Characterization of gold distribution in sediments and prediction of gold prospectivity in Laos

doi:10.13745/j.esf.sf.2024.10.28

Abstract

Abstract:

Under the Belt and Road initiative China and Laos have carried out national-scale 1∶1000000 geochemical mapping in Laos. This study marked the first national-scale geochemical study of gold, a dominant mineral species, in Laos, where the geochemical background and spatial distribution characteristics of gold in Laos were preliminarily investigated, and the geochemical anomaly and prospective areas of gold in Laos were delineated. A total of 2079 geochemical samples were collected and analyzed for gold element, using foam adsorption-graphite furnace atomic absorption spectrometry (FAS-GAAS), a high-precision analytical technique, and strict quality control measures. Gold contents in Laos aquatic sediments ranged between 0.10-913.70 ng/g, with mean and median (background) values of 2.44 and 1.00 ng/g, respectively. Gold occurred across the country with scattered distribution, mainly along extended large fractures affected by tectonic activities and magmatism. Using 85% quantile (1.99 ng/g) as the anomaly detecton limit, 17 gold anomaly areas were identified, with eight reaching a geochemical province scale (>1000 km²); seven prospective gold mineralization zones were classified according to anomaly identification, taking into consideration the spatial distribution of gold, geologic background, regional tectonics and mineral distribution. The results provide basic information for gold exploration in Laos and fill the gap of geochemical mapping for gold exploration in Laos.

Key words: gold, stream sediment, national-scale geochemical mapping, geochemistry, Laos

CLC Number:

WANG Wei, WANG Xueqiu, ZHANG Bimin, LIU Dongsheng, LIU Hanliang, Sounthone LAOLO, Phomsylalai SOUKSAN, CHI Qinghua, ZHOU Jian, HAN Zhixuan. Characterization of gold distribution in sediments and prediction of gold prospectivity in Laos[J]. Earth Science Frontiers, 2025, 32(1): 78-90.

Figures/Tables 11

References 89

[1]	BUTT C R M, NICHOL I. The identification of various types of geochemical stream sediment anomalies in Northern Ireland[J]. Journal of Geochemical Exploration, 1979, 11(1): 13-32.
[2]	谢学锦. 地球化学填图的历史发展(代总序)[J]. 地质通报, 2007, 26(11): 1399-1404.
[3]	谢学锦. 地球化学填图的历史发展(代总序)[J]. 地质通报, 2008, 27(2): 163-168.
[4]	王学求. 勘查地球化学80年来重大事件回顾[J]. 中国地质, 2013, 40(1): 322-330.
[5]	谢学锦. 全球地球化学填图[J]. 中国地质, 2003, 30(1): 1-9.
[6]	谢学锦. 勘查地球化学: 发展史·现状·展望[J]. 地质与勘探, 2002, 38(6): 1-9.
[7]	谢学锦. 区域化探(区域地质调查野外工作方法第四分册)[M]. 北京: 地质出版社, 1979.
[8]	王学求. 矿产勘查地球化学: 过去的成就与未来的挑战[J]. 地学前缘, 2003, 10(1): 239-248.
[9]	OHTA A, IMAI N, TERASHIMA S, et al. Application of multi-element statistical analysis for regional geochemical mapping in Central Japan[J]. Applied Geochemistry, 2005, 20(5): 1017-1037.
[10]	BÖLVIKEN B, BOGEN J, DEMETRIADES A, et al. Regional geochemical mapping of Western Europe towards the year 2000[J]. Journal of Geochemical Exploration, 1996, 56(2): 141-166.
[11]	CHENG Z Z, XIE X J, YAO W S, et al. Multi-element geochemical mapping in Southern China[J]. Journal of Geochemical Exploration, 2014, 139(100): 183-192. PMID
[12]	ELSENBROEK J, NESER J. An environmental application of regional geochemical mapping in understanding enzootic geophagia of calves in the Reivilo area, South Africa[J]. Environmental Geochemistry and Health, 2002, 24(2): 159-181.
[13]	OTTESEN R T, BOGEN J, BØLVIKEN B, et al. Overbank sediment: a representative sample medium for regional geochemical mapping[J]. Journal of Geochemical Exploration, 1989, 32(1/2/3): 257-277.
[14]	ZHU Y F, AN F, TAN J J. Geochemistry of hydrothermal gold deposits: a review[J]. Geoscience Frontiers, 2011, 2(3): 367-374.
[15]	XIE X J, MU X Z, REN T X. Geochemical mapping in China[J]. Journal of Geochemical Exploration, 1997, 60(1): 99-113.
[16]	谢学锦, 任天祥, 奚小环, 等. 中国区域化探全国扫面计划三十年[J]. 地球学报, 2009, 30(6): 700-716.
[17]	刘大文, 谢学锦, 严光生, 等. 地球化学块体的方法技术在山东金资源潜力预测中的应用[J]. 地球学报, 2002, 23(2): 169-174.
[18]	奚小环. 多目标的地质大调查: 21世纪勘查地球化学的战略选择[J]. 物探与化探, 2007, 31(4): 283-288.
[19]	谢学锦, 刘大文. 地球化学填图与地球化学勘查[J]. 地质论评, 2006, 52(6): 721-732, 865-868.
[20]	李玉松, 张玉清, 马立柯. 老挝普老地区多金属矿地球化学异常特征及找矿前景[J]. 中国地质, 2016, 43(5): 1780-1790.
[21]	刘君, 潘亮, 赵鹤森, 等. 水系沉积物测量在老挝巴乌地区的应用[J]. 金属矿山, 2015(2): 92-97.
[22]	雷传扬, 李瑞峰, 赵保顺, 等. 老挝平然地区水系沉积物测量地球化学特征及找矿意义[J]. 物探与化探, 2014, 38(3): 453-460.
[23]	杜涛, 朵雪莲, 汪博. 老挝会晒地区地球化学特征及成矿预测分析[J]. 世界有色金属, 2017(11): 139-140.
[24]	FAN P F. Accreted terranes and mineral deposits of Indochina[J]. Journal of Asian Earth Sciences, 2000, 18(3): 343-350.
[25]	WAKITA K, METCALFE I. Ocean plate stratigraphy in East and Southeast Asia[J]. Journal of Asian Earth Sciences, 2005, 24(6): 679-702.
[26]	YIN F G, PAN G T, WANG F, et al. Tectonic facies along the Nujiang-Lancangjiang-Jinshajiang orogenic belt in Southwestern China[J]. Sedimentary Geology and Tethyan Geology, 2006, 26(4): 33-39.
[27]	李兴振, 江新胜, 孙志明, 等. 西南三江地区碰撞造山过程[M]. 北京: 地质出版社, 2002.
[28]	WANG W, WANG X Q, ZHANG B M, et al. National-scale geochemical baseline of 69 elements in Laos stream sediments[J]. Minerals, 2022, 12(11): 1360.
[29]	王玮, 王学求, 张必敏, 等. 老挝表层沉积物69种元素地球化学背景值[J]. 地球科学, 2022, 47(8): 2765-2780.
[30]	王学求, 徐善法, 程志中, 等. 国际地球化学填图新进展[J]. 地质学报, 2006, 80(10): 1598-1606.
[31]	王玮, 王学求, 张必敏, 等. 老挝全国地球化学填图与成矿远景区预测[J]. 地球学报, 2020, 41(1): 80-90.
[32]	严城民, 朱延浙, 吴军, 等. 老挝万象地区基础地质调研的主要进展[J]. 地球学报, 2006, 27(1): 81-84.
[33]	朱延浙, 吴军, 胡建军, 等. 老挝地质矿产概论[M]. 昆明: 云南科技出版社, 2009.
[34]	贾润幸, 方维萱, 隗雪燕. 老挝地质矿产资源及开发概况[J]. 矿产勘查, 2014, 5(5): 826-833.
[35]	刘书生, 杨永飞, 郭林楠, 等. 东南亚大地构造特征与成矿作用[J]. 中国地质, 2018, 45(5): 863-889.
[36]	卢映祥, 刘洪光, 黄静宁, 等. 东南亚中南半岛成矿带初步划分与区域成矿特征[J]. 地质通报, 2009, 28(增刊1): 314-325.
[37]	施美凤, 林方成, 李兴振, 等. 东南亚中南半岛与中国西南邻区地层分区及沉积演化历史[J]. 中国地质, 2011, 38(5): 1244-1256.
[38]	王宏, 林方成, 李兴振, 等. 老挝及邻区构造单元划分与构造演化[J]. 中国地质, 2015, 42(1): 71-84.
[39]	KHIN ZAW, SANTOSH M, GRAHAM I T. Tectonics and metallogeny of mainland SE Asia: preface[J]. Gondwana Research, 2014, 26(1): 1-4.
[40]	ZAW K, MEFFRE S, LAI C K, et al. Tectonics and metallogeny of mainland Southeast Asia: a review and contribution[J]. Gondwana Research, 2014, 26(1): 5-30.
[41]	邓军, 杨立强, 王长明. 三江特提斯复合造山与成矿作用研究进展[J]. 岩石学报, 2010, 27(9): 37-42.
[42]	潘桂棠, 肖庆辉, 陆松年, 等. 中国大地构造单元划分[J]. 中国地质, 2009, 36(1): 1-28.
[43]	KAMVONG T, KHIN ZAW, MEFFRE S, et al. Adakites in the Truong Son and Loei Fold belts, Thailand and Laos: genesis and implications for geodynamics and metallogeny[J]. Gondwana Research, 2014, 26(1): 165-184.
[44]	WANG X Q. China geochemical baselines: sampling methodology[J]. Journal of Geochemical Exploration, 2015, 148: 25-39.
[45]	张勤, 白金峰, 王烨. 地壳全元素配套分析方案及分析质量监控系统[J]. 地学前缘, 2012, 19(3): 33-42.
[46]	RUDNICK R L, GAO S. Composition of the continentalcrust[M]// HOLLAND H D, TUREKIAN K K. Treatise on geochemistry. Amsterdam: Elsevier, 2003: 1-64.
[47]	王学求, 周建, 徐善法, 等. 全国地球化学基准网建立与土壤地球化学基准值特征[J]. 中国地质, 2016, 43(5): 1469-1480.
[48]	鄢明才, 王春书, 迟清华, 等. 岩石和疏松沉积物中金丰度值的初步研究[J]. 地球化学, 1990, 19(2): 144-152.
[49]	王学求, 谢学锦. 金的勘查地球化学理论与方法·战略与战术[M]. 济南: 山东科学技术出版社, 2000.
[50]	任天祥, 李明喜, 徐耀先, 等. 高寒山区表生作用地球化学特征及区域化探方法的初步研究[J]. 地质论评, 1983, 29(5): 428-436.
[51]	BUTT C R M. Geomorphology and climatic history: keys to understanding geochemical dispersion in deeply weathered terrain, exemplified by gold[C]// The proceedings of exploration ’87. Toronto:Ontario Geological Survey, 1989, 3: 323-334.
[52]	王天瑞, 侯林, 林方成, 等. 老挝-越南长山成矿带古特提斯构造岩浆演化与成矿作用[J]. 沉积与特提斯地质, 2022, 42(2): 212-227.
[53]	张必敏, 王学求, 贺灵, 等. 内蒙古半干旱草原区隐伏矿地球化学勘查方法试验[J]. 物探与化探, 2013, 37(5): 804-10.
[54]	胡庆成, 吕新彪, 高奇, 等. 热液金矿金的溶解和迁移研究进展[J]. 地球科学进展, 2012, 27(8): 847-856.
[55]	王燕, 谭凯旋, 刘顺生, 等. 矿物吸附金的实验研究及其在红土型金矿形成中的意义[J]. 地球科学, 2003, 28(1): 26-30.
[56]	王学求, 徐善法, 迟清华, 等. 中国金的地球化学省及其成因的微观解释[J]. 地质学报, 2013, 87(1): 1-8.
[57]	SELINUS O. Essentials of medicalgeology[M]// GARRETT R G. Natural distribution and abundance of elements. Amsterdam: Springer, 2013: 35-57.
[58]	谭亲平, 王学求. 秦岭地区水系沉积物和岩石金元素时空分布研究[J]. 矿物岩石地球化学通报, 2017, 36(5): 824-833.
[59]	XIE X J, WANG X Q. Geochemical exploration for gold: a new approach to an old problem[J]. Journal of Geochemical Exploration, 1991, 40(1/2/3): 25-48.
[60]	HAWKES H E, WEBB J S. Geochemistry in mineralexploration[J]. Soil Science, 1963, 95(4): 283.
[61]	LEAMAN P, MANAKA T, JARICAL K, et al. The geology and mineralization of the Long Chieng Track (LCT) subvolcanic Au-Ag-Cu-Pb-Zn deposit, Lao PDR[J]. Ore Geology Reviews, 2019, 106: 387-402.
[62]	郭林楠, 侯林, 刘书生, 等. 老挝帕奔金矿床成矿流体来源与矿床成因: 稀土元素和C、O、S同位素证据[J]. 矿床地质, 2019, 38(2): 233-250.
[63]	郭林楠, 刘书生, 聂飞, 等. 老挝琅勃拉邦—泰国黎府成矿带古特提斯构造-岩浆演化与金铜成矿作用[J]. 沉积与特提斯地质, 2022, 42(2): 228-241.
[64]	杨昌正, 沈利霞, 周琳, 等. 老挝帕奔金矿地质-构造地球化学特征及成矿机理[J]. 矿产与地质, 2017, 31(1): 11-22.
[65]	牛英杰, 胡金才, 李孝红. 老挝琅勃拉邦省帕奔金矿地球化学特征[J]. 地质调查与研究, 2013, 36(2): 92-99.
[66]	LIU S S, GUO L N, DING J, et al. Evolution of ore-forming fluids and gold deposition of the Sanakham Lode gold deposit, SW Laos: constraints from fluid inclusions study[J]. Minerals, 2022, 12(2): 259.
[67]	赵延朋, 莫江平, 王晓曼. 老挝班康姆铜金矿床找矿标志及成矿预测研究[J]. 矿产与地质, 2015, 29(2): 178-182, 188.
[68]	SMITH S, OLBERG D, MANINI T, et al. The Sepon gold deposits, Laos: exploration, geology and comparison to Carlin-type gold deposits in the Great Basin[C]// Proceedings of the Geological Society of Nevada symposium, Reno, Nevada. Las Vegas: Geological Society of Nevada, 2005: 899-915.
[69]	CROMIE P W. Geological setting, geochemistry and genesis of the Sepon gold and copper deposits, Laos[D]. Hobart: University of Tasmania, 2010.
[70]	MANAKA T. A study of mineralogical, geochemical and geochronological characteristics and ore genesis in Phuoc Son gold deposit area, central Vietnam[D]. Hobart: University of Tasmania, 2014.
[71]	WANG X F, METCALFE I, JIAN P, et al. The Jinshajiang-Ailaoshan suture zone, China: tectonostratigraphy, age and evolution[J]. Journal of Asian Earth Sciences, 2000, 18(6): 675-690.
[72]	刘俊来, 唐渊, 宋志杰, 等. 滇西哀牢山构造带: 结构与演化[J]. 吉林大学学报(地球科学版), 2011, 41(5): 1285-1303.
[73]	HOA T T, ANH T T, PHUONG N T, et al. Permo-Triassic intermediate-felsic magmatism of the Truong Son belt, eastern margin of Indochina[J]. Comptes Rendus Geoscience, 2008, 340(2/3): 112-126.
[74]	HIEU P T, LI S Q, YU Y, et al. Stages of late Paleozoic to early Mesozoic magmatism in the Song Ma belt, NW Vietnam: evidence from zircon U-Pb geochronology and Hf isotope composition[J]. International Journal of Earth Sciences, 2017, 106(3): 855-874.
[75]	QIAN X, WANG Y J, ZHANG Y Z, et al. Petrogenesis of Permian-Triassic felsic igneous rocks along the Truong Son zone in Northern Laos and their Paleotethyan assembly[J]. Lithos, 2019, 328: 101-114.
[76]	WANG S F, MO Y S, WANG C, et al. Paleotethyan evolution of the Indochina Block as deduced from granites in Northern Laos[J]. Gondwana Research, 2016, 38: 183-196.
[77]	VUONG N V, HANSEN B T, WEMMER K, et al. U/Pb and Sm/Nd dating on ophiolitic rocks of the Song Ma suture zone (northern Vietnam): evidence for upper Paleozoic paleotethyan lithospheric remnants[J]. Journal of Geodynamics, 2013, 69: 140-147.
[78]	刘翠, 邓晋福, 刘俊来, 等. 哀牢山构造岩浆带晚二叠世-早三叠世火山岩特征及其构造环境[J]. 岩石学报, 2011, 27(12): 3590-3602.
[79]	ZHANG R Y, LO C H, CHUNG S L, et al. Origin and tectonic implication of ophiolite and eclogite in the Song Ma suture zone between the South China and Indochina blocks[J]. Journal of Metamorphic Geology, 2013, 31(1): 49-62.
[80]	陈毓川, 王登红, 徐志刚, 等. 中国重要矿产和区域成矿规律[M]. 北京: 地质出版社, 2015.
[81]	HOU Z Q, ZAW K, PAN G T, et al. Sanjiang Tethyan metallogenesis in SW China: tectonic setting, metallogenic epochs and deposit types[J]. Ore Geology Reviews, 2007, 31(1/2/3/4): 48-87.
[82]	GOLDFARB R J, TAYLOR R D, COLLINS G S, et al. Phanerozoic continental growth and gold metallogeny of Asia[J]. Gondwana Research, 2014, 25(1): 48-102.
[83]	JEFFREY W H T. J F H G. R J, et al. One hundredth anniversary volume[M]. Littleton, Colorado: Society of Economic Geologists, 2005.
[84]	王玮, 王学求, 张必敏, 等. 老挝铜地球化学背景与异常特征[J]. 地球学报, 2020, 41(6): 861-867.
[85]	ZHAO H J, CHENG Y Q, LU Y X. Ore-forming model for Cu-Au-Fe ore deposits associated with granites in the Truongson ore-forming belt of Laos[J]. Geological Bulletin of China, 2011, 30(10): 1619-1627.
[86]	赵延朋, 王晓曼, 夏绪学, 等. 老挝甘蒙省南巴坦锡多金属矿田地质特征及成因浅析[J]. 有色矿冶, 2012, 28(6): 1-4.
[87]	CROMIE P, MAKOUNDI C, ZAW K, et al. Geochemistry of Au-bearing pyrite from the Sepon Mineral District, Laos DPR, Southeast Asia: implications for ore genesis[J]. Journal of Asian Earth Sciences, 2018, 164: 194-218.
[88]	NAKANO N, OSANAI Y, OWADA M, et al. Geologic and metamorphic evolution of the basement complexes in the Kontum Massif, central Vietnam[J]. Gondwana Research, 2007, 12(4): 438-453.
[89]	施美凤, 林方成, 刘朝基, 等. 东南亚缅泰老越柬五国与中国邻区成矿带划分及成矿特征[J]. 沉积与特提斯地质, 2013, 33(2): 103-112.

元素	原始数据金含量/(ng·g^-1)
元素	最小值	25%累频	平均值	50%累频	75%累频	85%累频	97.50%累频	最大值
Au	0.10	0.57	2.44	1.00	1.53	1.99	6.36	913.70
元素	剔除大于3倍离差样数据的金含量/(ng·g^-1)
元素	最小值	25%累频	平均值	50%累频 (背景值)	75%累频	85%累频	97.50%累频	最大值
Au	0.10	0.57	1.55	1.00	1.52	1.97	5.70	68.55

元素	原始数据金含量/(ng·g^-1)
元素	最小值	25%累频	平均值	50%累频	75%累频	85%累频	97.50%累频	最大值
Au	0.10	0.57	2.44	1.00	1.53	1.99	6.36	913.70
元素	剔除大于3倍离差样数据的金含量/(ng·g^-1)
元素	最小值	25%累频	平均值	50%累频 (背景值)	75%累频	85%累频	97.50%累频	最大值
Au	0.10	0.57	1.55	1.00	1.52	1.97	5.70	68.55

资料来源	样品数和金含量平均值
鄢明才等^[48]	7个1∶200 000图幅 (7 784件样品) 平均值为1.20 ng/g
王学求和谢学锦^[49]	416个1∶200 000图幅 (约50万件分析样品) 平均值为1.30 ng/g
任天祥等^[50]	400余万km² (约60万件分析样品) 平均值为1.31 ng/g
王玮等^[29]	老挝全境21万km² (约2 079件分析样品) 平均值为1.55 ng/g

资料来源	样品数和金含量平均值
鄢明才等^[48]	7个1∶200 000图幅 (7 784件样品) 平均值为1.20 ng/g
王学求和谢学锦^[49]	416个1∶200 000图幅 (约50万件分析样品) 平均值为1.30 ng/g
任天祥等^[50]	400余万km² (约60万件分析样品) 平均值为1.31 ng/g
王玮等^[29]	老挝全境21万km² (约2 079件分析样品) 平均值为1.55 ng/g