Geochemistry and Geochronology of Scheelites as constraints on the formation of gold ore deposits at Timmins West mine, Ontario

对于Lake海岸黄金公司（Tahoe Canada / Tahoe Resources Inc.的全资子公司）等矿业公司来说，新的金矿越来越难找到。在安大略的蒂明斯。金矿勘查中的关键参数是了解它们与地质作用的关系，获得矿床年龄的精确认识。金矿床的年龄测定具有挑战性，因为它们可能形成于寄主侵入体之后，含金流体的来源可能与侵入体本身、变质作用或来自地壳或地幔的更深部分有关。此外，用于长寿命放射性同位素系统的元素不能很好地分配到金中。邻近矿物并不总是可靠的，因为它们可能在不同流体的存在下结晶，或者是早于矿化本身的矿物。因此，在西提敏斯矿（TWM），目前没有建立金矿化的年表。只有矿脉主岩的年龄是可用的（巴里，1990年），可能早于成矿作用数千万年。在TWM中，黄金被发现于白钨矿（CaWO 4）和钛铁矿（CaTiSiO 5）等矿物旁边的矿脉中。在2016年使用NSERC Connect赠款成功访问海岸之后，当我们与该公司讨论我们可以使用什么地球化学和地质年代学工具来分析白钨矿时，我们在这里建议限制金属的来源，与金矿脉形成相关的地质过程，并确定其放射性年龄。了解何时以及有多少事件导致了金矿化，对于建立Timmins金矿沉积地质过程的“足迹”至关重要。我们的研究结果将提供限制潜在领域的未来勘探forLake海岸黄金公司。

New gold ore deposits are increasingly hard to find for mining companies such as Lake Shore GoldCorporation (a wholly owned subsidiary of Tahoe Canada / Tahoe Resources Inc.) in Timmins, Ontario. Keyparameters in gold exploration are to understand their relationship to geological processes and obtain preciseknowledge of the deposits' ages. Gold deposits are challenging to age date because they may be formed laterthan the host intrusions and the origin of the auriferous fluids can be associated with the intrusion itself,metamorphism or from deeper parts of the crust or mantle. Moreover, elements used for long-lived radioactivedecay systems do not partition well into gold. Neighbouring minerals are not always reliable either as they mayhave crystallized in the presence of different fluids or are minerals pre-dating the mineralization itself. As aconsequence, at the West Timmins mine (TWM), there is currently no chronology established for goldmineralization. Only the age of the host rocks of the veins are available (Barrie, 1990) and may pre-datemineralization by tens of million years. Gold is found in veins next to minerals such as scheelite (CaWO4) andtitanite (CaTiSiO5) at TWM. Following a successful visit of Lake Shore in 2016 using a NSERC Connectgrant, when we discussed with the company what geochemical and geochronological tools we can use foranalyzing scheelite, we propose here to constrain the source of metals, geological processes associated with theformation of gold veins, and determine their radiometric ages. Knowing when and how many events wereresponsible for gold mineralization is critical to build a "footprint" of the geological processes responsible forgold deposition in Timmins. Our results will provide constraints on potentially areas of future exploration forLake Shore Gold Corporation.