Pontiac Group, and is interpreted as a debris flow. Continue to T-Junction and
turn left. Also turn left at next T-junction.
Stop 3. Contact of conglomerates and Pontiac greywackes. Continue North; cross
railway track and topographic depresssion marking the Larder Lake Break.
Stop 4. Giant pillow lavas; tourmaline-bearing quartz veins, and Variolitic
lavas. Cross old road to see pillows, then descend to old road to see the
variolites. Continue down old road to meet' the bus. On Fig 88 of Dimroth and
Rocheleau, but not described by them.
Stop 5. Stadaconna breccia illustrating the Carlyle sequence (hyaloclastites).
Stop III-9, p. 136-137, Figs. 69-71 in Dimroth and Rocheleau.
Stop 6. Timiskaming fluviatile conglomerates at McWatters Travel east on highway
59 until you cross the railway track at McWatter's railway station. Take small
wood road on the north side of the tracks where they are crossed by highway 59.
Stop V-6 ,pages 169 - 173 and Figs. 86 and 87 of Dimroth and Rocheleau.
Stop 7. Amulet Mine. Travel north on highway 46 until you see Lake Dufault, turn
left onto mine road just before bridge over stream draining into the lake. Just
inside the mine property gate is the remains of Amulet A. Turn right at the
junction inside the gate to go to Amulet C. On the way note the columnar jointed
sill on the left. At Amulet C the ore is exposed at the contact of the Waite
rhyolite and the overlying Amulet pillow lavas dipping and younging to the
southeast. Retrace tracks to Amulet A, which is now an abandoned pit. Note the
well developed dalmatianite on the top edge of the pit.
DAY 8 Noranda to Kirkland Lake via Timmins.
Stop 1. Munroe Township komatiite; turn off highway where sign
indicates Potters Mine. Continue on road until you see some flat ground on your
left. There will be a road off to the left leading to the komatiite outcrop.
Stop 2. Timmins.
Falconbridge pit - gold in fractures in greywake turbidite and conglomerate in
an incompetent succession of shales.
Buffalo ankerite pit.
DAY 9 Kirkland Lake to Sudbury or Whitefish Falls.
Stop 1. Don Lou Motel section. Stop13, p. 105 GAC-MAC Field trip 4 by
Owsiacki and Lovell, 1984). Behind the hotel are outcrops of trachyte and augite
syenite cut by syenite and syenite porphyry. Augite syenite intrudes bedded
trachyte tuff and is intruded by resistant syenite porphyry dikes. At the south
end are pink trachytic agglomerate/conglomerate containing fragments of
intrusive material.
Stop 2. Take highway 66 back to highway 11; go north a short distance and take
next right to the old railway station. Walk westwards carefully along the rail
track. Outcrops of Timiskaming conglomerate with a large variety of clasts. At
the end of outcrop are sandstones with cross-beds.
Stop 3. Vigras Lake. Contact of polysutured basaltic komatiite and tholeiite
pillows. Fig. 9 of Jensen 1978; stop F on fig. 4; description on page 246. The
outcrops are located just west of where a pylon line crosses highway 66 about 5
km east of junction with highway 11 travelling back towards Kirkland Lake.
Stop 4. Misema River. See page 239 of Jensen 1978; note the greenish colour of
the carbonates; rocks were supposedly originally spinifex-textured komatiite
(see top of the exposure), but were also the type locality for exhalatiuve gold
bearing carbonates.
Stop 5. Gold bearing carbonate. optional
Stop 6. Carbonated komatiitic breccia. optional
Stop 7. 624 Bend. Description in Jensen 1978. p. 239 - 243.
Stop 8. Timiskaming cross bedded sandstones, Dixon Creek; Stop 3 on Fig. 4, p.
30, optional
Stop 9 Cobalt silver mines
Stop 10. Basal Gowganda Conglomerate, on highway 558 from Haileybury to highway
11; Fig. 4, p. 30.
Stop 11. Iron Formation, Timagemi; Fig. 5., p. 30; note graded tuffs indicating
younging to north, south end of outcrop, east side of the road.
Stop 12. Gowganda - Timiskaming conglomerates, Timagemi, Fig.5, p.30; quarry on
the east side of highway 11 just south of the lake at Timagemi exposes small
syncline of Gowganda overlying crudely bedded conglomerate (Timiskaming?).
Stop 13. Archean granitoids; stop illustrates four intrusive units of the
batholith belt; youngest unit is K-feldspar bearing granite.
DAY 10. Sudbury region
If travelling from Whitefish Falls take the Timmins exit before
getting to Sudbury. This road will join 144 at Larchwood.
Stop 1. Windy Lake breccia.
Stop 2. Felsic norite - opx plag cpx biotite
Stop 3. Quartz gabbro. Is pinkish material K-feldspar or hematite plag
Stop 4. Granophyre - micrographic quartz-K-feldspar stands out on weathered
surfaces because plag weathers more than K-feldspar.
Stop 2. Grey Onaping and impact melt; basal Grey Onaping contains large
fragments. The impact melt area is marked with flags and orange paint.
Stop 3. Black Onaping; carbonaceous mud balls.
Stop 4. Chelmsford Sandstone (Note: take second exit left nearest to the railway
track, not the first exit evident when the overpass comes into view travelling
south.) 'Fossils' are water escape channels; although most apparent on bedding
surfaces, they transect the bedding.
Stop 5. Shatter cones at Balsam St. junction with Highway 17.
Stop 6. Excellent exposures of shatter cones in vertical road cut on south side
of the road about 100-200 metres west of the descent down to the entrance to
Laurentian University. The shatter cones are best seen in the evening with the
sun setting in the West.
Lunch.
Stop 8. Espanola road cut.
Stop 9. open folding south of Espanola.
Stop 10. shatter cones in open folded sandstones.
Stop 11. Plane Table Lake.
Return to Sudbury
DAY. 11 Grenville Front at Coniston
Stop 1. Cross bedded Mississagi and shatter cones.
Stop 2. Mylonites.
Stop 3. Ramsay Lake pebbly sandstone.
Stop 4. migmatites.
Stop 5. cascade folded gneisses.
DAY. 12 Wanapitei to Killarney
DAY. 13 Killarney to Parry Sound
Day 14. Parry Sound
Section from Parry sound Bypass road cut to Nobel Station
The rocks of the road cut should be examined walking from east to west from on
top on the north side of the cut.
Rocks at the east end of the cut are mylonites, whereas rocks at the west end
are garnet amphibolites variably retrograded to white spot amphibolites.
Retrogression is most obvious in shear zones, where the white spots are clearly
flattened. Retrogression is therefore likely syn-shearing. The rocks in the cut
are gabbroic anorthosites showing variable strain with a few shear pods of
clearly discernable igneous textured rock. Garnet is well developed in rocks
towards the north end of the section, following a part of the anorthosite with
shear pods exhibiting narrow rims of amphibole around orthopyroxene. Shear pods
of the protolith are better developed at the north end of the section. The
gneisses to the north of the gabbro are dominated by the presence of amphibolite
layers. The base of the thrust just north of the side road to Badger's Corners
north of the turn off onto Highway 124 is marked by highly sheared gneisses
containing large porphyroclasts of pegmatoid feldspar. Below the gneisses are
layered gneisses followed by sheared orthogneiss dated by Van Breemen at 1350
Ma.
Ages
Reset titanite 12 km S of Grenv F. Krogh 1989 t 982
Re-crystallized NW late shear zone near Gagnon, Krogh 1989 m 992
French River melt pods, Krogh 1989 z 995
French River late pegmatite z 1007
French River late pegmatite r 1016
New z in Algonquin granulite, van Breemen et al. 1986 z 1030+50
Coronitic metagabbro Davidson and van Breemen z 1047+5
Zircon overgrowths in French River gneiss z 1050
Monazite in French River quartzite, Krogh 1989 m 1062
CMB syntectonic peg., van Breemen and Hanmer 1986 z 1070-1030
Keweenawan 1120-1100
Pegmatite in discrete shear van Breemen et al. 1986 1160-1100
Abitibi diabase Krogh et al 1987 z 1140.6+_2
Pegmatite leucosomes Krogh and Wardle 1984 z 1150
Morin anorthosite 1159-1126
Boudinaged and foliated pegmatite, van Breemen et al 1986 z 1159
New z in Parry Sound granulite van Breemen et al 1988 z 1161
CMB granite, syenite and gabbro plutons, Easton 1986 z 1170-1080
Coronitic metagabbro baddeleyite Davidson & v Breemen 1988 b 1170+30
Elzevir plutons, Heaman et al. 1986 z 1226
Sudbury diabase Krogh et al 1987 z 1238+4
St. Charles anorthosite, Prevec and Baadsgaard 1991 z 1268+20
Grenv SGroup volcanics Silver and Lumbers 1966 1286+15
Nobel gneiss, Connare and McNutt 1985 r 1330
Parry Sound marginal orthogneis, van Breemen 1986 z 1346+69
Parry Sound anorthosite, van Breemen et al 1986 z 1350-1450
Cosby granite pegmatite z 1400-1429
Pegmatite cuts foliation in Killarney porphyry felsite 1400
Cosby granite, Lumbers 1975 z 1400
Muskoka granite, Krogh and Davis 1968 z 1414
McKellar gneiss, SE of Whitstone anorthos. van Breemen 1986 z 1425+75
Local melts S of Gren F, Krogh 1989 z tips and titanite tz 1453+7
Muskoka granite, Krogh et al. 1967 r 1465
Britt Domain granite, van Breemen et al. 1986 z 1456+8.5
Algonquin domain metaplutonic rock van Breemen 1986 z 1460+60
Metaplutonic, Lake Muskoka, Krogh et al. 1967 r 1470+10
Bell Lake granite, Van Breemen and Davidson 1988 z 1471+3
Deformed granite SW GFTZ Krogh and Wardle 1974 z 1550
Killarney Granite Wanless and Loveridge 1972 r 1625
Mattawa quartzite euhed. to rounded z (995 min) Krogh 1989 z 1687+20
French River Granite, Krogh and Davis 1972 r 1689
Beaverstone Bay qtzte zircon needles, Krogh 1989 z 1700
Johnnie Lake granite Krogh et al. 1971 z 1730-
Killarney porphyry Van Breemen and Davidson 1988 z 1732+7
Deformed granite SW GFTZ Krogh and Wardle 1974 z 1740
Killarney granite Van Breemen and Davidson 1988 z 1742+1.4
Detrital zircon in Fench River gneiss, Krogh 1989 z 1744+11
Beaverstone Bay qtzte euhedral detrital z, Krogh 1989 z Archean
(20 titanite plot on an Archean - 1062 line)
(22 km S of GF near Hagar, z and t plot on an Archean - 993 line)
French River quartzite, detrital z, Krogh 1989 z Archean
Melt pod 60 km south of GF S of Val d'Or, Krogh 1989 m Archean
b - baddeleyite; z zircon; r - rubidium; m - monazite; t - titanite
yr[1991] lc[Grenville, Parry Sound] sa[PS90.1] cm[Sample of garnet-cpx
metagabbro core in amphibolite outcropping on west side of road; first roadcut
after swampy ground on east side of the road north of Nobel Station (GR
17TNA700301). Outcrop shows zones of 'white dot' garnet regression, and
epidosite. ~The amphibolitic margin of the body is foliated, and is probably
related to the bulbous amphibolite mass within the gneisses outcropping on the
east side of the road. Note the presence of a low strain shear pod of migmatitic
gneiss at the southern upper margin of the amphibolite pod. The northern end of
the road cut displays spectacular flow folds.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2] cm[Samples from pegmatoid
metagabbro and country rocks located about 10 mkm south of Pointe de Baril,
1.4km south of Shawanaga road and .25km north of Ba Sah Gim road, on east side
of Highway 69. Country rocks are heterogeneously sheared garnet bearing (similar
to Archean garnet rich granulites of the Grenville Front area south of Wanapitei
and Parc de la Verendrye) migmatitic gneisses with shear pods. On the east side
of the road the gneisses contain a metagabbro shear pod with pegmatoidal patches
preserved in its core. All the rocks have annealed fabrics, including the highly
sheared laminated gneisses. The gneisses adjacent to the metagabbro are coarsely
recrystallized and have large feldspar porphyroblasts. They clearly have no
deformation fabric and it therefore seems possible that the metagabbro and the
underlying gneisses and amphibolite all form part of a shear pod. The metagabbro
is foliated at the south end of the outcrop; at the north end the gneisses take
on a marked foliation, and are then variably foliated with shear pods of less
deformed migmatitic gneiss. ] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.1] cm[least recrystallized
metagabbro; some garnet present; collected above lower contact, south end of the
outcrop.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.2] cm[as PS90.2.1 but garnet
coronas more evident.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.3] cm[recrystallized but
undeformed garnet metagabbro, south end of the outcrop.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.4] cm[deformed and recrystallized
metagabbro, south end of the outcrop.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.5] cm[more deformed garnet bearing
amphibolitic metagabbro.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.6] cm[deformed and garnet free
amphibolitic matagabbro, south contact of metagabbro and gneiss. Note presence
of yellowish brown mineral (scapolite, epidote).] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.7] cm[contact of metagabbro and
gneiss. Note coarse feldspar porphyoblasts grown at the contact. Collected near
centre of the outcrop.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.8] cm[same as 7.] bx[] dr[] ts[]
pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.9] cm[gneiss near the contact.
Specimen is coarsely recrystallized at the end nearest to the metagabbro.] bx[]
dr[] ts[] pts[]^
North end of the outcrop.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.10] cm[unfoliated gneiss from
shear pod at the north end of the metagabbro.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.11] cm[foliated margin of the
shear pod.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[PS90.2.12] cm[laminated gneiss, from
south end of outcrops on the west side of the road.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.1] cm[Core of a boudinaged
metagabbro layer in amphibolitic gneisses, roadcut west side road just south of
the Horseshoe Lake Road, and north of the Rock Garden Camp road, north of the
Reptile House, north of the junction with Highway 141. (See Geological Highway
Map of Southern Ontario) Polygonal crystals of green cpx can be seen with a hand
lens. Specimen also contains a single patch of garnet.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.2] cm[as 1 but foliation now
evident; green cpx is evident with a hand lens.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.3] cm[well foliated metagabbro] bx[]
dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.4] cm[slightly more foliated than
3.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.5] cm[foliated and banded; near
margin of the boudin.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.6] cm[a,b strongly foliated
metagabbro from outer margin ofthe boudin.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.7] cm[country rock biotitic
amphibolitic gneiss collected from the north end of the outcrop.] bx[] dr[] ts[]
pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[HS90.1.8] cm[country rock layered
biotitic amphibolitic gneiss collected from the north end of the outcrop; green
cpx apparent in one of the thin layers of mafic material.] bx[] dr[] ts[] pts[]^
yr[1991] lc[Grenville, Parry Sound] sa[GL90.1] cm[garnet-biotite bearing
metadiabase cutting calcsilicate marble. Road cut west side of road south of
Gibson Lake Road, about 2 km north of Crooked Bay road, north of Oaks
Restaurant, north of Six Mile Provincial Park. At south end of the outcrop on
the east side of the road the marble forms an 'breccia' foot sized rounded
fragments of calcsilicate rock. It superficially resembles an olistostrome. May
be the most northerly occurrence of Grenville marble.] bx[] dr[] ts[] pts[]