| 大兴安岭多宝山地区泥鳅河组沉积-构造响应：来自火山岩夹层锆石U-Pb年龄新证据 |
| 投稿时间：2026-05-20 修订日期：2026-08-04 |
| 关键词:Niqiuhe Formation volcanic interbeds zircon U-Pb dating Lochkovian (Early Devonian) Duobaoshan area northern Great Xing’an Range |
| 基金项目:中国地质调查局项目（编号：DD202402079, DD20221632）、国家自然科学基金项目（编号：92479206, 42172024）和辽宁省自然科学基金项目（编号：2024-MSLH-496）联合资助 |
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| 摘要: |
| Sedimentary-Tectonic Responses of Niqiuhe Formation in the Duobaoshan Area, Great Xing’an Range: New Constraints from Zircon U-Pb Ages of Intercalated Volcanic Rocks |
| The Devonian Niqiuhe Formation in the northern Great Xing’an Range represents a key stratigraphic unit for studying the Silurian–Devonian transition. Due to the absence of high-precision geochronological constraints, its depositional age and tectonic affinity have long remained controversial. On the basis of field stratigraphic section measurements, this study performed LA-ICP-MS zircon U-Pb isotopic dating on two volcanic interlayers within the Niqiuhe Formation from the Duobaoshan area, northern Great Xing’an Range. The weighted mean ²??Pb/²³?U zircon ages yielded are 409.8 ± 2.0 Ma (n = 17, MSWD = 0.26) and 415.3 ± 2.0 Ma (n = 19, MSWD = 0.35), respectively. Therefore, the depositional age of the Niqiuhe Formation is constrained to the Lochkovian Stage of the Early Devonian. Comprehensive analyses of lithological assemblages, sedimentary structures and paleontological fossils reveal that the Niqiuhe Formation accumulated in a tectonically active shallow-marine environment, recording sedimentary infill characteristics of a remnant ocean basin and a back-arc remnant basin. This result indicates that the amalgamation of the Xing’an Orogenic Belt and the Songnen Block occurred prior to the Early Devonian. These new data provide robust constraints for Devonian stratigraphic division, regional tectono-sedimentary evolution of the northern Great Xing’an Range, and the metallogenic setting of the Duobaoshan polymetallic ore cluster. |
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