李壯 王立強(qiáng) 張忠 羅茂澄 冷秋鋒 康浩然 孟展
摘 要:西藏邦鋪斑巖鉬(銅)多金屬礦床位于岡底斯成礦帶東段,礦區(qū)侵入巖期次和類型多樣,主要包括成礦前期黑云母二長(zhǎng)花崗巖、成礦期閃長(zhǎng)玢巖和二長(zhǎng)花崗斑巖及成礦后期石英二長(zhǎng)斑巖和輝綠玢巖等5種。在系統(tǒng)總結(jié)前人研究成果基礎(chǔ)上,利用LA-ICP-MS技術(shù)獲得了礦區(qū)閃長(zhǎng)玢巖巖體鋯石微量元素特征。結(jié)果表明:邦鋪礦區(qū)侵入巖鋯石類型主要包括巖漿鋯石和熱液鋯石;5種侵入巖球粒隕石標(biāo)準(zhǔn)化稀土元素配分模式顯示具相似的特征,曲線左傾,整體較陡,表現(xiàn)為明顯的Ce正異常和Eu負(fù)異常,輕稀土元素虧損,重稀土元素富集。通過鋯石Ti含量地質(zhì)溫度計(jì)計(jì)算出侵入巖鋯石結(jié)晶溫度,顯示出成礦期和成礦后期侵入巖體巖漿來源于在水近飽和條件下發(fā)生的部分熔融。根據(jù)鋯石中特定微量元素和稀土元素特征變化,各侵入巖鋯石均是從陸殼巖漿中結(jié)晶分異形成的,與鋯石相對(duì)應(yīng)的寄主巖石均形成于陸殼環(huán)境。
關(guān)鍵詞:多金屬礦床;侵入巖;微量元素;成因類型;鋯石Ti含量地質(zhì)溫度計(jì);結(jié)晶環(huán)境;西藏
中圖分類號(hào):P595 文獻(xiàn)標(biāo)志碼:A
Zircon Trace Element Characteristics of Intrusions in Bangpu Porphyry
Mo(Cu) Polymetallic Deposit of Tibet and Their Geological Significance
LI Zhuang1, WANG Li-qiang2, ZHANG Zhong3, LUO Mao-cheng4, LENG Qiu-feng1,
KANG Hao-ran2, MENG Zhan1
(1. School of Earth Sciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China;
2. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China;
3. Tibet Tianyuan Mineral Exploration Co. Ltd., Shigatse 857000, Tibet, China;
4. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China)
Abstract: The Bangpu porphyry Mo(Cu) polymetallic deposit is located in the eastern part of Gangdise metallogenic belt. The period and type of intrusive rocks in this area are various, mainly including biotite monzonitic granite during the early mineralization, diorite porphyrite and monzonitic granite during the mineralization, and quartz monzonitic porphyry and allgovite during the late mineralization. On basis of summarizing the previous research, the characteristics of zircon trace elements from diorite porphyrite in Bangpu deposit were studied by the LA-ICP-MS technology. The results show that the types of zircon from intrusive rocks mainly include magmatic and hydrothermal zircons; chondrite-normalized REE patterns of the above five types of intrusive rocks are similar, and the curves are left deviation and steep with the characteristics of positive Ce anomaly, negative Eu anomaly, LREE enrichment and HREE depletion. Crystallization temperatures of zircon from the above five intrusive rocks calculated by the Ti-in-zircon geothermometer show that the magma of intrusive rock during the mineralization and late mineralization are derived from the partial melting under the condition of nearly water saturation. According to the characteristics of special zircon trace element and REE, the zircons of the above five intrusive rocks are crystallized and differentiated from continental crust magma, and the host rocks corresponding to zircon form in the continental crust environment.
Key words: polymetallic deposit; intrusive rock; trace element; genetic type; Ti-in-zircon geothermometer; crystallization environment; Tibet
0 引 言
西藏岡底斯斑巖成礦帶位于雅魯藏布江碰撞結(jié)合帶北側(cè),其形成和發(fā)展過程(尤其南岡底斯)記錄了雅魯藏布江特提斯洋殼向北俯沖,直至印度與亞洲大陸碰撞、碰撞后伸展過程的巖漿和構(gòu)造演化事件[1-2],是青藏高原近年來發(fā)現(xiàn)的最具經(jīng)濟(jì)價(jià)值的成礦帶之一[3-5]。目前,該成礦帶上已發(fā)現(xiàn)10余處大型、超大型斑巖銅鉬礦床(包括甲瑪、驅(qū)龍、雄村、吉如等)[6-10]和許多矽卡巖型鉛鋅多金屬礦床(包括蒙亞啊、洞中拉、拉屋等)[11-12],幾乎都形成于青藏高原陸-陸碰撞之后(中新世)地殼伸展環(huán)境[13]或碰撞擠壓-隆升伸展轉(zhuǎn)換過渡構(gòu)造環(huán)境[14-15]。西藏邦鋪斑巖鉬(銅)多金屬礦床位于墨竹工卡縣尼瑪江熱鄉(xiāng),隸屬于岡底斯—念青唐古拉板片東段中部,是甲瑪—驅(qū)龍銅鉬多金屬礦集區(qū)內(nèi)一個(gè)十分重要的超大型斑巖鉬(銅)礦床。自2007年起,該礦區(qū)詳細(xì)的地質(zhì)勘探和研究工作才正式拉開帷幕,并逐步細(xì)致深入。近年來,研究主要集中在該礦床成巖成礦時(shí)代[16-17]、成礦流體性質(zhì)[18-19]、流體包裹體及同位素[20]、礦床成因[21-22]、成礦物質(zhì)來源[23-25]、巖漿演化過程[26-27]等方面。
鋯石是自然界一種最常見的副礦物,普遍存在于巖漿巖、沉積巖和變質(zhì)巖中,并有著極其穩(wěn)定的晶體結(jié)構(gòu),能在復(fù)雜的地質(zhì)環(huán)境中完好地保存下來[28-29],且鋯石中稀土元素和微量元素對(duì)巖漿源區(qū)性質(zhì)和巖漿形成過程具有非常重要的指示作用[30]?;诖?,筆者在前人研究基礎(chǔ)上,通過系統(tǒng)總結(jié)邦鋪礦區(qū)5種不同類型侵入巖的鋯石微量元素和稀土元素特征,對(duì)不同類型侵入巖鋯石成因類型進(jìn)行探討,并對(duì)侵入巖形成環(huán)境做出合理解釋。
1 區(qū)域地質(zhì)
自中生代以來,特提斯構(gòu)造域就不斷演化,并完好記錄了特提斯洋盆裂解→擴(kuò)張→俯沖→碰撞的完整演化過程,增生造山與碰撞造山連續(xù)發(fā)育,成礦作用豐富多彩[31]。古新世初,非洲大陸的北移造就了特提斯主體洋盆的閉合[32],而特提斯洋盆的閉合造成了印度、阿拉伯板塊與歐亞大陸的碰撞[33]。Zhu等研究認(rèn)為岡底斯帶是與印度—?dú)W亞大陸碰撞有關(guān)的新生代造山帶[34],且經(jīng)歷了新生代主碰撞陸陸聚合(41~65 Ma)、晚碰撞構(gòu)造轉(zhuǎn)換(26~40 Ma)和后碰撞地殼伸展(0~25 Ma)等過程,最終演變?yōu)樯煺估瓘埖年憙?nèi)構(gòu)造環(huán)境[35-38]。
研究區(qū)位于岡底斯—念青唐古拉板片南北界及雅魯藏布江縫合帶與班公湖—怒江結(jié)合帶之間,東西兩側(cè)分別與西南“三江”構(gòu)造帶和帕米爾—喀喇昆侖構(gòu)造帶相連(圖1)。該區(qū)侵入巖復(fù)雜多樣,從基性的輝長(zhǎng)巖到酸性的花崗巖都有發(fā)現(xiàn),呈EW向帶狀展布,時(shí)間上可分為晚三疊世—侏羅紀(jì)(152~205 Ma)、白堊紀(jì)(80~109 Ma)、古新世—始新世(41~65 Ma)和漸新世—中新世(13~33 Ma)4個(gè)階段[39],空間上可分為北帶、中帶和南帶3個(gè)亞帶[40],從而使研究區(qū)發(fā)生不同程度的深部地球構(gòu)造圈層物質(zhì)、能量交換等過程,并伴隨著強(qiáng)烈的流體作用和成礦作用發(fā)生。
圖件引自文獻(xiàn)[27],有所修改
圖1 西藏岡底斯成礦帶東段主要銅多金屬礦床分布
Fig.1 Distribution of Main Copper-polymetallic Deposits in the East Section of Gangdise Metallogenic Belt, Tibet
2 礦床地質(zhì)
邦鋪礦區(qū)地層出露較為簡(jiǎn)單,主要包括礦區(qū)南部下二疊統(tǒng)洛巴堆組(P1l)、礦區(qū)中部和北部的古近系典中組(E1d)及第四系(Q),典中組與洛巴堆組主要呈逆沖斷層接觸(圖2)。礦區(qū)構(gòu)造以斷層為主,包括正斷層和逆斷層,另發(fā)育少量節(jié)理構(gòu)造,其中礦區(qū)南部正斷層為矽卡巖型鉛鋅礦的導(dǎo)礦容礦構(gòu)造。礦區(qū)巖漿活動(dòng)頻繁,發(fā)育不同類型和期次的侵入巖體,包括中西部成礦期的二長(zhǎng)花崗斑巖(年齡為(16.23±0.19)Ma)[41]、中西部成礦后期的石英二長(zhǎng)斑巖(年齡為(15.43±0.12)Ma)[42]、北部成礦后期的基性輝綠巖(年齡為(15.21±0.29)Ma)[43]、中東部成礦期的閃長(zhǎng)玢巖(年齡為(14.96±0.16)Ma)[17]以及南部成礦前期的黑云母二長(zhǎng)花崗巖(年齡為(62.1±1.9)Ma)[44]。主成礦期的侵入巖體成巖年齡與早期輝鉬礦成礦年齡((15.32±0.79)Ma)[16]較一致。在時(shí)間上,黑云母二長(zhǎng)花崗巖體最早形成,其次為二長(zhǎng)花崗巖體、石英二長(zhǎng)斑巖和輝綠玢巖,最后為閃長(zhǎng)玢巖;在空間上,各巖體均為隱伏巖體,相互之間無明顯的穿插關(guān)系。二長(zhǎng)花崗斑巖和閃長(zhǎng)玢巖分別是鉬、銅礦體的主要成礦巖體;石英二長(zhǎng)斑巖與鉛鋅礦體成礦關(guān)系密切;黑云母二長(zhǎng)花崗巖和輝綠玢巖不含礦。
蝕變主要由邦鋪礦區(qū)中西部二長(zhǎng)花崗斑巖巖體中心向上顯示出典型的鉀硅酸鹽化帶、黃鐵絹云巖化帶(局部泥化帶)及青磐巖化蝕變帶。鉀硅酸鹽化主要發(fā)育于二長(zhǎng)花崗斑巖和閃長(zhǎng)玢巖中;絹云母化主要發(fā)育于二長(zhǎng)花崗斑巖內(nèi);青磐巖化主要發(fā)育于古近系典中組中,表現(xiàn)為廣泛發(fā)育的綠簾石、綠泥石礦物組合。
礦化類型主要有邦鋪礦區(qū)中部鉬(銅)礦化、銅(鉬)礦化和鉛鋅礦化。鉬礦化主要發(fā)育于中西部二長(zhǎng)花崗斑巖中;銅礦化主要發(fā)育于中東部閃長(zhǎng)玢巖中;鉛鋅礦化發(fā)育于南部下二疊統(tǒng)洛巴堆組矽卡巖中及矽卡巖與大理巖的接觸帶內(nèi)。
邦鋪礦區(qū)礦石礦物成分較簡(jiǎn)單,主要有輝鉬礦,黃銅礦,斑銅礦,黃鐵礦及少量方鉛礦、閃鋅礦、磁鐵礦、黝銅礦等;脈石礦物主要包括長(zhǎng)石類、石英、黑云母,次為絹云母、綠泥石、綠簾石、方解石和硬石膏等。礦石結(jié)構(gòu)主要包括他形晶結(jié)構(gòu)、半自形—自形晶結(jié)構(gòu)、交代結(jié)構(gòu)、填隙結(jié)構(gòu)等。礦石構(gòu)造主要有浸染狀構(gòu)造、脈狀構(gòu)造,其次為團(tuán)塊狀、條帶狀、網(wǎng)脈狀構(gòu)造等。
3 分析測(cè)試
用于分析測(cè)試的樣品為閃長(zhǎng)玢巖,采自平硐PD5205中,采樣位置見圖2。樣品較新鮮,表面呈灰黑色至灰白色,具有斑狀結(jié)構(gòu)和塊狀構(gòu)造。巖石斑晶主要由斜長(zhǎng)石組成,局部可見少量黑云母斑晶;基質(zhì)由斜長(zhǎng)石及角閃石組成。斜長(zhǎng)石多為半自形至自形,粒徑大小不等,蝕變相對(duì)較弱。
鋯石的原位微量元素分析在西北大學(xué)大陸動(dòng)力學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室進(jìn)行。將采集的各侵入巖樣品經(jīng)人工破碎,采用磁選和浮選方法分選出鋯石后,在雙目鏡下挑選出晶形和色澤較好、無裂隙、無包裹體的鋯石顆粒,粘在雙面膠上并用環(huán)氧樹脂固定,待環(huán)氧樹脂充分固化后,將鋯石靶表面拋光,然后進(jìn)行鋯石
圖件引自文獻(xiàn)[41],有所修改
圖2 邦鋪礦區(qū)地質(zhì)圖
Fig.2 Geological Map of Bangpu Deposit
顆粒內(nèi)部結(jié)構(gòu)分析(反射光和透射光照相和陰極發(fā)光圖像研究),最后進(jìn)行鋯石LA-MC-ICP-MS微量元素測(cè)定。LA-ICPMS分析設(shè)備為德國(guó)MicroLas公司生產(chǎn)的GeoLas200M激光剝蝕系統(tǒng)與Elan6100DRCICP-MS聯(lián)機(jī),激光束斑直徑為30 μm,激光剝蝕深度為20~40 μm,采用的標(biāo)準(zhǔn)鋯石為91500。鋯石陰極發(fā)光(CL)圖像采集設(shè)備為英國(guó)Gatan公司生產(chǎn)的場(chǎng)發(fā)射掃描電子顯微鏡附屬的Gatan MonoCL3+陰極發(fā)光裝置系統(tǒng),圖像采集工作條件為240 μA分析電流、10 kV電壓。
4 分析結(jié)果
4.1 鋯石特征
閃長(zhǎng)玢巖樣品中選出的鋯石透明度一般,顏色少數(shù)較深,呈灰黑色,多為淺灰白色或無色(圖3)。鋯石顆粒大小不等,粒徑大小多在70~150μm之間,個(gè)別顆粒較大。鋯石呈長(zhǎng)柱狀、板狀及渾圓狀和不規(guī)則狀,晶體長(zhǎng)寬介于1∶1~2∶1。鋯石自形程度較好,局部發(fā)育完整的柱面和錐面。其余4種侵入巖體鋯石陰極發(fā)光圖像表明鋯石透明度均較好,大多呈淺灰白色,鋯石顆粒粒徑大小不等,局部發(fā)生破碎,大小相對(duì)變化。鋯石自形程度較高,多呈長(zhǎng)柱狀、板柱狀,晶體長(zhǎng)寬不一,多發(fā)育較好的柱面和錐面。鋯石具有明顯的震蕩環(huán)帶和扇形環(huán)帶,環(huán)帶較窄[42-43,45],說明其在低溫條件下結(jié)晶,微量元素?cái)U(kuò)散速度慢[46]。
圖3 閃長(zhǎng)玢巖鋯石陰極發(fā)光圖像
Fig.3 CL Images of Zircons from Diorite Porphyrite
4.2 稀土元素和微量元素分析
鋯石微量元素和稀土元素分析結(jié)果見表1。閃長(zhǎng)玢巖中Th含量(質(zhì)量分?jǐn)?shù),下同)為(146.87~547.84)×10-6,平均值為326.53×10-6;U含量為(251.23~1 668.37)×10-6,平均值為720.32×10-6;w(Th)/w(U)值較小,為0.20~1.51。其余4種侵入巖體中w(Th)/w(U)值均較大,平均值均大于1。閃長(zhǎng)玢巖中所有鋯石測(cè)點(diǎn)稀土元素總含量為(427.06~964.13)×10-6,平均值為625.19×10-6;wLREE/wHREE值為0.03~0.44,平均值為0.13;Ce呈正異常(0.96~86.50),平均值為12.25;Eu呈負(fù)異常(0.12~0.35),平均值為0.24。黑云母二長(zhǎng)花崗巖所有鋯石測(cè)點(diǎn)稀土元素總含量為(599.22~2 773.13)×10-6,平均值為1 514.60×10-6;wLREE/wHREE值為0.01~0.08,平均值為0.03;Ce呈正異常(7.40~124.17),平均值為70.56;Eu呈負(fù)異常(0.12~0.57),平均值為0.34。二長(zhǎng)花崗斑巖所有鋯石測(cè)點(diǎn)稀土元素總含量為(348.83~649.26)×10-6,平均值為495.44×10-6;wLREE/wHREE值為0.11~0.24,平均值為0.14;Ce呈正異常(2.96~105.01),平均值為52.29;Eu呈負(fù)異常(0.31~0.37),平均值為0.35。
表1 侵入巖微量元素和稀土元素分析結(jié)果
Tab.1 Analysis Results of Trace and Rare Earth Elements from Intrusive Rocks
注:閃長(zhǎng)玢巖數(shù)據(jù)為本文數(shù)據(jù);石英二長(zhǎng)斑巖數(shù)據(jù)引自文獻(xiàn)[42];輝綠玢巖數(shù)據(jù)引自文獻(xiàn)[43];二長(zhǎng)花崗斑巖和黑云母二長(zhǎng)花崗巖數(shù)據(jù)引自文獻(xiàn)[45];測(cè)點(diǎn)號(hào)以A開頭的樣品為閃長(zhǎng)玢巖,以B開頭的為黑云母二長(zhǎng)花崗巖,以C開頭的為二長(zhǎng)花崗斑巖,以D開頭的為石英二長(zhǎng)斑巖,以E開頭的為輝綠玢巖;w(·)為元素或化合物含量;wREE為稀土元素總含量;wLREE為輕稀土元素總含量;wHREE為重稀土元素總含量;δ(Eu)為Eu異常;w(·)N為元素含量球粒隕石標(biāo)準(zhǔn)化后的值。石英二長(zhǎng)斑巖所有鋯石測(cè)點(diǎn)稀土元素總含量為(390.20~769.08)×10-6,平均值為517.30×10-6;wLREE/wHREE值為0.13~0.60,平均值為0.21;Ce呈正異常(1.54~132.63),平均值為43.71;Eu呈負(fù)異常(0.35~0.47),平均值為0.38。輝綠玢巖所有鋯石測(cè)點(diǎn)稀土元素總含量為(416.43~1 197.24)×10-6,平均值為606.30×10-6;wLREE/wHREE值為0.10~0.85,平均值為0.19;Ce呈正異常(1.16~98.80),平均值為46.59;Eu呈負(fù)異常(0.26~0.42),平均值為0.36。
ws為樣品含量;wc為球粒隕石含量;球粒隕石標(biāo)準(zhǔn)化值引自文獻(xiàn)[47];圖中線條對(duì)應(yīng)不同樣品
圖4 侵入巖球粒隕石標(biāo)準(zhǔn)化稀土元素配分模式
Fig.4 Chondrite-normalized REE Patterns for Intrusive Rock
邦鋪礦區(qū)5種不同類型侵入巖中,閃長(zhǎng)玢巖Eu異常平均值最小,球粒隕石標(biāo)準(zhǔn)化稀土元素配分模式總體比較相似,曲線較陡[圖4(a)~(e)],稀土元素含量從La至Lu之間迅速增加。除閃長(zhǎng)玢巖外,其余4種侵入巖體均表現(xiàn)為明顯Ce正異常和Eu負(fù)異常,輕稀土元素虧損,而重稀土元素富集。不同類型侵入巖球粒隕石標(biāo)準(zhǔn)化稀土元素配分模式平均值[圖4(f)]也顯示出具典型的Ce正異常和Eu負(fù)異常,輕稀土元素虧損,重稀土元素富集。
5 討 論
5.1 鋯石成因類型
鋯石w(Th)/w(U)值常被用作判斷其成因的標(biāo)志,以區(qū)分巖漿、變質(zhì)和熱液環(huán)境。Th4+離子半徑與Zr4+離子半徑非常接近,電價(jià)相同,很容易進(jìn)入鋯石中;又因U4+離子半徑比Th4+小,更接近Zr4+,所以鋯石中U含量常高于Th[48]。邦鋪礦區(qū)除閃長(zhǎng)玢巖外,其余4種侵入巖體中鋯石w(Th)/w(U)值都較高,平均值均大于1。黑云母二長(zhǎng)花崗巖中鋯石w(Th)/w(U)值為0.27~2.17,平均值為1.16;二長(zhǎng)花崗斑巖中鋯石w(Th)/w(U)值為1.10~1.34,平均值為1.26;石英二長(zhǎng)斑巖中鋯石w(Th)/w(U)值為1.09~1.46,平均值為1.29;輝綠玢巖中鋯石w(Th)/w(U)值為1.17~1.65,平均值為1.37。不同成因鋯石的Th、U含量及其比值差異較大,一般巖漿鋯石w(Th)/w(U)值大于0.4,熱液鋯石w(Th)/w(U)值小于0.1[44,49-51]。據(jù)此觀點(diǎn)可知,上述4種侵入巖鋯石應(yīng)屬典型的巖漿鋯石類。然而,Hidaka等研究發(fā)現(xiàn)一些典型巖漿鋯石也會(huì)具有非常低的w(Th)/w(U)值[52],因此,不能僅僅根據(jù)鋯石的w(Th)/w(U)值來區(qū)分鋯石的成因類型。此外,趙振華通過研究鋯石微量元素地球化學(xué)特征也證實(shí):w(Th)/w(U)值主要反映的是母體的特點(diǎn)或形成時(shí)局部的甚至包括流體源區(qū)的化學(xué)環(huán)境[43]。因此,當(dāng)用w(Th)/w(U)值來判定鋯石成因時(shí)必須謹(jǐn)慎,應(yīng)當(dāng)與其他綜合地球化學(xué)指標(biāo)相結(jié)合最終作出合理判斷。
Ferry等研究發(fā)現(xiàn),利用鋯石(Sm/La)N-(Lu/Gd)N圖解和δ(Ce)-δ(Eu)圖解可以比較準(zhǔn)確地區(qū)分熱液鋯石和巖漿鋯石[53]。據(jù)此方法對(duì)邦鋪礦區(qū)侵入巖鋯石作(Sm/La)N-(Lu/Gd)N圖解和δ(Ce)-δ(Eu)圖解。閃長(zhǎng)玢巖鋯石在圖5(a)中有10個(gè)測(cè)點(diǎn)落入熱液鋯石區(qū)域,在圖5(b)中有9個(gè)測(cè)點(diǎn)落入熱液鋯石區(qū)域,據(jù)此可判斷閃長(zhǎng)玢巖鋯石主要為熱液鋯石類;二長(zhǎng)花崗斑巖鋯石在圖5(a)中有10個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,在圖5(b)中同樣有10個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,因此,二長(zhǎng)花崗斑巖鋯石主要屬于巖漿鋯石類;黑云母二長(zhǎng)花崗巖鋯石在圖5(a)中有10個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,在圖5(b)中有11個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,因此,黑云母二長(zhǎng)花崗巖鋯石應(yīng)主要為巖漿鋯石類;石英二長(zhǎng)斑巖鋯石在圖5(a)中有9個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,在圖5(b)中同樣有9個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,據(jù)此可推斷此類鋯石亦主要為巖漿鋯石類;基性輝綠玢巖鋯石在圖5(a)中有10個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,在圖5(b)中有9個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,據(jù)此可判定輝綠玢巖鋯石主要為巖漿鋯石類。
此外,(Sm/La)N-La圖解和δ(Ce)-(Sm/La)N圖解也可以很好地區(qū)分巖漿鋯石和熱液鋯石。圖6(a)中黑云母二長(zhǎng)花崗巖鋯石有8個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,3個(gè)測(cè)點(diǎn)落在巖漿鋯石邊界區(qū)域內(nèi),圖6(b)中有8個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,3個(gè)測(cè)點(diǎn)落在巖漿鋯石邊界區(qū)域,因此,此類鋯石主要屬于巖漿鋯石類;圖6(a)中輝綠玢巖鋯石有5個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,5個(gè)測(cè)點(diǎn)落在巖漿鋯石邊界區(qū)域內(nèi),圖6(b)中有6個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,2個(gè)測(cè)點(diǎn)落在巖
底圖引自文獻(xiàn)[53]
圖5 侵入巖(Sm/La)N-(Lu/Gd)N圖解和δ(Ce)-δ(Eu)圖解
Fig.5 Diagrams of (Sm/La)N-(Lu/Gd)N and δ(Ce)-δ(Eu) for Intrusive Rocks
底圖引自文獻(xiàn)[54]
圖6 侵入巖(Sm/La)N-La圖解和δ(Ce)-(Sm/La)N圖解
Fig.6 Diagrams of (Sm/La)N-La and δ(Ce)-(Sm/La)N for Intrusive Rocks
漿鋯石邊界區(qū)域, 2個(gè)測(cè)點(diǎn)靠近巖漿鋯石區(qū)域,因此,輝綠玢巖鋯石主要為巖漿鋯石類;二長(zhǎng)花崗斑巖鋯石在圖6(a)中有5個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,4個(gè)測(cè)點(diǎn)落在巖漿鋯石邊界區(qū)域,在圖6(b)中有8個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域內(nèi),因此,二長(zhǎng)花崗斑巖鋯石主要屬巖漿鋯石類;石英二長(zhǎng)斑巖鋯石在圖6(a)中有4個(gè)測(cè)點(diǎn)落在巖漿鋯石區(qū)域,2個(gè)測(cè)點(diǎn)落在過渡區(qū)域(更靠近巖漿鋯石區(qū)域),在圖6(b)中有7個(gè)測(cè)點(diǎn)落入巖漿鋯石區(qū)域,3個(gè)測(cè)點(diǎn)落入巖漿鋯石邊界區(qū)域,因此,石英二長(zhǎng)斑巖鋯石主要屬于巖漿鋯石類;閃長(zhǎng)玢巖鋯石在圖6(a)中有6個(gè)測(cè)點(diǎn)落入熱液鋯石邊界區(qū)域內(nèi),1個(gè)測(cè)點(diǎn)落在熱液鋯石區(qū)域內(nèi), 5個(gè)測(cè)點(diǎn)靠近熱液鋯石區(qū)域,在圖6(b)中有6個(gè)測(cè)點(diǎn)落在熱液鋯石區(qū)域,2個(gè)測(cè)點(diǎn)落在熱液鋯石邊界區(qū)域,因此,閃長(zhǎng)玢巖鋯石主要屬熱液鋯石類。
綜上所述,邦鋪礦區(qū)閃長(zhǎng)玢巖鋯石主要為熱液鋯石類,其余4種侵入巖體(包括黑云母二長(zhǎng)花崗巖、二長(zhǎng)花崗斑巖、輝綠玢巖和石英二長(zhǎng)斑巖)中鋯石均主要屬巖漿鋯石類。
5.2 鋯石Ti含量地質(zhì)溫度計(jì)
由于鋯石自身的高度穩(wěn)定性及鋯石中Ti含量(w(Ti))與地質(zhì)溫度(T)密切相關(guān),其關(guān)系呈對(duì)數(shù)線性變化,根據(jù)此種關(guān)系可以大致判斷巖漿當(dāng)時(shí)的結(jié)晶溫度。近年來,Harrison等提出的鋯石Ti含量地質(zhì)溫度計(jì)[55]引起了普遍關(guān)注。Watson等提出的鋯石Ti含量地質(zhì)溫度計(jì)計(jì)算公式為:T=(5 080±30)/[(6.01±0.03)-lg w(Ti)]-273[56]。由于此溫度計(jì)所表現(xiàn)出的簡(jiǎn)單實(shí)用性,引起了許多研究者的關(guān)注并被廣泛應(yīng)用,且Zheng等已經(jīng)嘗試著將此溫度計(jì)應(yīng)用于不同成因的鋯石中[57]。
應(yīng)用上述鋯石Ti含量地質(zhì)溫度計(jì)計(jì)算出邦鋪礦區(qū)不同類型侵入巖體中鋯石的結(jié)晶溫度(表2)。從表2可以看出,閃長(zhǎng)玢巖鋯石結(jié)晶溫度為399.27 ℃~614.02 ℃,平均為546.92 ℃;黑云母二長(zhǎng)花崗巖鋯石結(jié)晶溫度為638.65 ℃~905.12 ℃,平均為755.86 ℃;二長(zhǎng)花崗斑巖鋯石結(jié)晶溫度為639.24 ℃~978.74 ℃,平均為732.21 ℃;石英二長(zhǎng)斑巖鋯石結(jié)晶溫度為681.12 ℃~721.67 ℃,平均為691.11 ℃;輝綠玢巖鋯石結(jié)晶溫度為604.44 ℃~720.70 ℃,平均為691.59 ℃。
Richards等研究表明,含礦巖漿富水是形成斑巖礦床的關(guān)鍵因素[58-59]。周金勝等通過大量計(jì)算得到,絕大部分高溫條件(大于750 ℃)下形成的巖漿巖鋯石結(jié)晶溫度均落在濕花崗巖固相線以上,低的鋯石結(jié)晶溫度(如680 ℃)表明巖漿經(jīng)歷了在水近飽和條件下發(fā)生的熔融過程[60]。據(jù)邦鋪礦區(qū)侵入巖鋯石結(jié)晶溫度計(jì)算結(jié)果(表2)可以看出:二長(zhǎng)花崗斑巖、輝綠玢巖和閃長(zhǎng)玢巖中70%的鋯石結(jié)晶溫度小于700 ℃;石英二長(zhǎng)斑巖中近90%的鋯石結(jié)晶溫度小于700 ℃;黑云母二長(zhǎng)花崗巖鋯石平均結(jié)晶溫度大于750 ℃。因此,推測(cè)邦鋪礦床成礦前期的侵入巖體巖漿來源于缺水條件下發(fā)生的部分熔融,而成礦期和成礦后的侵入巖體巖漿來源于在水近飽和條件下發(fā)生的部分熔融。
表2 侵入巖鋯石Ti含量地質(zhì)溫度計(jì)計(jì)算結(jié)果
Tab.2 Calculation Results of Intrusive Rocks by the Means of Ti-in-zircon Geothermometer
注:T1~T5分別為黑云母二長(zhǎng)花崗巖、二長(zhǎng)花崗斑巖、閃長(zhǎng)玢巖、石英二長(zhǎng)斑巖和輝綠玢巖地質(zhì)溫度。5.3 巖漿結(jié)晶環(huán)境
鋯石中微量元素可以很好地記錄并揭示出寄主巖石的結(jié)晶環(huán)境。將鋯石中微量元素U和稀土元素相結(jié)合,繪制U-Yb、U/Yb-Y圖解;這2種圖解可以明顯區(qū)分洋殼成因鋯石和陸殼成因鋯石,進(jìn)而區(qū)分鋯石是從大陸還是從洋殼巖漿結(jié)晶,從而可以很好地揭示侵入巖鋯石的源區(qū)[30]。依據(jù)此方法對(duì)邦鋪礦區(qū)5種侵入巖鋯石數(shù)據(jù)進(jìn)行U-Pb和U/Yb-Y投圖(圖7)。從圖7可以看出,邦鋪礦區(qū)5種侵入巖所有鋯石測(cè)點(diǎn)均落入陸殼區(qū)域,從而可以推測(cè)邦鋪礦區(qū)5種侵入巖體鋯石結(jié)晶環(huán)境為陸殼環(huán)境。
底圖引自文獻(xiàn)[30]
圖7 侵入巖U/Yb-Y圖解和U-Yb圖解
Fig.7 Diagrams of U/Yb-Y and U-Yb for Intrusive Rocks
在區(qū)域上,整個(gè)岡底斯花崗巖具有年輕的模式年齡,巖石圈地幔部分熔融后又發(fā)生底侵[61]。地幔物質(zhì)透過巖漿底侵-巖漿混合作用大量進(jìn)入地殼,黑云母二長(zhǎng)花崗巖與其同時(shí)代的林子宗群火山巖具有相同的起源,均為俯沖板片及卷入的陸源沉積物部分熔融形成[40]。大約在16 Ma,已經(jīng)斷裂且下沉的洋殼殘?bào)w在下沉過程中不斷被軟流圈熔融形成二長(zhǎng)花崗斑巖[45];石英二長(zhǎng)斑巖可能為晚期含礦二長(zhǎng)花崗斑巖的母巖漿演化而成[42]。巖漿源區(qū)帶混染了越來越多的古老地殼物質(zhì)成分,且成礦作用一般發(fā)生在巖漿-熱液活動(dòng)中后期。
周雄等通過鋯石Hf同位素研究,發(fā)現(xiàn)石英二長(zhǎng)斑巖Hf同位素組成特征[18]與鉬(銅)礦區(qū)二長(zhǎng)花崗斑巖鋯石Hf同位素組成特征[45]一致,且在區(qū)域及相鄰礦區(qū)也得到了證實(shí)。甲瑪含礦巖漿在結(jié)晶分異過程中受到了外來物質(zhì)的混染[62],驅(qū)龍含礦斑巖巖漿源區(qū)主要為沉積物熔體對(duì)巖石圈地幔交代而成,巖石圈地幔部分熔融而后發(fā)生底侵作用[61]。最終證實(shí)源區(qū)物質(zhì)主要來源于年輕地幔的組分,且在后期巖漿侵位過程中受到了古老地殼物質(zhì)的混染,從而結(jié)晶形成于陸殼區(qū)域。
綜上所述,邦鋪礦區(qū)侵入巖巖漿最初來源于地幔成分,隨著部分熔融作用而后發(fā)生底侵作用,并在后期巖漿侵位上升過程中同時(shí)受到古老地殼物質(zhì)的混染,并最終于陸殼環(huán)境結(jié)晶分異成不同類型的侵入巖體。
6 結(jié) 語
(1)西藏邦鋪礦區(qū)閃長(zhǎng)玢巖、二長(zhǎng)花崗斑巖、黑云母二長(zhǎng)花崗巖、石英二長(zhǎng)斑巖及輝綠玢巖等5種不同類型的侵入巖稀土元素球粒隕石標(biāo)準(zhǔn)化配分模式總體呈現(xiàn)相似的特征,曲線均較陡。除閃長(zhǎng)玢巖外,其余4種侵入巖鋯石均表現(xiàn)為明顯的Ce正異常和Eu負(fù)異常,輕稀土元素虧損,重稀土元素富集。
(2)邦鋪礦區(qū)各侵入巖中鋯石成因不盡相同,鋯石成因類型主要包括巖漿鋯石、熱液鋯石兩種類型。其中,閃長(zhǎng)玢巖中鋯石主要為熱液鋯石類,其余4種侵入巖體中鋯石主要屬巖漿鋯石類。
(3)根據(jù)鋯石Ti含量地質(zhì)溫度計(jì)計(jì)算得到的結(jié)晶溫度顯示出礦區(qū)含礦二長(zhǎng)花崗斑巖、閃長(zhǎng)玢巖及石英二長(zhǎng)斑巖體為在水近飽和條件下發(fā)生部分熔融形成的。U/Y-Y圖解和U-Yb圖解表明礦區(qū)侵入巖體主要結(jié)晶形成于近水飽和的陸殼環(huán)境中。
野外地質(zhì)調(diào)查過程中得到了西藏天仁礦業(yè)公司的大力支持,試驗(yàn)過程中得到了西北大學(xué)大陸動(dòng)力學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室第五春榮、柳小明等老師的幫助,在此一并表示感謝!
參考文獻(xiàn):
References:
[1] 朱弟成,莫宣學(xué),趙志丹,等.西藏南部二疊紀(jì)和早白堊世構(gòu)造巖漿作用與特提斯演化:新觀點(diǎn)[J].地學(xué)前緣,2009,16(2):1-20.
ZHU Di-cheng,MO Xuan-xue,ZHAO Zhi-dan,et al.Permian and Early Cretaceous Tectonomagmatism in Southern Tibet and Tethyan Evolution:New Perspective[J].Earth Science Frontiers,2009,16(2):1-20.
[2] 莫宣學(xué),趙志丹,朱弟成,等.西藏南部印度—亞洲碰撞帶巖石圈:巖石學(xué)-地球化學(xué)約束[J].地球科學(xué),2009,34(1):17-27.
MO Xuan-xue,ZHAO Zhi-dan,ZHU Di-cheng,et al.On the Lithosphere of Indo-Asia Collision Zone in Southern Tibet:Petrological and Geochemical Constraints[J].Earth Science,2009,34(1):17-27.
[3] 鄭有業(yè),多 吉,王瑞江,等.西藏岡底斯巨型斑巖銅礦帶勘查研究最新進(jìn)展[J].中國(guó)地質(zhì),2007,34(2):324-334.
ZHENG You-ye,DUO Ji,WANG Rui-jiang,et al.New Advances in the Study of the Gigantic Gangdise Porphyry Copper Metallogenic Zone,Tibet[J].Geology in China,2007,34(2):324-334.
[4] 唐菊興,王立強(qiáng),鄭文寶,等.岡底斯成礦帶東段礦床成礦規(guī)律及找礦預(yù)測(cè)[J].地質(zhì)學(xué)報(bào),2014,88(12):2545-2555.
TANG Ju-xing,WANG Li-qiang,ZHENG Wen-bao,et al.Ore Deposits Metallogenic Regularity and Prospecting in the Eastern Section of the Gangdese Metallogenic Belt[J].Acta Geologica Sinica,2014,88(12):2545-2555.
[5] ZHENG Y Y,SUN X,GAO S B,et al.Metallogenesis and the Minerogenetic Series in the Gangdese Polymetallic Copper Belt[J].Journal of Asian Earth Sciences,2015,103:23-39.
[6] ZHENG Y Y,SUN X,GAO S B,et al.Multiple Minera-lization Events at the Jiru Porphyry Copper Deposit,Southern Tibet:Implications for Eocene and Miocene Magma Sources and Resource Potential[J].Journal of Asian Earth Sciences,2014,79(2):842-857.
[7] 應(yīng)立娟,陳毓川,王登紅,等.中國(guó)銅礦成礦規(guī)律概要[J].地質(zhì)學(xué)報(bào),2014,88(12):2216-2226.
YING Li-juan,CHEN Yu-chuan,WANG Deng-hong,et al.Metallogenic Regularity of Copper Ore in China[J].Acta Geologica Sinica,2014,88(12):2216-2226.
[8] LANG X H,TANG J X,LI Z J,et al.U-Pb and Re-Os Geochronological Evidence for the Jurassic Porphyry Metallogenic Event of the Xiongcun District in the Gangdese Porphyry Copper Belt, Southern Tibet,PRC[J].Journal of Asian Earth Sciences,2014,79(2):608-622.
[9] 唐菊興,鄧世林,鄭文寶,等.西藏墨竹工卡縣甲瑪銅多金屬礦床勘查模型[J].礦床地質(zhì),2011,30(2):179-196.
TANG Ju-xing,DENG Shi-lin,ZHENG Wen-bao,et al.An Exploration Model for Jiama Copper Polymetallic Deposit in Maizhokunggar County,Tibet[J].Mineral Deposits,2011,30(2):179-196.
[10] 楊歡歡,唐菊興,林 彬,等.西藏甲瑪銅多金屬礦床成礦系統(tǒng)元素的活動(dòng)性及質(zhì)量平衡[J].地球科學(xué)與環(huán)境學(xué)報(bào),2014,36(2):51-61.
YANG Huan-huan,TANG Ju-xing,LIN Bin,et al.Element Mobility and Mass Balance of Ore-forming System in Jiama Copper Polymetallic Deposit of Tibet[J].Journal of Earth Sciences and Environment,2014,36(2):51-61.
[11] 劉 妍,趙元藝,王瑞江,等.西藏拉屋鋅銅多金屬礦床巖礦相學(xué)特征及意義[J].礦床地質(zhì),2010,29(6):1054-1078.
LIU Yan,ZHAO Yuan-yi,WANG Rui-jiang,et al.Facieology and Mineragraphy Characteristics of Lawu Zinc-copper Polymetallic Ore Deposit in Tibet and Their Significance[J].Mineral Deposits,2010,29(6):1054-1078.
[12] 費(fèi)光春,多 吉,溫春齊,等.西藏洞中拉鉛鋅礦床S、Pb、Sr同位素組成對(duì)成礦物質(zhì)來源的示蹤[J].礦物巖石,2011,31(4):52-57.
FEI Guang-chun,DUO Ji,WEN Chun-qi,et al.S,Pb and Sr Isotopic Compositions for Tracing Sources of Ore-forming Materials in Dongzhongla Lead-zinc Deposit in Tibet[J].Journal of Mineralogy and Petrology,2011,31(4):52-57.
[13] 李德威.青藏高原南部晚新生代板內(nèi)造山與動(dòng)力成礦[J].地學(xué)前緣,2004,11(4):361-369.
LI De-wei.Late Cenozoic Intraplate Orogeny and Dynamic Metallogeny in the Southern Qinghai-Tibet Plateau[J].Earth Science Frontiers,2004,11(4):361-369.
[14] 李光明,馮孝良,黃志英,等.西藏岡底斯構(gòu)造帶中段多島弧-盆系及其演化[J].沉積與特提斯地質(zhì),2000,20(4):38-46.
LI Guang-ming,F(xiàn)ENG Xiao-liang,HUANG Zhi-ying,et al.The Multiple Island Arc-basin System and Their Evolution in Gangdise Tectonic Belt,Tibet[J].Sedimentary Geology and Tethyan Geology,2000,20(4):38-46.
[15] 秦克章,李光明,趙俊興,等.西藏首例獨(dú)立鉬礦——岡底斯沙讓大型斑巖鉬礦的發(fā)現(xiàn)及其意義[J].中國(guó)地質(zhì),2008,35(6):1101-1112.
QIN Ke-zhang,LI Guang-ming,ZHAO Jun-xing,et al.Discovery of Sharang Large-scale Porphyry Molybdenum Deposit,the First Single Mo Deposit in Tibet and Its Significance[J].Geology in China,2008,35(6):1101-1112.
[16] 孟祥金,侯增謙,高永豐,等.西藏岡底斯東段斑巖銅鉬鉛鋅成礦系統(tǒng)的發(fā)育時(shí)限:邦鋪銅多金屬礦床輝鉬礦Re-Os年齡證據(jù)[J].礦床地質(zhì),2003,22(3):246-252.
MENG Xiang-jin,HOU Zeng-qian,GAO Yong-feng,et al.Development of Porphyry Copper-molybdenum-lead-zinc Ore-forming System in East Gangdese Belt,Tibet:Evidence from Re-Os Age of Molybdenite in Bangpu Copper Polymetallic Deposit[J].Mineral Deposits,2003,22(3):246-252.
[17] WANG L Q,CHEN Y C,TANG J X,et al.LA-ICP-MS Zircon U-Pb Dating of Intermediate-acidic Intrusive Rocks and Molybdenite Re-Os Dating from the Bangpu Mo(Cu) Deposit,Tibet and Its Geological Implication[J].Acta Geologica Sinica:English Edition,2012,86(5):1225-1240.
[18] 周 雄,溫春齊,霍 艷,等.西藏墨竹工卡地區(qū)邦鋪鉬銅多金屬礦床成礦流體的特征[J].地質(zhì)通報(bào),2010,29(7):1039-1048.
ZHOU Xiong,WEN Chun-qi,HUO Yan,et al.Characteristics of Ore-forming Fluid of Bangpu Molybdenum-copper Polymetallic Deposit,Maizhokunggar Area,Tibet,China[J].Geological Bulletin of China,2010,29(7):1039-1048.
[19] 溫 泉,溫春齊,霍 艷,等.西藏邦鋪鉬銅礦區(qū)He、Ne和Ar同位素及成礦流體示蹤[J].硬質(zhì)合金,2012,29(2):106-110.
WEN Quan,WEN Chun-qi,HUO Yan,et al.He,Ne and Ar Isotopic Composition and Origin of Ore-forming Fluids of Bangpu Mo-Cu Mine Area,Tibet[J].Cemented Carbide,2012,29(2):106-110.
[20] 羅茂澄.西藏邦鋪斑巖鉬銅礦床-成礦流體演化和礦床成因[D].北京:中國(guó)地質(zhì)大學(xué),2012.
LUO Mao-cheng.The Porphyry Molybdenum-copper Deposit at Bangpu,Tibet:Fluid Evolution and Mineralization[D].Beijing:China University of Geosciences,2012.
[21] 周 雄.西藏邦鋪鉬銅多金屬礦床流體包裹體研究[D].成都:成都理工大學(xué),2012.
ZHOU Xiong.Study on the Fluid Inclusions of the Bangpu Molybdenum Copper Polymetallic Deposit,Tibet[D].Chengdu:Chengdu University of Technology,2012.
[22] 王立強(qiáng),唐菊興,鄭文寶,等.西藏岡底斯成礦帶東段主要鉬多金屬礦床成礦規(guī)律研究[J].地質(zhì)論評(píng),2014,60(2):363-379.
WANG Li-qiang,TANG Ju-xing,ZHENG Wen-bao,et al.Study on Metallogency of Main Molybdenum Polymetallic Deposits in the Eastern Section of the Gangdese Metallogenic Belt[J].Geological Review,2014,60(2):363-379.
[23] 王立強(qiáng),羅茂澄,袁志潔,等.西藏邦鋪鉛鋅礦床S、Pb、C、O同位素組成及成礦物質(zhì)來源研究[J].地球?qū)W報(bào),2012,33(4):435-443.
WANG Li-qiang,LUO Mao-cheng,YUAN Zhi-jie,et al.Sulfur,Lead,Carbon and Oxygen Isotope Composition and Source of Ore-forming Materials of the Bangpu Pb-Zn Ore Deposit in Tibet[J].Acta Geoscientica Sinica,2012,33(4):435-443.
[24] WANG L Q,TANG J X,CHENG W B,et al.Origin of the Ore-forming Fluids and Metals of the Bangpu Porphyry Mo-Cu Deposit of Tibet,China:Constraints from He-Ar, H-O,S and Pb Isotopes[J].Journal of Asian Earth Sciences,2015,103:276-287.
[25] 王立強(qiáng),唐菊興,陳 偉,等.西藏邦鋪鉬多金屬礦床矽卡巖礦物學(xué)特征及其地質(zhì)意義[J].中國(guó)地質(zhì),2014,41(2):562-576.
WANG Li-qiang,TANG Ju-xing,CHEN Wei,et al.Mineralogical Characteristics of Skarn in the Bangpu Mo Polymetallic Deposit,Tibet,and Their Geological Significance[J].Geology in China,2014,41(2):562-576.
[26] 趙曉燕,楊竹森,侯增謙,等.西藏邦鋪礦區(qū)輝綠玢巖成因及對(duì)區(qū)域構(gòu)造巖漿演化的指示[J].巖石學(xué)報(bào),2013,29(11):3767-3778.
ZHAO Xiao-yan,YANG Zhu-sen,HOU Zeng-qian,et al.Petrogenesis of Diabase Porphyrite in Bangpu Deposit of Tibet and Its Instructions to the Regional Tectonic and Magmatic Evolution[J].Acta Petrologica Sinica,2013,29(11):3767-3778.
[27] 李光明,劉 波,屈文俊,等.西藏岡底斯成礦帶的斑巖-矽卡巖成礦系統(tǒng)[J].大地構(gòu)造與成礦學(xué),2005,29(4):482-490.
LI Guang-ming,LIU Bo,QU Wen-jun,et al.The Porphyry-skarn Ore-forming System in Gangdese Metallogenic Belt,Southern Tibet[J].Geotectonica et Meta-llogenia,2005,29(4):482-490.
[28] BELOUSOVA E A,GRIFFIN W L,OREILLY S Y,et al.Igneous Zircon:Trace Element Composition as an Indicator of Source Rock Type[J].Contributions to Mineralogy and Petrology,2002,143(5):602-622.
[29] 李長(zhǎng)民.鋯石成因礦物學(xué)與鋯石微區(qū)定年綜述[J].地質(zhì)調(diào)查與研究,2009,33(3):161-174.
LI Chang-min.A Review on the Minerageny and Situ Microanalytical Dating Techniques of Zircons[J].Geological Survey and Research,2009,33(3):161-174.
[30] GRIMES C B,JOHN B E,KELEMEN P B,et al.Trace Element Chemistry of Zircons from Oceanic Crust:A Method for Distinguishing Detrital Zircon Provenance[J].Geology,2007,35(7):643-646.
[31] 張洪瑞,侯增謙,楊志明.特提斯成礦域主要金屬礦床類型與成礦過程[J].礦床地質(zhì),2010,29(1):113-133.
ZHANG Hong-rui,HOU Zeng-qian,YANG Zhi-ming.Metallogenesis and Geodynamics of Tethyan Metallogenic Domain:A Review[J].Mineral Deposits,2010,29(1):113-133.
[32] MOIX P,BECCALETTO L,KOZUR H W,et al.A New Classification of the Turkish Terrances and Sutures and Its Implication for the Paleotectonic History of the Region[J].Tectonophysics,2008,451(1/2/3/4):7-39.
[33] 侯增謙,莫宣學(xué),楊志明,等.青藏高原碰撞造山帶成礦作用:構(gòu)造背景、時(shí)空分布和主要類型[J].中國(guó)地質(zhì),2006,33(2):340-351.
HOU Zeng-qian,MO Xuan-xue,YANG Zhi-ming,et al.Metallogenesis in the Collisional Orogen of the Qinghai-Tibet Plateau:Tectonic Setting,Tempo-spatial Distribution and Ore Deposit Types[J].Geology in China,2006,33(2):340-351.
[34] ZHU D C,CHUNG S L,MO X X,et al.The 132 Ma Comei-Bunbury Large Igneous Province:Remnants Identified in Present-day Southeastern Tibet and Southwestern Australia[J].Geology,2009,37(7):583-586.
[35] 侯增謙,楊竹森,徐文藝,等.青藏高原碰撞造山帶:Ⅰ.主碰撞造山成礦作用[J].礦床地質(zhì),2006,25(4):337-358.
HOU Zeng-qian,YANG Zhu-sen,XU Wen-yi,et al.Metallogenesis in Tibetan Collisional Orogenic Belt:Ⅰ.Mineralization in Main Collisional Orogenic Setting[J].Mineral Deposits,2006,25(4):337-358.
[36] 侯增謙,潘桂棠,王安建,等.青藏高原碰撞造山帶:Ⅱ.晚碰撞轉(zhuǎn)換成礦作用[J].礦床地質(zhì),2006,25(5):521-543.
HOU Zeng-qian,PAN Gui-tang,WANG An-jian,et al.Metallogenesis in Tibetan Collisional Orogenic Belt:Ⅱ.Mineralization in Late-collisional Transformation Setting[J].Mineral Deposits,2006,25(5):521-543.
[37] 侯增謙,曲曉明,楊竹森,等.青藏高原碰撞造山帶:Ⅲ.后碰撞伸展成礦作用[J].礦床地質(zhì),2006,25(6):629-651.
HOU Zeng-qian,QU Xiao-ming,YANG Zhu-sen,et al.Metallogenesis in Tibetan Collisional Orogenic Belt:Ⅲ.Mineralization in Post-collisional Extension Setting[J].Mineral Deposits,2006,25(6):629-651.
[38] HOU Z Q,YANG Z M,QU X M,et al.The Miocene Gangdese Porphyry Copper Belt Generated During Post-collisional Extension in the Tibetan Orogen[J].Ore Geology Reviews,2009,36(1/2/3):25-51.
[39] 紀(jì)偉強(qiáng),吳福元,鐘孫霖,等.西藏南部岡底斯巖基花崗巖時(shí)代與巖石成因[J].中國(guó)科學(xué):D輯,地球科學(xué),2009,39(7):849-871.
JI Wei-qiang,WU Fu-yuan,ZHONG Sun-lin,et al.Geochronology and Petrogenesis of Granitic Rocks in Gangdese Batholith,Southern Tibet[J].Science in China:Series D,Earth Sciences,2009,39(7):849-871.
[40] 莫宣學(xué),董國(guó)臣,趙志丹,等.西藏岡底斯帶花崗巖的時(shí)空分布特征及地殼生長(zhǎng)演化信息[J].高校地質(zhì)學(xué)報(bào),2005,11(3):281-290.
MO Xuan-xue,DONG Guo-chen,ZHAO Zhi-dan,et al.Spatial and Temporal Distribution and Characteristics of Granitoids in the Gangdese,Tibet and Implication for Crustal Growth and Evolution[J].Geological Journal of China Universities,2005,11(3):281-290.
[41] 王立強(qiáng),唐菊興,陳毓川,等.西藏邦鋪鉬(銅)礦床含礦二長(zhǎng)花崗斑巖LA-ICP-MS鋯石U-Pb定年及地質(zhì)意義[J].礦床地質(zhì),2011,30(2):349-360.
WANG Li-qiang,TANG Ju-xing,CHEN Yu-chuan,et al.LA-ICP-MS Zircon U-Pb Dating of Ore-bearing Monzogranite Porphyry in Bangpu Molybdenum(Copper) Deposit,Tibet and Its Significance[J].Mineral Deposits,2011,30(2):349-360.
[42] 陳 偉,王立強(qiáng),胡正華,等.西藏邦鋪鉛鋅礦區(qū)石英二長(zhǎng)斑巖鋯石U-Pb年齡、Hf同位素和稀土元素特征及其地質(zhì)意義[J].地球?qū)W報(bào),2012,33(4):569-578.
CHEN Wei,WANG Li-qiang,HU Zheng-hua,et al.Zircon U-Pb Ages,Hf Isotope and REE of Quartz Monzonite Porphyry in the Bangpu Pb-Zn Mining Area of Tibet and Their Geological Significance[J].Acta Geoscientica Sinica,2012,33(4):569-578.
[43] 冷秋鋒,王立強(qiáng),應(yīng)立娟,等.西藏邦鋪鉬(銅)礦床輝綠玢巖脈體LA-ICP-MS鋯石U-Pb定年及其地質(zhì)意義[J].地球?qū)W報(bào),2012,33(4):559-568.
LENG Qiu-feng,WANG Li-qiang,YING Li-juan,et al.LA-ICP-MS Zircon U-Pb Dating of Allgovite in the Bangpu Molybdenum (Copper) Deposit in Tibet and Its Geological Significance[J].Acta Geoscientica Sinica,2012,33(4):559-568.
[44] RAYNER N,STERN R A,CARR S D.Grain-scale Variations in Trace Element Composition of Fluid-altered Zircon,Acasta Gneiss Complex,Northwestern Canada[J].Contributions to Mineralogy and Petrology,2005,148(6):721-734.
[45] 羅茂澄,王立強(qiáng),冷秋鋒,等.邦鋪鉬(銅)礦床二長(zhǎng)花崗斑巖、黑云二長(zhǎng)花崗巖鋯石Hf同位素和Ce4+/Ce3+比值[J].礦床地質(zhì),2011,30(2):266-278.
LUO Mao-cheng,WANG Li-qiang,LENG Qiu-feng,et al.Zircon Hf Isotope and Ce4+/Ce3+ Ratio of the Monzogranite Porphyry and Biotite Monzonitic Granite in Bangpu Mo(Cu) Deposit,Tibet[J].Mineral Deposits,2011,30(2):266-278.
[46] 吳元保,鄭永飛.鋯石成因礦物學(xué)研究及其對(duì)U-Pb年齡解釋的制約[J].科學(xué)通報(bào),2004,49(16):1589-1604.
WU Yuan-bao,ZHENG Yong-fei.Zircon Genetic Mineralogy Research and Its Restriction to U-Pb Age[J].Chinese Science Bulletin,2004,49(16):1589-1604.
[47] SUN S S,MCDONOUGH W F.Chemical and Isotopic Systematics of Oceanic Basalts:Implications for Mantle Composition and Processes[J].Geological Society,London,Special Publications,1989,42:313-345.
[48] 趙振華.副礦物微量元素地球化學(xué)特征在成巖成礦作用研究中的應(yīng)用[J].地學(xué)前緣,2010,17(1):267-286.
ZHAO Zhen-hua.Trace Element Geochemistry of Accessory Minerals and Its Applications in Petrogenesis and Metallogenesis[J].Earth Science Frontiers,2010,17(1):267-286.
[49] PETTKE T,AUDETAT A,SCHALTEGGER U,et al.Magmatic-to-hydrothermal Crystallization in the W-Sn Mineralized Mole Granite(NSW,Australia) Part Ⅱ:Evolving Zircon and Thorite Trace Element Chemistry[J].Chemical Geology,2005,220(3/4):191-213.
[50] 魏安軍,邊 飛,馬 曄,等.大場(chǎng)金礦熱液鋯石特征研究[J].長(zhǎng)江大學(xué)學(xué)報(bào):自然科學(xué)版,2012,9(7):38-40.
WEI An-jun,BIAN Fei,MA Ye,et al.The Character of Hydrothermal Zircons and Its Geological Significance in Dachang Gold Deposit[J].Journal of Yangtze University:Natural Science Edition,2012,9(7):38-40.
[51] 彭花明,夏 菲,嚴(yán)兆彬,等.江西大嶺上鎢礦花崗斑巖鋯石特征、成因及意義[J].巖石礦物學(xué)雜志,2014,33(5):811-824.
PENG Hua-ming,XIA Fei,YAN Zhao-bin,et al.Features,Genesis and Geological Significance of Zircons from the Granite Porphyry in the Dalingshang Tungsten Deposit,Jiangxi Province[J].Acta Petrologica et Mineralogica,2014,33(5):811-824.
[52] HIDAKA H,SHIMIZU H,ADACHI M.U-Pb Geochronology and REE Geochemistry of Zircons from Palaeoproterozoic Paragneiss Clasts in the Mesozoic Kamiaso Conglomerate,Central Japan:Evidence for an Archean Provenance[J].Chemical Geology,2002,187(3/4):278-293.
[53] FERRY J M,WATSON E B.New Thermodynamic Models and Revised Calibrations for the Ti-in-zircon and Zr-in-rutile Thermometers[J].Contributions to Mineralogy and Petrology,2007,154(4):429-437.
[54] HOSKIN P W O.Trace-element Composition of Hydrothermal Zircon and the Alteration of Hadean Zircon from the Jack Hills,Australia[J].Geochimica et Cosmochimica Acta,2005,69(3):637-648.
[55] HARRISON T M,SCHMITT A K.High Sensitivity Mapping of Ti Distributions in Hadean Zircons[J].Earth and Planetary Science Letters,2007,261(1/2):9-19.
[56] WATSON E B,WARK D A,THOMAS J B.Crystallization Thermometers for Zircon and Rutile[J].Contributions to Mineralogy and Petrology,2006,151(4):413-433.
[57] ZHENG Y F,GAO X Y,CHEN R X,et al.Zr-in-rutile Thermometry of Eclogite in the Dabie Orogen:Constraints on Rutile Growth During Continental Subduction-zone Metamorphism[J].Journal of Asian Earth Sciences,2011,40(2):427-451.
[58] RICHARDS J P.Postsubduction Porphyry Cu-Au and Epithermal Au Deposits:Products of Remelting of Subduction-modified Lithosphere[J].Geology,2009,37(3):247-250.
[59] HOU Z Q,ZHENG Y C,ZENG L S,et al.Eocene-Oligocene Granitoids of Southern Tibet:Constraints on Crustal Anatexis and Tectonic Evolution of the Himalayan Orogen[J].Earth and Planetary Science Letters,2012,349/350:38-52.
[60] 周金勝,孟祥金,臧文栓,等.西藏青草山斑巖銅礦金礦含礦斑巖鋯石U-Pb年代學(xué)、微量元素地球化學(xué)及地質(zhì)意義[J].巖石學(xué)報(bào),2013,29(11):3755-3766.
ZHOU Jin-sheng,MENG Xiang-jin,ZANG Wen-shuan,et al.Zircon U-Pb Geochronology and Trace Element Geochemistry of the Ore-bearing Porphyry in Qingcao-shan Porphyry Cu-Au Deposit,Tibet,and Its Geological Significance[J].Acta Petrologica Sinica,2013,29(11):3755-3766.
[61] 曲曉明,江軍華,辛洪波,等.西藏岡底斯造山帶幾乎同時(shí)形成的兩套埃達(dá)克巖為什么一套含礦一套不含礦? [J].礦床地質(zhì),2010,29(3):381-394.
QU Xiao-ming,JIANG Jun-hua,XIN Hong-bo,et al.A Study of Two Groups of Adakite Almost Simulteneously Formed in Gangdese Collisional Orogen,Tibet:Why Does One Group Contain Copper Mineralization and the Other Not? [J].Mineral Deposits,2010,29(3):381-394.
[62] 唐菊興,王登紅,汪雄武,等.西藏甲瑪銅多金屬礦礦床地質(zhì)特征及其礦床模型[J].地球?qū)W報(bào),2010,31(4):495-506.