东北婆罗洲古地理重建:巴利奥宗(Baliojong)大洋板块地层碎屑物源和年代学  

Paleogeographic reconstruction of Northeast Borneo: Detrital geochronology and provenance of Baliojong Ocean Plate stratigraphy

作　　者：许迪 Suzanna H A van de LAGEMAAT Junaidi ASIS 曹立成 Eldert L ADVOKAAT 姚会强[4] XU Di;Suzanna H A van de LAGEMAAT;Junaidi ASIS;CAO Licheng;Eldert L ADVOKAAT;YAO Huiqiang(College of Marine Science and Technology,China University of Geosciences,Wuhan,Hubei 430074,China;Department of Earth Sciences,Utrecht University,3584 CB Utrecht,the Netherlands;Faculty of Science and Natural Resources,Universiti Malaysia Sabah,88400 Kota Kinabalu,Malaysia;Key Laboratory of Marine Mineral Resources of Ministry of Land and Resources,Guangzhou Marine Geological Survey,Guangzhou,Guangdong 510075,China)

机构地区：[1]中国地质大学(武汉)海洋学院,湖北武汉430074 [2]乌特勒支大学地球科学系,荷兰乌特勒支3584 CB [3]沙巴大学自然与科学学院,马来西亚亚庇88400 [4]广州海洋地质调查局国土资源部海底矿产资源重点实验室,广东广州510075

出　　处：《地质学报》2025年第2期382-398,共17页Acta Geologica Sinica

基　　金：国家自然科学基金青年基金项目(编号42106073)资助的成果。

摘　　要：受古大洋持续俯冲活动的影响,东南亚现存微陆块众多,其成因和构造演化复杂,使得该地区古地理重建难度极大,特别是东北婆罗洲地块的构造属性和前新生代古地理尚有较大争议。东北婆罗洲出露的巴利奥宗(Baliojong)大洋板块地层,是记录古大洋由洋壳扩张至俯冲消亡的珍贵素材。本文对该地层西段两个浊积岩剖面开展了详细的物源和年代学调查,综合运用全岩地球化学、矿物学、锆石U-Pb年代学-地球化学-形态学来限定其沉积时代和组成成分,进而揭示古大洋俯冲历史和上覆板块古地理。结果显示两剖面样品的各物源和年代学指标均存在较大差异,东侧浊积岩(剖面BF2)较西侧浊积岩(剖面BF5)具有更年轻的沉积年龄、更高的成分成熟度和碎屑组分含量、偏基性的母岩成分、更丰富和更大粒径的加里东期和印支期锆石颗粒。这些信息明确指示两套浊积岩为不同期次的俯冲增生产物。综合新获得碎屑年代学最大沉积年龄指标以及前人测定的硅质岩和玄武岩年龄,推测两套浊积岩形成于晚白垩世(~87 Ma和~93 Ma)。通过对比巴利奥宗浊积岩与婆罗洲及周缘板块物源区的锆石U-Pb年龄信号,发现其与印支地块南缘—东马地块—西北婆罗洲一带存在潜在的源汇联系,推测巴利奥宗大洋板块地层形成的俯冲带位置更靠近巽他大陆,而不是华南大陆。本研究揭示的东北婆罗洲晚白垩世古地理对重建南海—东南亚地区中生代古大洋俯冲体系具有重要意义。The continuous subduction of paleo-oceans has resulted in the presence of numerous microplates in Southeast Asia,characterized by complex origins and tectonic evolution.This complexity poses significant challenges for paleogeographic reconstruction,particularly concerning the Northeast Borneo terrane,whose tectonic attributes and pre-Cenozoic paleogeography remain highly controversial.The Baliojong Ocean Plate stratigraphy outcropping in Northeast Borneo serves as a valuable record of paleo-oceanic history,spanning from crustal spreading to subduction and extinction.In this study,we conducted detailed provenance and geochronological investigations on two turbidite sections in the western part of the Baliojong Ocean Plate stratigraphy.By integrating whole-rock geochemistry,mineralogy,and zircon U-Pb geochronology-geochemistry-morphology,we determined the depositional ages and compositions,thereby revealing the subduction history and paleogeography of the overlying plates.Our results demonstrate significant differences between the two sections in terms of individual provenance and geochronological proxies.Turbidites in the eastern section(BF2)exhibit younger sedimentary ages,higher compositional maturity and detrital content,mafic-dominated source composition,and a greater abundance of larger-sized zircon grains of Caledonian and Indosinian ages compared to those in the western section(BF5).These lines of evidence clearly indicate that the two turbidite sequences are products of distinct accretionary periods.Combining our newly obtained maximum depositional age proxies based on detrital geochronology with published ages of radiolarian cherts and basalts,we interpret the deposition of the turbidite sequences to have occurred in the Late Cretaceous(~87 Ma and~93 Ma).Comparison of the zircon U-Pb age signatures of the Baliojong turbidites with those of potential source areas in Borneo and surrounding plates suggests a provenance linkage to the zone encompassing the southern Indochina margin-East Malaya-Northwest Borne

关 键 词：古太平洋 东北婆罗洲 古地理 晚白垩世 锆石U-PB年代学 沉积年龄 大洋板块地层 

分 类 号：G63[文化科学—教育学]