Revisiting early Neoproterozoic mafic sills in the North China Craton

IF 3.2 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Precambrian Research Pub Date : 2025-05-08 DOI:10.1016/j.precamres.2025.107788

Zhongwu Lan , Zhensheng Li , Sandra Kamo , Peng Peng , Mingguo Zhai

{"title":"Revisiting early Neoproterozoic mafic sills in the North China Craton","authors":"Zhongwu Lan , Zhensheng Li , Sandra Kamo , Peng Peng , Mingguo Zhai","doi":"10.1016/j.precamres.2025.107788","DOIUrl":null,"url":null,"abstract":"<div><div>Neoproterozoic Large Igneous Provinces (LIPs) continue to receive worldwide attention due to their genetic links with supercontinent dispersal and use in paleocontinental reconstructions, formation of ore deposits, climate shifts, and biological extinctions. However, their utility is hampered by a lack of high precision geochronology. Here we present a new U-Pb ID-TIMS baddeleyite age for a Neoproterozoic mafic sill intrusion in the North China Craton (NCC). A mafic intrusion within the Huaibei/Huaihe Group of Xuhuai Basin, previously dated between 915 Ma and 900 Ma (U-Pb zircon/baddeleyite LA-ICP-MS) gives a baddeleyite age of 906.5 ± 1.1 Ma. Given the wide occurrence of 915–900 Ma mafic intrusions dated previously, this new age potentially suggests a widespread ca. 907 Ma mafic intrusive event across NCC. Furthermore, this baddeleyite age constrained the Huaibei/Huaihe Group to have deposited in an age span of 1121–907 Ma. Apatite grains from the mafic sills have also been dated by U-Pb LA-ICP-MS, which produced dates that range from 984 ± 64 Ma to 930 ± 57 Ma, with errors similar to previous zircon/baddeleyite U-Pb LA-ICP-MS dates, indicating the feasibility of apatite U-Pb geochronology to constrain the timing of mafic intrusions. REE distribution patterns coupled with the Sr/Y-LREE discrimination plots demonstrate a primary origin for the dated apatite grains. Apatite crystallized from mafic magmas following earlier crystallization of feldspar that incorporated significant amounts of Eu.</div><div>Recalculation of nearly 600 radio-isotopic data points on Neoproterozoic mafic intrusions in the NCC yield three age peaks at ca. 940 Ma, ca. 915 Ma and ca. 885 Ma, respectively. The major age peak at ca. 915 Ma is broadly consistent with our U-Pb ID-TIMS baddeleyite age that is suggestive of the main episode of mafic intrusion. Further high precision U-Pb ID-TIMS geochronology is necessary to precisely constrain the timing of the ca. 940 Ma and ca. 885 Ma mafic intrusions.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107788"},"PeriodicalIF":3.2000,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Precambrian Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0301926825001147","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

Neoproterozoic Large Igneous Provinces (LIPs) continue to receive worldwide attention due to their genetic links with supercontinent dispersal and use in paleocontinental reconstructions, formation of ore deposits, climate shifts, and biological extinctions. However, their utility is hampered by a lack of high precision geochronology. Here we present a new U-Pb ID-TIMS baddeleyite age for a Neoproterozoic mafic sill intrusion in the North China Craton (NCC). A mafic intrusion within the Huaibei/Huaihe Group of Xuhuai Basin, previously dated between 915 Ma and 900 Ma (U-Pb zircon/baddeleyite LA-ICP-MS) gives a baddeleyite age of 906.5 ± 1.1 Ma. Given the wide occurrence of 915–900 Ma mafic intrusions dated previously, this new age potentially suggests a widespread ca. 907 Ma mafic intrusive event across NCC. Furthermore, this baddeleyite age constrained the Huaibei/Huaihe Group to have deposited in an age span of 1121–907 Ma. Apatite grains from the mafic sills have also been dated by U-Pb LA-ICP-MS, which produced dates that range from 984 ± 64 Ma to 930 ± 57 Ma, with errors similar to previous zircon/baddeleyite U-Pb LA-ICP-MS dates, indicating the feasibility of apatite U-Pb geochronology to constrain the timing of mafic intrusions. REE distribution patterns coupled with the Sr/Y-LREE discrimination plots demonstrate a primary origin for the dated apatite grains. Apatite crystallized from mafic magmas following earlier crystallization of feldspar that incorporated significant amounts of Eu.

Recalculation of nearly 600 radio-isotopic data points on Neoproterozoic mafic intrusions in the NCC yield three age peaks at ca. 940 Ma, ca. 915 Ma and ca. 885 Ma, respectively. The major age peak at ca. 915 Ma is broadly consistent with our U-Pb ID-TIMS baddeleyite age that is suggestive of the main episode of mafic intrusion. Further high precision U-Pb ID-TIMS geochronology is necessary to precisely constrain the timing of the ca. 940 Ma and ca. 885 Ma mafic intrusions.

查看原文本刊更多论文

华北克拉通新元古代早期基性岩质特征重访

新元古代大火成岩省（LIPs）由于其与超大陆扩散和古大陆重建、矿床形成、气候变化和生物灭绝的遗传联系而继续受到全世界的关注。然而，由于缺乏高精度的地质年代学，它们的应用受到了阻碍。本文给出了华北克拉通新元古代基性岩浆岩侵入的一个新的U-Pb ID-TIMS坏岩体年龄。徐淮盆地淮北/淮河群内的基性侵入岩（U-Pb锆石/坏辉石LA-ICP-MS）测定的坏辉石年龄在915 ~ 900 Ma之间，为906.5±1.1 Ma。考虑到之前广泛发生的915-900 Ma的岩浆侵入事件，这个新时代可能表明在NCC广泛发生了约907 Ma的岩浆侵入事件。此外，这一不良成岩年龄限制了淮北/淮河群沉积的年龄跨度为1121 ~ 907 Ma。利用U-Pb LA-ICP-MS对基性岩浆岩中的磷灰石颗粒进行了测年，测年范围为984±64 Ma至930±57 Ma，误差与之前的锆石/坏锆石U-Pb LA-ICP-MS测年结果相似，表明了磷灰石U-Pb年代学方法约束基性岩浆岩侵入时间的可行性。稀土元素分布模式与Sr/Y-LREE判别图结合，显示了年代测定的磷灰石颗粒的主要成因。磷灰石是在早期长石结晶之后从基性岩浆中结晶出来的，长石中含有大量的铕。重新计算了近600个新元古代基性岩体的放射性同位素数据点，得到了三个年龄峰，分别为约940 Ma、约915 Ma和约885 Ma。约915 Ma的主要年龄峰值与我们的U-Pb ID-TIMS坏代年龄基本一致，暗示了岩浆入侵的主要时期。需要进一步进行高精度的U-Pb ID-TIMS年代学，以精确地约束约940 Ma和约885 Ma岩浆侵入的时间。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Precambrian Research 地学-地球科学综合

CiteScore

7.20

自引率

28.90%

发文量

325

审稿时长

12 months

期刊介绍： Precambrian Research publishes studies on all aspects of the early stages of the composition, structure and evolution of the Earth and its planetary neighbours. With a focus on process-oriented and comparative studies, it covers, but is not restricted to, subjects such as: (1) Chemical, biological, biochemical and cosmochemical evolution; the origin of life; the evolution of the oceans and atmosphere; the early fossil record; palaeobiology; (2) Geochronology and isotope and elemental geochemistry; (3) Precambrian mineral deposits; (4) Geophysical aspects of the early Earth and Precambrian terrains; (5) Nature, formation and evolution of the Precambrian lithosphere and mantle including magmatic, depositional, metamorphic and tectonic processes. In addition, the editors particularly welcome integrated process-oriented studies that involve a combination of the above fields and comparative studies that demonstrate the effect of Precambrian evolution on Phanerozoic earth system processes. Regional and localised studies of Precambrian phenomena are considered appropriate only when the detail and quality allow illustration of a wider process, or when significant gaps in basic knowledge of a particular area can be filled.