GS-15 Sayisi Dene Mapping Initiative, Tadoule Lake area, Manitoba (part of NTS 64J9, 10, 15, 16) by L.A. Murphy and A.R. Carlson Murphy, L.A. and Carlson, A.R. 2009: Sayisi Dene Mapping Initiative, Tadoule Lake area, Manitoba (part of NTS 64J9, 10, 15, 16); in Report of Activities 2009, Manitoba Innovation, Energy and Mines, Manitoba Geological Survey, p. 154–159. Summary metasedimentary units and rafts In the summer of 2009, the Manitoba Geological Sur- of possible Archean provenance. vey (MGS) conducted the first half of a four-week geo- Petrology, geochemistry and Sm- logical mapping course with the Sayisi Dene First Nation Nd isotope analyses of samples at Tadoule Lake, Manitoba. The goals of the program are collected in the Tadoule Lake area will provide constraints to help increase awareness of the region’s geology and necessary to determine the nature, ages and contact rela- mineral resources, provide the basic skills needed to work tionships of exposed rock types. This work may help in a mineral-exploration camp and foster information- interpret geological domain boundaries in the Tadoule sharing between First Nation communities and the MGS. Lake area in conjunction with other projects that are all Four members of the community were hired as student- part of the ongoing Manitoba Far North Geomapping Ini- trainees and three completed the first half of the program. tiative (Anderson, et al., GS-13, this volume). One of the trainees was hired by the MGS as a field assis- tant to geologists working in the Seal River–Great Island Introduction area between Tadoule Lake and Churchill. The Sayisi Dene First Nation community of Tadoule The Tadoule Lake area, and Stony Lake to the north, Lake, Manitoba is located approximately 250 km west of transect marginal zones of the Great Island, Seal River Churchill and is accessible by commercial air transpor- and Chipewyan domains in the Hearne Province. Prelimi- tation or charter float plane. The location of the Tadoule nary observations confirm the presence of a Paleoprotero- Lake project area is outlined in red on the domain map in zoic granitoid complex, granite pegmatite and subordinate Figure GS-15-1, and the distribution of rock units in the HHearneearne cratoncraton TIK Ennadai Block Hudson Bay Nunavut 0 Nunavut 60 MUDJA Manitoba NEJANILINI Manitoba Saskatchewan ON SEAL RIVER Athabasca Basin Tadoule Lake GREAT ISLAND WOLLAST Churchill 0 CHIPEWYAN 58 SOUTHERN HUDSON INDIAN BAY 0 40 BASIN km 0 0 102 96 Figure GS-15-1: Major geological domains along the southern margin of the Hearne craton in northern Manitoba, as interpreted by Schledewitz (1986; modified after Manitoba Industry, Trade and Mines, 2002), with the location of the Tadoule Lake map area outlined in red. 154 Manitoba Geological Survey project area is shown on the simplified map in Figure GS- The Tadoule Lake area was previously mapped by 15-2. During the summer of 2009, MGS geologists, in MGS in the 1970s (Schledewitz, 1986). Tadoule Lake is partnership with the Sayisi Dene First Nation, mapped located at the western edge of the Great Island Domain, an area totalling 400 km2 at 1:50 000 scale. The geologi- sandwiched between the Seal River Domain to the north cal mapping program was supported by Manitoba Com- and the Chipewyan Domain to the south. Metasedimen- petitiveness, Training and Trade (Labour Market Skills tary rocks in the Seal River Domain were interpreted by Division) and Manitoba Science, Technology, Energy and Schledewitz (1986) as higher-metamorphic-grade equiva- Mines (Manitoba Geological Survey) under the auspices lents to those in the Great Island Domain. The geological of the Manitoba Far North Geomapping Initiative (Ander- mapping project in the Tadoule Lake area builds on this son et al., GS-13, this volume). This report provides an previous work with new mapping and collection of a sam- overview of the course methodology and the bedrock ple set for petrological, geochemical and Sm-Nd isotope- geology mapped by MGS geologists with the assistance ratio analysis of all rock types found in the Tadoule Lake of student-trainees from the Sayisi Dene First Nation area, to characterize and help delineate the boundaries of community in Tadoule Lake. the Seal River and Great Island domains. 6525000N 555000E Intrusive Leucogabbro Stony Lake Granodiorite, pegmatite Granite syenogranite dikes; Shethanei pegmatite; arkosic inclusions Lake Metasedimentary Mudstone with pebbly sandstone interbeds Negassa Quartzofeldspathic garnet-bearing Lake biotite-muscovite schist and arkose Quartz arenite and arkose Cobble conglomerate and quartz arenite Bedding Foliation Geological contact: Tadoule defined approximate assumed Fault Limit of mapping Lake 0 10 kilometres 525000E 6480000N Figure GS-15-2: Simplified geology of the Tadoule Lake area, integrating data from the 2009 field season with previous mapping by the Manitoba Geological Survey (Schledewitz, 1986). Report of Activities 2009 155 Methodology approximately 15 km north of the community. Stony Lake The focus of the program is to build a working rela- is accessible from Tadoule Lake by vehicle using a road tionship based on open communication and information atop an esker. Forty-four stations were recorded. Thin exchange between MGS geologists and members of the sections were made from thirteen of the collected rock Sayisi Dene First Nation community. In spring 2009, prior samples for petrographic analysis, eight samples were to the field season, MGS project geologists conducted two sent for geochemical analysis and one sample was sent to one-day visits to the Tadoule Lake community. The pur- be assayed for Cu-Ni and platinum-group elements. pose of these visits was to engage community and Band Council members in the planning process for the mapping Regional setting program, and to pursue possible employment options for The Tadoule Lake area, and Stony Lake to the north, the Dene people of Tadoule Lake with the MGS mapping transect marginal zones of the Great Island, Seal River program in the Seal River–Great Island area (Anderson et and Chipewyan domains in the Hearne Province (Figure al., GS-13, this volume). Additional open meetings were GS-15-1). The domains in the Hearne craton are delin- held during the summer program to encourage commu- eated, in part, by the distribution of assumed Archean nity involvement and the exchange of information. The basement, the type of overlying Paleoproterozoic cover authors resided in the community from July 15 to 29, 2009 rock, and metamorphic grade (Schledewitz, 1986). Meta- and learned much on how to maintain respectful commu- morphosed sedimentary rocks in the Tadoule Lake area nication and the importance of traditional perspectives were interpreted as greenschist-grade sedimentary rocks from discussions with student-trainees and community of the Great Island Domain, whereas similar sedimentary members. rocks to the north at Stony Lake are of higher metamor- The four student-trainees who participated in the phic grade and part of the Seal River Domain. geological mapping program have different life and work This project captured structural data and geological experience: two of the student-trainees are artists (one of contacts from the original Seal River Project mapping whom also teaches), one is a hunting guide and one is a of Schledewitz (1986) and combined them with the new recent high-school graduate. Classroom time was flexible mapping data compiled during the 2009 field season (Fig- and limited to four-hour segments. Teaching components ure GS-15-2). Bedrock in the Tadoule Lake area is com- for the mapping program started at the Grade 10 science monly obscured by glacially derived clay, sand, gravel level and progressed to basic first-year university geol- and boulders that are deposited as eskers, so aerial photo- ogy. During this process, underlying concepts in science, graphs were used to locate the rare exposures. In addition, such as mineral shapes, crystallization and relative age unusually high water levels during the summer of 2009 relationships, were cognitively reinforced during geologi- further limited the number of bedrock exposures along the cal field mapping by having the student-trainees assist in lakeshore. identifying minerals, measuring foliation and bedding of the rock exposures and determining the age relation- The abundance of pegmatitic granitoid rock, particu- ship between Precambrian rocks and the Quaternary larly along the south shore of Tadoule Lake, is attributed landforms in the Tadoule Lake area. Of the 140 hours to granitic plutonism along the northern margin of the ca. in the mapping program, student-trainees participated 1.86 Ga Chipewyan Batholith (Fumerton et al., 1984; Van in 25 hours of classroom time, learning basic geologi- Schmus and Schledewitz, 1986). This period of major cal concepts, and designing and selecting pictures for the pegmatitic magmatism is interpreted to have succeeded a D folding event indicated by a moderate to tight, north- community poster; 20 hours of practical experience in the 1 use of scientific field equipment; 10 hours of preparation east-trending fold pattern at map scale in metasedimen- for and attendance at community information meetings; tary rocks of the Tadoule Lake area (Schledewitz, 1986). 25 hours of field equipment maintenance; and 60 hours in the field assisting in geological mapping. The mapping Bedrock geology program gave the student-trainees an opportunity to learn The geology of the Tadoule Lake area is dominated safe work practices according to MGS standards, use field by a felsic plutonic complex that includes granite, syeno- equipment, input GIS data and gain hands-on geological granite, granodiorite and their pegmatitic equivalents. mapping experience within their traditional land-use area. Sedimentary rocks include quartz arenite, arkose and rare Each individual was responsible for various aspects of arkosic inclusions within or along margins of the plutonic geological fieldwork, including maintaining field equip- suite, garnet-bearing quartzofeldspathic mica schist, and ment, preparing daily traverses and recording of data.