Whitehorse 2016 June 1 - 3, 2016
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Throug gins h Ti ar me M Whitehorse, YT G R AC -MAC 2016 Whitehorse 2016 June 1 - 3, 2016 Abstracts - Résumés Volume 39 COMPARATIVE STUDY OF GARNETS FROM STREAM SEDIMENT AND SKARN onshore and offshore deposits of both placer and vein types. The OUTCROP ON THE CLY PROPERTY, SOUTHEASTERN BRITISH COLUMBIA relationship of metallogeny of the shelf areas and islands with the Ajibode, O.O., Cuthbertson, J.P. and Howard, W., Department of adjacent continental regions is traced clear. Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, AB Most commonly three types occur - placers of gold, tin, ferrous T2N 1N4 metals with Zr and V; locally - placers of platinum, and precious stones on the shelf of all these water areas. The CLY property is a polymetallic Au+W prospect located in the Nelson mining division of B.C., 16 km southwest of the town of The tin bearing potential of the Russian Arctic Shelf can be Salmo and 6 km north of the international border. The historic compared to the world largest tin provinces. The majority of these Bunker Hill mine is located in central CLY, and minor production sites are concentrated in the Laptev and East Siberian seas of the of silver and gold (0.30 oz/ton Au and 0.87 oz/ton Ag) occurred Arctic ocean. from 1933 to 1942 in an intrusive-related gold system. The Lefevre The unique Ryveem deposit of the Chukchi Sea shoreline is skarn is found within 500 m of the Bunker Hill mine, and formed characterized by a combination of two types of gold placers at the contact between mid-Paleozoic limestone units and the (alluvial and littoral). There are also parallels between these gold Cretaceous Wallack Creek stock. The current study shows that placers and equivalent bench placers at Nome in Alaska. the skarn is composed mainly of garnet, amphibole, epidote, and calcite, with a variably brecciated texture. The garnets are anhedral, One of the main tasks lying ahead of us is the development of partially replaced by silicate minerals, and appear to have formed Arctic gold placers. In order to succeed, it is necessary to carry out as aggregates of small grains. The skarn garnets are characterized indepth reseach of the Arctic ocean shoreline and islands on the by a pale pink colour and are not isotropic in cross-polarized light, Arctic shelf. a feature that has also been observed in garnets from other skarns. We are considering the shelf and deep-water areas of the Far Eastern Accessory minerals such as pyrite, sphalerite, fluorite and zinc were seas: the south-western part of the Bering Sea, the Bering Sea and also identified in the skarn. Electron microprobe analyses identified the Pacific coastal sea area of Kamchatka and the Kuril Islands. the skarn garnets as grossular, the Ca-Al end-member of the garnet solid solution series. Heavy mineral surveys of small creeks on The active coastal erosion is observed around the Bering Sea and CLY prospect in 2015 found anomalously high grain counts of in the eastern part of Kamchatka and the Kuril Islands. The major garnets, which include grossular, andradite (Ca-Fe end-member), placer minerals near shore are ferrous metals with Zr. and spessartine (Mn-Al end-member). New SEM imaging of the The South Koryak platinum - bearing ophiolite zone continues to creek spessartine garnets reveals that some are euhedral, with the area of the Karaginskiy Bay of the Bering Sea. There are placers distinct crystal faces, while others display a highly rounded shape. of which gold and platinum in the area of Karaginskiy Bay can be The creek spessartine garnets show a zoning trend of increasing economically important. Fe towards the rims and increasing Ca and Mn towards the core, whereas there is no zoning visible in the brecciated skarn garnets. In the back-arc Bering Sea area, north of the Commander Islands, an Geochemical analysis indicates that the grossular garnets in the ore-bearing hydrothermal activity associated with the Pyep volcano streams may be sourced from the skarn deposit, but the source of was recorded; the pellets of native copper were found in the littoral the spessartine garnets remains unknown. The variable degree of zone of the Bering Island. rounding of the creek spessartine grains suggests that there could Mineral resources of the Far East seas, along with the adjoining be multiple sources, one of which may be quite local in order land, are waiting for their development. They can fully ensure a to explain the euhedral crystals. Trace element analysis of both successful self-sufficient economic development of the Far Eastern the creek and skarn garnets will be conducted in order to further border regions of Russia. investigate chemical differences, and to gain insight on a possible source for the creek garnets. STENIAN-CAMBRIAN TECTONIC EVOLUTION OF CENTRAL MADAGASCAR: INSIGHTS FROM GEOCHEMICAL AND ISOTOPIC DATA FROM MAGMATIC ROCKS APPLICATIONS OF “FOUR BILLION YEARS AND COUNTING” AT THE Archibald, D.B., [email protected], Collins, A.S., SECONDARY LEVEL: STUDENT ENGAGEMENT, STUDENT UNDERSTANDING, AND Foden, J.D., The University of Adelaide, North Terrace Campus, Adelaide, USE OF THIS TEXT AS A TEACHING RESOURCE Australia 5005, Payne, J.L., University of South Australia, Mawson Lakes, SA, Alpert, S.E., University of Victoria, 3800 Finery Road, Victoria, BC V8P 5C2 Australia, 5095, Holden, P., The Australian National University, Canberra, Australia, 2601, and Razakamanana, T., Département des Sciences de la My interest following the publication of Four Billion Years and Terre, Université de Toliara, Toliara, Madagascar Counting surrounds the question of its application in a high school setting. In collusion with a master teacher working in Victoria, I Madagascar occupies an important location within the East African intend to use this book as a resource within a science classroom. My Orogen. This extensive orogen involves a collage of Proterozoic intention is to do both pre and post assessment of student interest microcontinents and arc terranes wedged between older cratonic in earth science, and their engagement and understanding in topics units during Gondwana assembly. Oceanic crust is an important covered during my time in the class. These assessments would help component of palaeogeographic reconstructions that is often instructors to gauge whether the book is a good resource for these overlooked since exposures of in situ oceanic crust older than ~200 students and how it can best be applied in a high school setting. Myr are rare. Therefore, studies of ancient oceanic crust require This provides an important opportunity to evaluate this Canadian- proxies such as analysing the products of magmatic arcs. The focused resource in a high school setting and to determine what Malagasy basement preserves three magmatic suites emplaced aspects of the text and online component are effective for teachers consecutively from ~1100-500 Ma. During this time, the Rodinia and students. supercontinent amalgamated then dispersed and the Gondwana supercontinent formed. The magmatic episodes are ~1080-960 Ma (Dabolava Suite), ~850-750 Ma (Imorona-Itsindro Suite) and ~650- MINERAL RESOURCE POTENTIAL NORTH –EASTERN SEAS OF RUSSIA 520 Ma (Kiangara and Ambalavao Suites). Mainly gabbroic and Andreev, S.I., Babaeva, S.F., [email protected], and Smirnov, A.N., granitoid rocks of the Stenian-Tonian Dabolava suite combined with Acad. I. Gramberg, VNIIOkeangeologia, Russia, St. Petersburg the probably coeval Ikalamavony Group represent a magmatic arc Geological prospecting works on the shelf, islands and deep- and marginal volcano-sedimentary sequence deposited in an arc water areas of the Eastern Arctic and Far Eastern seas of Russia tectonic setting based on geochemical characteristics. The Tonian have made it possible to establish mineral resource potential of the Imorona-Itsindro suite represents contemporaneous emplacement of an assortment of magmas with their collective genesis most GAC®-MAC 2016 Whitehorse abstract volume 1 reliably explained by plate margin processes. Tonian arc magma CHEMICAL COMPOSITION OF THE KITTILÄ OROGENIC GOLD MINE (FINLAND) generation coincided with oceanic plate subduction during closure INDICATOR MINERALS of the Mozambique Ocean along the Betsimisaraka Suture in 1 1 eastern Madagascar. Recently, some authors have questioned Auger, C.C. , [email protected], Beaudoin, G. , Huot, F.1 and Valimaa, J.2; 1Département de géologie et de génie géologique, the presence of an active continental margin and consequent 2 suture zone in favour of intraplate magma generation based on Université Laval, Québec, QC; Agnico Eagle Kittilä mine, Finland limited geochemical characteristics. The Ediacaran to Cambrian The Kittilä deposit, a world-class orogenic gold mine, is located Kiangara-Ambalavao suite is a post-collisional, mainly granitoid along the 25 km-long north-south striking Kiistala Shear Zone. It suite emplaced during the final assembly of Gondwana. In this is hosted within the Kittilä Group of the Paleoproterozoic Central whole-rock geochemical and zircon isotopic study, we attempt Lapland greenstone belt. The rocks are mostly volcanic and to: (1) resolve the conundrum of the presence or absence of metamorphosed to the greenschist facies. Neoproterozoic suture zones in east central Madagascar and (2) reconstruct the tectonic geography of central Madagascar from Mineralization is contained in arsenopyrite and pyrite, mostly as the Stenian to Cambrian. Preliminary inferences question published invisible gold. Ore zones are strongly albitized and carbonate palaeogeographic reconstructions. Interpretations also imply the alteration is common. Sampling of 38 drill core, selected from 10 possibility of a previously unrecognized and long-lived (~500 Ma) cross-sections along the 4.5 km long deposit, provides a good spatial active subduction margin similar to the present-day western Pacific representation of the deposit geology. Rutile and tourmaline, were Ocean. This large isotopic dataset is critical for understanding identified in polished thin sections and analyzed by microprobe for Madagascar’s tectonic evolution during the amalgamation and their chemical composition.