杨文涛，朱仅坤，付强. 华北南部奥陶系马家沟组一段碎屑锆石年代特征及物源分析[J].河南理工大学学报（自然科学版），doi: 10.16186/j.cnki.1673-9787.2024120064.

YANG W T,ZHU J K,FU Q. Detrital zircon U-Pb chronology and provenance analysis from the first member of Ordovician Majiagou Formation in the southern North China[J]. Journal of Henan Polytechnic University( Natural Science), doi: 10.16186/j.cnki.1673-9787.2024120064.

华北南部奥陶系马家沟组一段碎屑锆石年代特征及物源分析

杨文涛¹，朱仅坤²，付强²

（1.河南理工大学 生物遗迹与成矿过程国际联合实验室，河南 焦作 4540003；河南理工大学 资源环境学院 河南 焦作 454003）

摘要：目的 为探讨早奥陶世北秦岭造山带构造演化过程，方法 野外地质调查工作基础上，对华北南部焦作地区马家沟组一段进行了碎屑锆石U-Pb年代学分析。结果 结果表明，马家沟组一段具有新太古代-古元古代和早古生代2个碎屑锆石年龄组，并形成了3个年龄峰值：483 Ma、1 840 Ma、2 445 Ma，其中，新太古代-古元古代（~1 840 Ma、~2 445 Ma）碎屑锆石来自华北克拉通基底，,早古生代（483 Ma）碎屑锆石来自北秦岭造山带。物源分析结果与古地理特征一致，暗示了北秦岭造山带早奥陶世时期发生弧陆碰撞造山带作用。早奥陶世之前，宽坪洋尚未完全关闭，二郎坪岛弧地体由于洋盆的隔离无法向华北盆地输送碎屑物质；早奥陶世时期，宽坪洋闭合，使得二郎坪岛弧地体与华北发生弧陆碰撞，来自二郎坪岛弧的碎屑物质顺利进入华北盆地早奥陶世地层中。华北南部奥陶系马家沟组一段砂岩中的碎屑锆石年龄说明了在早奥陶世华北盆地南部的物源可能由北秦岭提供，且年代学数据中并未出现晚古生代的碎屑锆石年龄，而晚古生代的碎屑锆石年龄是内蒙古隆起的特征年龄，而这一年龄峰值的缺失或许能佐证古亚洲洋的南向俯冲并不剧烈。而新太古代-古元古代的碎屑锆石年龄峰值是华北克拉通基底的特征年龄，形成这2个年龄峰值的物源或许是华北克拉通再旋回的产物。结论 早奥陶世之前，宽坪洋尚未完全关闭，二郎坪岛弧由于洋盆的隔离无法向华北盆地提供碎屑物质；早奥陶世时期，二郎坪岛弧地体拼贴到华北克拉通南缘，二郎坪岛弧成为华北南部马家沟组一段的重要物源区。

关键词：沉积物源、马家沟组、碎屑锆石、宽坪洋、二郎坪岛弧

Doi： 10.16186/j.cnki.1673-9787.2024120064

基金项目：国家自然科学基金资助项目（222300420046）

收稿日期：2024-12-28

修回日期：2025-04-24

网络首发日期：2026-04-20

Detrital zircon U-Pb chronology and provenance analysis from the first member of Ordovician Majiagou Formation in the southern North China

Yang Wentao ¹ ，Zhu Jinkun ²，Fu Qiang²

（1.Henan International Joint Laboratory of Biogenic Traces and Sedimentary Minerals, Henan Polytechnic University，Jiaozuo 454003，Henan，China； 2. School of Resources and Environment, Henan Polytechnic University Jiaozuo 454003，,Henan ，China）

Abstract: Objectives To explore the tectonic evolution process of the North Qinling Orogenic Belt during the Early Ordovician period,Methods based on the field geological survey work, the detrital zircon U-Pb chronology analysis was carried out on the first member of the Majiagou Formation in the Jiaozuo area of the southern North China. Results The results show that the first member of the Majiagou Formation has two detrital zircon age groups, namely the Neoarchean-Paleoproterozoic and the Early Paleozoic, and three age peaks are formed: 483 Ma, 1840 Ma, and 2445 Ma. Among them, the Neoarchean-Paleoproterozoic (~1840 Ma, ~2445 Ma) detrital zircons are derived from the basement of the North China Craton, while the Early Paleozoic (483 Ma) detrital zircons are from the North Qinling Orogenic Belt. The results of the provenance analysis are consistent with the paleogeographical features, suggesting that the arc-continent collision orogenic belt activity occurred in the North Qinling Orogenic Belt during the Early Ordovician period. Before the Early Ordovician period, the Kuanping Ocean had not been completely closed, and due to the isolation of the ocean basin, the Erlangping island arc terrane was unable to transport detrital materials to the North China Basin; during the Early Ordovician period, due to the closure of the Kuanping Ocean, the arc-continent collision between the Erlangping island arc terrane and North China occurred, enabling the detrital materials from the Erlangping island arc to smoothly enter the Early Ordovician strata of the North China Basin. We have realized that the detrital zircon ages of the sandstone in the first member of the Ordovician Majiagou Formation in the southern North China indicate that the provenance of the southern part of the North China Basin during the Early Ordovician may be provided by the North Qinling, and the detrital zircon ages of the Late Paleozoic do not appear in the chronological data. The detrital zircon ages of the Late Paleozoic are the characteristic ages of the Inner Mongolia Uplift, and the absence of this age peak may support the fact that the southward subduction of the Paleo-Asian Ocean was not intense. The age peaks of the Neoarchean-Paleoproterozoic detrital zircons are the characteristic ages of the basement of the North China Craton, and the provenance forming these two age peaks may be the products of the recycling of the North China Craton. Conclusions Before the Early Ordovician, the Kuanping Ocean had not yet completely closed, and the Erlangping island arc was unable to supply clastic materials to the North China Basin due to the isolation of the ocean basin. During the Early Ordovician, the Erlangping island arc terrane was accreted to the southern margin of the North China Craton, making the Erlangping island arc an important provenance for the first member of the Majiagou Formation in southern North China.

Key words：sediment source, Majiagou Formation, detrital zircon , Kuanping Ocean, Erlangping island arc