Thermodynamic-Geochemical Signatures of Ore-Forming Fluids in the Gudui Sb-Polymetallic District, Southern Tibet: Implications for Sb Enrichment and Deposit Genesis

doi:10.19657/j.geoscience.1000-8527.2024.115

Abstract

Abstract:

The Gudui area of southern Tibet is situated in the mid-Himalayan segment of the Tethys-Himalayan tectonic domain, adjacent to the Yarlung Tsangpo suture zone in the north. A series of Sb-polymetallic deposits have been newly discovered in this region, though limited scientific research currently constrains understanding of their genesis and regional metallogenic controls. This study investigates three representative deposits (Qiaga, Naqiong, and Zhuomuri) through detailed geological characterization and systematic analysis of ore-forming fluids to constrain physicochemical conditions (composition, temperature, salinity, pressure) and metallogenic depth. Our results reveal that Sb-dominated ores contain primarily liquid-rich fluid inclusions, whereas Pb-Zn ores host three-phase (liquid-vapor-solid) inclusions. Stibnite mineralization temperatures (180-208 ℃) are slightly lower than Pb-Zn mineralization (203-230 ℃), with salinities of 3.0%-9.9% NaCl eq. The CO₂-dominated gas phase contains minor N₂, CH₄, and H₂O, consistent with a medium-low temperature, low-salinity NaCl-H₂O hydrothermal system. Calculated pressures (33-71 MPa) and depths (1.2-2.6 km) indicate shallow crustal mineralization. Hydrogen and oxygen isotopes reveal mixed fluid sources: δD_(V-SMOW) values (-64.6‰ to -70.2‰ and -135.2‰ to -129.4‰) and δ¹⁸ $O H 2 O$ values (+2.9‰ to +5.2‰ and +6.6‰ to +9.9‰) suggest formation water dominance with shallow crustal contributions. These findings demonstrate that the Gudui Sb-polymetallic deposits represent shallow epithermal systems dominated by formation waters, with vertical zonation implying potential Au-Sb and Pb-Zn-Sb mineralization at depth beneath existing Sb ores.

Key words: Sb-polymetallic deposit, ore-forming fluid, fluid inclusion, thermodynamic and geochemical signatures, Gudui area, Southern Tibet

CLC Number:

P597
P618.66

LOU Yuanlin, CHENG Ming, CHEN Wu, TANG Yao, ZENG Hao, CHEN Kun, YUAN Yongsheng, YANG Tao. Thermodynamic-Geochemical Signatures of Ore-Forming Fluids in the Gudui Sb-Polymetallic District, Southern Tibet: Implications for Sb Enrichment and Deposit Genesis[J]. Geoscience, 2025, 39(02): 263-266.

Figures/Tables 10

Fig.1 Sketch map showing the distributions of structures (a) and ore deposits (b) in Gudui area, Southern Tibet (modified after reference [18])

Fig.2 Geological sketches of Qiaga(a), Naqiong(b) and Zhuomuri(c) antimony polymetallic deposits in Gudui area, Southern Tibet (modified after references [14,20,21])

Fig.3 Outcrop and microscopic characteristics of typical antimony polymetallic deposit in Gudui area, Southern Tibet

Table 1 Key parameters of fluid inclusions in typical antimony polymetallic deposits in Gudui area, Southern Tibet

矿区名称	测试矿物	包裹体个数	类型	大小 (μm)	均一温度 (℃)	NaCl盐度 (%)	δD (‰)	δ¹⁸O_含水矿物 (‰)	δ¹⁸ $O H 2 O$ (‰)	资料来源
恰嘎	石英	47	富液包裹体	2×2~ 10×15	123~241(180)	5.9~8.6 (6.9)	-131.5~ -129.4 (-130.5)	19.7~ 21.7 (20.7)	6.6~8.6 (7.6)	本文
那穷	石英	70	富液包裹体	3×4~ 15×25	161~256(208)	5.6~8.4 (6.7)	-135.2~ -131.4 (-133.3)	20.5~ 21.1 (20.8)	9.3~9.9 (9.6)	本文
卓木日	石英	5	H₂O-CO₂ 三相包裹体	10×15~ 15×30	V_co₂→L_co₂ 24~29(27)	3.0~9.8 (5.0)	-64.6~ -70.2 (-67.4)	14.4~ 16.7 (15.6)	2.9~ 5.2 (4.1)	本文
		5	H₂O-CO₂ 三相包裹体	10×15~ 15×30	V_co₂→L_H₂O 221~240(230)	3.0~9.8 (5.0)
		105	富液包裹体	3×4~ 15×50	147~261 (203)	3.0~9.9 (6.9)
马扎拉	辉锑矿- 方解石脉、石英脉石英	-	H₂O-CO₂ 三相包裹体	5~30	134~324	0.4~7.8	-138.0~ -63.0	14.6~ 22.7	7.8~ 14.9	[13,38]
查拉普	石英型矿石	-	富液包裹体	2~15	164~308	2.7~9.3	-124.0~ -101.0	11.6~ 17.4	3.2~ 9.7	[13]
查拉普	蚀变岩型矿石	-	富液包裹体	2~15	164~308	2.7~9.3	-68.0~ -85.5	15.0~ 19.9	-1.8~ 2.3	[13]
扎西康	闪锌矿-铁锰碳酸盐脉闪锌矿和菱锰矿	-	富液包裹体	6~12	225~276	8.0~12.5	-165.0~ -138.0	-1.3~ 21.4	-13.7~ 12.5	[11, 13,18]
	方铅矿- 石英脉石英			5~15	253~328	1.1~5.1
	辉锑矿- 石英脉石英			8~15	164~313	1.2~5.3
	辰砂-辉锑矿- 石英脉石英			2~10	211~261	0.7~2.4
车穷卓布	辉锑矿-石英脉石英	-	富液包裹体	4~10	121~235	1.4~4.7	-160.0~ -111.0	-3.5~ -1.5	-15.9~ -13.9	[13]
车穷卓布	辉锑矿-方解石脉方解石	-	富液包裹体	4~10	145~312	1.2~3.6	-160.0~ -111.0	-3.5~ -1.5	-15.9~ -13.9	[13]
哲古	-	-	-	-	-	-	-118.0~ -72.0	14.2~ 23.9	2.4~ 12.0	[13]

Table 1 Key parameters of fluid inclusions in typical antimony polymetallic deposits in Gudui area, Southern Tibet

矿区名称	测试矿物	包裹体个数	类型	大小 (μm)	均一温度 (℃)	NaCl盐度 (%)	δD (‰)	δ¹⁸O_含水矿物 (‰)	δ¹⁸ $O H 2 O$ (‰)	资料来源
恰嘎	石英	47	富液包裹体	2×2~ 10×15	123~241(180)	5.9~8.6 (6.9)	-131.5~ -129.4 (-130.5)	19.7~ 21.7 (20.7)	6.6~8.6 (7.6)	本文
那穷	石英	70	富液包裹体	3×4~ 15×25	161~256(208)	5.6~8.4 (6.7)	-135.2~ -131.4 (-133.3)	20.5~ 21.1 (20.8)	9.3~9.9 (9.6)	本文
卓木日	石英	5	H₂O-CO₂ 三相包裹体	10×15~ 15×30	V_co₂→L_co₂ 24~29(27)	3.0~9.8 (5.0)	-64.6~ -70.2 (-67.4)	14.4~ 16.7 (15.6)	2.9~ 5.2 (4.1)	本文
		5	H₂O-CO₂ 三相包裹体	10×15~ 15×30	V_co₂→L_H₂O 221~240(230)	3.0~9.8 (5.0)
		105	富液包裹体	3×4~ 15×50	147~261 (203)	3.0~9.9 (6.9)
马扎拉	辉锑矿- 方解石脉、石英脉石英	-	H₂O-CO₂ 三相包裹体	5~30	134~324	0.4~7.8	-138.0~ -63.0	14.6~ 22.7	7.8~ 14.9	[13,38]
查拉普	石英型矿石	-	富液包裹体	2~15	164~308	2.7~9.3	-124.0~ -101.0	11.6~ 17.4	3.2~ 9.7	[13]
查拉普	蚀变岩型矿石	-	富液包裹体	2~15	164~308	2.7~9.3	-68.0~ -85.5	15.0~ 19.9	-1.8~ 2.3	[13]
扎西康	闪锌矿-铁锰碳酸盐脉闪锌矿和菱锰矿	-	富液包裹体	6~12	225~276	8.0~12.5	-165.0~ -138.0	-1.3~ 21.4	-13.7~ 12.5	[11, 13,18]
	方铅矿- 石英脉石英			5~15	253~328	1.1~5.1
	辉锑矿- 石英脉石英			8~15	164~313	1.2~5.3
	辰砂-辉锑矿- 石英脉石英			2~10	211~261	0.7~2.4
车穷卓布	辉锑矿-石英脉石英	-	富液包裹体	4~10	121~235	1.4~4.7	-160.0~ -111.0	-3.5~ -1.5	-15.9~ -13.9	[13]
车穷卓布	辉锑矿-方解石脉方解石	-	富液包裹体	4~10	145~312	1.2~3.6	-160.0~ -111.0	-3.5~ -1.5	-15.9~ -13.9	[13]
哲古	-	-	-	-	-	-	-118.0~ -72.0	14.2~ 23.9	2.4~ 12.0	[13]

Fig.4 Microscopic photos of fluid inclusions in typical antimony polymetallic deposits in Gudui area, Southern Tibet

Fig.5 Histogram for homogenization temperature and salinity of fluid inclusions in Qiaga ((a) and (d)), Naqiong ((b) and (e)) and Zhuomuri((c) and (f)) antimony polymetallic deposits in Gudui area, Southern Tibet

Fig.6 Covariation histogram of homogenization temperature and salinity of fluid inclusions in antimony polymetallic deposits in Gudui area, Southern Tibet

Fig.7 Laser Raman spectrum of fluid inclusions in Qiaga ((a) and (b)), Naqiong ((c) and (d)) and Zhuomuri ((e) and (f)) antimony polymetallic deposits in Gudui area, Southern Tibet

Fig.8 Hydrogen and oxygen isotope composition in Gudui area, Southern Tibet (modified after reference [14], the ranges of magmatic water, metamorphic water, formation water and geothermal water in Tibet are according to Taylor[41], Giggenbach[42], Sheppard[43] and Zheng et al.[44], respectively)

Fig.9 Regional metallogenic model of antimony polymetallic deposits in Gudui area, Southern Tibet (modified after reference [13])

References 48

[1]	郑有业, 多吉, 马国桃, 等. 藏南查拉普岩金矿床特征、发现及时代约束[J]. 地球科学, 2007, 32(2): 185-193.
[2]	许国雨. 藏南查拉普金矿床成矿流体特征及其对矿床成因的指示[D]. 北京: 中国地质大学(北京), 2020.
[3]	谢玉玲, 杨科君, 李应栩, 等. 藏南马扎拉金-锑矿床: 成矿流体性质和成矿物质来源[J]. 地球科学, 2019, 44(6): 1998-2016.
[4]	王军, 张均, 郑有业. 西藏南部马扎拉金锑矿成矿规律初探[J]. 黄金科学技术, 2001, 9(S1): 5-11.
[5]	王军, 张均. 西藏南部马扎拉金锑矿成矿特征及找矿方向[J]. 黄金地质, 2001, 7(3): 15-20.
[6]	李任杰, 张文磊, 马健飞, 等. 西藏扎西康铅锌锑多金属矿床地质特征及成因[J]. 现代矿业, 2016, 32(10): 133-134, 154.
[7]	李洪梁. 特提斯喜马拉雅东段扎西康矿集区造山型金矿床成矿作用研究[D]. 成都: 成都理工大学, 2020.
[8]	聂凤军, 胡朋, 江思宏, 等. 藏南地区金和锑矿床(点)类型及其时空分布特征[J]. 地质学报, 2005, 79(3): 373-385.
[9]	高伟. 藏南拆离带沙拉岗锑矿床地质地球化学特征及成因机制研究[D]. 北京: 中国地质大学(北京), 2006.
[10]	孟祥金, 杨竹森, 戚学祥, 等. 藏南扎西康锑多金属矿硅-氧-氢同位素组成及其对成矿构造控制的响应[J]. 岩石学报, 2008, 24(7): 1649-1655.
[11]	张建芳. 北喜马拉雅扎西康铅锌锑银矿床成因研究[D]. 武汉: 中国地质大学, 2010.
[12]	朱黎宽. 西藏扎西康铅锌锑多金属矿床地质特征及流体包裹体研究[D]. 北京: 中国地质大学(北京), 2011.
[13]	张刚阳. 藏南金锑多金属成矿带成矿模式与找矿前景研究[D]. 武汉: 中国地质大学, 2012.
[14]	娄元林, 陈武, 袁永盛, 等. 西藏隆子县恰嘎锑矿床流体包裹体及H、O、S同位素组成特征[J]. 矿床地质, 2018, 37(5): 1124-1140.
[15]	许云鹏. 藏南古堆地区金锑多金属矿床形成深度及找矿潜力分析[J]. 矿产与地质, 2021, 35(2): 202-210.
[16]	付伟, 周永章, 杨志军, 等. 藏南多层位金锑含矿建造特征及其控矿因素制约[J]. 大地构造与成矿学, 2005, 29(3): 321-327.
[17]	杨竹森, 侯增谦, 高伟, 等. 藏南拆离系锑金成矿特征与成因模式[J]. 地质学报, 2006, 80(9): 1377-1391.
[18]	娄元林, 唐侥, 郭威, 等. 藏南古堆地区主要矿种的成矿模式与找矿模型[J]. 地质论评, 2021, 67(S1): 193-195.
[19]	戚学祥, 曾令森, 孟祥金, 等. 特提斯喜马拉雅打拉花岗岩的锆石SHRIMP U-Pb定年及其地质意义[J]. 岩石学报, 2008, 24(7): 1501-1508.
[20]	娄元林, 唐侥, 郭威, 等. 西藏隆子县那穷锑金矿地质特征及找矿前景分析[J]. 地质力学学报, 2022, 28(3): 406-416.
[21]	钱建利, 喜俊生, 刘蓓, 等. 西藏措美县卓木日金多金属矿地质特征及找矿潜力[J]. 矿产勘查, 2021, 12(5): 1221-1227.
[22]	娄元林, 陈武, 陈东太, 等. 西藏隆子县恰嘎锑矿4号脉原生晕特征及深部找矿预测[J]. 西北地质, 2016, 49(4): 146-164.
[23]	娄元林, 陈武, 杨桃. 西藏隆子县邦卓玛金矿床成矿模式与找矿模型[J]. 地质通报, 2019, 38(S1): 449-461.
[24]	娄元林, 成明, 唐侥, 等. 藏南古堆地区岩浆岩岩石地球化学特征、构造环境分析及成矿响应[J]. 现代地质, 2023, 37(2): 353-374.
[25]	刘斌, 沈昆. 流体包裹体热力学[M]. 北京: 地质出版社, 1999: 1-290.
[26]	卢焕章. 成矿流体[M]. 北京: 北京科学技术出版社, 1997: 1-230.
[27]	卢焕章. 高盐度、高温和高成矿金属的岩浆成矿流体: 以格拉斯伯格Cu-Au矿为例[J]. 岩石学报, 2000, 16(4): 465-472.
[28]	卢焕章, 范宏瑞, 倪培, 等. 流体包裹体[M]. 北京: 科学出版社, 2004: 1-487.
[29]	郑永飞, 徐宝龙, 周根陶. 氢氧化物族矿物的氧同位素分馏[J]. 地球化学, 1998, 27(2): 141-152.
[30]	郑永飞, 徐宝龙, 周根陶. 矿物稳定同位素地球化学研究[J]. 地学前缘, 2000, 7(2): 299-320.
[31]	郑永飞, 陈江峰. 稳定同位素地球化学[M]. 北京: 科学出版社, 2000: 1-316.
[32]	BODNAR R J. Revised equationand table for determining the freezing point depression of H₂O-Nacl solutions[J]. Geochimica et Cosmochimica Acta, 1993, 57(3): 683-684.
[33]	COLLINS P L F. Gas hydratesin CO₂-bearing fluid inclusions and the use of freezing data for estimation of salinity[J]. Economic Geology, 1979, 74(6): 1435-1444.
[34]	BROWN P E. FLINCOR: a microcomputer program for the reduction and investigation of fluid-inclusion data[J]. American Mineralogist, 1989, 74(11): 1390-1393.
[35]	COLEMAN M L, SHEPHERD T J, DURHAM J J, et al. Reduction of water with zinc for hydrogen isotope analysis[J]. Analytical Chemistry, 1982, 54(6): 993-995.
[36]	CLAYTON R N, MAYEDA T K. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis[J]. Geochimica et Cosmochimica Acta, 1963, 27(1): 43-52.
[37]	CLAYTON R N, O’NEIL J R, MAYEDA T K. Oxygen isotope exchange between quartz and water[J]. Journal of Geophysical Research, 1972, 77(17): 3057-3067.
[38]	郑有业, 陈静, 赵永鑫. 西藏措美县马扎拉金、锑矿控矿因素与成矿规律研究[R]. 武汉: 中国地质大学(武汉), 2001.
[39]	张德会, 徐九华, 余心起, 等. 成岩成矿深度: 主要影响因素与压力估算方法[J]. 地质通报, 2011, 30(1): 112-125.
[40]	邵洁涟, 梅建明. 浙江火山岩区金矿床的矿物包裹体标型特征研究及其成因与找矿意义[J]. 矿物岩石, 1986, 6(3): 103-111.
[41]	TAYLOR H P. The application of oxygen and hydrogen isotopestudies to problems of hydrothermal alteration and ore deposition[J]. Economic Geology, 1974, 69(6): 843-883.
[42]	GIGGENBACH W F. Isotopic shifts in waters from geothermal and volcanic systems along convergent plate boundaries and their origin[J]. Earth and Planetary Science Letters, 1992, 113(4): 495-510.
[43]	SHEPPARD S M F. Characterization and isotopic variations in natural waters[J]. Reviews in Mineralogy and Geochemistry, 1986,16:165-184.
[44]	郑淑蕙, 张知非, 倪葆龄, 等. 西藏地热水的氢氧稳定同位素研究[J]. 北京大学学报(自然科学版), 1982, 18(1): 99-106.
[45]	杜泽忠, 顾雪祥, 李关清, 等. 藏南拉木由塔锑(金)矿床S、Pb同位素组成及指示意义[J]. 现代地质, 2011, 25(5): 853-860.
[46]	郭文铂, 郑文宝, 唐菊兴, 等. 西藏甲玛铜多金属矿床流体、成矿物质来源的地球化学约束[J]. 中国地质, 2014, 41(2): 510-528.
[47]	柯贤忠, 王晶, 钟石玉, 等. 西藏则学地区热液脉型铅锌矿S、Pb同位素组成及其对成矿物质来源的启示[J]. 中国地质, 2019, 46(3): 629-641.
[48]	郑有业, 王达, 易建洲, 等. 西藏北喜马拉雅成矿带锑金属成矿作用及找矿方向[J]. 地学前缘, 2022, 29(1): 200-230. DOI