The Flin Flon Belt of Canada contains Paleoproterozoic volcanic–sedimentary sequences that are related to the Trans‐Hudson Orogeny. The sequences include island arc volcanic and volcaniclastic rocks (Amisk Group) that are unconformably overlain by subaerial sedimentary rocks (Missi Group), and younger deep facies sediments. In the Flin Flon area, several north–south trending faults divide the sequences into blocks and obscure the depositional environment of the deep facies sediments. Locally, within the Flin Flon area, the Embury Lake Formation is in fault contact with island arc volcanic–sedimentary sequences of the Amisk and Missi Groups. To identify the depositional environment of the Embury Lake Formation, we used lithologic and geochemical approaches. Here, we report carbon isotopic values in organic matter (δ¹³C_org) and sulfur isotopes (δ³⁴S), as well as total organic carbon and total sulfur measurements for the black shale in the formation. Samples were taken from a drill core that contains alternating bands of sandstone and black shale. Pyrite in the black shale is divided into four textural types: euhedral, vein‐type, elliptical, and microcrystalline. Microcrystalline pyrite is typically generated by microbially mediated sulfate reduction. An extremely low S/C ratio (avg. = 0.04) is consistent with lacustrine deposition. The ranges of δ¹³C_org (−36 ‰ to −27 ‰) and δ³⁴S (+3.0 ‰ to +7.7 ‰) values can be explained by bacterial photosynthesis that involved Calvin cycle and acetyl CoA pathways, and sulfate reduction in a low‐sulfate environment. Considering the depositional age reported in a previous study of < 1.84 Ga, the Embury Lake Formation was likely emplaced in a lacustrine setting during the Trans‐Hudson Orogeny.

中文翻译：

---

地球化学对加拿大弗林弗隆带1.84 Ga Embury湖组沉积环境的制约

加拿大的Flin Flon带包含与跨哈德逊造山带有关的古元古代火山-沉积序列。层序包括岛弧火山岩和火山碎屑岩（Amisk组），它们被陆上沉积岩（Missi组）不整合地覆盖，以及较年轻的深相沉积物。在弗林弗隆地区，一些南北向的断裂将层序划分为块，并掩盖了深相沉积物的沉积环境。在弗林弗隆地区，埃姆伯里湖组在局部地区与艾米斯克和密西群岛的岛弧火山沉积相断层接触。为了确定Embury湖组的沉积环境，我们使用了岩性和地球化学方法。在这里，我们报告中的有机质碳同位素值（δ ¹³Ç_组织）和硫同位素（δ ³⁴ S），以及总的有机碳和总硫测量用于在地层中黑色页岩。样品取自包含交替排列的砂岩和黑色页岩带的钻芯。黑色页岩中的硫铁矿分为四种质地类型：全面，静脉型，椭圆形和微晶。微晶黄铁矿通常通过微生物介导的硫酸盐还原而产生。极低的S / C比（平均= 0.04）与湖相沉积相一致。δ的范围¹³ Ç_有机（-36‰至-27‰）和δ ³⁴S（+3.0‰至+7.7‰）值可通过涉及Calvin循环和乙酰CoA途径的细菌光合作用以及低硫酸盐环境中的硫酸盐还原来解释。考虑到先前研究中报道的<1.84 Ga的沉积年龄，在跨哈德逊造山过程中，Embury湖组可能被置于湖相环境中。