| 杨莉,田鹏,袁万明,王伟,艾金彪.东昆仑造山带斑岩成矿系统找矿潜力的剥蚀量约束[J].矿产勘查,2025,16(8):1939-1951 |
| 东昆仑造山带斑岩成矿系统找矿潜力的剥蚀量约束 |
| Erosion constraints on the prospecting potential of porphyry metallogenic systems in the East Kunlun orogenic belt |
| 投稿时间：2025-06-29 |
| DOI：10.20008/j.kckc.202508010 |
| 中文关键词: 东昆仑造山带 低温热年代学 剥蚀量 斑岩成矿系统 矿床保存性 |
| 英文关键词: Eastern Kunlun orogenic belt low-temperature thermochronology erosion magnitude porphyry mineralization system deposit preservation potential |
| 基金项目:本文受国家自然科学基金重大研究计划(92062217)和中国博士后科学基金第76批面上资助项目(2024M763068)联合资助。 |
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| 中文摘要: |
| 本文基于东昆仑造山带 421个低温热年代学数据，重建了该区域自印支期以来的多期次剥露历史，并定量探讨其对三叠纪斑岩型矿床保存与找矿潜力的制约作用。研究区低温热年代学数据记录了 3个主要剥蚀阶段:(1)印支期(约 239.5~200 Ma)，以岩浆-成矿事件后的初始快速冷却为特征，平均剥露速率为 0.21 mm/a，主要分布于中东段(92°~98°E)；(2)燕山期(200~66 Ma)，构造活动相对平缓，主体区域剥蚀速率低于 0.05 mm/a，为斑岩成矿系统提供了稳定的保存环境；(3)喜马拉雅期(66~0 Ma)呈现显著化剥蚀，早期(66~10 Ma)平均剥露速率为 0.06 mm/a，晚期(<10 Ma)局部地区剥露速率因青藏高原，快速隆升的远程效应而急剧增加至 0.5~4.2 mm/a，高剥露速率区主要集中在东段(94°~101°E)和西段(86°~92°E)。研究结果表明，2~3 km的累积剥蚀量构成斑岩成矿系统的最佳保存窗口。已知三叠纪斑岩矿床(236~218 Ma)主要分布于燕山期以来低剥蚀强度区域(<0.1 mm/a)，显示良好保存条件。研究认为东昆仑中东段长期维持低剥蚀环境的区域形成了有利于斑岩系统完整保存的“最佳保存窗口”，具有较高的深部找矿潜力。 |
| 英文摘要: |
| Based on 421 low-temperature thermochronologic data from the Eastern Kunlun orogen, this studyreconstructs a multi-episodic exhumation history since the Indosinian and quantitatively evaluates how exhumationhas governed the preservation and exploration potential of Triassic porphyry-type deposits. The thermochronologicrecord delineates three principal exhumation stages: (1) Indosinian (ca. 239.5-200 Ma), characterized by initialrapid post-magmatic cooling with a mean exhumation rate of 0.21 mm/a, concentrated in the central-eastern seg-ment (92°-98°E); (2) Yanshanian (200-66 Ma), marked by relatively subdued tectonism and basin-wide exhuma-tion rates <0.05 mm/a, providing a stable preservation environment for porphyry systems; and (3) Himalayan (66-0Ma), showing pronounced exhumation, with an early-stage (66-10 Ma) mean of 0.06 mm/a and a late-stage (<10Ma) acceleration to 0.5-4.2 mm/a in places due to far-field effects of rapid Tibetan Plateau uplift—high-rate zoneschiefly in the eastern (94°-101°E) and western (86°-92°E) segments. The results indicate that a cumulative exhu-mation of 2-3 km defines the optimal preservation window for porphyry mineral systems. Known Triassic porphyrydeposits (236-218 Ma) are chiefly concentrated in areas that have experienced low exhumation intensity since theYanshanian (<0.1 mm/a), reflecting favorable preservation conditions. We infer that regions in the central-easternEastern Kunlun that have maintained persistently low exhumation constitute this“optimal preservation window”,and therefore possess high potential for deep (concealed) mineral exploration. |
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