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海南岛北部古生界时代:碎屑锆石U-Pb年代学约束
张立敏1, 王岳军1,2, 张玉芝1, 刘汇川1, 张新昌1     
1. 中山大学地球科学与工程学院, 广州 510275;
2. 广东省地质过程与矿产资源探查重点实验室, 广州 510275
摘要: 海南岛古生界主要分布于南部三亚地块,并在琼中地块零星出露。相对于三亚地块,琼中地块内的古生界由于缺乏古生物化石证据及精细年代学数据,其地层划分及时代归属问题一直广受争议,严重限制了对海南岛北部古生代构造属性的认识。目前,利用沉积岩碎屑锆石年龄限定地层的沉积时代已得到广泛应用。本文在野外地质调查基础上,对海南岛北部邦溪、儋州、琼海等地区原划属为古生界的相关样品进行了锆石激光U-Pb年代学研究。锆石U-Pb年代学分析表明:于邦溪地区原划为奥陶系南碧沟组中采集的变质砂岩和儋州、琼海地区原划为志留系陀烈组中采集的变质砂岩的碎屑锆石给出的最年轻206Pb/238U表观年龄分别为373、352和369 Ma,其年龄谱系与屯昌地区二叠系砂岩相类似,总体上年龄峰值为370 Ma左右,另外在约447、980、1 969~1 520和2 681~2 328 Ma呈现次要峰值。结合其他资料,本文认为前人在海南岛北部划属的下古生界中至少有部分岩石应划属石炭系—下二叠统。上述研究丰富了海南岛古生界的年代学资料,也为海南岛构造演化等问题提供了新的约束。
关键词: 碎屑锆石     晚古生代     锆石U-Pb年代学     海南岛     石炭纪—早二叠世    
Age of Paleozoic Strata in Northern Hainan Island: Constraints from the Detrital Zircon U-Pb Geochronology
Zhang Limin1, Wang Yuejun1,2, Zhang Yuzhi1, Liu Huichuan1, Zhang Xinchang1     
1. School of Earth Sciences and Engineering, Sun Yat-Sen University, Guangzhou 510275, China;
2. Key Laboratory of Mineral Resources & Geological Processes, Guangdong Province, Guangzhou 510275, China
Supported by National Basic Research Program of China ("973" Program) (2014CB440901) and National Natural Science Foundation of China(41190073, 41372198)
Abstract: The Paleozoic sedimentary rocks in the Hainan Island are outcropped mainly in the southern Sanya and sporadically in Qiongzhong terranes. Unlike the Sanya terrane, the depositional period of the Paleozoic sedimentary rocks in the Qiongzhong terrane remains as a controversy due to the absence of fossils and geochronological data. This paper presents laser zircon U-Pb dating results for the representative sandstone samples from the Paleozoic sequences in the northern Hainan Island. The three samples collected from the previously-mapped Ordovician (11HN-23) and Silurian (11HN-07, -19) give the youngest 206Pb/238U apparent age-peaks at 373 Ma, 352 Ma and 369 Ma, respectively. Their detrital zircon age spectrum are similar to those of the sandstone samples taken from the Permian E'cha Formation (11HN-45). These samples yield a predominant age-peak at ~370 Ma and two subordinary age-peaks at ~980 Ma, ~447 Ma, along with two age spans of 1 969-1 520 Ma and 2 681-2 328 Ma. Our results suggest that part of the metasedimentary rocks, which were previously-mapped as Ordovician and Silurian in the northern Hainan Island, were most likely deposited in between Carboniferous and Early Permian. This study enriches the geochronological data for the Paleozoic strata and provides new constraints on the tectonic evolution of the Hainan Island.
Key words: detrital zircon     Late-Paleozoic     U-Pb geochronology     Hainan Island     Carboniferous-Early Permian    

0 前言

海南岛南渡江中游一带(包括白沙、儋县琼中、澄迈、屯昌等县的交界部位)出露一套浅变质岩系,主要由板岩、千枚岩、变质砂岩、变粉砂岩、变质砾岩组成,偶夹结晶灰岩和大理岩,属低绿片岩相产物。由于缺乏古生物及同位素年龄方面的证据,其划分和时代归属问题一直广受争议[1-5]。最初,广东省地质局区域地质测量大队海南分队对海南全岛进行1:20万区调时分别在东方陀烈、昌化江、青天峡谷地区建立标准剖面,创建陀烈群、青天峡组及不整合于青天峡组之下与陀烈群呈断层接触的岳岭群,根据地层中微植物化石将陀烈群划归为寒武系,根据青天峡组内腕足类化石将其定为晚石炭世地层,由接触关系认为岳岭群的形成时代为晚泥盆世—早石炭世;并通过进一步岩性对比,将分布在儋州、白沙、万宁及琼海地区的浅变质碎屑岩划归入陀烈群。1977年,广东省地质局区域地质调查队沿用岳岭群的时代划分,并根据地层内腕足类化石证据将出露于保亭南好矿区的南好组划归为石炭系,与青天峡组一起分属于早、晚石炭世,将陀烈群下部归入震旦纪,认为其上部地层可与广东八村群对比,时代仍属寒武纪,但缺乏古生物证据。夏邦栋和任震鹏[1]认为岳岭群与陀烈群沉积建造特征相似,时代大体相当,将陀烈群划为泥盆纪,与旧村岭群上部相当。在此之后,地质工作者先后在石碌地区的陀烈群及青天峡、江边村地区的岳岭群中分别采获早石炭世及二叠纪化石,因而,海南地质大队于1981年废弃“岳岭群”及“陀烈群”,将其中发现的早石炭世、二叠纪化石的地层划出,下部地层新建“南碧沟群”,归为奥陶纪—志留纪;并指出南碧沟群与标准陀烈群层位基本相当,地层发育更为齐全。汪啸风等[2]在陀烈群下段中发现几丁虫化石及微植物化石,认为时代应归属于早志留世—中志留世。海南地质大队在开展东方、玉道两幅1:5万区调联测时,与宜昌地化所共同测制陀烈村剖面,改“陀烈群”为“陀烈组”,并在南碧沟剖面中陀烈组之下新发现一段岩层,整合于陀烈组之下,将其命名为南碧沟组,并用全岩作U-Pb法等时线年龄得到447.1 Ma的年龄,而将其时代归为奥陶纪。随着科技手段的发展,近年来,地质工作者先后在原划分地层内获取不同时代的古生物化石:刘月清[3]在琼西军营地区原划为石炭系中发现志留纪微古植物化石;曾庆銮等[4]在保亭毛感地区原划为下石炭统南好组中发现早志留世腕足动物群及三叶虫化石;龙文国等[5]在儋州—屯昌地区原划为石炭系青天峡组内采获二叠纪化石。以上资料表明,琼中地块古生界由于古生物化石证据的不完整性及精细年代学数据的缺失,其地层划分及时代归属问题仍不甚清晰,已严重限制了对海南岛北部古生代构造属性的理解。沉积物中碎屑锆石U-Pb年代学作为一种新的技术手段,被认为能有效约束沉积物最大沉积年龄[6-8]

① 广东省地质局区域地质测量大队.海南岛区域地质测量报告(1:20万).海口:海南省地质调查院, 1964.

② 广东省地质局区域地质测量大队.广东省1:50万地质图说明书.海口:海南省地质调查院, 1977.

③ 海南地质大队. 1:5万东方幅、玉道幅区域地质调查报告.海口:海南省地质调查院, 1990.

为了更好地约束琼中地块古生界时代,本次研究针对海南岛北部地区原划为奥陶系南碧沟组、志留系陀烈组及二叠系峨查组中的长石石英砂岩开展了4个代表性样品的碎屑锆石U-Pb年代学研究。上述结果为相应采样地层的沉积时代进行了重新限定,丰富了海南岛古生代地层年代学资料,同时对认识海南岛古生代构造属性、解决古特提斯洋是否东延至海南岛等科学问题具有意义。

1 地质概况与样品描述

海南岛是我国第二大岛,地处华南板块、印度板块与欧亚板块之间(图 1a),大地构造位置独特。九所—陵水、尖峰—吊罗、昌江—琼海、王五—文教4条东西向断裂和白沙北东向断裂贯穿全岛[9-11],昌江—琼海与尖峰—吊罗断裂之间发育戈枕韧性断裂带(图 1b)。岛内地层除侏罗系尚无报道外,自元古宇至第四系被认为皆有分布,其中海南岛古生代地层出露面积不足全岛面积的18%。区内由于第四系覆盖及后期构造叠加影响,其古生代沉积环境和构造属性厘定异常困难。夹持于王五—文教断裂与九所—陵水断裂带之间的五指山块体内发育一套古生界,这套地层被认为自上而下分别有上奥陶统南碧沟组、下志留统陀烈组、石炭系南好组和青天峡组及二叠系峨查组与鹅顶组。

a据文献[12]修编;b据文献[13-14]修编。 图 1 海南岛大地构造位置(a)及海南岛地质图(b) Figure 1 Tectonic sketch map(a) and simplified geological map(b) of Hainan Island

原划为南碧沟组的岩性由一套浅变质岩和基性火山岩组成,浅变质岩包括有千枚岩、变粉砂岩、炭质板岩。原划为下志留统的陀烈组为一套由变质石英砂岩、变粉砂岩、绢云板岩和炭质绢云板岩组成的浅变质岩系。区域上原划为石炭系上统的以碳酸盐岩类为主,下统以石英砂岩、砂岩、板岩、粉砂质板岩等碎屑岩沉积为主,夹灰岩及火山质岩石。原划为二叠系的为一套由浅变质暗紫-灰褐色为主的细碎屑岩类夹薄层透镜体状碳酸盐岩所组成的碳酸盐陆屑沉积,在岩石组成上整套地层呈渐变关系。其中,石炭系与下志留统陀烈组被认为呈不整合接触[11]

在海南省地质调查院编制的1:50万数字化地质图中,本次采集样品对应于原划为上奥陶统南碧沟组、下志留统陀烈组及二叠系峨查组的层位(图 2)。样品主要由石英、长石、云母等矿物及少量岩屑组成。其中,采自琼海市龙滚镇的样品11HN-07原划为下志留统陀烈组上部,为灰色中粒岩屑石英砂岩。镜下观察主要成分为石英(80%)、云母(15%)及少量长石(5%)。样品为块状构造,分选较差,颗粒为棱角状,结构成熟度低(图 3a)。样品11HN-23采自儋州市洛基镇,原划为下志留统陀烈组上部,为灰色细粒长石质石英砂岩,主要由石英(75%)、长石(20%)及少量岩屑(5%)组成。块状构造,分选中等,次圆状,颗粒支撑。长石因高岭石化致表面呈云雾状(图 3b)。样品11HN-19采自东方市邦溪镇,原划为奥陶系南碧沟组上部,为中细粒长石砂岩,呈颗粒支撑,主要由石英(70%)、长石(25%)及云母(5%)组成。样品呈灰色,块状构造,分选中等,次棱角—次圆状,空隙胶结,胶结物主要为白云母及少量黏土矿物(图 3c)。11HN-45采自屯昌县晨星农场,原划为二叠系峨查组,为灰色细粒石英杂砂岩,碎屑主要由石英组成,杂基主要由细粒石英和黏土矿物组成,泥质部分重结晶成绢云母;杂基支撑,分选差,石英颗粒呈次棱角状(图 3d)。

据文献[2]、脚注① 修编。 图 2 海南岛北部古生界柱状对比图 Figure 2 Composite stratigraphic columns of the Paleozoic sequences from the northern Hainan Island
Q.石英;Pl.长石;Ms.云母。 图 3 海南岛北部晚古生代砂岩显微照片特征 Figure 3 Microphotographic photos for the sandstone in the northern Hainan Island

① 黄香定, 陈哲培, 钟盛中, 等. 1:50万海南省数字地质图修编说明书.海口:海南省地质矿产勘查开发局, 1998.

2 样品处理及分析方法

采用人工重砂分离方法遴选出锆石样品。首先在双目镜下手工挑选出晶型完好、透明度高、无明显包裹体、无破裂的锆石颗粒,使用环氧树脂固定、抛光,使锆石颗粒核部裸露;之后对锆石靶上的锆石进行透反射光拍摄,使用阴极发光装置系统采集阴极发光(CL)图像,据其观察锆石形态和内部结构特征。阴极发光图像采集在北京锆年领航科技有限公司完成。锆石U-Pb测试在西安大陆动力学国家重点实验室,使用激光剥蚀电感耦合等离子质谱仪通过Nu Plasma HR型号的多接收器等离子质谱仪与德国Lambda Physik AG公司的GeoLas 2005激光剥蚀系统联用完成。样品分析之前选取体积分数为3%的HNO3清洗样品表面的污染。分析中采用的激光斑束直径为24 μm,频率为8 Hz。LA-ICP-MS激光剥蚀采用单点剥蚀方式,U-Pb同位素分馏用锆石标样91500来校正,以保证测试分析精度。测试中,每测定10个样品点,测定2个GJ-1;每测定20个样品点,测定2个91500。数据处理采用ICPMSDatacal 8.7软件[15]。锆石谐和图用ISOPLOT(3.0版)软件[16]进行处理,具体分析方法和步骤及普通Pb校正见参考文献[17-18]。

运用上述流程, 本文对样品中的碎屑锆石进行了系统的LA-ICP-MS U-Pb年代学测试分析。其数据结果列于表 1

表 1 海南岛北部代表性砂岩激光锆石U-Pb年代学测试结果 Table 1 LA-MC-ICPMS zircon U-Pb dating results for the representative sandstone in the northern Hainan Island
样品号 wB/10-6 Th/U 同位素比值 年龄/Ma
Th U 207Pb/
206Pb
207Pb/
235U
206Pb/
238U
207Pb/
206Pb
207Pb/
235U
206Pb/
238U
谐和度/
%
11HN-07-011 8351 8001.020.069 340.002 951.542 300.068 110.160 620.005 5190988947279603198
11HN-07-023043760.810.164 850.006 3010.843 230.442 920.474 020.015 652 506642 510382 5016899
11HN-07-031 6142 5300.640.052 380.002 340.439 860.019 980.060 730.002 1630213437014380697
11HN-07-045777060.820.087 480.003 543.207 360.131 530.264 690.008 671 372741 459321 5144496
11HN-07-051 3581 7740.770.109 340.004 485.078 500.215 700.335 050.011 321 789701 833361 8635598
11HN-07-063593181.130.105 090.005 094.830 050.244 140.331 560.011 831 717891 790431 8465796
11HN-07-074485100.880.160 150.006 9410.314 200.452 900.465 280.016 092 457732 463412 4637199
11HN-07-087257510.970.078 070.003 432.087 760.096 600.193 270.006 811 150881 145321 1393799
11HN-07-093437740.440.051 270.002 420.432 180.020 040.061 240.002 0125411436514383595
11HN-07-104689070.520.056 280.003 600.468 570.029 830.060 420.002 2546513839021378696
11HN-07-111955650.350.050 730.002 780.419 740.023 740.060 050.002 0022812635617376794
11HN-07-124074240.960.071 610.004 041.660 430.096 890.167 740.005 53976116994371 0003199
11HN-07-132525470.460.055 860.002 680.550 550.026 420.071 350.002 2345610344517444899
11HN-07-142635510.480.053 130.002 920.425 560.025 410.057 900.001 8434512136018363599
11HN-07-151 0181 4580.700.051 910.001 970.423 580.016 520.058 930.001 822838735912369797
11HN-07-164259430.450.111 550.003 895.063 800.184 630.327 780.010 831 825631 830311 8285399
11HN-07-174641 1300.410.054 190.002 340.448 440.020 110.059 680.001 963899637614374399
11HN-07-184289070.470.051 920.002 410.419 790.019 300.058 440.001 8728310635614366497
11HN-07-194193941.060.097 950.003 803.781 600.148 280.278 670.009 011 587731 589311 5854599
11HN-07-204894221.160.075 910.003 931.929 250.107 700.183 140.006 541 0941041 091371 0843699
11HN-07-214651 1190.420.051 310.002 270.425 000.019 100.059 960.001 9525410236014375795
11HN-07-224948690.570.053 750.002 560.439 570.021 710.059 210.002 0136110737015371499
11HN-07-233056640.460.054 200.003 060.449 160.026 410.060 100.002 2238912337719376599
11HN-07-255351 5620.340.052 570.002 520.429 750.021 610.059 170.002 04309109363153711297
11HN-07-263489100.380.053 200.002 820.518 180.028 460.070 410.002 3934512042419439996
11HN-07-271 9233 6050.530.053 670.002 230.432 120.019 940.058 130.002 0936797365143641399
11HN-07-282826640.420.054 660.003 260.422 290.024 400.056 190.002 0139813535817352698
11HN-07-292451 0090.240.074 620.003 231.965 750.104 380.190 230.008 371 057871 104361 1234598
11HN-07-303116500.480.057 970.003 060.480 560.025 330.060 060.001 9852811539817376294
11HN-07-311714290.400.057 780.003 410.482 030.029 160.060 350.002 1352013439920378894
11HN-07-323462691.290.166 490.006 6411.014 300.475 150.477 900.017 352 524672 524402 5187699
11HN-07-333826820.560.093 020.003 603.341 690.131 590.259 430.008 261 489741 491311 4874299
11HN-07-349178081.130.109 230.004 054.984 290.190 020.329 470.010 871 787681 817321 8365398
11HN-07-351982 3710.080.072 390.002 721.688 670.066 090.168 380.005 76998761 004251 0033299
11HN-07-365941 4860.400.053 950.002 390.445 590.019 670.059 770.002 0036910037414374499
11HN-07-375949140.650.075 740.003 001.906 730.079 470.181 540.006 151 088801 083281 0753499
11HN-07-384079750.420.057 800.003 080.569 000.032 270.071 070.002 775208445721443896
11HN-07-396308460.740.076 060.003 051.944 590.082 100.184 620.006 601 098811 097281 0923699
11HN-07-406481 2440.520.053 900.002 710.431 230.023 050.057 670.002 0936911336416361499
11HN-07-415881 2360.480.057 650.002 540.476 490.021 660.059 600.002 005179639615373594
11HN-07-421856170.300.052 580.003 080.433 270.024 830.059 750.002 1630913336518374397
11HN-19-018071 5500.520.106 440.002 984.771 530.136 710.323 300.008 711 739521 780241 8064298
11HN-19-024087620.530.163 870.004 5510.739 510.305 830.473 070.012 812 496462 501262 4975699
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11HN-19-046411 3830.460.075 260.002 141.853 020.053 110.177 940.004 751 076571 065191 0562699
11HN-19-051702680.630.074 310.002 801.807 790.068 280.176 230.004 761 050761 048251 0462699
11HN-19-06941 7050.060.097 690.002 783.756 900.107 400.278 040.007 391 581531 584231 5823799
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11HN-19-081552580.600.059 830.002 310.693 690.026 390.084 490.002 3459879535165231497
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11HN-19-112236020.370.068 730.002 051.552 470.047 410.163 620.004 4990062951199772597
11HN-19-121564770.330.108 910.003 215.076 500.152 380.337 300.009 111 781541 832251 8744497
11HN-19-133784830.780.111 050.003 255.230 050.156 660.340 940.009 311 817531 858261 8914598
11HN-19-147041 7730.400.079 690.002 322.243 280.065 100.203 540.005 401 191621 195201 1942999
11HN-19-156426231.030.097 700.002 803.885 190.113 410.287 780.007 831 581531 611241 6303998
11HN-19-163305300.620.057 070.002 190.586 360.022 410.074 480.002 064948346914463598
11HN-19-174477440.600.075 580.005 331.636 580.050 760.167 770.004 711 08320984201 0002698
11HN-19-184745770.820.074 690.002 261.969 690.059 460.191 010.005 191 061611 105201 1272898
11HN-19-194731 2280.390.114 170.003 365.307 760.160 370.335 500.009 241 933541 870261 8654599
11HN-19-2071900.790.158 900.005 1010.156 740.328 610.462 580.013 012 444542 449302 4515799
11HN-19-219229400.980.081 010.002 392.556 650.076 430.227 950.006 261 222581 288221 3243397
11HN-19-222042920.700.075 350.002 531.698 690.056 730.163 780.004 501 080671 008219782596
11HN-19-238083292.460.064 920.002 231.313 390.044 380.146 430.003 9777272852198812296
11HN-19-243817220.530.136 410.004 376.118 030.218 410.320 190.009 842 183561 993311 7914889
11HN-19-254292 0670.210.070 130.002 231.670 100.052 860.171 940.004 7293132997201 0232697
11HN-19-264171 7520.240.071 450.002 201.807 460.057 290.182 510.005 14972631 048211 0812896
11HN-19-273732 0500.180.071 070.002 111.869 660.057 040.189 650.005 25961241 070201 1192895
11HN-19-281 0194 5430.220.053 700.001 620.530 590.017 080.071 200.002 053677343211443697
11HN-19-298881 4760.600.055 620.001 720.539 110.016 780.069 990.001 904396943811436799
11HN-19-308221 9800.420.076 640.002 252.273 650.067 060.214 060.005 781 122581 204211 2503196
11HN-19-315301 6190.330.110 310.003 165.075 160.148 750.331 940.009 191 806531 832251 8484499
11HN-19-326837660.890.071 350.002 161.616 140.049 510.163 520.004 4396961976199762599
11HN-19-336179020.680.106 150.003 054.858 490.145 230.330 990.009 471 800531 795251 8434697
11HN-19-341 2489891.260.056 850.001 830.723 160.023 250.092 030.002 5348770553145681597
11HN-19-352962951.000.075 590.002 542.319 890.077 370.223 180.006 381 084311 218241 2993493
11HN-19-373435760.600.101 910.003 074.062 340.128 810.287 730.008 261 659561 647261 6304198
11HN-19-399819601.020.069 100.002 161.397 400.043 610.146 850.004 2490265888188832499
11HN-19-407871 3840.570.054 980.001 930.546 080.018 220.072 080.002 024137844212449798
11HN-19-418829020.980.069 980.002 101.706 230.052 010.175 830.004 80928621 011201 0442696
11HN-19-422322600.900.054 900.002 560.554 650.026 690.072 630.002 0840910444817452499
11HN-19-43951730.550.072 210.002 111.622 210.048 920.162 750.004 8899259979199722799
11HN-19-441241920.640.076 460.002 221.975 970.058 900.187 250.005 571 107581 107201 1063099
11HN-19-45752660.280.082 820.002 412.341 480.069 800.204 970.006 111 265571 225211 2023398
11HN-19-461351301.030.071 930.002 101.620 310.047 880.163 270.004 8098359978199752799
11HN-19-472282061.100.059 040.001 730.578 440.017 540.070 900.002 105696546311442895
11HN-19-481703000.570.056 380.001 660.465 380.014 600.059 580.001 794783238810373496
11HN-19-49972770.350.071 180.002 071.584 270.046 780.161 290.004 7596359964189642699
11HN-19-50102821.240.112 340.003 274.909 150.144 730.316 770.009 321 839581 804251 7744698
11HN-19-5167870.780.108 640.003 164.752 640.140 240.316 970.009 291 777521 777251 7754599
11HN-19-5288861.020.108 330.003 164.728 960.143 050.315 940.009 421 772531 772251 7704699
11HN-19-531451301.120.080 290.002 342.087 420.061 960.188 550.005 591 206571 145201 1143097
11HN-19-54120542.240.118 660.003 465.530 080.162 500.338 460.010 011 936521 905251 8794898
11HN-19-551291390.930.073 530.002 141.732 140.051 500.170 850.005 061 028591 021191 0172899
11HN-19-562602591.000.055 600.001 630.459 900.013 570.060 010.001 76435673849376497
11HN-19-572792830.980.055 820.001 640.460 390.013 610.059 860.001 77456603859375397
11HN-19-58651050.620.167 440.004 8710.993 420.326 300.476 070.014 112 532492 523282 5106299
11HN-19-5976741.040.162 240.004 7210.440 630.310 900.466 670.013 872 479492 475282 4696199
11HN-19-601092960.370.072 280.002 101.626 900.048 610.163 210.004 8699426981199752799
11HN-19-61691070.650.166 990.004 8810.912 540.321 090.474 720.014 072 527482 516272 5046199
11HN-19-63182872.090.068 400.002 001.549 280.046 310.164 350.004 9088060950189812796
11HN-19-64941330.700.095 810.002 793.862 220.115 050.292 370.008 701 544551 606241 6534397
11HN-19-6576751.010.157 680.004 5910.133 370.307 780.466 010.014 122 431492 447282 4666299
11HN-19-66571180.480.173 550.005 0511.840 910.357 540.494 760.014 912 592482 592282 5916499
11HN-19-67941310.720.111 290.003 244.989 830.148 520.325 240.009 681 821521 818251 8154799
11HN-19-68642010.320.111 360.003 245.003 440.149 010.325 990.009 711 822531 820251 8194799
11HN-19-69882670.330.070 730.002 101.545 260.047 040.158 480.004 7495061949199482699
11HN-19-702212650.830.056 230.001 640.554 390.016 790.071 550.002 164616544811446599
11HN-19-712052970.690.055 660.001 650.465 150.013 900.060 610.001 774396538810379297
11HN-19-7247990.470.160 030.004 6710.227 810.302 270.463 580.013 622 457502 456272 4556099
11HN-19-731692570.660.054 890.001 670.454 300.013 970.060 050.001 784096938010376298
11HN-19-741591920.830.071 350.002 081.591 940.047 120.161 830.004 7796959967189672699
11HN-19-7567960.700.153 960.004 489.501 820.282 160.447 720.013 282 390502 388272 3855999
11HN-19-76681190.570.108 420.003 174.807 210.145 730.320 850.009 531 773531 786251 7944799
11HN-19-771602250.710.070 880.002 091.444 420.056 290.147 110.005 2095460908238852997
11HN-19-78601450.410.120 770.003 525.641 180.167 430.338 780.010 031 969531 922261 8814897
11HN-19-79701570.450.105 750.003 083.880 000.117 140.266 040.008 011 728531 610241 5214194
11HN-19-80823900.210.072 360.002 111.626 490.049 820.162 780.004 8999627981199722799
11HN-19-811002130.470.075 970.002 221.922 220.056 730.183 670.005 431 094291 089201 0873099
11HN-19-821202720.440.070 850.002 061.587 790.047 390.162 500.004 8395460965199712799
11HN-23-01381820.210.103 850.002 704.150 430.110 910.289 760.007 731 694441 664221 6403998
11HN-23-02701070.660.101 750.002 654.104 830.110 340.292 520.007 861 657491 655221 6543999
11HN-23-03803070.260.070 950.001 851.556 180.042 510.159 030.004 3496754953179512499
11HN-23-04621440.430.055 990.001 510.483 820.013 350.062 730.001 69454594019392397
11HN-23-051111120.990.072 610.001 891.650 840.044 020.164 820.004 381 00353990179842499
11HN-23-06611410.440.113 040.002 945.037 450.134 580.323 210.008 651 850421 826231 8054298
11HN-23-08841280.660.100 180.002 613.144 980.084 350.227 670.006 101 628441 444211 3223291
11HN-23-09421660.250.113 770.002 965.236 830.146 430.333 920.009 341 861471 859241 8574599
11HN-23-10983880.250.054 490.001 430.465 080.012 550.061 840.001 65391593889387899
11HN-23-11661260.530.065 610.001 780.947 780.027 640.105 080.003 0479453677146441895
11HN-23-121672600.640.056 770.001 480.539 990.014 380.069 010.001 83483534389430998
11HN-23-141202000.600.056 320.001 470.457 390.012 280.058 920.001 58465573829369696
11HN-23-15641840.350.072 440.001 891.574 830.041 640.157 710.004 1699852960169442398
11HN-23-16631350.470.113 560.002 965.071 440.135 300.323 960.008 621 857471 831231 8094298
11HN-23-171972100.940.055 890.001 470.544 410.015 030.070 740.001 954565944110441899
11HN-23-1877920.830.112 500.002 935.005 360.134 850.322 810.008 661 840471 820231 8034299
11HN-23-2047820.580.103 880.002 724.268 570.118 240.297 790.008 051 695441 687231 6804099
11HN-23-21341790.190.154 820.004 048.186 260.219 010.384 050.010 252 400442 252242 0954892
11HN-23-221232290.540.056 370.001 490.477 420.012 960.061 530.001 65478593969385497
11HN-23-23551360.400.124 310.003 246.079 550.164 030.355 090.009 512 020461 987241 9594598
11HN-23-241442100.690.058 000.001 510.680 170.018 770.085 160.002 335325752711527699
11HN-23-252002490.800.055 810.001 460.531 120.014 750.069 080.001 894565743310431699
11HN-23-262607090.370.073 520.002 771.735 350.066 260.170 700.004 841 028761 022251 0162799
11HN-23-273864340.890.070 300.002 751.611 980.064 140.166 010.004 9193981975259902798
11HN-23-285324981.070.059 070.002 600.761 650.033 700.093 250.002 685699457519575499
11HN-23-291 0057651.310.077 230.002 792.056 960.077 510.192 280.005 841 128721 135261 1343299
11HN-23-311122 7720.040.059 250.002 200.775 760.028 580.094 410.002 715768058316582599
11HN-23-326351 7490.360.161 810.005 8310.334 930.368 780.460 750.013 202 476942 465332 4435899
11HN-23-3384960.880.160 690.006 3810.336 810.424 590.465 010.014 812 463672 465382 4626599
11HN-23-341764250.410.056 440.003 770.591 670.040 120.075 830.002 5747814447226471499
11HN-23-358052 4940.320.075 310.002 501.908 420.071 070.182 930.005 831 076671 084251 0833299
11HN-23-362051 2020.170.073 680.002 831.765 360.086 890.173 230.007 261 032781 033321 0304099
11HN-23-371281360.940.097 850.004 773.877 180.190 040.288 270.009 681 584861 609401 6334898
11HN-23-381647650.210.113 860.004 005.280 200.193 370.335 480.009 901 862631 866311 8654899
11HN-23-392861 1820.240.070 160.002 751.472 430.058 040.151 810.004 4093381919249112599
11HN-23-404348110.540.058 120.004 160.473 340.031 640.059 760.002 4060015739322374794
11HN-23-416661 0220.650.106 940.003 554.619 220.159 750.312 400.009 241 748611 753291 7534599
11HN-23-425371 5930.340.073 110.002 631.652 730.059 240.163 430.004 751 01773991239762698
11HN-23-436468950.720.057 690.003 360.475 960.026 570.059 900.002 0751713039518375594
11HN-23-441852350.790.204 870.007 9414.903 110.607 390.525 520.016 752 865632 809392 7237196
11HN-23-453265400.600.183 030.006 1312.994 580.436 610.512 870.014 312 681562 679322 6696199
11HN-23-463173111.020.066 100.003 411.218 900.063 200.133 500.004 06809112809298082399
11HN-23-473945700.690.055 990.003 290.549 320.031 570.071 080.002 1445413044521443499
11HN-23-483044320.700.172 760.005 8511.722 890.413 690.490 190.014 582 584562 583332 5716399
11HN-23-495261 0640.490.077 840.002 951.993 160.076 730.184 960.005 481 143761 113261 0943098
11HN-23-503938420.470.059 310.002 970.597 890.028 460.073 570.002 5658910947618458796
11HN-23-514053081.310.070 500.003 001.564 760.067 780.160 600.004 8394387956279602799
11HN-23-523938010.490.077 780.002 802.080 910.078 910.193 210.005 731 143391 143261 1393199
11HN-23-534317270.590.072 810.003 051.623 010.068 290.161 420.004 801 00990979269652798
11HN-23-545969580.620.109 830.003 864.905 570.177 680.322 700.009 071 798641 803311 8034499
11HN-23-554154840.860.108 240.004 204.818 730.192 560.322 210.009 751 770711 788341 8004899
11HN-23-561 0191 0021.020.110 540.004 224.818 360.183 730.315 520.009 401 809691 788321 7684698
11HN-23-572052590.790.103 630.004 064.260 860.174 450.297 690.009 081 700721 686341 6804599
11HN-23-582166520.330.098 610.003 523.697 480.131 130.271 190.007 641 598671 571281 5473998
11HN-23-597381 6880.440.056 010.002 170.553 910.022 470.071 650.002 3645411844815446799
11HN-23-602005990.330.203 410.006 7515.409 950.535 310.547 640.016 332 854542 841332 8156899
11HN-23-613121 5060.210.056 420.002 540.463 890.021 940.059 420.002 0047810038715372296
11HN-23-621 0792 0730.520.078 840.002 692.136 590.074 220.195 810.005 611 169691 161241 1533099
11HN-23-634475330.840.100 300.003 714.029 720.157 960.290 960.009 571 629691 640321 6464899
11HN-23-641381 7060.080.107 670.004 484.276 500.189 530.286 890.008 701 761761 689361 6264496
11HN-23-653016080.490.057 130.003 500.571 040.034 950.072 640.002 4549813645923452598
11HN-45-01942000.470.077 080.002 241.969 340.058 380.185 370.005 501 124621 105201 0963099
11HN-45-031732480.700.056 560.001 650.502 590.014 760.064 510.001 904766541310403597
11HN-45-04731610.450.096 230.002 803.571 760.105 250.269 310.007 951 554541 543231 5374099
11HN-45-05114951.200.078 870.002 302.097 040.061 790.192 970.005 691 169581 148201 1373199
11HN-45-06761580.480.094 250.002 743.426 520.104 650.263 490.008 011 522561 510241 5084199
11HN-45-0792930.990.098 000.002 853.722 040.110 180.275 440.008 141 587541 576241 5684199
11HN-45-081043190.330.058 530.001 840.578 500.022 830.071 920.002 845506946315448696
11HN-45-09942350.400.080 920.002 352.326 120.068 750.208 480.006 161 220571 220211 2213399
11HN-45-101353700.370.055 640.001 620.523 800.015 500.068 300.002 024396542810426699
11HN-45-11651030.630.098 250.002 863.786 340.117 930.279 170.008 601 591601 590251 5874399
11HN-45-121051190.880.079 380.002 312.016 020.059 970.184 150.005 451 183571 121201 0903097
11HN-45-14831130.730.096 740.002 823.563 740.105 700.267 420.007 931 562551 541241 5284099
11HN-45-151572880.550.054 170.001 580.435 170.012 970.058 270.001 73389603679365499
11HN-45-16101971.050.098 430.002 863.568 390.107 540.262 870.007 911 595541 543241 5054097
11HN-45-17481270.380.148 440.004 318.780 580.257 700.429 150.012 622 328502 315272 3025799
11HN-45-18781250.630.094 520.002 753.463 210.102 420.265 890.007 881 520551 519231 5204099
11HN-45-192421550.630.056 940.001 660.613 670.018 060.078 180.002 30500604 8611485599
11HN-45-2052810.640.160 250.004 6510.221 110.300 480.462 500.013 582 458492 455272 4516099
11HN-45-21761230.610.111 260.003 234.940 150.145 760.322 020.009 501 820531 809251 8004699
11HN-45-221412060.690.054 490.001 600.451 530.013 470.060 090.001 78391673789376699
11HN-45-231833020.610.054 600.001 590.471 880.014 030.062 730.001 873946739210392399
11HN-45-241831880.970.056 870.001 660.586 500.017 310.074 870.002 214876546911465799
11HN-45-25683890.180.068 610.001 991.386 100.040 590.146 530.004 3088760883178812499
11HN-45-261902660.710.054 370.001 580.432 400.012 800.057 670.001 70387653659361399
11HN-45-27742150.340.094 550.002 743.478 070.104 030.266 710.007 971 520541 522241 5244199
11HN-45-281552030.760.057 020.001 670.602 510.018 080.076 590.002 2750063479114761099
11HN-45-291732990.580.056 010.001 630.539 950.015 950.069 920.002 074546543811436899
11HN-45-30941050.900.105 570.003 064.449 780.132 390.305 690.009 101 724531 722251 7194599
11HN-45-31461000.460.169 890.004 9311.293 470.334 960.482 040.014 302 556492 548282 5366299
11HN-45-321262850.440.058 030.001 740.460 080.013 620.057 640.001 70532653849361593
11HN-45-33582260.260.103 700.003 014.234 010.126 770.296 410.008 921 692541 681251 6734499
11HN-45-342092110.990.056 130.001 640.550 970.016 340.071 230.002 114576544611444699
11HN-45-35911260.720.090 420.002 633.136 270.093 050.251 670.007 481 435501 442231 4473999
11HN-45-36453720.120.075 700.002 201.888 900.055 750.181 000.005 361 087581 077201 0722999
11HN-45-37602930.200.071 070.002 061.568 860.045 940.160 130.004 7096160958189572699
11HN-45-38953870.250.059 230.001 720.761 180.023 090.093 090.002 8057665575135741799
11HN-45-392072330.890.054 800.001 600.467 150.013 830.061 840.001 824066738910387399
11HN-45-402052610.790.054 450.001 610.441 560.013 490.059 100.001 873916737110370299
11HN-45-412012760.730.054 910.001 600.452 880.013 370.059 850.001 77409653799375498
11HN-45-421482960.500.057 480.001 680.559 490.016 430.070 770.002 095096545111441897
11HN-45-431312170.600.056 940.001 710.467 060.014 740.059 220.001 755006738910371795
11HN-45-442092540.820.054 470.001 580.441 830.012 970.058 820.001 72391653729368599
11HN-45-461573330.470.054 110.001 570.431 550.012 880.057 810.001 72376653649362699
11HN-45-471742250.770.058 750.001 780.585 330.017 600.072 460.002 135676746811451896
11HN-45-48852150.400.071 280.002 071.527 920.045 390.155 440.004 6196564942189312698
11HN-45-491821860.980.058 260.001 710.442 610.013 230.055 120.001 63539693729346492
11HN-45-502162650.820.054 460.001 580.425 270.012 590.056 620.001 67391653609355398
3 测试结果

随机挑选的230颗碎屑锆石颗粒岩浆生长环带清晰(图 4),Th/U值多为0.10~1.77,显示出明显岩浆锆石特征,详细数据见表 1图 5

图 4 海南岛北部晚古生代砂岩代表性样品碎屑锆石CL图像 Figure 4 Representative CL images of detrital zircons from the sandstone in the northern Hainan Island
图 5 海南岛北部晚古生代砂岩锆石U-Pb年龄谐和图及频率分布直方图 Figure 5 Diagrams of zircon U-Pb concordia and probability density plots for the Late Paleozoic sandstone samples in the northern Hainan Island

样品11HN-07:样品锆石颗粒细小(粒径小于100 μm),多呈短柱状、椭圆状,无色或棕色,有明显韵律环带。42颗锆石颗粒U-Pb同位素分析中除1个数据点偏离谐和线外,其他41点均落于或靠近谐和线,有较高谐和度(图 5a)。测得206Pb/238U (<1 000 Ma)及207Pb/206Pb (>1 000 Ma)年龄为2 524~352 Ma。除少量碎屑锆石数据记录太古宙年龄信息外(3颗锆石),根据样品年龄及其频率分布特征大致可以分为4组:第1组20颗锆石年龄于383~352 Ma处聚集形成显著峰(图 5e),约占分析数量的49%,206Pb/238Pb年龄加权平均值为(372.0±3.5) Ma (MSWD=0.64);第2组锆石(n=3, 8%)年龄为444~439 Ma,峰值为440 Ma;第3组碎屑锆石年龄为1 150~960 Ma(n=8, 约占分析数量的20%)形成宽缓峰;第4组碎屑锆石(n=7, 17%)年龄为1 825~1 372 Ma (图 5e)。

样品11HN-19:碎屑锆石颗粒呈棕色,粒径30~100 μm,短柱状或椭圆状,韵律环带清晰,Th/U值大于0.10,显示明显岩浆成因锆石特征。79组谐和度较高的LA-ICP-MS U-Pb年龄表明,碎屑锆石中除少量颗粒具有震旦纪和新元古代晚期的年龄信息(如728~523 Ma)外(图 5f),其余样品的年龄大致可分为5组:第1组5颗锆石年龄为379~373 Ma,约占分析数量的6%,锆石206Pb/238U年龄加权平均值为(376.6±4.3) Ma (MSWD=0.23);第2组锆石(n=11, 14%)206Pb/238U年龄加权平均值为(449.0±8.7 Ma) (MSWD=0.39);第3组碎屑锆石(n=34,占分析颗粒的43%)主体年龄为1 265~876 Ma,虽然时代跨度较大,但没有明显的年龄间断,在年龄频率直方图(图 5f)上可以看出,该组年龄以973 Ma为主;第4组碎屑锆石(n=19, 占分析颗粒的24%)年龄为1 969~1 544 Ma,以1 799及1 584 Ma为主(图 5f);第5组锆石(n=10, 13%)207Pb/206Pb年龄为2 952~2 183 Ma,形成宽缓峰。

样品11HN-23:样品锆石颗粒较小,一般粒径小于100 μm,阴极发光图像上大多数显示清晰的韵律环带结构(图 4)。U、Th质量分数分别为(82~2 772)×106、(34~1 079)×106,Th/U值除11HN-23-31,11HN-23-64两点小于0.10之外,其他数据点集中于0.17~1.31,显示锆石主要为岩浆岩物源区。样品65颗锆石,除11HN-23-07、19、30、66这4个数据点明显偏离谐和线(后期构造热事件造成Pb丢失)不参与讨论外,其他61点均较好地落在谐和线上或其附近(图 5c),测得的206Pb/238U (<1 000 Ma)及207Pb/206Pb (>1 000 Ma)年龄为2 865~369 Ma。碎屑锆石中除少量颗粒具有震旦纪年龄信息(如644~527 Ma)外(图 5g),其余样品的年龄大致可分为5组:第1组7颗锆石为392~369 Ma,约占分析总量的11%,锆石206Pb/238U年龄加权平均值为(378.1±8.4) Ma (MSWD=1.7);第2组碎屑锆石年龄数据为471~430 Ma (n=8, 13%),锆石206Pb/238U年龄加权平均值为(450.0±12.0) Ma (MSWD=1.4);第3组碎屑锆石年龄为1 169~911 Ma(n=16,约占分析总量的24%),主体年龄为965及1 137 Ma;第4组年龄(n=18, 29%)为1 862~1 584 Ma,期间没有明显的年龄间断,在年龄频率直方图(图 5g)上可以看出,该组年龄以1 692、1 850 Ma为主;第5组锆石(n=8, 13%)207Pb/206Pb年龄为2 865~2 020 Ma,形成宽缓峰。

样品11HN-45:镜下观察样品锆石颗粒粒径为50~120 μm,韵律环带结构明显,U质量分数为(81~389)×106,Th质量分数为(45~242)×106,Th/U值为0.12~1.20,均大于0.10,指示锆石岩浆成因。11HN-45-02、13、45不谐和度>10%予以剔除之外,获取47组碎屑锆石年龄数据,为2 556~346 Ma。除1颗碎屑锆石颗粒记录震旦纪(574 Ma)信息外,其他组年龄数据在403~346 Ma (n=14, 30%)处形成主峰,206Pb/238U年龄加权平均值为(369.0±7.9) Ma (MSWD=4.0);在485~426 Ma(n=9, 19%)形成次级峰,206Pb/238U年龄加权平均值为(452.0±16.0) Ma (MSWD=1.9);8颗锆石颗粒年龄为1 220~881 Ma,约为分析数据的17%;12组年龄数据在1 820~1 435 Ma形成宽缓峰(图 5dh),占分析数据的26%;3组年龄数据为2 556~2 328 Ma,形成宽缓峰,占分析数据的6%。

4 沉积时代

本次对海南岛北部邦溪地区原划为奥陶系南碧沟组样品(11HN-19)、琼海、儋州地区原划为志留系陀烈组样品(11HN-07、23) 及屯昌地区下二叠统峨查组样品(11HN-45) 的测试结果显示,所测试的变砂岩均记录有1 862~1 435、1 265~911、485~430、392~346 Ma四组年龄信息及少量太古宙信息。最小年龄组(392~346 Ma)在4个样品内均有显示,峰期年龄为380~369 Ma(图 5e, f, g, h)。总体上,该组年龄数据质量较好,可以作为分析研究区变砂岩沉积时代下限的有力证据。严格意义上讲,如果忽略分析误差,碎屑锆石中最小年龄代表了原岩沉积的年龄下限[6-8]。4个样品中碎屑锆石最小年龄分别为373、369、352及346 Ma,与陈新跃等[19]报道的屯昌地区原划为二叠系安山岩给出的346 Ma锆石结晶年龄一致,指示所测试样品地层更应该沉积于早石炭世或早石炭世以后,而非前人所认为的奥陶纪或志留纪。

海南岛二叠纪—三叠纪侵入岩广泛分布,岩石类型复杂多样,从基性到酸性岩均有出露。谢才富等[20]识别出琼中五指山地区二叠纪中基性侵入岩形成于(272±7) Ma;琼中五指山地区及万宁、陵水、乐东地区等地与俯冲作用相关的弧花岗岩体,SHRIMP及LA-ICPMS锆石U-Pb年龄为272~262 Ma[21-23];琼海烟塘岩体单颗粒锆石U-Pb年龄为248 Ma[24];琼中岩基三叠纪岩体锆石SHRIMP U-Pb年龄为238~236 Ma[25],单颗粒锆石U-Pb年龄为(234.2 ± 2.3)~(226.5± 2.9) Ma[26];万宁地区辉长岩结晶年龄为240 Ma[27];琼西南地区三叠纪基性岩脉锆石U-Pb年龄为(242.2±2.6) Ma[28];公爱地区韧性剪切带变形年龄为250~248 Ma[29];琼中花岗岩体形成年龄为(237±3) Ma,尖峰岭岩体结晶于(249±5) Ma[30]。以上表明,海南岛广泛发育的二叠纪—三叠纪岩浆作用主要集中于272~237 Ma,而所测试的3个年龄数据中最年轻锆石年龄分别为352、369、373 Ma,均没有该期岩浆事件的记录,指示该地层沉积时代应早于270 Ma。另外,龙文国等[5]在儋州—屯昌一带该套变质岩系顶部原划为石炭系石岭组内采获早—中二叠世的放射虫Pseudoalbaillella sp.(假阿尔拜虫属),将其划归为早二叠世鹅顶组,从古生物化石方面限定了该套变质岩系的沉积上限。因此,本次对海南岛北部邦溪地区原划为奥陶系南碧沟组样品(11HN-19),琼海、儋州地区原划为志留系陀烈组样品(11HN-07、23) 及屯昌地区下二叠统峨查组样品(11HN-45) 的测试结果显示,该研究样品应归属于石炭系—下二叠统。海南岛北部邦溪、琼海、儋州地区原南碧沟组及原陀烈组的划分需要重新考虑,至少有一部分应划归为石炭系—下二叠统。

5 地层年龄谱系特征与意义

本次对海南岛4个沉积岩样品的分析测试表明,测得的230组碎屑锆石除少数锆石颗粒记录了太古宙的信息外,其余U-Pb年代学数据主要集中于1 862~1 435,1 265~911,485~430及392~346 Ma,并在373 Ma处聚集形成主峰,在980及447 Ma形成次级峰(图 6)。目前,古元古代—中元古代年龄信息被认为与Cloumbia超大陆的聚合、离散有关[37],现有的报道表明该时期的岩浆信息在华夏板块及海南岛本地皆有报道[38-43];中元古代晚期—新元古代早期年龄信息在华夏板块已有大量报道,被认为与Rodinia超大陆的聚合有关[44-47];广西期花岗质类岩浆多显示过铝质性质,被认为代表了Gondwana大陆的最终拼合,广泛分布于华夏板块东南部[14, 46, 48-50];而370 Ma左右的年龄信息则少有报道。

华夏板块数据据文献[31-35], 印支板块数据据文献[13, 36]。 图 6 海南岛北部碎屑锆石U-Pb年龄与其周边块体锆石年龄对比图 Figure 6 Probability curves of ages for detrital zircons from the northern Hainan Island and its surrounding terranes

本次测得的年龄为392~346 Ma的碎屑锆石主要呈长柱状,自形程度较高,峰期年龄为373 Ma(图 5ad, 6a)。目前,370 Ma左右的岩浆岩仅在海南岛昌江、琼海地区出露[51-53]。据Burrett等[13]研究表明,越南中部、老挝长山地区(Truong Son)、泰国北部晚二叠世—三叠纪地层及马来西亚中部晚石炭世—早二叠世地层中出露有年龄为380~330 Ma的碎屑锆石,印支板块内Da Rang河流沙中也出露有石炭纪(约360 Ma)的碎屑锆石[53]。同时,该期次年龄信息在华夏板块内福建永定及湖南耒阳的中—晚二叠世砂岩中也有报道[31]。碎屑岩中约370 Ma显著峰期年龄的识别表明,370 Ma左右的年龄信息不仅在福建永定、湖南耒阳中—晚二叠世砂岩中局部体现[31],更可能代表了晚古生代一次较大范围内的构造岩浆事件。这些碎屑锆石U-Pb年代学数据为探究海南岛及华夏板块的构造演化提供了新资料。

6 结论

1) 海南岛北部邦溪地区原划为奥陶系,儋州、琼海地区原划为志留系的3个代表性样品最小的206Pb/238U表观年龄分别为373、352和369 Ma,与屯昌地区二叠系砂岩年龄谱系相类似。该地区原南碧沟组及原陀烈组的划分需要重新考虑,至少有一部分应划归为石炭系—下二叠统。

2)370 Ma左右的年龄信息可能代表了晚古生代一次较大范围的构造岩浆事件。

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http://dx.doi.org/10.13278/j.cnki.jjuese.201704116
吉林大学主办、教育部主管的以地学为特色的综合性学术期刊
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文章信息

张立敏, 王岳军, 张玉芝, 刘汇川, 张新昌
Zhang Limin, Wang Yuejun, Zhang Yuzhi, Liu Huichuan, Zhang Xinchang
海南岛北部古生界时代:碎屑锆石U-Pb年代学约束
Age of Paleozoic Strata in Northern Hainan Island: Constraints from the Detrital Zircon U-Pb Geochronology
吉林大学学报(地球科学版), 2017, 47(4): 1187-1206
Journal of Jilin University(Earth Science Edition), 2017, 47(4): 1187-1206.
http://dx.doi.org/10.13278/j.cnki.jjuese.201704116

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收稿日期: 2016-10-21

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