Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5155
EASTING 574204 NORTHING 6049562 ZONE 14 DATUM NAD83
Date of mapping 07/20/1983

STRUCTURAL DATA

Layering:
Layering type | Strike | Dip | top Direction
igneous cumulous layering | 320 | 77 |

PETROLOGIC DATA

Rock Number: 1

Rock Type: pegmatitc granite
Field Description:

-C.R. Mc Gregor
-Adamellite Study
-layering is adamelite on reef 320/77
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SEE 5155 ROCK 2 for all relavent DATA

Rock Number: 2

Rock Type: pegmatitc granite
Field Description:

0 - 15 m
-very gradational contact between granite and pegmatite; morelike assimilation pegmatite is all over the area but no strong direction with granite is seen. Granite is leucogranite in which the muscovite show strong preferred orientation at 241 degrees.
Abundant garnets around 20 % . They are also concentrated along the muscovite orientaton and are finer-grained that the others away from the clusters of muscovite flakes.
Localized pegmatite veins at 241 degrees that is composed of coarse grained toumaline, muscovite feldspars (no garnets 10 cm wide). The one that are heavily composed of tourmaline(ie around 50 %) have no garnets; others that have smaller amounts of tourmaline (10 to 20 %) have garnets including the ones that have garnets within the tourmaline.
Also, have assimilation of country rocks within both granite and pegmatites. Some sharp contact is seen between pegs and granites. Pegs have very little garnets.
15 m - 30 m
-Abundant peg veins intruding metasediments (greywackes) of various widths (10cm to 1 m wide) striking 270 degrees
30 - 45 m (SAMPLE #1)
-abundant peg. veins intruding meta sediments (greywackes some have abundant feldspar fragments of even sizes) large peg. vein at edge (10 m) at shoreline then metasediments true north 70 m. till get peg. veins (1 m wide or more)-abundant and of various widths but are folded along the general direction of 270 degrees.
Also have granite (sample #1)
Abundant garnets (around 25 %) fine - grained, ab. toumaline in localized areas
45 - 60 m (SAMPLE #2)
-There seems to be some kind of characteristic here where the peg that is largely within the greywackes is extremely coarse grained and massive whereas going north (true north) across the strike is peg that are a mixture of coarse and fine grained-granite-massve one has ab booklets?? of primary muscovite and some large tourmaline crystals whereas the other has secondary muscovite and abundant smaller tourmaline crystals whereas the other has secondary muscovite and abundant smaller tourmaline crystals, 10 m north of shoreline is greywacke with an occassional peg. veins and north of that is the granite. There is a localized peg. 2 m wide within the finer grained variety that contains primary musc. and some tourmaline crystals (sharp contact between coarse and granite, coarse gr. running in same direction as he muscovite in fine grained.)
60 - 75 m (SAMPLE #3)
-very coarse grained peg. veins 1 - 2 metres wide near shoreline and going north 35 m to get into granite veins that have also muscovite (fine gr.) orientated 270 degrees. Country rock assimilated by granitic variety. Both types of veins follow the foliation of country rock but some small veins are also folded. Garnets in fine grained around 15 % (extremly fine grained) with some tour crystals (around 5 %).
75-90 m
-Similar as previous station; north peg. has localized larger peg. associated with grainte-gradational contact. Large coarse. gr. peg. vein stops here. In finer grained variety both coars and fine grained have around 15 % very fine - grained garnets with some tour that are sometimes concentrated into veinlets of tour and garnets have gradational contact with peg. containing primary musc and coarse gr. tour (some) with finer grained matierial)
90-105 m (SAMPLE #4)
-North peg. ass. with fine- gr. "granite" which is largely foliated as shown from the stron musc. orientation at 270 degrees and containing around 15 % very fine grained garnets although some are med. gr. and containing some tour crystals. Peg. contain around 1 % garnets and around 5 % tour. South Peg. in eye-shaped pods-1m long and .5 m wide and in largely country rocks.
105-120 m (SAMPLE #5)
-Largly strongly foliated greywackes with thin veinlets and pods of granites. South peg. small pods 3 m long .5 m wide and phasing out. Some grass-green apatites here, contains primary musc, feld, some tour, and some garnets that are coarser-gr. than those in granites. Granites contain around 10 % very fine grained garnets plus around 5 % tour. South peg. veins not as strongly folded as those of granites.
120-135 m (SAMPLE #6)
-Largely strongly foliated greywackes with thin to fairly wide veins of medium grained granites that are localized pegmatites especially in cores of veins (gradational contact with granites) tour around 5% and garnets around 10 % both are coarser grained in localized areas that in the finer grained areas. Localized pegs. don't have musc. strongly foliated like the granites. South pegmatite is pinching out (contain booklet musc.)
135-150 m
-largely strongly foliated greywackes with thin veins 10 cm to .25 m wide that are folded, localized pegmatitic with granite around 10 % very fine grained garnets and 5 % tour.
150-165 m (SAMPLE #7)
-largely strongly foliated greywackes with few very thin veinlets of granites with around 10 % garnets around 5 % tour except for a large coarse grained granitic vein at water edge.
165-180 m
-largly strongly foliated greywackes with few thin veinlets of granites with >1% garnets and >5% tourmaline
180-195 m (SAMPLE #8)
-35 m, (starting at 180 m), from shoreline greywackes with thin veinlets of granites. North thicker veins that have muscovite showing preferred orientation along the foliation of greywackes 260 degree. Veins range from .5 m wide to 10 m. wide. Granites have around 5% garnets (fine gr.) and 15 % tour. (fine-to coarse gr.). Localized areas within granite veins are pegmatitic with large prismatic tourm. along with feld+quartz+>1% garnets. Tourm. in fine gr. show same orientation as micas but those in peg. areas show random orientation.
195-210 m
-(moved line around 50 m north because shoreline is north) South is greywackes with veins of granites (thin) that may be localized pegmatitic and tourmalization. North is peg and granites similar to previous station, around 2 m wide peg. vein between country rock south and granite in north fairly sharp contact between granite and peg., granite has localized pegmatite veins. Peg. has primary musc. booklets. Around 15 to 20 % tourm. and 5% garnets in granite (garnets are slightly coarser-grained the earlier stations).
210-225 (SAMPLE #9)
-assimilation of country rocks by peg., south shore country rock phased out slighlty sharp to gradational contact between granite and peg. 10% garnets (coarser gr. than before). Thin peg. vein within granite in between thin layers of country rock.
225-240 m
-Largely peg. (some grassy green apatites in peg) with some granites. Fairly sharp to gradational contact between granites and pegmatites. Peg. tend to show some fine gr. granite, especially at contact of country rock inclusions (same strike 270 degrees). Granite and peg. not clear cut. Garnet in granite around 10 %, tour. around 10 %.
240-255 m
-Almost all peg. with some recrystalization?? and some country rock inclusions have both musc. flakes and booklets. Flakes show strong orientation, booklets random orientation.
255-270 m
-country rock around 3 m. wide then peg. and granite. Sharp contact between granite and peg. since granite shows strong musc. orientation and peg show thin booklets of random orientation. The peg. seems to interfinger into the granite or vice versa. Both granite and peg. orientated 270 degrees and show minor folding.
270-285 m (SAMPLE #10)
-Largely strongly foliated granites with inter fingering of peg. all striking 290 degrees (sharp contact). There seems to be a peg. vein 10 cm wide that is crosscutting the granite (288 degrees) although the mica flakes in granites tend to reorientate themselves to the new strike. Also, garnet in granite are slightly coarser grained than before, amount of garnet is around 15 %.
285-305 m
-largely peg. with some country rock inclusions and granites . Granite appears to be interfingering the peg. (sharp contacts). Right at 305 m mark towards the marsh there is some suggestion that both granite and peg are cross cutting the strike at 292 degrees, probably some minor folding.
305-320 m (SAMPLE #11)
-largely strongly foliated granites with peg. interfingering both strike at 246 degrees and sharp contacts. Garnet content around 15 % and tourmaline around 10 % in granites. There is one minor peg. vein (around 10 cm wide) that is cross cutting both granite and peg. veins at 12 degrees and is slightly folded.
320-335 m.
-largely strongly foliated granites with peg. veins (1 to 3 m. wide). Garnets around 15 %, tourm. around 5%. Both granite and peg. strike 254 degrees, sharp contacts between the two
335-350 m.
-strongly foliated granite at 260 degrees. Pegs, blebs, and small veins crosscutting foliation at general direction 340 to 354 degrees. One large peg vein 1 m wide cut granite at 354 degrees. All have sharp contacts with granites. Peg. also folded but granite does not foliate with peg. Garnets around 5% and tourmaline around 5 %
350-365 m
-strongly foliated granite at 260 degrees. AB peg. veins 10 cm to 1 m wide crosscutting each other and granites and are slightly folded. Two general directions of peg veins 16 and 306 degrees, however there are no main or wide peg. veins cutting another wide peg. Garnet around 5% and tourm. around 5%.
365-380 m (SAMPLE #12)
-strongly foliated granite at 260 degrees with abundant peg. veins crosscutting each other at general directions of 40 degrees and 260 degrees and are slightly folded. Garnet around 5 % and tourm. around 5%.
380-395 m
-foliated granite at 260 degrees with ab. peg veins similar to last station
-also some granites are folded
-one shows a fold with trough pointing south, ie see field notes for a brief diagram
-also minor peg. (around 10 cm) vein cutting both gr. and other peg. at 360 degrees
-foliation of gran. does not change with intrusion of peg. and even when folded
-Garnet (around 5%)
-Tourm (around 5%)
-tourm larger than garnet (size of garnet constant so far)
395-415 m
-foliated granite (260 degrees) with several small peg. veins including one larg one (around 6 metres wide)
-all striking at 260 degrees
-Garnet around 5%
-Tourm around 5%
415-430 m (SAMPLE #13)
-starting to turn west
-fol. granite (260 degrees) with several small peg. veins all striking 260 degrees except for those that crosscut the gr. and peg. at 40 degrees and in some cases form minor folds amoung the granite in the same way as the drawing, from previous, is about
-garnet around 5% and tourmaline around 5% and both are coarser than before
430-450 m (SAMPLE #14)
-foliation granite (260 degrees) with small peg. veins running at 3 directions 260, 110, 170 degrees all cutting each other (sharp contacts)
-one large (1 m. wide) peg. vein cut gran. at 170 degreesl
-garnet and tourm. > 5% and are finer grained
450-465 m
-largely fol. granite at 270 degrees with few peg. veins running in 2 general directions 260 + 160 degrees
-garnet and tourm. > 5% and are finer grained
465-480 m
-largely fol. gran. at 260 degrees with few peg. veins running in the general direction of 278 degrees
-garnet and tourmaline around 5% and are coarser grained
480-538 m
-grass, no outcrop
538-545 m (SAMPLE #15)
-strongly fol. gran. at 260 degrees with few pegmatitic blobs and veins running in the general direction of 280 degrees
-garnet and tourmaline > 5% and finer grained
***********
0-73 m
-grass, no outcrop
73-88 m
-strongly foliated gran. at 260 degrees with a few small peg. blobs and veins (one run at 144 degrees) part of gran. has a tendency to have coarser grained clusters of muscovite booklets at the general strike direction of 260 degrees
-garnet coarse grained and tourm. >5%
88-103 m (SAMPLE #16)
-strongly foliated granite at 260 degree with a few peg. veins (one runs at 210 degrees)
-muscovite tends to be in clusters
-coarse grained garnet >5%, very little tourmaline
103-118 m
-not as strongly foliated gran. at 270 degrees with one small peg. vein cross cutting at 170 degrees
-coarse grained gar >5%, very little tourmaline except in some peg.
118-133 m (SAMPLE #17)
-similar to previous station fol. at 270 degrees, no peg. veins
-coarse grained Gar. >5%, very little tourmaline
133-148
-largely strongly foliated (at 260 degrees) granite with around 5% garnets (coarse grained) and very little tourmaline
-few peg. veins (.5 to 1 m) wide running in the general direction of 160 and also folded along the foliation, sharp contact with gran.
148-163 m (swing to 280 degrees)
-largely strongly fol. granite (at 260 degrees) with around 5% garnet
-few peg. veins (more numerous then in previous station) running in two general directions 290 and 170 degrees (the ones running (100 m) at 170 degrees are generally much thicker (1 m) than the ones that are running in the other direction)
-those that are at 290 degrees are folded (slightly) along the fol. of country rocks mere so than those at 170 degrees
163-198 m
-grass
198-213 m (SAMPLE #18)
-largly strongly fol. granite (at 230 degrees) with slightly coarse grained (than previous station) garnet >5%, no tourm.
-no peg.
-gran. shows slight banding of (yellowish white) light and slightly darker (light grey) bands (Alteration products(?))
in same direction as foliation
213-228 m
-around 40 % outcrop
-strongly foliated granite at 240 degrees with few peg. veins (around 10 cm) running in general direction of 170 degrees
-garnet >5% and coarse grained (tourm. in peg. veins)
228-243 m
-strongly fol. granite at 260 degrees with few peg. veins (around 10 cm) plus one larger one (around 1 m. wide) running in a general direction of 170 degrees
-granite slightly banded (as previous) in same direction as foliation
-Garnet >5% and coarse grained
-sharp contact between gran. and peg. but becomes gradational towards shoreline
243-258 m (SAMPLE #19)
-strongly foliated granite at 260 degrees with a few peg. veins (around 100 cm) running in general direction of 170 degrees
-(peg tends to develope sharp contact with gran. but sometimes send out feeds that oare gradational with granites)
-garnet >5% and coarse grained
258-273 m
-strongly foliated granl. at 240 degrees with 2 fairly wide veins (around .5 m wide) at 140 and 170 degrees
-sharp contact but tends to send out feeders which become more or less gradational towards north with granites
-garnet 1% and coarse grained
273-288 m
-strongly foliated granite at 260 degrees with one small peg. vein running at 260 degrees
-(size of peg. not determined because it is largely eroded away)
-garnet 1%
288-303 m
-strongly foliated gran. at 260 degrees with no peg. veins
-garnet 1%
303-318 m (SAMPLE #20)
-gran. not as strongly fol. as before and in general directions of 260 degrees
-one small peg. vein around 10 cm and cuts granite at 150 degrees
-garnet 1% and finer grained
318-333 m
-gr. (same as previous station) fol. in 260 degrees
-no peg. veins
-gar 1% and coarser grained
333-348 m
-mod. fol. granite (260 degrees)
-peg. veins (around .5 m. wide) cutting granite at 160, 190, 200 degrees are also folded along the granite foliation
-garnet 1% finer grained
348-363 m (110 degrees into swamp)
-mod. fol. granite (260 degrees)
-no peg. veins
-20 % outcrop
-little garnet
363-378 m (210 degrees)
-30% outcrop
-mod. fol. gran. (240 degrees)
-gar. 1% coarser grained
-one small peg. vein at 140 degrees (around 10 cm wide)
378-393 m (SAMPLE # 21)
-mod. fol. gran. (260 degrees)
-no peg. veins
-garnet >1%
393-408 m.
-mod. fol. gran. (260 degrees)
-no peg. veins
-gar >1%
408-540 m
-grassy marsh
540 - 547
-mod fol gran (260 degrees)
-abundant peg. veins that show both mostly gradational and sharp contact
-sharp contact along 170 degrees, also some along 260 degrees
-garnet around 15% coarse and finer grained
ALL GRASS ----->
-no tourmilzation with country rock
-mineralogy: KF, QZ, Albite, tourm, garnet, grass-green apatite
-largely KF, albite and quartz (blocky KF and Albite)
-garnets generally very fine grained and commonly occur as clusters
-tourmaline variable in amount and texture
-apatite is rare
-pegs are generally of uniform widths (around .5 m) and are folded and slightly sheared
-thin veins are tourmalized

Manitoba Geological Survey, 2017