本文選題：脈巖侵入作用系列 + 花崗斑巖��； 參考：《核工業(yè)北京地質(zhì)研究院》2015年碩士論文

【摘要】：相山鈾礦田是我國迄今為止發(fā)現(xiàn)的最大的火山巖型鈾礦田。礦田內(nèi)產(chǎn)出的花崗斑巖、中基性脈巖與鈾成礦存在較為密切的時空關(guān)系,但關(guān)于這類巖石的地質(zhì)特征、形成機制及其與鈾成礦等問題缺乏系統(tǒng)研究。本文初步查明了花崗斑巖、中基性脈巖分布范圍、規(guī)模、產(chǎn)狀特征,系統(tǒng)開展巖石學和礦物學、巖石地球化學、同位素年代學和Sr-Nd同位素特征等研究,結(jié)合礦床地質(zhì)特征、礦床地球化學特征等,探討了研究區(qū)花崗斑巖、中基性脈巖與鈾成礦作用的時空及成因關(guān)系,取得了以下幾點認識:(1)在前人工作基礎(chǔ)上,依據(jù)巖漿巖的產(chǎn)狀、成巖年齡及成因,將相山火山盆地巖漿巖劃分為流紋英安巖-碎斑流紋巖-環(huán)形花崗斑巖火山作用系列和脈狀花崗斑巖-輝綠巖-煌斑巖脈巖侵入作用系列,把花崗斑巖劃分為早期沿火山構(gòu)造侵入的環(huán)形花崗斑巖和晚期沿盆地中斷裂構(gòu)造充填形成的脈狀花崗斑巖。(2)同位素年代學研究表明,環(huán)形花崗斑巖形成于134~132Ma,居隆庵礦區(qū)其中一期煌斑巖年齡在87Ma左右。根據(jù)盆地內(nèi)已有的中基性脈巖年齡數(shù)據(jù),初步將中基性脈巖劃分為128~125Ma、109Ma以及87~85Ma三期。其中,87~85Ma可能代表了火山盆地內(nèi)中基性脈巖集中侵入的主要時期。(3)巖石地球化學及Sr、Nd同位素組成表明,花崗斑巖屬于鉀玄質(zhì)、過鋁質(zhì)S型花崗巖系列,為上地殼物質(zhì)部分熔融形成,成巖過程中有少量幔源物質(zhì)參與;中基性脈巖主要為同一地幔源區(qū)不同程度部分熔融形成。(4)礦石微量元素研究,S、Pb、C-O、He-Ar多元同位素示蹤研究表明,相山礦田鈾成礦物質(zhì)和成礦流體來源于殼�；旌献饔皿w系,幔源流體在鈾成礦過程中具有重要意義。(5)花崗斑巖、中基性脈巖與鈾成礦時空關(guān)系研究表明,花崗斑巖、中基性脈巖在空間上與鈾礦關(guān)系密切,花崗斑巖、中基性脈巖可作為鈾成礦重要識別標志。脈狀花崗斑巖、中基性脈巖侵入年齡(85~128Ma)與礦田內(nèi)兩期成礦年齡較為相近,這與該時期我國南方大規(guī)�；鹕角秩牖顒雍�,地殼區(qū)域伸展拉張引起的深源斷裂活動時間基本一致。在白堊紀強烈伸展拉張構(gòu)造環(huán)境下,深源流體攜帶部分成礦物質(zhì)并交代萃取富鈾地殼形成富鈾熱液,并上升遷移至淺部,與火山盆地花崗斑巖、中基性脈巖定位于同構(gòu)造中,在適宜的溫度、壓力等物理化學條件下,含鈾熱液沉淀、富集成礦。
[Abstract]:Xiangshan uranium ore field is the largest volcanic type uranium deposit discovered in China so far. There is a close temporal and spatial relationship between granitic porphyry and uranium mineralization in the ore field, but there is no systematic study on the geological characteristics, formation mechanism and uranium mineralization of these rocks. In this paper, the distribution range, scale, occurrence characteristics of granitic porphyry and intermediate basic dike rocks have been preliminarily identified. Systematic studies on petrology and mineralogy, rock geochemistry, isotopic chronology and Sr-Nd isotopic characteristics have been carried out, combined with geological characteristics of the deposit. Based on the geochemical characteristics of ore deposits, the spatio-temporal and genetic relationships between granitic porphyry, intermediate basic dike rocks and uranium mineralization in the study area are discussed. The results are as follows: (1) on the basis of previous work, according to the occurrence of magmatic rocks, diagenetic age and genesis, The magmatic rocks in the Xiangshan volcanic basin are divided into the series of fluid-striated dolomite, plaster rhyolite and annular granitic porphyry volcanism and the series of vein granitic porphyry diabase lamprophyry dike intrusions. Granitic porphyry is divided into annular granitic porphyry intrusive along volcanic structure and vein granitic porphyry formed in late period along the middle fault structure of basin. (2) Isotope chronological study shows that, The annular granitic porphyry was formed in 134N 132Ma.The first stage lamprophyre age of Julongan mine is about 87Ma. According to the existing age data of mesobitic dikes in the basin, the middle basic-dike rocks are preliminarily divided into three stages: 128- 125Ma-109Ma and 87-85Ma. Among them, Yi-87-85 Ma may represent the main period of concentrated intrusion of meso-basic-dike rocks in the volcanic basin. (3) the petrogeochemistry and Sr-nd-isotopic composition indicate that granitic porphyry belongs to the kalitic and peraluminous S-type granite series, and that the granitic porphyry belongs to the K-type, peraluminous S-type granite series. In the process of diagenesis, a small amount of mantle-derived materials are involved in the diagenetic process, and the intermediate basic dike rocks are mainly formed by partial melting in the same mantle source. (4) the trace element study of ores shows that the trace elements of ore are SbPbCC-OOHe-Ar multicomponent isotopic tracer. Uranium ore-forming materials and ore-forming fluids in Xiangshan Orefield are derived from the mixed crust and mantle systems, and mantle-derived fluids play an important role in the uranium mineralization process. (5) the temporal and spatial relationship between granitic porphyry, intermediate basic dike rocks and uranium mineralization shows that granitic porphyry, and granitic porphyry, Middle-base dikes are closely related to uranium deposits in space. Granitic porphyry and medium-basic dikes can be used as important indicators for uranium mineralization. The intrusive age of the vein granitic porphyry (85 ~ 128 Ma) is similar to that of the two stages in the ore field, which is consistent with the time of the deep fault activity caused by the extensional extension of the crust after the large-scale volcanic intrusions in the southern part of China during this period. In the Cretaceous strongly extensional tectonic environment, the deep source fluids carried some ore-forming materials and metasomatically extracted the uranium-rich crust to form uranium-rich hydrothermal solution, and migrated upward to the shallow, which was located in the same structure as the granitic porphyry in the volcanic basin and the middle basic dike rock. Under the suitable physical and chemical conditions, such as temperature and pressure, uranium-bearing hydrothermal precipitates and enriched ore-forming.
【學位授予單位】：核工業(yè)北京地質(zhì)研究院
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P619.14;P588.1

【參考文獻】

相關(guān)期刊論文 前7條

1 林文蔚，彭麗君;由電子探針分析數(shù)據(jù)估算角閃石、黑云母中的Fe~（3＋）、Fe~（2＋）[J];長春地質(zhì)學院學報;1994年02期

2 胡瑞忠;金景福;;上升熱液浸取成礦過程中鈾的遷移沉淀機制探討——以希望鈾礦床為例[J];地質(zhì)論評;1990年04期

3 陳正樂;王永;周永貴;韓鳳彬;王平安;宮紅良;邵飛;唐湘生;徐金山;;江西相山火山-侵入雜巖體鋯石SHRIMP定年及其地質(zhì)意義[J];中國地質(zhì);2013年01期

4 周文斌;;相山礦田成礦熱水溶液中硫的存在形式[J];華東地質(zhì)學院學報;1992年03期

5 陳迪云;周文斌;周魯民;吳伯林;譚敬華;孫占學;;相山鈾礦田同位素地質(zhì)學特征[J];礦床地質(zhì);1993年04期

6 鄧家瑞,張志平;贛杭構(gòu)造帶區(qū)域大地構(gòu)造背景的探討[J];鈾礦地質(zhì);1999年02期

7 劉昌實,薛紀越,張根娣,沈渭洲,陳繁榮,張富生;江西相山碎斑熔巖成因和鉀長石亞顯微結(jié)構(gòu)[J];巖石礦物學雜志;1992年03期

相關(guān)會議論文 前1條

1 林錦榮;胡志華;王勇劍;王峰;;相山火山盆地鈾礦床空間定位式與預(yù)測評價模型[A];《鈾礦地質(zhì)》2015增刊1[C];2015年

相關(guān)博士學位論文 前1條

1 楊水源;華南贛杭構(gòu)造帶含鈾火山盆地巖漿巖的成因機制及動力學背景[D];南京大學;2013年

相關(guān)碩士學位論文 前1條

1 饒澤煌;江西相山鈾礦田基性巖特征及意義研究[D];東華理工大學;2012年

，

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