本文選題：巖漿流體作用 + 成巖成礦機(jī)理　； 參考：《吉林大學(xué)》2017年博士論文

【摘要】：中國(guó)東北部的小興安嶺地區(qū)是我國(guó)重要的金屬礦產(chǎn)產(chǎn)業(yè)基地,區(qū)內(nèi)已知Fe、Mo、Au、Cu、Pb、Zn、W、Ag等多種礦產(chǎn)品,均為經(jīng)濟(jì)發(fā)展與國(guó)民生產(chǎn)急需的礦產(chǎn)類型,近年來隨著礦產(chǎn)勘查程度的深入,找礦工作不斷取得重大突破,已成為中國(guó)北方貴金屬和有色金屬大規(guī)模成礦的集中區(qū)域。鑒于此,為了揭示制約小興安嶺內(nèi)生金屬成礦的關(guān)鍵基礎(chǔ)問題以及成礦規(guī)律,本文在前人研究的基礎(chǔ)上,針對(duì)區(qū)內(nèi)發(fā)育的矽卡巖型鐵銅(鉬)多金屬礦床開展系統(tǒng)的礦床地質(zhì)、流體包裹體、成巖成巖年代學(xué)和礦床地球化學(xué)等方面的研究,并取得了如下重要成果與進(jìn)展。1.通過對(duì)研究區(qū)典型矽卡巖型鐵銅(鉬)多金屬礦床的礦床地質(zhì)特征研究,進(jìn)一步得出該類型礦床在下寒武統(tǒng)鉛山組碳酸鹽巖-碎屑巖建造與侵入巖接觸部位的矽卡巖礦化蝕變帶內(nèi)富集成礦,形成以鐵、鋅、銅、鉬為主,其次為鎢、鉛、金、錫,并伴生鎵、銦、鎘、銀等有益組分的多金屬礦體;礦體主要呈透鏡狀、扁豆?fàn)�、似層狀和脈狀等形式產(chǎn)出,而且沿走向或傾向多有膨脹、收縮和分支復(fù)合現(xiàn)象出現(xiàn);常見的圍巖蝕變有矽卡巖化、綠簾石化、綠泥石化、硅化、螢石化、絹云母化、碳酸鹽化等;成礦階段可劃分為早期矽卡巖階段、退化蝕變階段、氧化物階段、石英-硫化物階段和碳酸鹽階段,整體符合矽卡巖礦床經(jīng)典的兩期五個(gè)成礦階段的劃分模式。2.各典型礦床的流體包裹體研究揭示:(1)早期矽卡巖階段均發(fā)育氣液兩相包裹體和含子礦物三相包裹體;石英-硫化物階段主要為氣液兩相包裹體和含子礦物三相包裹體,其次為少量含CO_2三相包裹體、純氣相以及純液相包裹體;晚階段的方解石中僅發(fā)育富液相包裹體和純液相包裹體;(2)寶山礦床中流體包裹體的均一溫度從早至晚階段分別為376.5~512.4℃、291.2~419.5℃、156.3~247.8℃,鹽度依次為4.2~49.4%Na Cleqv、1.9~42.2%Na Cleqv、0.7~4.5%Na Cleqv;(3)翠宏山礦床中流體包裹體的均一溫度從早至晚階段分別為332.5~525.5℃、187.3~422.1℃、142.3~235.2℃,鹽度依次為14.8~44.1%Na Cleqv、1.4~44.0%Na Cleqv、0.7~6.7%Na Cleqv;(4)二股礦床中流體包裹體的均一溫度從早至晚階段分別為348.9~524.5℃、231.6~380.4℃、152.9~231.6℃,鹽度依次為1.9~46.84%Na Cleqv、1.2~37.4%Na Cleqv、1.4~4.5%Na Cleqv;(5)激光拉曼分析結(jié)果顯示,早期矽卡巖階段的石榴子石、透輝石和綠簾石中的包裹體的氣相成分均為H_2O,未見其它成分;石英硫化物階段的石英中包裹體的氣相成分為CO_2或CO_2+CH_4,指示流體具有較強(qiáng)還原性;晚階段方解石中包裹體的成分主要為H_2O;(6)氫-氧同位素結(jié)果顯示,區(qū)內(nèi)矽卡巖型鐵銅(鉬)多金屬礦床的初始成礦流體可能為殘余巖漿水,隨著成礦作用的進(jìn)行大氣降水混入的比例逐漸增加,到成礦晚階段主要為大氣降水流體。綜合顯微測(cè)溫、拉曼成分分析和氫氧同位素結(jié)果,進(jìn)一步揭示研究區(qū)矽卡巖型鐵銅(鉬)多金屬成礦系統(tǒng)的初始含礦流體來源于殘余巖漿出溶的高溫、高鹽度、高氧逸度的H_2O-Na Cl-CO_2±CH_4體系,流體演化過程中不斷有大氣降水加入;并且成礦過程中巖漿熔-流分離作用和水-巖作用使成礦物質(zhì)富集,而流體沸騰和混合作用是導(dǎo)致成礦物質(zhì)最終沉淀的成礦機(jī)制。3.研究區(qū)內(nèi)矽卡巖型鐵銅(鉬)多金屬礦床的成巖成礦年代學(xué)研究表明:(1)首次限定寶山銅多金屬礦床的成礦時(shí)代在245~255Ma之間,即晚二疊世-早三疊世,矽卡巖型礦化與角閃石英二長(zhǎng)巖關(guān)系密切;(2)翠宏山礦區(qū)內(nèi)至少存在三期巖漿活動(dòng),其中第二期早侏羅世二長(zhǎng)花崗巖巖漿作用與成礦關(guān)系最為密切,礦床形成于198~204Ma,即晚三疊世晚期-早侏羅世早期;(3)二股西山和東山礦段的成礦作用發(fā)生在180~184Ma之間,成礦與黑云母二長(zhǎng)花崗巖巖漿活動(dòng)密切相關(guān);響水河礦段的成礦時(shí)限為191~194Ma,較前者成礦早約10Ma。結(jié)合本文及前人的研究成果,我們認(rèn)為研究區(qū)內(nèi)矽卡巖型鐵銅(鉬)多金屬礦床的有兩個(gè)成礦期,分別為晚二疊世-早三疊世(245~255Ma;以寶山礦床為代表)和晚三疊世-早侏羅世(180~205Ma),后者還可劃分為198~205Ma(以翠宏山、大西林、前進(jìn)東山礦床為代表)、191~193Ma(以響水河、大安河礦床為代表)和180~184Ma(以二股西山、二股東山、徐老九溝礦床為代表)三個(gè)成礦階段。4.在矽卡巖礦物學(xué)方面,研究區(qū)內(nèi)典型矽卡巖型鐵銅(鉬)多金屬礦床的石榴子石和輝石組成與世界上對(duì)應(yīng)礦種的矽卡巖型礦床的石榴子石和輝石的分布區(qū)間基本一致,其中寶山和二股礦床中的石榴子石主要為鈣鐵榴石,其次為鈣鋁榴石,翠宏山礦床僅發(fā)育鈣鐵榴石;三個(gè)礦床中輝石均以透輝石為主,僅翠宏山礦床中出現(xiàn)少量鈣鐵輝石;這些特征均指示早期矽卡巖階段整體處于酸性、高溫、高氧逸度的環(huán)境,高氧逸度促使Fe3+進(jìn)入到石榴子石和輝石中形成鈣鐵榴石和透輝石,并且有向弱還原性環(huán)境演化的趨勢(shì),從而形成少量的鈣鋁榴石和鈣鐵輝石。5.與成礦密切相關(guān)的侵入巖巖相學(xué)和元素地球化學(xué)研究揭示,寶山礦床的成礦巖體為一套準(zhǔn)鋁質(zhì)高鉀鈣堿性的角閃石英二長(zhǎng)巖-似斑狀黑云母花崗巖組合;翠宏山礦床成礦與準(zhǔn)鋁質(zhì)高鉀鈣堿性的二長(zhǎng)花崗巖有關(guān),還發(fā)育有成礦前的堿長(zhǎng)花崗巖以及成礦后的花崗斑巖;二股礦床成礦巖體為準(zhǔn)鋁質(zhì)、鉀玄巖-高鉀鈣堿性黑云母二長(zhǎng)花崗巖。三個(gè)礦床與成礦相關(guān)的侵入巖多具有高硅、富鋁和富堿,稀土元素含量較高,輕重稀土之間分異明顯,富集LREE、Th、U及大離子親石元素Rb、K,虧損HREE、Ba及高場(chǎng)強(qiáng)元素Nb、Ta、P、Ti等,與翠宏山和二股礦床的成礦巖體顯示明顯的Eu負(fù)異常不同,寶山礦床與成礦有關(guān)侵入巖發(fā)育弱的Eu負(fù)異常。6.與成礦密切相關(guān)的侵入巖的Sr-Nd和Lu-Hf同位素研究表明,寶山礦床與成礦相關(guān)的角閃石英二長(zhǎng)巖起源于中元古代增生的下地殼物質(zhì);翠宏山礦床的巖漿屬性有兩種,堿長(zhǎng)花崗巖的巖漿起源于古老的陸殼基底的部分熔融,二長(zhǎng)花崗巖的巖漿起源于新-中元古代新生下地殼或巖石圈地幔,并受到少量古老陸殼物質(zhì)混染;二股礦床成礦巖體黑云母二長(zhǎng)花崗巖與翠宏山二長(zhǎng)花崗巖具有相似的Sr-Nd和Lu-Hf同位素,其巖漿起源于新-中元古代增生的下地殼物質(zhì)或巖石圈地幔,并可能有少量古老地殼組分加入。7.將流體演化、巖漿作用與區(qū)域構(gòu)造演化背景相結(jié)合,揭示研究區(qū)矽卡巖型鐵銅(鉬)多金屬礦床的成巖成礦地質(zhì)過程:(1)晚二疊世-早三疊世,隨著古亞洲洋的最終閉合,華北板塊與松嫩地塊持續(xù)的陸-陸碰撞作用導(dǎo)致下地殼加厚并發(fā)生拆沉作用,進(jìn)入到下伏地幔中并發(fā)生部分熔融形成埃達(dá)克質(zhì)巖漿,并且?guī)r漿在上升過程中與地幔橄欖巖發(fā)生了強(qiáng)烈的交代作用,從而使銅等成礦元素在巖漿系統(tǒng)中富集,隨著埃達(dá)克質(zhì)巖漿上升到地殼淺部就位,從埃達(dá)克質(zhì)巖漿中出溶形成富銅的成礦流體,在與碳酸鹽巖地層的接觸帶內(nèi)形成大范圍的矽卡巖化以及相關(guān)的礦化,最終形成的寶山矽卡巖型銅多金屬礦床;(2)晚三疊世-早侏羅世早期,適值西伯利亞板塊與華北板塊碰撞造山后的伸展構(gòu)造環(huán)境,區(qū)域性的巖石圈伸展造成大規(guī)模軟流圈物質(zhì)上涌致使新生玄武質(zhì)加厚下地殼發(fā)生部分熔融,形成初始的含礦巖漿,并且在上侵過程中受到少量的古老地殼混染,隨著巖漿上升到地殼淺部就位,巖漿熔體演化晚期分離出大量含揮發(fā)分和Fe、Mo、W等成礦元素的流體,在構(gòu)造應(yīng)力和巖漿熱的驅(qū)使下,含礦流體發(fā)生側(cè)向逃逸并與周圍碳酸鹽巖地層發(fā)生交代反應(yīng),最終形成的翠宏山矽卡巖型鐵多金屬礦床;(3)早侏羅世晚期,太平洋板塊向歐亞大陸的俯沖過程中板片脫水釋放的流體交代早期元古代次生巖石圈地幔發(fā)生部分熔融形成玄武質(zhì)巖漿,并與地幔橄欖巖發(fā)生了強(qiáng)烈的交代作用,從而使Fe、Cu等成礦元素在巖漿系統(tǒng)中富集,隨后玄武質(zhì)巖漿底侵下部地殼,促使下地殼巖石發(fā)生部分熔融形成花崗質(zhì)巖漿并與玄武質(zhì)巖漿發(fā)生混合,這一殼�；旌蠋r漿在上升演化過程中受到少量的地殼混染,最終在近地表冷凝成巖,并與附近的碳酸鹽地層發(fā)生大規(guī)模的接觸交代作用,導(dǎo)致Fe、Zn、Cu等成礦元素發(fā)生大規(guī)模沉淀形成二股矽卡巖型鐵多金屬礦床。
[Abstract]:The small Xingan ridge area in northeastern China is an important metal mineral industry base in China. It is known that Fe, Mo, Au, Cu, Pb, Zn, W, Ag and other mineral products are all the mineral types which are urgently needed for economic development and national production. In recent years, with the depth of mineral exploration, the prospecting work has made great breakthroughs and has become the precious metal in the north of China. In view of this, in order to reveal the key basic problems and metallogenic regularities of the inner metallization of the small Xingan ridge, this paper, based on the previous studies, carried out a systematic deposit geology, fluid inclusions and formation rock age on the basis of previous studies. Studies on the geology and geochemistry of ore deposits have made the following important achievements and progress.1. through the study of the geological characteristics of the typical skarn type copper (molybdenum) polymetallic deposit in the study area, and further concluded that this type of ore deposit is in the carbonatite mineralization of the lower Cambrian carbonate rock debris rock formation and intrusive rocks. A polymetallic ore formed in the altered zone, formed mainly of iron, zinc, copper, molybdenum, followed by beneficial components such as tungsten, lead, gold, tin, and associated with gallium, indium, cadmium, silver and other useful components; the orebodies are mainly lenslike, lentil like, like lamellar and pulse forms, and appear more expansive, contractile and branching complex phenomena along the direction or tendency; common surrounding rock erosion. There are skarn, epidote, chlorinization, silicification, fluorofossilization, sericification, carbonation, and so on. The metallogenic stage can be divided into early skarn stage, degenerated alteration stage, oxide stage, quartz sulfide stage and carbonate stage, which are in accordance with the classic five stages of the skarn deposit. Fluid inclusion studies of type deposits reveal: (1) both gas-liquid inclusions and three phase inclusions are developed in the early skarn phase, and the phase of quartz sulfide is mainly gas-liquid and subphase inclusions containing subaqueous minerals, followed by a small amount of CO_2 inclusions, pure gas and pure liquid inclusions, and the late phase solution. The rich liquid inclusions and pure liquid inclusions are developed only in the stone. (2) the homogeneous temperature of fluid inclusions in the Baoshan deposit is from early to late stage at 376.5~512.4, 291.2~419.5 and 156.3~247.8, respectively, and the salinity is 4.2~49.4%Na Cleqv, 1.9~42.2%Na Cleqv, 0.7~4.5%Na Cleqv, and (3) the homogeneous temperature of fluid inclusions in the Cui Hong mountain deposit The early and late stages are 332.5~525.5 C, 187.3~422.1 C, 142.3~235.2 C, and the salinity is 14.8~44.1%Na Cleqv, 1.4~44.0%Na Cleqv, 0.7~6.7%Na Cleqv. (4) the homogeneous temperature of fluid inclusions in the two strand deposits is 348.9~524.5 C, 231.6~ 380.4 C, 152.9~231.6, and salinity, respectively. 4%Na Cleqv, 1.4~4.5%Na Cleqv; (5) the results of laser Raman analysis show that the gas phase composition of the inclusions in the diopside and epidote of the early skarn phase is H_2O, and no other components are found. The gas phase composition of the inclusions in the quartz sulfide phase is CO_2 or CO_2+CH_4, indicating that the fluid has a strong reducibility and late order. The composition of the inclusions in the calcite is mainly H_2O; (6) the results of hydrogen oxygen isotope show that the initial ore-forming fluid of the skarn type iron copper (molybdenum) polymetallic deposit in the region may be residual magma water, and the proportion of the mixing of meteoric water gradually increases with the mineralization, and it is mainly atmospheric precipitation fluid at the late stage of mineralization. The results of temperature, Raman composition analysis and hydrogen and oxygen isotopes further reveal that the initial ore bearing fluid of the skarn type iron copper (molybdenum) metallogenic system in the study area is derived from the high temperature, high salinity, high oxygen fugacity H_2O-Na Cl-CO_2 + CH_4 system of the residual magma, and the continuous atmospheric precipitation in the process of fluid evolution; and the rocks in the process of mineralization. The Cheng Yan metallogenic chronology of the skarn copper (molybdenum) polymetallic deposit in the.3. study area of the study area of the skarn type copper (molybdenum) polymetallic deposit in the study area of the study area in the study area of the skarn type iron copper (molybdenum) deposit in the study area of the metallogenic mechanism for the final precipitation of the ore-forming process in the study area of the ore-forming mechanism.3. in the study area of the ore-forming mechanism in the study area of the skarn type and copper (molybdenum) polymetallic deposit in the area of (1) the first limitation of the metallogenic epoch of the copper polymetallic deposit in the 245~255Ma. In the Late Permian early three fold, the skarn mineralization is closely related to the hornblende quartz two long rocks; (2) there are at least three stages of magmatic activity in the Cui Hongshan mining area, of which the second phase of the early Jurassic two feldspar magmatism is most closely related to the mineralization, and the deposit formed in 198~ 204Ma, that is, late late three early Jurassic and (3) two strands. The mineralization of the Xishan and Dongshan mines occurs between 180~184Ma, and mineralization is closely related to the magmatic activity of the biotite two granitic magma, and the metallogenic time limit of the Xiang Shui River section is 191~194Ma, which is earlier than the former 10Ma. combined with the previous research results, and we think that there are two of the skarn type copper (molybdenum) polymetallic deposits in the study area. The metallogenic period is the Late Permian early three fold (245~255Ma; the Baoshan deposit as the representative) and the late three fold early Jurassic (180~205Ma), and the latter can also be divided into 198~205Ma (the cuihongshan, Daxilin, the forward Dongshan ore deposit), 191~193Ma (represented by the Hongshui River, the Da'an River deposit) and 180~184Ma (with the two strands of Xishan, two shares Dongshan, Xu Lao " The nine gully deposit is the representative) the three metallogenic stage.4. in the skarn mineralogy, the garnet and pyroxene composition of the typical skarn type iron copper (molybdenum) polymetallic deposit in the study area is basically the same as the garnet and pyroxene in the skarn type ore deposits in the world, including the garnet in Baoshan and two strands. It is mainly calcite, followed by calcite. The Cui Hong mountain deposit only develops calcite. The three deposits are mainly diopside, only a small amount of calcite pyroxene occurs in the Cui Hong mountain deposit. These characteristics indicate that the early skarn stage was in the environment of acid, high temperature, high oxygen fugacity, and high oxygen fugacity promoted Fe3+ into the pomegranate. The formation of calcite and Diopside in the zigzite and pyroxene, and the trend towards the evolution of the weak reductive environment, forms a small amount of calcite and calcite.5., which is closely related to the metallogenic and elemental geochemistry of the mineralization. The ore-forming body of the Baoshan deposit is a set of paralic, high potassium calc alkaline quartz. Two long rocks like porphyritic biotite granites, the cuihongshan ore deposit is related to the paralic high potassium calc alkaline two feldspar granite, the alkali feldspar granite before the mineralization and the granite porphyry after the mineralization; the two ore deposits are paralic, potassium basalite and high potassium calcicine biotite two granitic granite. Three ore deposits and metallogenic facies. The intrusive rocks are high in silicon, rich in aluminum and rich in alkali, with high rare-earth elements and obvious differentiation between heavy and heavy rare earth elements, enriched with LREE, Th, U and large ion stone elements Rb, K, HREE, Ba and high field strength elements Nb, Ta, P, Ti, etc., which are different from that of the Cui Hong and two ore deposits. The Sr-Nd and Lu-Hf isotopes of the intrusive rocks closely related to the mineralization of the weakly intrusive Eu indicate that the Baoshan deposit and the ore-forming hornblende quartzite two long rocks originate from the Mesoproterozoic lower crust material, and the magma property of the Cui Hong mountain deposit is two, and the magma of the alkali long flower granitic rocks originates from the ancient continental crust basement. The magma of the two granites originates from the Neozoic Mesoproterozoic Neozoic lower crust or lithosphere mantle, and is contaminated by a small amount of ancient continental crust material, and the two strands of the black mica two granite and the Cui Hongshan two granites have similar Sr-Nd and Lu-Hf isotopes, and their magma originated from the new Mesoproterozoic accretion. The crust material or lithosphere mantle, and may have a small amount of ancient crustal components joining.7. to combine the fluid evolution, magmatism and regional tectonic evolution background, reveals the diagenesis and metallogenic geological process of the skarn type iron copper (molybdenum) polymetallic deposit in the study area: (1) the Late Permian early three fold, with the final closure of the ancient Asian Ocean, the North China plate and the North China plate The continuous continental collision in the Songnen block resulted in the thickening and delamination of the lower crust, which entered the lower mantle and formed part of the partial melting to form the enactic magma, and the magma had a strong metasomatism with the mantle peridotite during the rising process, thus enriching the copper and other metallogenic elements in the magma system. The qualitative magma ascended to the shallow part of the crust and formed a rich copper rich metallogenic fluid from the ark magma, forming a wide range of skarite and related mineralization in the contact zone with the carbonate strata, and finally formed the Baoshan skarn copper polymetallic deposit; (2) the late three fold early Jurassic period and the appropriate value of the Siberia plate. In the extensional tectonic environment after the collision of the North China plate, the regional lithosphere extension causes the mass of the massive asthenosphere to cause the partial melting of the new basaltic thickening lower crust and the formation of the initial ore bearing magma, and in the process of invasion, a small amount of ancient crust is mixed, and as the magma ascends to the shallow part of the crust, the rock is in place. In the late evolution of the pulp melts, a large number of fluids containing volatile components and Fe, Mo, W and other metallogenic elements were separated from the tectonic stress and magmatic heat, and the ore fluid occurred laterally and formed a metasomatism with the surrounding carbonate rocks, and finally formed the cuihongshan skarn type iron polymetallic deposit; (3) the late Early Jurassic, the Pacific plate direction. During the subduction of the Eurasian continent, the early metasomatism of the Proterozoic secondary lithospheric mantle was partially fused to form basaltic magma, which had a strong metasomatism with the mantle peridotite, thus enriching the Fe, Cu and other metallogenic elements in the magma system, and then the basaltic magma undertook the lower crust, prompting the lower earth. The partial melting of the crust rock formed granitic magma and mixed with the basaltic magma. This crust mantle mixed magma was contaminated by a small amount of crust during the process of rising and evolution, and finally condensed into rock in the near earth surface, and had a large contact metasomatism with the adjacent carbonate strata, leading to the large regulation of Fe, Zn, Cu and other metallogenic elements. Die formed two skarn iron polymetallic deposit.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：P618.2
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本文編號(hào)：2040851