【作者】 刘园园；

【导师】 马昌前；

【作者基本信息】 中国地质大学 ， 矿物学、岩石学、矿床学， 2013， 博士

【摘要】 华南由扬子地块和华夏地块构成,是国内乃至世界上著名的花岗岩省,尤其是在中生代发育了巨量的花岗质岩浆活动,同时伴有广泛的金属成矿作用,常常形成世界级超大型矿床,自上世纪二三十年代就有学者开始探索岩浆岩与成矿作用之间的关系,且一直受到广大学者的持续关注。三叠纪岩浆岩绝大多数为花岗质岩石,罕见中基性岩石的报道,仅在道县发现三叠纪基性包体,未见火山岩。前人多次总结三叠纪岩浆岩岩的空间分布规律,随着高精度年龄资料的增多,三叠纪花岗岩在整个印支期均有一定分布,但现有研究多集中在湖南、赣南、粤北、广西等地区,其他诸如浙江、福建等地区的研究程度相对较弱。本文以浙江、福建以及赣东等不同地区的三叠纪橄榄玄粗岩系列岩石、A型花岗岩为主要研究对象,包括浙中地区石英二长岩-(石英)正长岩、浙西南地区石英二长岩-正长花岗岩-二长花岗岩、闽西地区正长岩类-正长花岗岩以及赣东地区石英二长岩-二长花岗岩。对它们进行了详细的野外地质考察、岩相学、锆石U-Pb年龄、主量元素和微量元素、Sr-Nd同位素和锆石Hf同位素组成的多方面研究,结合前人在华南三叠纪研究的相关成果,探讨了华南三叠纪橄榄玄粗岩系列、A型花岗岩的时空分布规律、岩石成因及其所处的大地构造背景。主要认识如下：(1)浙江中部(诸暨-东阳-嵊州)地区三叠纪岩浆岩有石坂岩体、大爽岩体和周庄岩体。石坂岩体的岩性为(石英)正长岩；大爽岩体的岩性包括(石英)正长岩和似斑状石英二长岩；周庄岩体的岩性为似斑状石英二长岩。对该地区的三个岩体的不同岩性分别进行了LA-ICP-MS锆石U-Pb定年,结果分别为238±2Ma、240±3Ma、236±3Ma和237±2Ma；年龄分布在236-240Ma之间,三个岩体均形成于中三叠世。石坂正长岩和大爽正长岩均为过铝质花岗岩(A/CNK值均为1.02),大爽石英二长岩为准铝质(A/CNK介于之间0.90-0.98),周庄石英二长岩在准铝质和过铝质区域均有分布,但大部分分布于过铝质区域中(A/CNK介于0.93-1.05之间)；四类样品均落入橄榄玄粗岩系列区域内。从Harker图解中可以看出石坂正长岩与大爽正长岩极有可能存在成因上的联系,该地区的正长岩中富集Th.K等元素,亏损Ba、Sr、P等元素和Nb.Ta.Ti等高场强元素；轻稀土富集,具有Eu负异常,Eu/Eu’介于0.28～0.4之间；(La/Yb)N介于106～175之间。石英二长岩的地球化学特征同样显示了不同岩体的石英二长岩具有亲密的成因关系,石英二长岩中富集Ba、Th等元素,亏损Sr、P、Nb、Ta、Ti等；轻稀土富集,具有明显的Eu负异常,Eu/Eu*介于0.60～0.70之间,(La/Yb)N介于30.12～43.79之间。全岩Sr-Nd同位素研究结果表明,石坂正长岩、大爽正长岩、大爽石英二长岩和周庄石英二长岩的εNd(t)值分别为-8.60～8.71、-8.35～-8.46、-8.26～-10.92和-9.24～-10.13；相对应的两阶段模式年龄T2DM分别为1.70-1.71Ga、1.68～1.71Ga、1.68～1.89Ga和1.77～1.83Ga。锆石Hf同位素测试结果表明,石坂正长岩、大爽正长岩和大爽石英二长岩的εHf(t)加权平均值为分别为-6.6±0.33、-6.91±0.33和-11.21土0.72；对应的两阶段Hf模式年龄分别为1.62～1.75Ga、1.64～1.79Ga、1.8-2.07Ga。(2)浙西南(松阳-丽水)地区的三叠纪岩浆岩有梅田岩体和靖居岩体。梅田岩体的岩性包括斑状二长花岗岩和斑状石英二长岩；靖居岩体的岩性包括斑状石英二长岩和正长花岗岩。对梅田岩体二长花岗岩、石英二长岩及石英二长岩脉进行的LA-ICP-MS锆石U-Pb定年,结果分别为238±2Ma、236±2Ma、228±2Ma,表明岩体为中-晚三叠世的产物。梅田花岗岩为过铝质(A/CNK介于1.00-1.23之间),梅田的石英二长岩(A/CNK介于0.96～1.09之间)与靖居的正长花岗岩(A/CNK介于0.88-1.12之间)在准铝质与过铝质区域内均有分布,靖居的石英二长岩主要为准铝质(A/CNK介于0.83-1.04之间)。除了少量的梅田二长花岗岩落入高钾钙碱性系列区域内,其余均落入橄榄玄粗岩系列区域内。在Harker图解中,石英二长岩在总体上CaO、TiO2、Fe2O3T和P2O5与SiO2表现为负相关性,其余氧化物同SiO2无明显的相关性,说明岩浆演化过程中可能存在Ti-Fe氧化物、磷灰石等矿物的结晶分异作用；二长花岗岩TiO、Fe2O3T和P2O5与SiO2表现为负相关性;正长花岗岩MgO、Al2O3、CaO、TiO2、Fe2O3T和P2O5与SiO2呈现出负相关性,随着SiO2含量的增多,MnO无明显相关性,表明在岩浆的演化过程中可能存在长石、铁镁矿物、钛铁氧化物和磷灰石的分异结晶。该地区石英二长岩中强烈亏损Ba、Sr、P等元素和Nb、Ta、Ti等高场强元素；轻稀土富集,可见无-弱的Eu的负异常；Eu/Eu*介于0.58-1.04之间,(La/Yb)N介于15.53～4.05之间。梅田二长花岗岩非常富集Th、Rb,亏损Ba、Sr、P等元素和Nb、Ta、Ti等高场强元素：在稀十分配模式上表现,表现山轻稀土富集,Eu负异常不明显,Eu/Eu*介于0.85-2.32之间,(La/Yb)N介于24.61～47.30之间。正长花岗岩明显富集Th和Rb、K等大离子亲石元素,亏损Ba、Sr、P等元素和Ｎb、Ta、Ti等高场强元素;正长花岗岩稀土元素的含量(933-1772ppm)非常的高,轻稀土富集,Eu出现负异常;Eu/Eu＊介于0.38~0.77之间,(La/Yb)N介于50.23-255.45之间。全岩Sr-Nd同位素研究结果表明,梅田石英二长岩和二长花岗岩的εNd(t)值分别为-13.72～-14.25和-14.57；相对应的两阶段模式年龄T2DM分别为2.12-2.16Ga和2.19Ga。锆石Hf同位素测试结果表明,梅田二长花岗岩、梅田石英二长岩、梅田石英二长岩脉和靖居正长花岗岩的εHf(t)加权平均值为分别为-17.51±0.43、-19.01±0.46、-15.19±0.48和-10.90±0.67；对应的两阶段Hf模式年龄分别为2.37-2.54Ga、2.29-2.45Ga、2.14-2.3Ga和1.84-2.08Ga。(3)闽西(明溪-清流)地区的三叠纪岩浆岩有坪浒(角闪)黑云母辉石正长岩、正长岩、柏亨岩体正长花岗岩和莒林正长花岗岩。通过对坪浒角闪黑云母辉石正长花岗岩、正长岩、柏亨正长花岗岩和莒林正长花岗岩进行了高精度的LA-ICP-MS锆石U-Pb定年,其结果分别为232Ma±2Ma、235.0±1.3Ma、236±2Ma和225±2Ma,岩体均形成于中-晚三叠世。坪浒(角闪)黑云母辉石正长花岗岩(A/CNK介于0.42～0.45之间)、坪浒正长岩(A/CNK介于0.50～0.80之间)、莒林正长花岗岩(A/CNK介于1.06～1.10之间)和柏亨正长花岗岩(A/CNK介于0.8～1.06之间)准铝质和过碱质区域内均有分布,其中柏亨正长花岗岩在弱过铝质区域也有分布。除了少量的柏亨正长花岗岩落入高钾钙碱性系列区内外,其余都落入橄榄玄粗岩系列区域内。在Harker图解中,坪浒(角闪)黑云母辉石正长岩CaO、Fe2O3T和MnO与SiO2之间呈现负相关性,随SiO2含量的增多,Al2O3与Na2O的含量增大；坪浒正长岩MgO、MnO、Fe2O3T和P2O5与SiO2具有一定的负相关性,Al2O3随SiO2含量的增加有所增加；柏亨正长花岗岩中MgO、Al2O3、CaO、K2O、TiO2、Fe2O3T和P2O5含量与SiO2含量存在明显的负相关性,表明在岩浆演化过程中可能存在镁铁质矿物、长石、钛铁氧化物和磷灰石的结晶分异作用；柏亨岩体正长花岗岩中可见MgO、Al2O3、CaO、TiO2、Fe2O3T和P2O5与SiO2存在明显的负相关性,随着SiO2含量的增多,MnO的含量先增大后较小,表明在岩浆演化过程中可能存在有镁铁矿物、长石、钛铁氧化物和磷灰石的分异结晶。(角闪)黑云母辉石正长岩富集Rb、Ba,亏损Nb、Ta、Ti等高场强元素；轻稀土富集,(La/Yb)N介于53.75～63.76之间,基本不见Eu的负异常,Eu/Eu*=0.77～0.98。正长岩亏损Sr、P等元素和Nb、Ta、Ti等高场强元素；总稀土含量很高,轻稀土富集,Eu略微负异常；Eu/Eu*介于0.744～0.84之间,(La/Yb)N介于41.41～87.63之间。正长花岗岩富集Th、U,损Ba、P和Ta、Ti等元素；轻稀土富集,具有Eu负异常,表明了存在斜长石的分离结晶作用或源区残留斜长石,Eu/Eu*介于0.35～0.71之间,(La/Yb)N介于7.22～19.23之间。莒林正长花岗岩中明显亏损Ba、P、Sr和Ta、Ti等高场强元素；轻稀土富集,具有明显的Eu负异常,Eu/Eu*介于0.14～0.23之间,(La/Yb)N介于9.99-22.86之间。锆石Hf同位素测试结果表明,坪浒角闪黑云母辉石正长岩、坪浒正长岩、莒林正长花岗岩和柏亨正长花岗岩的εHf(t)加权平均值为分别为-11.28±0.48、-9.88±0.36、-6.54～5.29和-8.86±0.27；对应的两阶段Hf模式年龄分别为1.88-2.05Ga、1.8-1.96Ga、1.60-1.68Ga和1.79～1.88Ga。(4)在赣东(宁都-兴国)地区的三叠纪花岗岩为宝华山岩体,岩性包括似斑状二长花岗岩和似斑状石英二长岩。对宝华山二长花岗岩进行LA-ICP-MS锆石U-Pb定年结果表明,二长花岗岩的年龄为228±2Ma,形成于晚三叠世。宝华山石英二长岩为准铝质(A/CNK介于0.88～0.99之间),二长花岗岩在准铝质和弱过铝质区域内均有分布(A/CNK介于0.93-1.07之间)。除了个别的二长花岗岩落入高钾钙碱性区域内,其余皆落在橄榄玄粗岩系列区域内。在Harker图解中两种岩性的岩石同SiO2均无明显的线性关系。石英二长岩中富集Th、U和Rb、K等大离子亲石元素,亏损Ba、Sr、P和Nb、Ta、Ti等高场强元素。岩石中轻稀土元素富集,可见明显的Eu负异常,表现了岩浆演化过程中斜长石的分离结晶作用或源区残留斜长石；Eu/Eu*介于0.35～0.65之间,(La/Yb)N介于12.22～46.03之间。在二长花岗岩中,Th、U和Rb、K等大离子亲石元素富集,Ba、Sr、P等元素和Nb、Ta、Ti等高场强元素出现亏损；样品中轻稀土富集,具有明显的Eu负异常,Eu/Eu*介于0.36～0.75之间,(La/Yb)N介于10.76-28.81之间。在稀土元素分配模式中,重稀土含量有所升高,可能为含有较多富稀土副矿物的结果。全岩Sr-Nd同位素研究结果表明,宝华山二长花岗岩的εNd(t)值为-9.6-9.99；相对应的两阶段模式年龄T2DM分别为1.79～1.82Ga。锆石Hf同位素测试结果表明,宝华山二长花岗岩的εHf(t)加权平均值为分别为-7.68±0.48,对应的两阶段Hf模式年龄分别为1.67～1.85Ga。(5)综合上述资料,浙中地区三叠纪石英二长岩是在幔源物质参与下,深部古老地壳物质熔融形成的熔体,经斜长石、角闪石、黑云母、磷灰石及钛铁氧化物等矿物结晶分异作用形成的；而正长岩类是源自相对年轻的地壳的熔体,经碱性长石、角闪石、黑云母、磷灰石等矿物结晶分异作用形成的。浙西南三叠纪二长花岗岩是源自古老地壳的熔体,经碱性长石、斜长石、黑云母、磷灰石及钛铁氧化物等矿物结晶分异作用形成的；石英二长岩是在少量地幔物质参与下形成的壳源岩浆,经经斜长石、角闪石、黑云母、磷灰石及钛铁氧化物等矿物结晶分异作用形成的；而晚期正长花岗岩则可能是相对年轻的地壳岩石熔融的产物。闽西地区正长岩类是富集岩石圈地幔部分熔融形成的,而柏亨正长花岗岩则是地壳熔融形成的熔体经碱性长石、角闪石、黑云母、磷灰石及铁钛氧化物结晶分异作用形成的,而莒林正长花岗岩的成因与浙西南正长花岗岩成因相似。赣东地区宝华山花岗岩类特征与闽西正长花岗岩相似,因而形成过程可能与闽西地区正长花岗岩相似。(6)为了深入认识华南三叠纪岩浆活动的构造背景,与越南北部进行了对比。越南北部构造热事件形成的时间、构造线走向、运动学方向与华南均存在一定的差异。越南北部构造热事件多集中在早-中三叠世(250-240Ma),而华南地区仅广西和浙江这一时期的构造热事件发育,其他地区构造热事件多形成于中-晚三叠世；越南北部三叠纪构造线走向多为NW向,而华南除西南地构造线走向与其相似外,其他地区区三叠纪构造线走向多为NE向或NNE向；越南北部三叠纪构造运动学方向多为右旋韧性走滑剪切,而华南除西南地区发育有右旋韧性走滑剪切外,其他地区多为左旋韧性走滑剪切。因而,从构造作用角度而言,发育在越南的印支造山作用对华南的影响有限。同时,其也难以解释华南三叠纪NE向橄榄玄粗岩系列-A型花岗岩带的形成。而古太平洋板块俯冲作用则可以很好的解释上述印支造山作用无法解释的问题,而近两年在朝鲜半岛、日本、菲律宾等地发现的晚二叠世-早三叠世弧岩浆岩,进一步证实了三叠纪古太平洋板块俯冲作用的存在,因而,华南三叠纪构造-岩浆作用主要与古太平洋板块俯冲作用有关。更多还原

【Abstract】 South China, consisting of Yangtze Block and Cathaysia Block, is one of the most famous granite provinces in China and even in the world. Large scale granitic magma activities and related metal mineralization in Mesozoic developed in the area, forming many world-class mineral deposits. The relationships between magmatism and metal mineralization have been studied as early as the last century and still attract much attention now. Most Triassic magma rocks in the area were granitic rocks while mafic rocks were rarely reported except the mafic xenoliths in Daoxian, and volcanics were not reported. There were some studies summed up the spatial distribution regularities of the Triassic magma rocks, and with more and more high precision age data recently, many people considered that Indosinian granite were developed all over the Indosinian period. The exiting researches were mainly focused on the area to the west of the Mesozoic volcanics line of South China, while the research of the east of the line is still relatively weak.The thesis selected the Triassic shoshonite series and A-type granite located in several areas on the east of the Mesozoic volcanics line as study objects, which including the quartz monzonite-(quartz) syenite in the middle of Zhejiang province, quartz monzonite-syenogranite-monzogranite in the southwest of Zhejiang province, syenites-syenogranite in the west of Fujian province and quartz monzonite-monzogranite in the east of Jiangxi province. Detailed studies on field geology and petrography were taken in the first period, and the comprehensive studies on the zircon U-Pb age, major elements, trace elements, Sr-Nd isotope and zircon Hf isotope were taken later. Combined with the previous study achievements on Triassic geology in south China, the thesis discusses the petrogenesis, spatial distribution and tectonic setting of the Triassic shoshonite series and A-type granite in south China This paper has some understandings as follows:(1) The Triassic plutons in central Zhejiang province include Shiban intrusion, Dashuang intrusion and Zhouzhuang intrusion. The lithology of Shiban intrusion is quartz-syenite, and Dashuang intrusion consists of quartz-syenite and porphyritic quartz monzonite, while the Zhouzhuang intrusion consists of porphyritic quartz monzonite. LA-ICP-MS zircon U-Pb dating for the different lithologies of the three intrusions gives magma crystallization ages of238±2Ma,240±3Ma,236±3Ma and237±2Ma, respectively. These ages rang from236Ma to240Ma, indicating magmatism occurred at middle Triassic. The Shiban and Dashuang syenites belong to peraluminous granites (A/CNK>1.02), Dashuang quartz monzonites are metaluminous granites (A/CNK=0.90-0.98), while the Zhouzhuang quartz monzonites distribute in both metaluminous and peraluminous areas, with most of the samples are peraluminous granites (A/CNK=0.93-1.05). All the four type samples are shoshonite granites. Syenites in this area show enrichment of Th, K, depletion of Ba, Sr and high field strength elements (Ta, Ti). The chondrite-normalized REE patterns show that all syenites are enriched in light rare earth elements (LREE) with (La/Yb)N of106-175, and have pronounced negative Eu anomalies with Eu/Eu*values of0.280～0.40. The quartz monzonite samples are enriched in Ba and Th, and are depleted in Sr, P, Ta and Ti. The chondrite-normalized REE patterns show that all quartz monzonite samples are enriched in LREE ((La/Yb)N=30.12-43.79), and have pronounced negative Eu anomalies with Eu/Eu’ values of0.60～0.70. Total bulk Sr-Nd isotope results show that Shiban syenite, Dashuang syenite, Dashuang quartz monzonite and Zhouzhuang quartz monzonite have εNd(t) values of-8.60～-8.71,-8.35～-8.46,-8.26～-10.92and-9.24～-10.13, respectively, and the corresponding TDM2of1.70-1.71Ga,1.68-1.71Ga,1.68-1.89Ga and1.77-1.83Ga. The zircon Hf isotope results show that Shiban syenite, Dashuang syenite and Dashuang quartz monzonite have εHf(t) values of-6.6±0.33,-6.91±0.33and-11.21±0.72, respectively, and the corresponding TDM2of1.62-1.75Ga,1.64-1.79Ga and1.8-2.07Ga.(2) The Triassic magmatic rocks in Southwest Zhejiang province include Meitian intrusion and Jingju intrusion. The lithologies of Meitian intrusion include porphyritic monzonite granite and porphyritic quartz monzonite, while the Jingju intrusion consists of syenogranite and quartz monzonite. LA-ICP-MS zircon U-Pb dating for Meitian monzogranite, quartz monzonite and quartz monzonitic dyke show crystallization ages of238±2Ma,236±2Ma and228±2Ma, respectively, indicating these intrusions formed in middle Triassic. The Meitian granites belong to peraluminous granites (A/CNK=1.00-1.23), and the Meitain quartz monzonite (A/CNK=0.96-1.09) and Jingju syenogranite (A/CNK=0.88-1.12) show wide rang between metaluminous and peraluminous areas, while the Jingju quartz monzonites mainly belong to metaluminous granites (A/CNK=0.83-1.04). All the Triassic plutons in Southwest Zhejiang province are shoshonitic granites except few samples in Meitian monzogranite which are high-K calc-alkaline granites. On the Harker diagrams for the quartz monzonites, the TiO2, Fe2O3T, CaO and P2O5show linear negative correlations with SiO2, while others show nearly no correlations with SiO2, For the monzogranites and syenogranites, the MgO, Al2O3, CaO, TiO2, Fe2O3T and P2O5show linear negative correlations with SiO2, while the MnO show negative correlations with SiO2first and then become positive. All the Harker diagrams suggest that the magma might have evolved by fractional crystallization of feldspars, iron-magnesium minerals, Ti-Fe oxides and apatites. Quartz monzonite in this area show enrichment of Th, Rb, and depletion of Ba, Sr and high field strength elements (Ta, Ti). The chondrite-normalized REE patterns show that quartz monzonite are enriched in LREE ((La/Yb)N=15.53-34.05), and show pronounced negative Eu anomalies with Eu/Eu values of0.58-1.04. The monzogranites in Meitian are enriched in Rb, Th, and depleted in Ba, P, Ta and Ti. The chondrite-normalized REE patterns show that monzogranites are enriched in LREE ((La/Yb)N=24.61～47.30), and show pronounced negative Eu anomalies with Eu/Eu values of0.85～2.32. Syenogranite are enriched in large ion lithophile elements (K, Rb, Th), and depleted in U, Ba, P, Ta and Ti. Samples in syenogranite have high rare earth content (933-1772ppm), and are enriched in LREE (La/Yb)N=50.23～255.45), and show pronounced negative Eu anomalies with Eu/Eu*values of0.38-0.77. Total bulk Sr-Nd isotope results show that Meitian quartz monzonite and monzonite granite have εNd(t) values and TDM2of-13.72～-14.25and-14.57, and2.12-2.16Ga and2.19Ga, respectively. The zircon Hf isotope results show that Meitian monzonite granite, quartz monzonite and quartz monzonitic dyke and Jingju syenogranite have εHf(t) values of-17.51±0.43,-19.01±0.46,-15.19±0.48and-10.90±0.67, respectively, with the corresponding TDM2of2.37～2.54Ga,2.29-2.45Ga,2.14-2.3Ga and1.84～2.08Ga.(3) The Triassic magmatic rocks from the Western Fujian (Mingxi-Qingxi) area are composed of Pinghu biotite-pyroxene syenites, Pinghu syenites, Baiheng syenogranites and Julin syeno granites. LA-1CP-MS zircon U-Pb analyses suggest the formation ages are232Ma±2Ma,235.0±1.3Ma,236±2Ma and225±2Ma, respectively. The samples from Pinghu biotite-pyroxene syenites have low A/CNK ratios ranging from0.42to0.45, and show metaluminous-peralkaline and shoshonitic compostions. The Harker diagrams show negative correlations between CaO, Fe2O3T, MnO and SiO2but positive correlations between Al2O3, Na2O and SiO2, indicating the fractionation of mafic minerals, feldspar and Fe-Ti oxides. All the samples are characterized by enrichment of LREE relative to HREE ((La/Yb)N=53.75±63.76), slight negative Eu anomalies, enrichment of Rb and Ba, depletion of high field strength elements (HFSE, such as Nb, Ta and Ti) and enriched εHf(t)(-11.28±0.48) with old TDM2(1.88-2.05Ga). The Pinghu syenites have A/CNK ratios ranging from0.50to0.80, plotted in the metaluminous and peralkaline areas on the A/NK-A/CNK diagrams. All samples exhibit egative correlations between MgO, Fe2O3T, MnO, P2O5and SiO2but positive correlations between A12O3and SiO2on the Harker diagrams, suggesting the fractionation of mafic minerals, feldspar, Fe-Ti oxides and apatites. They are characterized by enrichment of LREE relative to HREE ((La/Yb)N=41.41-87.63), negative Eu anomalies (Eu/Eu*=0.74～0.84), depletion of Sr, P, Nb, Ta and Ti, and enriched εHf(t)(-9.88±0.36) with old TDM2(1.8-1.96Ga).The Baiheng syenogranites have A/CNK ratios ranging from0.80to1.06, plotted in the metaluminous, peralkaline and peraluminous areas on the A/NK-A/CNK diagrams. All samples exhibit negative correlations between MgO, A12O3, Fe2O3r, MnO, P2O5, CaO, K2O and SiO2on the Harker diagrams, suggesting the fractionation of mafic minerals, feldspar, Fe-Ti oxides and apatites. They are characterized by enrichment of LREE relative to HREE ((La/Yb)N=7.22～19.23), negative Eu anomalies (Eu/Eu*=0.35～0.71),enrichment of Th and U, depletion of Ba, P, Ta and Ti, and enriched εHF(T)(-6.54～-5.29) with old TDM2(1.60-1.68Ga).The Julin syenogranites have A/CNK ratios ranging from1.06to1.10, plotted in the metaluminous and peralkaline areas on the A/NK-A/CNK diagrams. All samples exhibit negative correlations between MgO, Al2O3, Fe2O3T, P2O5, CaO, TiO2and SiO2on the Harker diagrams, suggesting the fractionation of mafic minerals, feldspar, Fe-Ti oxides and apatites. They are characterized by strong enrichment of LREE relative to HREE ((La/Yb)N=9.99～22.86), negative Eu anomalies (Eu/Eu*=0.14-0.23), enrichment of Th and U, depletion of Ba, P, Sr, Ta and Ti, and enriched εHf(t)(-8.86±0.27) with old TDM2(1.79～1.88Ga).(4) The Triassic magmatic rocks from the Eastern Jiangxi (Ningdou-Xingguo) consist of porphyritic monzonitic granites and Quartz monzonites. LA-ICP-MS zircon U-Pb analyses suggest that the formation age of monzonitic granites are228±2Ma. On the A/NK-A/CNK diagrams, most samples from the two rock types plot in the metaluminous area (A/CNK ratios are0.93～1.07and0.88～0.99, respectively), but some from the monzonitic granites plot in the peraluminous and weak peraluminous. Most samples exhibit shoshonitic compostions. However, some samples from monzonitic granites show High K calc-alkali compositions. On the Harker diagrams, all the samples from the two rock types exhibit no correlation with SiO2. The samples from Quartz monzonites display enrichment of LREE ((La/Yb)N=12.22～46.03), Th, U, Rb and K, depletion of Ba, P, Sr, Nb, Ta and Ti, and obvious negative Eu anomalies (Eu/Eu*=0.35～0.65) The samples from monzonitic granites are characterized by strong enrichment of LREE relative to HREE ((La/Yb)N=10.76～28.81), negative Eu anomalies (Eu/Eu*=0.36～0.75), enrichment of Th,U,Rb and K, depletion of Ba, P, Sr, Nb, Ta and Ti. They have relatively high HREE contents, indicating the presence of heavy minerals. The samples from monzonitic granites have enrichedd(t)(-9.6～9.99) and εHft)(-7.68±0.48), with old T2DM(1.79～1.82Ga) and TDM2(1.67～1.85Ga).(5) In summary, the Triassic quartz monzonites from the central Zhejiang area were derived from partial melting of old deep crustal materials with the participation of mantle materials and crystal fractionation of plagioclases, hornblendes, biotites, apatites and Fe-Ti oxides. However, the syenites were derived partial melting of relatively young crustal materials and crystal fractionation of alkali-feldspars, hornblendes, biotites and apatites. The Triassic monzonitic granites from Southwestern Zhejiang were generated by partial melting of old crustal materials and crystal fractionation of alkali-feldspars, biotites, apatites and Fe-Ti oxides, while the quartz monzonites were generated by partial melting of crustal materials with the participation of some mantle materials and crystal fractionation of plagioclases, hornblendes, biotites, apatites and Fe-Ti oxides. And the late monzonitic granites were mainly generated by partial melting of relatively young crustal materials. The syenites were derived partial melting of an enriched lithospheric mantle, while the Baiheng syenogranites were generated by partial melting of crustal materials and crystal fractionation of alkali-feldspars, hornblendes, biotites, apatites and Fe-Ti oxides. The origin of Julin syenogranites is similar to the syenogranites from the southwest Zhejiang area. The Baohuashan granites from Eastern Jiangxi area have the same compositions as the syenogranites from the western Fujian area, indicating they have similar genesis.(6)This paper compared the geology of South China to that of North Vietnam for understanding the tectonic settings of the Triassic magmatisms in South China. They have different times, strikes and kinematic directions of tectonothemal events. The tecotonothemal events developed in the North Vietnam concentrated in Early to Middle Triassic, striked Northwest (NW) and had dextral ductile strike-slip shearings. However, the tecotonothemal events developed in the South China (Guangxi and Zhejiang) concentrated in Middle to Late Triassic, striked NE or NNE. Most areas had sinistral ductile strike-slip shearings, but Southwestern areas have dextral ductile strike-slip shearings. Therefore, the Indosinian orogeny developed in the North Vietnam had less impact on the South China, and was not used to interpret the generation of Triassic NE trending shoshonitic series-A-type granitic belt in the South China. Late Permian to Early Triassic Arc magmatisms had been reported in the Korean Peninsula, Janpan and Philippines in the past two years, indicating the subduction of Paleo-Pacific plate. Take together, we propose that the Triassic magmatisms in South China are mainly related to the subduction of Paleo-Pacific plate.更多还原