sign in sign up
<<
Home , Granitoid, Tonalite

Geochemical Character of the - Suite of the Tonalite- Complex, Deception Lake, Saskatchewan I

1 2 1 1 Chris T. Coolican , Kevin M Ansde/1 , Rob Kerrich , and Mel Stauffer

Coolican, C.T., Ansdell, K.M., Kerrich, R .. and Stauffer, M. (2000): Gcm:hemical character of the tonalite-trondhjemitc suite of the Tonalite-Migmatite Complex, Deception Lake, Saskatchewan; in Summary of Investigations 2000, Volume 2. Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2000-4.2.

Abstract understand the origin and emplacement of in the Davin Lake Complex of the Tonalite-Migmatite Deception lake straddles the boundary between the Complex. Their data was interpreted to indicate that Wathaman Batholith and the Tonalite-Migmatite the pink and white were derived from Complex in the Trans-Hudson Orogen. The focus ofth e metasedimentary and metavolcanic sources geochemical study is the tonalite-trondhjemite suite of respectively, and that they were emplaced in a suture the Tonalite-Migmatite Complex. At outcrop scale, zone along the southeast margin of the Wathaman cross-cutting relationships indicate that multiple Batholith. In contrast, Lewry et al. ( 1981) suggested tonalite phases have been emplaced which both pre­ that the contact is a defonned intrusive relationship. and posr-date the Wathaman Batholith. Although This project was initiated to improve the understanding similarities in mineralogy hinder correlation of of the Tonalite-Migmatite Complex by mapping a individual tonalite phases beyond the outcrop scale, it transect across the contact between the Wathaman is possible to subdivide them on geochemical Batholith and the Tonalite-Migmatite Complex at characteristics. Deception Lake. Using the structural constraints, geochemical analysis of the rocks will Geochemical characteristics ofthe tonalite­ provide significant information about th e origin and trondhjemite suite include high Al contents ( 14.1 to evolution of the TMC. 18.3 wt %}, high Sr (397 to 782 ppm), very low Rb/Sr ratio (0.029 to 0.092), low Y (< 15.47 ppm), negative This report will discuss preliminary results from Nb anomaly, LREE enrichment.fractionated HREE, samples collected at Deception Lake in the summer of and slight negative or positive Eu anomaly. Based on I 999 (Coolican et al. , 1999). differences in the magnitude of REE fractionation and Eu, Nh, Sr, and Ti anomalies.four groups oftonalite have been distinguished Overall, these geochemical characteristics are typical ofh igh-Al tonalite­ 2. General Geology trondhjemite- suites, characteristic of Deception Lake, in the northwest margin of the Trans­ Archean granitic gneiss terrains. They are interpreted Hudson Orogen, straddles the boundary between the to have crystallizedfrom derived from melting Wathaman Batholith and the Tonalite-Migmatite ofs ubducted oceanic crust. Complex (Figure 1). The TMC consists of a migmatitic supracrustal sequence that has been intruded by a tonalitic to trondhjemitic intrusive suite. The contact 1. Introduction between the WB and the TMC is marked by a zone of mainly granodioritic intrusions with increasing The fonnation of the Trans-Hudson Orogen (THO) is a pegmatitic and aplitic dikes towards the WB. The WB result of collisions between the Superior, Sask, and comprises mainly porphyritic to Hearne and juvenile terrains of the Reindeer granodiorite that crosscuts all the other intrusive rocks, Zone (Chiarenzelli et al. , 1996; Lewry and Collerson, representing the youngest intrusive unit recogni zed. 1990). Collisional processes occurring between the northern margin of the THO and the Archean Hearne Two ductile deformational events were distinguished. are poorly understood, and therefore more Early migmatization and deformation of the geological work is needed to unravel the history of this supracrustal rocks was followed by intrusion of the part of the Orogen. The relationships within the rocks tonalite-trondhjem ite suite and occurred during D1• The comprising the Tonalite-Migmatite Complex (TMC) dominant regional fabric, S 1, strikes southwest­ and the Wathaman Batholith (WB) are crucial to northcast and dips northwest, and is axial planar to interpreting the northern margin of the THO. minor F I folds. An Sc foliation strikes slightly oblique to S 1 and has a shallow westward dip. F2 fo lds, the Previous geochemical work by Clarke and Hendry dominant folds, are isoclinal to ti ght, recumbent to near ( 1993, 1994, 1995) in the Davin Lake area of the recumbent with hinge lines trending north-northwest to Tonalite-Migmatite Complex was undertaken to

I Funded by NS ERC LITHOPROBE Special Studies Gram; LITHOPRO BE Publication # 1196. 2 Department of Geological Sciences, University of Saskatchewan, 11 4 Science Place, Saskatoon. SK S7N 5E2.

86 Summa,y of Investigations 2()()(), Volume 2 Wathaman Batholith granitoids ( ~) Transition Zone granitoids

Tonalite-Migmatite Complex f.Z) Tonalite C) Migmatitic Supracrustals @°iI) Sample Location

~ Figure I - Simplified geological tnJJP of the eastern Deception Lake area showing the locations ofJith ogeochemical .famples (cellter of ellip.~e). north-northeast, and shallow northwest dipping axial relationships; these are highlighted by variations in planes. D~ fabrics continued to form during the defonnational fabric or grain size (Coolican et al., intrusion of the WB, which acquired weak to intense S2 1999). Generally, the older tonalite-trondhjemite foliation. Upper amphibolite grade metamorphic phases have a more intense S 1 foliation and smaller conditions were attained during 0 1 as indicated by the grain size (Figure 2), and the youngest phase is homblende- assemblage in pegmatitic tonalite. However, at outcrops with only volcanogen ic units, and folded (F 1) in situ tonalitic one tonalite phase, identification of the specific phase leucosomes in the supracrustal units. Tonalitic is impossible because of the similar lithologies of the leucosomc fo lded by F1, also indicates it was generated tonalite intrusives . This also makes it difficult to prior to the intrusion of the WB at ca. 1865 Ma (Ray extend individual phases beyond outcrop scale, and and Wanless, 1980; Van Schmus et al. , 1987; Bickford therefore it is li kely that more than three tonalite et al. , 1990; Meyer et al. , 1992). In addition, fol iated phases are present in the study area. Geochemically, amphibolite xenolith s within the WB indicate that a the have been subdivided into four groups considerable pre-Wathaman deformational event based on their trace element compositions, as discussed occurred. in the section.

Due to the similar lithologies of the tonalite intrusives, 3. of Intrusive Phases the following petrographic description is relative to all the tonalite phases. The tonalites are composed of a) Tonalite-Migmatite Complex qu artz (20 to 35%), plagioclase (An25•35 ; 45 to 65%), microcline (<5%), biotite (5 to 20%), and muscovite The earliest intrusive phases within the study area are (<2%); with accessory zircon, apatite and magnetite. the tonalite-trondhjemite suite of the TMC. At outcrop Alteration of plagioclase to sericite varies between scale, three phases can be distinguished by intrusive samples and ranges from slight alteration along grain

Saskatchewan Geological Survey 87 oriented microcline phenocrysts up to 5 cm long; locally the phenocrysts exhibit a weak fl ow alignment. Homblende-biotite-rich mafic xenoliths are most common, but pelitic to psammopelitic and tonalitic xenoliths also occur.

The g ranodiorites in the Wathaman Batholith are

composed of (20 to 30%), plagioclase (An2q 0 20 to 30%), microcline (35 to 45 %), biotite (5 to 15%), and muscovite (up to 2%); accessory include zircon, apatite, magnetite, and chlorite. Microcline varies from tine interstitia l grains to phenocrysts several centimetres lo ng th at commonly have inclus ions of plagioclase. biotite. and/or magnetite. Carlsbad twinning is common, as is Figure 2 - Intensely foliated tonalite crosscut by a massive, microperthite. Plagioclase grains are 0.5 to 3 mm long, coarser grained phase. and commonly altered to sericite along grain boundaries and fractures. Parallel orientation of biotitc boundaries to pervas ive throughout the crystal. is well developed. Biotite grains arc 0.2 to 2 mm long, Plagioclase grains are generally subhedral with well­ and commonly have pleochroic haloes; rarely, developed twin planes, and commonly contain muscovite occurs as intergrown microcrystalline fl akes inclusions of quartz, biotite, and accessory minerals. with biotite or along grain boundaries. Some grain s are fractured or bent, and grain size ranges up to 4 mm, with some samples coarser grained th an others. Quartz grains are anhedral, commonly 4. Geochemistry fractured, and 0.1 to 2 mm wide. Microcline is generally anhedral to subhedral, and occurs either as A total of 44 whole samples were crushed and grains up to 3 mm wide with inclusions o r as ground in agate, and analysed for majo r elements myrmekitic intergrowths with quartz. Biotite together with Rb, Sr, Y. Zr, N b, and Ba using X-ray commonly has a strong parallel orientation and may fluorescence spectrometry (XRF) at X-ray Assay show a second oblique cleavage; however, random Laboratories (Don Mills, Ontario). Twenty of these orientation also occurs. Biotite crystals are generally samples were th en analysed at the University of less than 2 mm in size; fine-grained muscovite is along Saskatchewan using inductively coupled plasma grain boundaries of some samples. emission mass spectrometry (lCP- MS) to obtain a complete set of trace element data including hi gh field b) Tonalite-Migmatitc Complex-Wathaman strength element (HFSE) and rare earth element (RE E) data. Batholith Contact Zone At the contact between the TMC and the WB is a zone Samples from the TMC and TMC-WB contact zone up to I km wide in which there are a variety of were initially selected given that the fi eld relationships intrusive phases ranging from tonalitic to granodioritic were most clearly understood. The remaining samples in composition. These intrusions are non-porphyritic, were selected to assure good geographic coverage of weakly foliated, and crosscut the strongly foliated the study area, and on the basis of sample quality. tonalite-trondhjem ite suite of the TMC. Representative samples from the WB were collected and analysed to allow local comparison with the The from the contact zone are composed samples fro m the TMC and TMC-WB contact zone (Table I). of quartz (20 to 30%), plagioclase (An2o.io 45 to 55%), microcline ( 15 to 25%), and bioti te ( IO to 15%); accessory phases include zircon, apatite, and/or The geochemistry of the Wathaman Batholith is well magnetite. The rocks are hypidiomorph ic granular, documented (Fumerton et al., 1984; Halden et al.. with alteration of plagioclase to sericite common, as is 1990; Meyer el al., 1992), and therefore the fo ll owing some degree of grain fracturing and warping of twin geochemica l discussion will focus on the tonalite­ lamellae. Quartz and plagioclase grains are up to 5 mm trondhjemite suite of the TMC. wide, but I to 3 mm is common. Microcline occurs as small interstitial grains and/or larger grain s up to 2 mm a) Major Element Geochemistry wide, commonly with plagioclase and biotitc inclusions. Biotite occurs in fl akes up to 3 mm long, As suggested by its name, the dominant rock type and exhibit either a moderate parallel orientation or are w ithin the T MC is tonalite; and trondhjemite is randomly oriented. subordinate, although granodiorite intrusives occur in th e WB-TMC contact zone. The dominantly tonalitic c) Wathaman Batholith nature of the intrusives is illustrated on the normative Ab-An-O r ternary diagram (Figure 3) by a cluster of The Wathaman Batholith comprises massive to samples w ithin the tonalite field; this al so demonstrates strongly foliated granodiorite to monzogranite. The the similarity of the various tonali te phases within the rocks are most commonly porphyritic with randomly

88 Summary of Investigations 2000. f'olume 2 Table I - Geochemical data ofrepr ew11tative sample.5from the Deception Lake area. TMC. Samples from the WB plot with in the field, clearly Samples Wl3 WU-T MC TMCGp I TMC (ip 2 TMC Gp 3 TMC Gp 4 separated from rocks of the TMC. 027 320 223 294A 189A 1898 S i0 2 (wt'Y.,j 72.5 69.l 73.S 68.8 70.9 63 .7 Selected elements for the Ti01 0 .296 0.261 0 .13 1 0.284 0.252 0.376 granitoids from the TMC and WB Al10 1 14. 1 15 .8 14.6 16.2 15.4 I 8.3 Fe 20 , 2.29 332 1.27 2.93 2.05 3.02 are plotted on Harker diagrams MnO 0.03 0 .05 0 0.02 0.01 0 .03 (F igure 4). Tonalite samples MgO 0.66 us 0.48 1.22 0.88 l.33 contain a narrow range of Si02 Cao 1.63 3.49 2 .8 3.53 3 .73 4 .76 between 65 to 75 wt %, and f-20 3.54 1.62 2.3 1 1.65 1.1 6 1.63 display a negative linear Nai O 4. 15 4 .29 4.18 4.87 4.49 5.21 relationship with Al 20,, MgO, P,Oi O. l 0 .09 0.04 0.07 0.09 0.42 Cao, Na,O, and TiO,. The K,0- LOI 0.75 0.7 0 .6 06 11 1.45 SiO, tren-d demonstrates an - Sum 100.3 100.2 100.3 100.3 100.3 100.4 extremely narrow range of K20 Rb (ppm) 99.87 15.08 14.59 14.34 24.77 32.99 in the TMC ranging from 1.5 to Sr 4 12.42 399.92 505.65 425.86 73 1.92 782. 72 2 wt %. WB have Cs 0.7 0.47 0.43 0.42 0.4 0.61 a range of SiO, contents from 70 Ba l 133.9 63638 2678.23 519 716.68 847.81 to 75 wt%, and can be Sc 5.44 8.22 175 4. 18 2.86 5.85 distinguished from the tonalites v 20.6 34.84 15.89 36 22.93 37. l by their higher K20 , and lower Ta 0.42 0.35 O.l 0.29 O I 0.25 CaO and Na20 concentrations. Nh 10. 16 5.08 3.22 8 3.59 7.86 Overall, the various phases of Zr 228.02 61.84 37.79 85 54.35 47.68 tonalite intrusions exhibit very I Ir 6.59 3.24 1.74 2.69 1.71 2.5 Th 23 02 2.76 14.51 6 07 0.33 0.87 similar major element L 1.87 0.39 0 .66 0.4 1 0 .15 0.42 compositions. y 12.36 5.11 3 .24 4 3.77 15.47 La 58. 76 5.56 42. 11 18 70 6.32 10.3 b) T race Element l'c 10753 22.86 114 .7 38.62 l l .05 24.32 Pr 11.66 1.6 11.36 4.2 1 1.26 2.99 Geochemistry Nd 39.95 6.55 42.24 15 .7 4.99 13 .73 Sm 6.41 1.68 7 06 2.75 0.97 3.6 Ra re Earth Elements Eu 0.78 0.46 lJ 0.85 0.95 I. I

Saskatchewan Geological Survey 89 2 0 2 The four tonalite/trondhjemite + groups were also plotted on primitive mantle normalized Oo x . 5 + multi-element plots (Figure 7). • x 00 x"" + As with the REE plots, the four + + ... x!•· groups generally have sim ilc1 r .. +"-Jr;* 1 t-i>zt ... t patterns, incl uding: (I) +• ... ~· fractionated pattern; (2) weak to + ib·. 0111 + 5 strong negative Nb, P, and Ti ~-1§1 t + anomalies; and (3) relatively 12 enriched Rb, Ba. K, and Sr. ' ' ... Overall, Group I tonalites have 0 0 0 + elevated Ba and Th, and stronger x X;+_.&t } <>x ... negative Nb, P, and T i relative to + 1t,! J'i • -".! . ,. + +"" .. + the other three groups. Groups 3 + + l- +),: + + - 4 +of ++ 111 Z, 0 0 and 4 have depleted Th contents o_ 0 relative to Groups I and 2, and 0 + z"' distinct negative Th anomalies. 0 0 0 Figure 8 shows multi-element plots for the TMC-WB contact zone and the Wathaman Batholith. These patterns are fJ generally similar to those of the TMC, displaying a negative 00 slope, negative Nb, P and Ti 5 0 + anomalies, and similar element + 4 0 +. ,. a abundances. Th and U ... + + ... 0 0 ¢>< ++-Mio + x 'n";.&.) + systematics are similar to those in ·~·~ • ... .1111 .. Groups I and 2 tonalites . . Granodiorites from the TMC- WB 0 0 contact zone have lower 60 70 75 10 ,o 65 70 '' 80 SiO, (wt%) SiO, (wt%) abundances in comparison to Figure 4 - Harker dit,grams for selected major elements. Symbol.r as in Figure 3. g ranodiorites from the WB.

or positive Eu anomalies and higher HREE abundances c) Petrogenetic and Tectonic Implications of th an the other groups. Tonalitesffrondhjemites As previously mentioned, three phases oftonalite were distinguished in the field, however, geochemical Classification analysis ofpegmatitic tonalite, the youngest of the three phases, was not attempted due to difficulty in Granito id rocks in this study have relatively high Na20 achieving sample homogeneity. The relative ages of (Na:z0>3.6; see Figure 3). metaluminous to slightly the four geochemical groups can partially be peraluminous character (Al-saturation index 0.95 to determined based on fi eld evidence. Intrusive 1.05), and < 1% normative corundum. These relationships indicate that Group 3 tonalite is older than characteristics are typical of I-type granitoids as Group 4, unfortunately samples comprising Group I defined by Chappell and White ( 1974) and Chappell and Group 2 are from outcrops with only one tonalite and Stephens ( 1988). phase, and therefore their relative age is uncertain . Further, sam~les from the TMC d isplay features typical The REE plots of two granodiorites from the TMC-WB of Archean high-Al trondhjemite-tonalite- (TTD) contact zone are displayed in Figure 6a. Sample 320 (Drummond and Defant, 1990; Drummond et al. . has a comparatively unfractionated pattern ((La/Yb)N = 1996) and TTG (trondhjemite-tonalit e-granodiorite) 5.7) relative to sample 478 ((La/Yb)" = 92), although (Martin. 1986, 1993) suites, including high A l contents both samples display LREE enrichment and only ( 14. 1 to 18.3 wt %), high Sr(397 to 782 ppm), very slig htly negative Eu anomalies. low Rb/Sr ratio (0.029 to 0.092), LREE enrichment ((La/Yb):-,, cc 7 to 265) with slight Eu anomalies, low Y Figure 6b also demonstrates the REE patterns of (< 15.47 ppm) and negative Nb anomalies. porphyritic granodiorite from the Watharnan Batholith. The two samples have similar fractionation trends Granitoid Source and Petrogenetic Processes ((La/Yb)r-; = 47 to 57) and abundances, and both samples have negative Eu anomalies. The high Al content in th e tonalite-trondhjemite su ite may have resulted from the removal of hornblende

9() Summary of lnwslif

100 extent, refractory garnet, hornblende, and --·------t ;~Tw1 have the opposite effect of plagioclase. The combined .. ~ --·---~-_j effects result in the weak Eu anomalies in Groups l , 2, and 4, and the minor positive Eu anomaly in Group 3. '~~ Refractory garnet can also explain the high Sr/Y ratio. ·------~ Sr behaves incompatibly during high-pressure partial melting of due to the instability of plagioclase; therefore, it will become concentrated in the melt (Drummond et al., 1996). Conversely, Y is strongly compatible with garnet and therefore is controlled by the presence of garnet in the residue. The combined effect of Sr concentration in the melt and Y concentration in the refractory garnet results in the high SrN ratio.

JO Multi-element plots (Figure 7) show clear negative Nb and Ti anomalies for all the tonalite/trondhjemites. Drummond and Defant ( I 990) postulate that retention of hornblende at the site of partial melting could account for these negative anomalies because of its strong affinity for Nb and Ti in siliceous melts. OI L·------~ ------Hornblende exclusion from the melt may also be the cause of the low to moderate K/Rb ratios because of

L=~===:---=::~:-=-~------·---- 10 I ______-~ -"----~-:~-~ =--- ·------·----==- T------.... -----...... --.. 2 o.1L ______·.::: "O La Cc P, Nd Sm Eu Gd Tb Dy llo Er 1·m Yb Lu Figure 5 - Chondrite normalized REE plots for ! 0.IL __ ------·------~ tonalitesltrondhjemites ofthe TMC. 000 1 -- --- . ....__ ratha~ao~/3atholith) from the melt either as a residual phase at the source, 1: or as a fractionation product (Barker and Arth, 1976; "' 100 \ - • , • -----1 ·•- 009A l Barker, 1979). Further, the metaluminous to slightly Cl'J I ' ------~::::::::~ ./·... ·-., .______------peraluminous character of these rocks indicates that 10 1------. ""-.. ------=--- . - -· hornblende is unlike ly to be the only refractory phase left at the source, because a basaltic parent with an I I- .. ____ ------~ ::~::_-: exclusively homblendic refractory residue would form strongly peraluminous magmas (Holloway and 0 1 i ---- · ------·- Burnham, 1972; Drummond and Defant, 1990). L, Cc r, Nd Sm l:.u Gd Th l)y llo f r Tm Yb Lu Figure 6 - Cho11drite normalized REE plots for the TMC­ WB contact z.one and Wathaman Batholith.

Saskatchewan Geological Survey 9/ characteristic of arc environments. They display very Group a;;~ similar characteristics to high-Al TTD granitoids that are interpreted to crystallize from magmas derived by -108A J. _____;__, ..._ :: ::;_ _ melting of subducted oceanic crust, resulting in a hornblende eclogite residue. This conclusion has implications for the model for the tectonic evolution of 10 the northwestern margin of the THO. Further refinement of this model will come with a better understanding of absolute age relationships. I·---

5. Summary 0.1 '------'------I) In the Deception Lake area, the earliest intrusive GrnupT,;,J phase in the Tonalite-Migmatite Complex is the -- 294A tonalite-trondhjemite suite. At outcrop scale, three ______, -- 652 100 phases oftonalite were identified, however, the -ij28 similarity of these phases make it difficult to correlate them across the area. 2) Chondrite nonnalized REE patterns for the tonalite-trondhjemite rocks of the TMC are

~ coherent, with enriched LREE, fractionated i:.. HREE, and only slightly negative or positive Eu ~ anomalies. These intrusive rocks were subdivided ..> into four chemical groups based on distinct ·.::s - - - --·--··- differences in magnitude of fractionation and 'i: ····------···· ·-· anomalies displayed in their trace element 1:1... 10001 · [Group Tl rcc geochemical patterns. Q. . - OISA "E - 189A 3) The tonalite-trondhjemite rocks of the TMC 100 en.. ------~ 227 display very similar characteristics to high-Al - 662 ' - 680A TID/TTG described by Martin (l 986, 1993), ~ 7408 Drummond and Defant ( 1990), and Drummond er 10

' WB-TMC.contact .zone( · +- 320 ·~1 ...... j<:'~~~ Fou,l

]·it 0~~-L··~-- .. ·= 0.1 v--- '-.. :§ 1000 11·- ·-··-- ·- ---. ·. - -~ i r:~an Bath~lithj o.1 L .. _ _ .. __ ___~ -·- ---- .. _ ___ ~ 1001---+-+---~" ~ ~ - o ~•n u Km u~ ~ ~P ITT b~h TITo ~Y n Figure 7 - Primitive mantle normalized multi-element plots for tonalites/trondhjemites ofthe TMC. Normalizing values ~ ~£~~:- ··- ·· after Sun and McDonough (1989). '" ~--,..... the preference of hornblende to accommodate K !·-·- · · - .. __ ~ ~ ;- relative to Rb (Arth and Hanson, 1975). I OIL ______,..~ .. ---·--- ·-~ Tectonic Implications C:• Rb Bo Th lJ K " b I.a Cc St Nd r Hf Zr Sin Eu Ti Th Dy Y Yb Figure 8 - Primitive mantle normalized multi-element ptors The tonalite-trondhjemite rocks of the TMC are I-type for TMC-WB contact zone. Normalizing values after Sun granitoids, and have a trace element profile and McDonough (/989).

92 Summary of In vestigations 2000, Vo lume 2 al. . ( 1996 ). The rocks were fo rmed in an arc Hajnal, Z. and Lewry, J.F. (eds.), LITHOPROBE environment, and are interpreted to have . Rep. 34, p 179-1 8 1. crystallized from magmas derived by meltmg of subducted oceanic crust. ( 1994): Petrochemical and struct~ral evidence for the origin of granitoid rocks m the Rottenstone Domain; in Hajnal, Z. and Lewry, J.F. 6. Acknowledgments (eds.), LITHOPROBE Rep. 38, pl88-195.

The project was funded by an NSERC LIT':IO~R(?BE ( 1995): Petrogenetic and tectonic Special Studies Grant. 1:hanks are due _to Q ianh Xie for - -s~ig-n~i=fi-cance of and granites in ~he. assistance with preparation and analysts of . . . Davin Lake area of the Ronenstone Domam; m geochemical sa1'!1plcs, an.ct ~ Jaine Novakovsk1 for thm Hajnal. Z. and Lewry, J.f. (eds.), LITHOPROBE section preparation. Log1st1cal support for field work Rep. 48, pl04-1 IO. from the Geolog ical Survey of Canada and . Saskatchewan Energy and Mines, and th~ assistance of Coolican, C.T., Ansdell, K.M., Stauffer, M.R. , and David Corri gan and Bill Slimmon in particular was Kerrich, R. ( 1999): Geology of the Tonalite­ oreatly appreciated. Thanks to Erm Chorney for her Migmatite Complex, Deception Lake: . ~aluable field assistance throughout the summe~. I ~lso Saskatchewan; in Summary of lnvest1gat1ons thank Charlie Harper and Gary Delaney for review mg 1999, Volume 2, Saskatchewan Geological th e manuscript. Survey, Sask. Energy Mines, Misc. Rep. 99-4.2, pl96-201. 7. References Defant, M.J ., Drummond, M.S., Arthur, J.D., and Ragland, P.C. ( 1988): An example of trondhjemite Arth, J.G. and Hanson, G.N. (1975): Geochemistry and petrogenesis: The Blakes Ferry pluton, Alabama, orioin of th e early Precambrian crust of U.S.A.; Lithos. v21 , pl61-181. northeastern Minnesota; Geochim. Cosmochirn. Acta, v39. p325-362. Drummond, M.S. and Defant, M.J. (1990): A model for trondhjemite-tonalite-dacite genesis and crustal Barker, F. and Arth, J.G. (1 976): Generation of growth via slab melting: Archean to modem trondhjemitic-tonalitic liquids and Archean comparisons; J. Geophys. Res., v95, p2 I ,503- bimodal trondhjemite-basalt suites; Geo\., v4, 2 1,521. p596-600. Drummond, M.S., Defant, M.J., and Kepezhinskas, Barker, F. ( 1979): Trondhjemite: Definition, P.K. ( 1996): Petrogenesis of slab-derived environment and hypothesis of ori gin; in trondhj em ite-tonalite-dacite/adak ite magmas, Trondhjemites, and Related Rocks; Trans. Roy. Soc. Edin. Earth Sci., v87, p205-2 l 5. Elsevier, Amsterdam, 356p. Fumerton, S.L., Stauffer, M.R., and Lewry, J.F. Bickford, M.E., Collerson, K.D., Lewry, J.F., Van ( 1984 ): The Wathaman Batho lith: La:gest known Sch mu s, W.R., and Chiarenzelli, J.R. ( 1990): Precambrian pluton; Can. J. Earth Set., v2 l, Proterozoic collisional tectonism in the Trans­ pl082- l097. Hudson Orogen, Saskatchewan; Geo!., v 18, p I 4- 18. Gromet, P.L. and Silver, L.T. ( 1987): REE variations across the Peninsular Ranges Batholiths; Chappell , B. W. and Stephens? W. E. ( 1988): Origin of implications for batholithic petrogenesis and infracrustal ( I-type) granite Magmas; Trans. Roy. crustal growth in magmatic arcs; J. Petrol., v28, Soc. Edin. Earth Sci., v79, p2-3. p75-125.

Chappell, B.W. and White, A.J .R. ( 1974): Two Halden, N.M., Clark, G.S., Corkery, M.T.. Lenton, contrasti ng granite types; Pac. Geo!., v8, p I 73- P.G., and Schledewitz, D.C . ( 1990): Trace-element 174. and Rb-Sr whole-rock isotopic constraints on the origin of the Chipewyan, Thorsteinson, and Chiarcnzelli, J.R. , Aspler, L. B., and Villeneuve, M. Baldock batholiths. Churchill Province, Manitoba; ( 1996 ): Characterization, origin, and in Lewry, J. F. and Stauffer, M.R. (eds.), The Early Paleoproterozoic history of the Saskatchewan Proterozoic Trans-Hudson Orogen of North craton and possible implications fo r the Trans­ America, Geol. Assoc. Can., Spec. Pap. 37, p201- Hudson Orogen; in Hajnal, Z. and Lewry, J.F. 2 14 . (eds.), LITHOPROBE Trans-Hudson O rogen Transect, Rep. 55, p26-38. Holloway, J.R. and Burnham. C. W. ( 1972): Melting relations of basalt with equilibrium water pressure Clarke, D.B. and Henry, A.S. (1993): Petrological and less than total pressure; J. Petrol., vl3, pl-29. geochemical in vesti gations in the Mig1:1atite­ Tonalite Belt of the Rottenstone Domam; in Lewry, J.F., Stauffer, M.R .• an_d ~umert~n, S. (1981):. A Cordilleran-type bathohth1c belt m the Churchill

Saskatchewan Geolog ical Survey 93 province in northern Saskatchewan; Precamb. Resear., v14, p277-313.

Lewry, J.F. and Collerson, K.D. (1990): The Trans­ Hudson Orogen: Extent, subdivision, and problems; in Lewry, J.F. and Stauffer, M.R. (eds.), The Early Proterozoic Trans-Hudson Orogen of North America, Geol. Assoc. Can., Spec. Pap. 37, pl-14.

Martin, H. ( I 986): Effects of steeper Archean geothennal gradient on geochemistry of subduction-zone magmas; Geo I., v 14, p753-756.

- ~ - ~(1993): The mechanism ofpetrogenesis of the Archean continental crust: Comparison with modern processes; Lithos, v30, p373-388.

Meyer, M.T., Bickford, M.E., and Lewry, J.F. ( 1992): The Wathaman Batholith: An early Proterozoic in the Trans-Hudson orogenic belt, Canada; Geol. Soc. Amer. Bull., v104, pl 073- 1085.

Ray, G.E. and Wanless, R.K. (1980): The age and geological history of the Wollaston, Peter Lake, and Rottenstone domains in northern Saskatchewan; Can. J. Earth Sci., vl7, p333-347.

Sun, S. and McDonough, W.F. ( 1989): Chemical and isotopic systematics of oceanic : Implications for mantle composition and processes; in Saunders, A.D. and Norry, M.J. (eds.), Magmatism in the Ocean Basins, Geol. Soc. Spec. Publ. 42, p3 I 3-345.

Van Schmus, W.R., Bickford, M.E., Lewry, J.F., and Macdonald, R. ( 1987): U- Pb geochronology in the Trans-Hudson Orogen, northern Saskatchewan, Canada; Can. J. Earth Sci., v24, p407-424.

94 Summary of Investigations 2000, l 'o/11me 2