Zircon U-Pb Age of Granitoids from the Mamu Pb-Zn Skarn Mineralized Area in Western Gangdese and Its Geological Significance

doi:10.19657/j.geoscience.1000-8527.2021.038

Abstract

Abstract:

The Mamu area in Gakyi, Tibet,China is a Pb-Zn skarn mineralized zone discovered in recent years. The area is located on the southern margin of the western central Gangdese metallogenic belt (or the central Lhasa terrane). Mineralization occurred in the contact zone between granite porphyry and limestone. Metallic minerals include galena, sphalerite, magnetite, specularite, and pyrite, whilst non-metallic ones include garnet, diopside, rhodonite, actinolite, epidote, quartz, feldspar, and calcite. Alteration styles include silicic, argillic, marl, and chlorite. The mineralization is hosted in the Jiega Formation (Fm.) limestone. To obtain geochronological constraints on the magmatism and mineralization, the granite porphyry is LA-ICP-MS zircon U-Pb dated to be (117.6±0.4) Ma, which shows that ore-causative porphyry was emplaced in the Early Cretaceous. The age of crystal lithic tuff is (119.7±0.5) Ma, and the tuff should thus belong to the Zenong Group (J₃K₁Z) instead of the Dianzhong Formation (E₁d) in the 1∶250,000 Yagra Geologic Map Sheet. The study area experienced intense medium-felsic volcanism and plutonism in the Early Cretaceous. Combined with previous studies, the deep geodynamic background was mainly controlled by the south-dipping subduction of the Bangong-Nujiang Suture Zone. As an Early Cretaceous Pb-Zn mineralization event, the Mamu Pb-Zn prospect is of great significance to supplement the study of regional Pb-Zn mineralization and to improve our understanding on multi-phase Pb-Zn metallogenic events.

Key words: zircon U-Pb age, Early Cretaceous magmatism, Pb-Zn mineralization, western Gangdese metallogenic belt

CLC Number:

P588.1
P597

LIU Chang, YANG Zhusen, XU Peiyan, ZHAO Xiaoyan, XIA Wenjie, YANG Xiaoxu. Zircon U-Pb Age of Granitoids from the Mamu Pb-Zn Skarn Mineralized Area in Western Gangdese and Its Geological Significance[J]. Geoscience, 2021, 35(02): 466-476.

Figures/Tables 8

References 46

[1]	戴自希, 盛继福, 白冶, 等. 世界铅锌资源的分布与潜力[M]. 北京: 地震出版社, 2005: 1-387.
[2]	戴自希, 张家睿. 世界铅锌资源和开发利用现状[J]. 世界有色金属, 2004(3):22-29.
[3]	侯增谦, 王二七. 印度—亚洲大陆碰撞成矿作用主要研究进展[J]. 地球学报, 2008,29(3):275-292.
[4]	于玉帅, 高原, 杨竹森, 等. 西藏措勤尼雄矿田滚纠铁矿侵入岩LA-ICP-MS锆石U-Pb年龄与地球化学特征[J]. 岩石学报, 2011,27(7):1949-1960.
[5]	邬秋敏, 陈翠华, 涂宗林, 等. 西藏蒙亚啊铅锌矿床矽卡岩矿物特征及其意义[J]. 现代地质, 2018,32(5):874-886.
[6]	李波, 胡道功, 林广奇, 等. 西藏甲玛矿区侵入岩成岩成矿年龄[J]. 现代地质, 2016,30(6):1234-1243.
[7]	付强, 杨竹森, 郑远川, 等. 加拉普铁矿区花岗闪长岩锆石U-Pb年龄、Hf同位素及地球化学研究[J]. 矿床地质, 2013,32(3):564-578.
[8]	程顺波, 庞迎春, 曹亮, 等. 西藏蒙亚啊矽卡岩铅锌矿床的成因探讨[J]. 华南地质与矿产, 2008,24(3):50-56.
[9]	高明, 张少波, 岳国利, 等. 西藏亚贵拉铅锌矿床地质特征及成因浅析[J]. 沉积与特提斯地质, 2010,30(2):97-102.
[10]	费光春, 温春齐, 王成松, 等. 西藏墨竹工卡县洞中拉铅锌矿床花岗斑岩锆石SHRIMP U-Pb定年[J]. 中国地质, 2010,37(2):470-476.
[11]	张遵遵, 李泽琴, 王奖臻, 等. 西藏冈底斯成矿带中铅锌矿床的成矿特征[J]. 地质找矿论丛, 2013,28(1):34-40.
[12]	FU Q, XU B, ZHENG Y C, et al. Two episodes of mineralization in the Mengya’a deposit and implications for the evolution and intensity of Pb-Zn-(Ag) mineralization in the Lhasa terrane, Tibet[J]. Ore Geology Reviews, 2017,90:877-896. DOI URL
[13]	侯增谦, 宋玉财, 李政, 等. 青藏高原碰撞造山带Pb-Zn-Ag-Cu矿床新类型: 成矿基本特征与构造控矿模型[J]. 矿床地质, 2008,27(2):123-144.
[14]	谭钢, 佘宏全, 常帼雄, 等. 西藏冈底斯多金属成矿带铅锌矿定位预测与资源潜力评价[J]. 岩石矿物学杂志, 2011,30(1):83-96.
[15]	HOU Z Q, LU Q T, QU X M, et al. Metallogenesis in the Tibetan collisional orogenic Belt[M]//Mineral Deposit Research: Meeting the Global Challenge. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005: 1231-1233.
[16]	HUANG K X, ZHENG Y C, ZHANG S, et al. LA-ICP-MS zircon U-Pb dating of two types of porphyry in the Yaguila mining area, Tibet[J]. Acta Petrologica et Mineralogica, 2012,31(3):348-360.
[17]	ZHENG Y C, FU Q, HOU Z Q, et al. Metallogeny of the northeastern Gangdese Pb-Zn-Ag-Fe-Mo-W polymetallic belt in the Lhasa terrane, southern Tibet[J]. Ore Geology Reviews, 2015,70:510-532. DOI URL
[18]	HOU Z Q, DUAN L F, LU Y J, et al. Lithospheric architecture of the Lhasa terrane and its control on ore deposits in the Himalayan-Tibetan orogen[J]. Economic Geology, 2015,110(6):1541-1575. DOI URL
[19]	侯增谦, 赵志丹, 高永丰, 等. 印度大陆板片前缘撕裂与分段俯冲: 来自冈底斯新生代火山-岩浆作用证据[J]. 岩石学报, 2006,22(4):761-774.
[20]	侯增谦, 潘桂棠, 王安建, 等. 青藏高原碰撞造山带:Ⅱ. 晚碰撞转换成矿作用[J]. 矿床地质, 2006,25(5):521-543.
[21]	XU R H, SCHÄRER U, ALLÈGRE C J. Magmatism and metamorphism in the Lhasa block (Tibet): A geochronological study[J]. The Journal of Geology, 1985,93(1):41-57. DOI URL
[22]	HARRIS N B W, INGER S, XU R H. Cretaceous plutonism in Central Tibet: An example of post-collision magmatism?[J]. Journal of Volcanology and Geothermal Research, 1990,44(1/2):21-32. DOI URL
[23]	KIRSTEIN L A, PEATE D W, HAWKESWORTH C J, et al. Early Cretaceous basaltic and rhyolitic magmatism in southern uruguay associated with the opening of the south Atlantic[J]. Journal of Petrology, 2000,41(9):1413-1438. DOI URL
[24]	朱弟成, 莫宣学, 王立全, 等. 新特提斯演化的热点与洋脊相互作用:西藏南部晚侏罗世—早白垩世岩浆作用推论[J]. 岩石学报, 2008,24(2):225-237.
[25]	朱弟成, 莫宣学, 赵志丹, 等. 西藏南部二叠纪和早白垩世构造岩浆作用与特提斯演化:新观点[J]. 地学前缘, 2009,16(2):3-22.
[26]	李吉均, 方小敏. 青藏高原隆起与环境变化研究[J]. 科学通报, 1998,43(15):1569-1574.
[27]	ZHU D C, ZHAO Z D, NIU Y L, et al. The Lhasa Terrane: Record of a microcontinent and its histories of drift and growth[J]. Earth and Planetary Science Letters, 2011,301(1/2):241-255. DOI URL
[28]	朱弟成, 莫宣学, 王立全, 等. 西藏冈底斯东部察隅高分异I型花岗岩的成因: 锆石U-Pb年代学、地球化学和Sr-Nd-Hf同位素约束[J]. 中国科学(D辑: 地球科学), 2009,39(7):833-848.
[29]	宋彪, 张玉海, 万渝生, 等. 锆石SHRIMP样品靶制作、年龄测定及有关现象讨论[J]. 地质论评, 2002,48(增):26-30.
[30]	于超, 杨志明, 周利敏, 等. 激光焦平面变化对LA-ICPMS锆石U-Pb定年准确度的影响[J]. 矿床地质, 2019,38(1):21-28.
[31]	PATON C, WOODHEAD J D, HELLSTROM J C, et al. Improved laser ablation U-Pb zircon geochronology through robust downhole fractionation correction[J]. Geochemistry, Geophysics,Geosystems, 2010, 11(3): Q0AA06.
[32]	LUDWIG K. A plotting and regression program for radiogenic isotope data[J]. Open-File Report, 1991,91.
[33]	HOSKIN P W O, SCHALTEGGER U. The composition of zircon and igneous and metamorphic petrogenesis[M]//HANCHAR J M, HOSKIN P W O. Zircon. Berlin, Boston: De Gruyter, 2003: 27-62.
[34]	朱弟成, 潘桂棠, 莫宣学, 等. 冈底斯中北部晚侏罗世—早白垩世地球动力学环境: 火山岩约束[J]. 岩石学报, 2006,22(3):534-546.
[35]	齐宁远, 赵志丹, 唐演, 等. 西藏中拉萨地块西段左左乡晚侏罗世—早白垩世花岗岩年代学、地球化学与岩石成因[J]. 岩石学报, 2019,35(2):405-422.
[36]	黄泽森, 江巴多吉, 达瓦次仁, 等. 西藏切穷地区早白垩世花岗岩年代学和地球化学特征及其构造环境[J]. 现代地质, 2019,33(4):703-714.
[37]	朱斯豹, 汪雄武, 彭惠娟, 等. 西藏索波贡巴地区中新世花岗岩类与矽卡岩型铅锌矿的关系[J]. 矿床地质, 2010,29(增):365-366.
[38]	田建涛, 喻亨祥, 扬准, 等. 矽卡岩成因及成矿作用研究进展综述[J]. 中国科技信息, 2005(23):107-107.
[39]	付强, 黄克贤, 郑远川, 等. 西藏蒙亚啊铅锌矿床矽卡岩型矿体白云母Ar-Ar年代学研究及其地球动力学意义[J]. 地质学报, 2015,89(3):569-582.
[40]	费光春, 温春齐, 周雄, 等. 西藏洞中拉铅锌矿床石英激光探针⁴⁰Ar-³⁹Ar定年及地质意义[J]. 矿物岩石, 2010,30(3):38-43.
[41]	段志明, 李光明, 王保弟, 等. 西藏中冈底斯成矿带查个勒铅锌矿床含矿斑岩年代学及其地质意义[J]. 吉林大学学报(地球科学版), 2015,45(6):1667-1690.
[42]	周梦林, 周向科, 卢世银, 等. 西藏列廷冈-勒青拉矽卡岩型Fe-Cu-Pb-Zn多金属矿床白云母⁴⁰Ar/³⁹Ar年龄及其地质意义[J]. 岩石矿物学杂志, 2017,36(2):241-258.
[43]	纪现华, 杨竹森, 于玉帅, 等. 西藏纳如松多铅锌矿床成矿岩体形成机制:岩浆锆石证据[J]. 矿床地质, 2012,31(4):758-774.
[44]	纪现华, 孟祥金, 杨竹森, 等. 西藏纳如松多隐爆角砾岩型铅锌矿床绢云母Ar-Ar定年及其地质意义[J]. 地质与勘探, 2014,50(2):281-290.
[45]	张树志, 郑有业, 高顺宝, 等. 西藏龙根铅锌矿床二长花岗斑岩锆石U-Pb年代学和微量元素地球化学特征[J]. 地质科技情报, 2019,38(3):30-39.
[46]	黄克贤, 郑远川, 张松, 等. 西藏亚贵拉矿区两期岩体LA-ICP-MS锆石U-Pb定年及地质意义[J]. 岩石矿物学杂志, 2012,31(3):348-360.

测点号	含量/10^-6						Th/U		同位素比值						年龄/Ma
测点号	Pb		Th		U		Th/U		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ
MM19-9-1-01	31.5		1 093.0		1 393.0		0.78		0.048 30±0.001 60		0.124 10±0.003 80		0.018 43±0.000 26		104.0±69.0		118.6±3.4		117.7±1.6
MM19-9-1-02	28.8		849.0		1 308.0		0.65		0.048 30±0.001 50		0.123 50±0.003 80		0.018 33±0.000 22		109.0±66.0		118.0±3.5		117.1±1.4
MM19-9-1-03	20.6		601.0		942.0		0.64		0.050 20±0.002 40		0.124 40±0.005 20		0.018 21±0.000 28		158.0±97.0		118.8±4.7		116.3±1.7
MM19-9-1-04	5.9		214.5		250.3		0.86		0.049 80±0.004 60		0.129 00±0.012 00		0.018 59±0.000 37		90.0±180.0		122.0±11.0		118.7±2.4
MM19-9-1-05	8.4		256.1		373.1		0.69		0.049 30±0.003 20		0.126 20±0.008 00		0.018 50±0.000 34		90.0±130.0		120.0±7.2		118.6±2.2
MM19-9-1-06	6.3		199.2		275.5		0.72		0.049 50±0.003 10		0.125 50±0.007 60		0.018 40±0.000 36		130.0±130.0		119.4±6.8		117.5±2.3
MM19-9-1-07	18.7		520.0		780.0		0.67		0.049 30±0.003 10		0.131 90±0.008 20		0.019 60±0.000 42		140.0±130.0		125.3±7.3		125.1±2.6
MM19-9-1-08	25.7		1 123.0		1 073.0		1.05		0.048 30±0.002 10		0.121 60±0.005 30		0.018 10±0.000 29		88.0±88.0		116.2±4.8		116.0±1.8
MM19-9-1-09	5.5		156.2		258.2		0.60		0.049 80±0.004 10		0.127 00±0.010 00		0.018 51±0.000 46		110.0±160.0		121.2±9.3		118.2±2.9
MM19-9-1-10	13.3		302.2		241.6		1.25		0.180 00±0.020 00		0.612 00±0.077 00		0.022 42±0.000 75		2 040.0±250.0		443.0±48.0		142.9±4.7
MM19-9-1-11	8.7		309.3		394.5		0.78		0.049 10±0.002 90		0.122 60±0.006 90		0.018 24±0.000 28		90.0±120.0		116.8±6.2		116.5±1.8
MM19-9-1-12	23.4		658.0		1 069.0		0.62		0.049 00±0.001 90		0.124 80±0.004 70		0.018 47±0.000 23		115.0±79.0		119.0±4.3		118.0±1.5
MM19-9-1-13	10.2		345.8		446.0		0.78		0.047 70±0.003 20		0.122 50±0.007 60		0.018 61±0.000 34		20.0±130.0		116.6±6.8		118.9±2.2
MM19-9-1-14	6.1		264.1		248.6		1.06		0.050 80±0.003 60		0.127 80±0.008 70		0.018 50±0.000 37		110.0±130.0		121.0±7.7		118.1±2.3
MM19-9-1-15	5.6		187.9		241.7		0.78		0.047 50±0.004 00		0.118 80±0.009 90		0.018 29±0.000 40		-20.0±150.0		112.7±8.9		116.8±2.5
MM19-9-1-16	4.4		200.7		172.9		1.16		0.052 00±0.005 80		0.132 00±0.014 00		0.018 80±0.000 51		110.0±210.0		124.0±12.0		120.0±3.3
MM19-9-1-17	7.8		275.1		332.4		0.83		0.048 70±0.002 90		0.124 50±0.007 40		0.018 62±0.000 29		60.0±110.0		118.3±6.6		118.9±1.8
MM19-9-1-18	6.7		232.4		287.7		0.81		0.047 40±0.003 00		0.125 10±0.008 10		0.018 96±0.000 34		30.0±120.0		118.7±7.2		121.1±2.1
MM19-9-1-19	14.8		429.0		678.0		0.63		0.048 30±0.002 70		0.124 40±0.006 80		0.018 56±0.000 40		90.0±110.0		118.6±6.1		118.6±2.5
MM19-9-1-20	5.0		154.6		229.7		0.67		0.051 00±0.003 50		0.127 20±0.008 60		0.018 28±0.000 34		130.0±140.0		120.5±7.7		116.8±2.2
MM19-9-1-21	11.3		299.7		423.0		0.71		0.087 30±0.007 00		0.243 00±0.020 00		0.019 93±0.000 37		1 110.0±150.0		216.0±16.0		127.2±2.4
MM19-9-1-22	4.7		197.3		188.2		1.05		0.055 90±0.004 40		0.146 00±0.012 00		0.018 84±0.000 39		350.0±160.0		136.0±10.0		120.3±2.5
MM19-9-1-23	2.3		79.5		106.0		0.75		0.048 10±0.006 90		0.119 00±0.016 00		0.018 31±0.000 60		-80.0±240.0		111.0±14.0		116.9±3.8
MM19-9-1-24	12.1		317.0		578.0		0.55		0.048 80±0.002 40		0.122 90±0.005 80		0.018 21±0.000 25		91.0±95.0		117.1±5.3		116.3±1.6
MM19-9-1-25	7.4		251.2		321.0		0.78		0.047 90±0.003 20		0.121 20±0.007 70		0.018 58±0.000 33		10.0±130.0		115.2±6.9		118.6±2.1
MM19-9-1-26	11.6		351.0		505.0		0.70		0.048 40±0.002 30		0.126 50±0.005 80		0.018 76±0.000 26		109.0±97.0		120.5±5.2		119.8±1.6
MM19-9-1-27	7.1		247.1		312.8		0.79		0.048 50±0.003 70		0.124 50±0.009 10		0.018 60±0.000 41		50.0±150.0		118.3±8.2		118.8±2.6
MM19-9-1-28	18.3		529.0		848.0		0.62		0.049 00±0.001 90		0.122 90±0.004 70		0.018 23±0.000 21		116.0±80.0		117.4±4.3		116.5±1.3
MM19-9-1-29	26.0		837.0		1 150.0		0.73		0.047 70±0.001 70		0.120 20±0.004 30		0.018 32±0.000 25		70.0±73.0		114.9±3.8		117.0±1.6
测点号		含量/10^-6						Th/U		同位素比值						年龄/Ma
测点号		Pb		Th		U		Th/U		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ
MM19-9-1-30		9.0		297.1		400.8		0.74		0.047 80±0.002 90		0.121 20±0.007 40		0.018 34±0.000 28		40.0±120.0		115.3±6.7		117.1±1.8
MM19-218-1-01		12.4		398.9		543.0		0.73		0.049 00±0.002 60		0.125 20±0.006 60		0.018 56±0.000 26		110.0±110.0		119.2±5.9		118.5±1.7
MM19-218-1-02		4.7		165.2		203.5		0.81		0.049 60±0.003 80		0.127 80±0.009 60		0.018 81±0.000 41		100.0±150.0		120.8±8.6		120.1±2.6
MM19-218-1-03		34.0		995.0		1 447.0		0.69		0.054 90±0.001 60		0.143 50±0.004 00		0.019 04±0.000 26		373.0±63.0		136.0±3.6		121.6±1.6
MM19-218-1-04		5.9		183.3		262.6		0.70		0.049 40±0.003 50		0.129 30±0.009 10		0.018 69±0.000 38		110.0±140.0		122.4±8.2		119.4±2.4
MM19-218-1-05		11.8		529.0		483.0		1.10		0.048 80±0.002 50		0.124 80±0.005 90		0.018 84±0.000 35		90.0±100.0		118.9±5.3		120.6±2.1
MM19-218-1-06		8.6		293.5		370.1		0.79		0.047 80±0.002 90		0.124 50±0.007 60		0.018 85±0.000 29		40.0±120.0		118.3±6.8		120.4±1.8
MM19-218-1-07		5.8		191.5		242.3		0.79		0.047 40±0.003 60		0.126 30±0.009 80		0.019 26±0.000 35		10.0±140.0		119.3±8.7		122.9±2.2
MM19-218-1-08		11.9		432.0		493.0		0.88		0.049 30±0.003 20		0.127 30±0.008 30		0.018 97±0.000 35		120.0±130.0		120.9±7.5		121.1±2.2
MM19-218-1-09		10.5		361.0		449.0		0.80		0.049 50±0.002 60		0.128 90±0.007 00		0.018 88±0.000 29		120.0±110.0		122.4±6.3		120.5±1.9
MM19-218-1-10		16.9		570.0		726.0		0.79		0.048 80±0.002 30		0.126 00±0.005 50		0.018 87±0.000 27		95.0±94.0		120.1±4.9		120.5±1.7
MM19-218-1-11		9.0		306.0		370.0		0.83		0.054 60±0.003 20		0.142 30±0.008 10		0.019 06±0.000 36		290.0±120.0		134.2±7.2		121.7±2.3
MM19-218-1-12		5.8		200.0		248.6		0.80		0.049 00±0.003 60		0.125 00±0.008 80		0.018 68±0.000 33		50.0±140.0		118.5±7.9		119.3±2.1
MM19-218-1-13		8.9		328.1		379.5		0.86		0.050 20±0.003 40		0.126 10±0.008 10		0.018 54±0.000 32		120.0±130.0		119.6±7.3		118.4±2.0
MM19-218-1-14		5.1		163.1		222.8		0.73		0.049 20±0.004 10		0.132 00±0.011 00		0.019 20±0.000 52		80.0±150.0		126.0±10.0		122.6±3.3
MM19-218-1-15		10.7		359.7		465.0		0.77		0.047 60±0.002 60		0.122 40±0.006 40		0.018 74±0.000 29		40.0±110.0		116.6±5.8		119.9±1.9
MM19-218-1-16		18.2		612.0		788.0		0.78		0.048 20±0.002 10		0.125 30±0.005 40		0.018 90±0.000 27		86.0±90.0		119.5±4.9		120.7±1.7
MM19-218-1-17		7.9		359.5		312.1		1.15		0.049 00±0.003 20		0.124 90±0.008 10		0.018 64±0.000 29		90.0±130.0		118.6±7.2		119.1±1.8
MM19-218-1-18		10.8		392.0		475.0		0.83		0.050 20±0.003 20		0.129 40±0.008 90		0.018 40±0.000 44		200.0±140.0		122.9±7.9		117.5±2.8
MM19-218-1-19		3.3		103.1		148.3		0.70		0.051 20±0.005 40		0.130 00±0.013 00		0.018 69±0.000 45		40.0±190.0		122.0±12.0		119.4±2.9
MM19-218-1-20		6.9		206.1		258.7		0.80		0.081 70±0.005 00		0.220 00±0.013 00		0.019 78±0.000 42		1 070.0±120.0		200.0±11.0		126.3±2.7
MM19-218-1-21		9.9		322.4		411.0		0.78		0.046 80±0.002 80		0.124 10±0.007 20		0.019 52±0.000 30		0.0±110.0		118.8±6.6		124.6±1.9
MM19-218-1-22		7.7		302.4		313.4		0.96		0.046 70±0.004 30		0.120 00±0.011 00		0.018 70±0.000 39		-20.0±170.0		113.9±9.6		119.4±2.5
MM19-218-1-23		6.6		236.0		268.3		0.88		0.047 10±0.003 60		0.123 70±0.009 10		0.019 51±0.000 38		-30.0±140.0		117.2±8.1		124.6±2.4
MM19-218-1-24		11.4		343.4		505.0		0.68		0.049 00±0.003 00		0.124 60±0.007 80		0.018 59±0.000 34		90.0±120.0		118.6±7.0		118.7±2.1
MM19-218-1-25		6.5		201.7		283.1		0.71		0.049 20±0.003 30		0.126 60±0.008 40		0.018 82±0.000 35		80.0±130.0		120.0±7.6		120.2±2.2
MM19-218-1-26		6.4		222.7		280.3		0.79		0.049 00±0.003 10		0.123 60±0.007 70		0.018 53±0.000 32		80.0±120.0		117.4±6.9		118.3±2.0
MM19-218-1-27		3.4		112.0		154.3		0.73		0.052 60±0.007 30		0.129 00±0.017 00		0.018 17±0.000 58		110.0±250.0		122.0±15.0		116.0±3.7
MM19-218-1-28		6.3		180.7		278.8		0.65		0.050 50±0.003 70		0.130 00±0.009 40		0.018 87±0.000 40		120.0±140.0		123.9±8.6		120.5±2.6

测点号	含量/10^-6						Th/U		同位素比值						年龄/Ma
测点号	Pb		Th		U		Th/U		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ
MM19-9-1-01	31.5		1 093.0		1 393.0		0.78		0.048 30±0.001 60		0.124 10±0.003 80		0.018 43±0.000 26		104.0±69.0		118.6±3.4		117.7±1.6
MM19-9-1-02	28.8		849.0		1 308.0		0.65		0.048 30±0.001 50		0.123 50±0.003 80		0.018 33±0.000 22		109.0±66.0		118.0±3.5		117.1±1.4
MM19-9-1-03	20.6		601.0		942.0		0.64		0.050 20±0.002 40		0.124 40±0.005 20		0.018 21±0.000 28		158.0±97.0		118.8±4.7		116.3±1.7
MM19-9-1-04	5.9		214.5		250.3		0.86		0.049 80±0.004 60		0.129 00±0.012 00		0.018 59±0.000 37		90.0±180.0		122.0±11.0		118.7±2.4
MM19-9-1-05	8.4		256.1		373.1		0.69		0.049 30±0.003 20		0.126 20±0.008 00		0.018 50±0.000 34		90.0±130.0		120.0±7.2		118.6±2.2
MM19-9-1-06	6.3		199.2		275.5		0.72		0.049 50±0.003 10		0.125 50±0.007 60		0.018 40±0.000 36		130.0±130.0		119.4±6.8		117.5±2.3
MM19-9-1-07	18.7		520.0		780.0		0.67		0.049 30±0.003 10		0.131 90±0.008 20		0.019 60±0.000 42		140.0±130.0		125.3±7.3		125.1±2.6
MM19-9-1-08	25.7		1 123.0		1 073.0		1.05		0.048 30±0.002 10		0.121 60±0.005 30		0.018 10±0.000 29		88.0±88.0		116.2±4.8		116.0±1.8
MM19-9-1-09	5.5		156.2		258.2		0.60		0.049 80±0.004 10		0.127 00±0.010 00		0.018 51±0.000 46		110.0±160.0		121.2±9.3		118.2±2.9
MM19-9-1-10	13.3		302.2		241.6		1.25		0.180 00±0.020 00		0.612 00±0.077 00		0.022 42±0.000 75		2 040.0±250.0		443.0±48.0		142.9±4.7
MM19-9-1-11	8.7		309.3		394.5		0.78		0.049 10±0.002 90		0.122 60±0.006 90		0.018 24±0.000 28		90.0±120.0		116.8±6.2		116.5±1.8
MM19-9-1-12	23.4		658.0		1 069.0		0.62		0.049 00±0.001 90		0.124 80±0.004 70		0.018 47±0.000 23		115.0±79.0		119.0±4.3		118.0±1.5
MM19-9-1-13	10.2		345.8		446.0		0.78		0.047 70±0.003 20		0.122 50±0.007 60		0.018 61±0.000 34		20.0±130.0		116.6±6.8		118.9±2.2
MM19-9-1-14	6.1		264.1		248.6		1.06		0.050 80±0.003 60		0.127 80±0.008 70		0.018 50±0.000 37		110.0±130.0		121.0±7.7		118.1±2.3
MM19-9-1-15	5.6		187.9		241.7		0.78		0.047 50±0.004 00		0.118 80±0.009 90		0.018 29±0.000 40		-20.0±150.0		112.7±8.9		116.8±2.5
MM19-9-1-16	4.4		200.7		172.9		1.16		0.052 00±0.005 80		0.132 00±0.014 00		0.018 80±0.000 51		110.0±210.0		124.0±12.0		120.0±3.3
MM19-9-1-17	7.8		275.1		332.4		0.83		0.048 70±0.002 90		0.124 50±0.007 40		0.018 62±0.000 29		60.0±110.0		118.3±6.6		118.9±1.8
MM19-9-1-18	6.7		232.4		287.7		0.81		0.047 40±0.003 00		0.125 10±0.008 10		0.018 96±0.000 34		30.0±120.0		118.7±7.2		121.1±2.1
MM19-9-1-19	14.8		429.0		678.0		0.63		0.048 30±0.002 70		0.124 40±0.006 80		0.018 56±0.000 40		90.0±110.0		118.6±6.1		118.6±2.5
MM19-9-1-20	5.0		154.6		229.7		0.67		0.051 00±0.003 50		0.127 20±0.008 60		0.018 28±0.000 34		130.0±140.0		120.5±7.7		116.8±2.2
MM19-9-1-21	11.3		299.7		423.0		0.71		0.087 30±0.007 00		0.243 00±0.020 00		0.019 93±0.000 37		1 110.0±150.0		216.0±16.0		127.2±2.4
MM19-9-1-22	4.7		197.3		188.2		1.05		0.055 90±0.004 40		0.146 00±0.012 00		0.018 84±0.000 39		350.0±160.0		136.0±10.0		120.3±2.5
MM19-9-1-23	2.3		79.5		106.0		0.75		0.048 10±0.006 90		0.119 00±0.016 00		0.018 31±0.000 60		-80.0±240.0		111.0±14.0		116.9±3.8
MM19-9-1-24	12.1		317.0		578.0		0.55		0.048 80±0.002 40		0.122 90±0.005 80		0.018 21±0.000 25		91.0±95.0		117.1±5.3		116.3±1.6
MM19-9-1-25	7.4		251.2		321.0		0.78		0.047 90±0.003 20		0.121 20±0.007 70		0.018 58±0.000 33		10.0±130.0		115.2±6.9		118.6±2.1
MM19-9-1-26	11.6		351.0		505.0		0.70		0.048 40±0.002 30		0.126 50±0.005 80		0.018 76±0.000 26		109.0±97.0		120.5±5.2		119.8±1.6
MM19-9-1-27	7.1		247.1		312.8		0.79		0.048 50±0.003 70		0.124 50±0.009 10		0.018 60±0.000 41		50.0±150.0		118.3±8.2		118.8±2.6
MM19-9-1-28	18.3		529.0		848.0		0.62		0.049 00±0.001 90		0.122 90±0.004 70		0.018 23±0.000 21		116.0±80.0		117.4±4.3		116.5±1.3
MM19-9-1-29	26.0		837.0		1 150.0		0.73		0.047 70±0.001 70		0.120 20±0.004 30		0.018 32±0.000 25		70.0±73.0		114.9±3.8		117.0±1.6
测点号		含量/10^-6						Th/U		同位素比值						年龄/Ma
测点号		Pb		Th		U		Th/U		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ		²⁰⁷Pb/²⁰⁶Pb±2σ		²⁰⁷Pb/²³⁵U±2σ		²⁰⁶Pb/²³⁸U±2σ
MM19-9-1-30		9.0		297.1		400.8		0.74		0.047 80±0.002 90		0.121 20±0.007 40		0.018 34±0.000 28		40.0±120.0		115.3±6.7		117.1±1.8
MM19-218-1-01		12.4		398.9		543.0		0.73		0.049 00±0.002 60		0.125 20±0.006 60		0.018 56±0.000 26		110.0±110.0		119.2±5.9		118.5±1.7
MM19-218-1-02		4.7		165.2		203.5		0.81		0.049 60±0.003 80		0.127 80±0.009 60		0.018 81±0.000 41		100.0±150.0		120.8±8.6		120.1±2.6
MM19-218-1-03		34.0		995.0		1 447.0		0.69		0.054 90±0.001 60		0.143 50±0.004 00		0.019 04±0.000 26		373.0±63.0		136.0±3.6		121.6±1.6
MM19-218-1-04		5.9		183.3		262.6		0.70		0.049 40±0.003 50		0.129 30±0.009 10		0.018 69±0.000 38		110.0±140.0		122.4±8.2		119.4±2.4
MM19-218-1-05		11.8		529.0		483.0		1.10		0.048 80±0.002 50		0.124 80±0.005 90		0.018 84±0.000 35		90.0±100.0		118.9±5.3		120.6±2.1
MM19-218-1-06		8.6		293.5		370.1		0.79		0.047 80±0.002 90		0.124 50±0.007 60		0.018 85±0.000 29		40.0±120.0		118.3±6.8		120.4±1.8
MM19-218-1-07		5.8		191.5		242.3		0.79		0.047 40±0.003 60		0.126 30±0.009 80		0.019 26±0.000 35		10.0±140.0		119.3±8.7		122.9±2.2
MM19-218-1-08		11.9		432.0		493.0		0.88		0.049 30±0.003 20		0.127 30±0.008 30		0.018 97±0.000 35		120.0±130.0		120.9±7.5		121.1±2.2
MM19-218-1-09		10.5		361.0		449.0		0.80		0.049 50±0.002 60		0.128 90±0.007 00		0.018 88±0.000 29		120.0±110.0		122.4±6.3		120.5±1.9
MM19-218-1-10		16.9		570.0		726.0		0.79		0.048 80±0.002 30		0.126 00±0.005 50		0.018 87±0.000 27		95.0±94.0		120.1±4.9		120.5±1.7
MM19-218-1-11		9.0		306.0		370.0		0.83		0.054 60±0.003 20		0.142 30±0.008 10		0.019 06±0.000 36		290.0±120.0		134.2±7.2		121.7±2.3
MM19-218-1-12		5.8		200.0		248.6		0.80		0.049 00±0.003 60		0.125 00±0.008 80		0.018 68±0.000 33		50.0±140.0		118.5±7.9		119.3±2.1
MM19-218-1-13		8.9		328.1		379.5		0.86		0.050 20±0.003 40		0.126 10±0.008 10		0.018 54±0.000 32		120.0±130.0		119.6±7.3		118.4±2.0
MM19-218-1-14		5.1		163.1		222.8		0.73		0.049 20±0.004 10		0.132 00±0.011 00		0.019 20±0.000 52		80.0±150.0		126.0±10.0		122.6±3.3
MM19-218-1-15		10.7		359.7		465.0		0.77		0.047 60±0.002 60		0.122 40±0.006 40		0.018 74±0.000 29		40.0±110.0		116.6±5.8		119.9±1.9
MM19-218-1-16		18.2		612.0		788.0		0.78		0.048 20±0.002 10		0.125 30±0.005 40		0.018 90±0.000 27		86.0±90.0		119.5±4.9		120.7±1.7
MM19-218-1-17		7.9		359.5		312.1		1.15		0.049 00±0.003 20		0.124 90±0.008 10		0.018 64±0.000 29		90.0±130.0		118.6±7.2		119.1±1.8
MM19-218-1-18		10.8		392.0		475.0		0.83		0.050 20±0.003 20		0.129 40±0.008 90		0.018 40±0.000 44		200.0±140.0		122.9±7.9		117.5±2.8
MM19-218-1-19		3.3		103.1		148.3		0.70		0.051 20±0.005 40		0.130 00±0.013 00		0.018 69±0.000 45		40.0±190.0		122.0±12.0		119.4±2.9
MM19-218-1-20		6.9		206.1		258.7		0.80		0.081 70±0.005 00		0.220 00±0.013 00		0.019 78±0.000 42		1 070.0±120.0		200.0±11.0		126.3±2.7
MM19-218-1-21		9.9		322.4		411.0		0.78		0.046 80±0.002 80		0.124 10±0.007 20		0.019 52±0.000 30		0.0±110.0		118.8±6.6		124.6±1.9
MM19-218-1-22		7.7		302.4		313.4		0.96		0.046 70±0.004 30		0.120 00±0.011 00		0.018 70±0.000 39		-20.0±170.0		113.9±9.6		119.4±2.5
MM19-218-1-23		6.6		236.0		268.3		0.88		0.047 10±0.003 60		0.123 70±0.009 10		0.019 51±0.000 38		-30.0±140.0		117.2±8.1		124.6±2.4
MM19-218-1-24		11.4		343.4		505.0		0.68		0.049 00±0.003 00		0.124 60±0.007 80		0.018 59±0.000 34		90.0±120.0		118.6±7.0		118.7±2.1
MM19-218-1-25		6.5		201.7		283.1		0.71		0.049 20±0.003 30		0.126 60±0.008 40		0.018 82±0.000 35		80.0±130.0		120.0±7.6		120.2±2.2
MM19-218-1-26		6.4		222.7		280.3		0.79		0.049 00±0.003 10		0.123 60±0.007 70		0.018 53±0.000 32		80.0±120.0		117.4±6.9		118.3±2.0
MM19-218-1-27		3.4		112.0		154.3		0.73		0.052 60±0.007 30		0.129 00±0.017 00		0.018 17±0.000 58		110.0±250.0		122.0±15.0		116.0±3.7
MM19-218-1-28		6.3		180.7		278.8		0.65		0.050 50±0.003 70		0.130 00±0.009 40		0.018 87±0.000 40		120.0±140.0		123.9±8.6		120.5±2.6