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1.
黄陵地区新元古代侵入杂岩可为研究扬子板块北缘新元古代构造演化过程及其深部动力学机制提供关键信息。依据岩石组合及分布特征，可将黄陵杂岩划分为黄陵庙岩套、三斗坪岩套、大老岭岩套和晓峰岩套四个单元。本文以黄陵杂岩的围岩崆岭杂岩中花岗片麻岩、黄陵庙黑云母花岗岩和三斗坪闪长岩为研究对象，在系统的野外地质和岩石学研究基础上，开展了LA- ICP- MS锆石U- Pb年代学分析。结果表明，崆岭杂岩花岗片麻岩原岩年龄为1978±13 Ma，且记录了2.5 Ga的构造- 热事件。黄陵庙黑云母花岗岩和三斗坪闪长岩分别形成于815±9 Ma和813±6 Ma，与黄陵庙岩套和三斗坪岩套的侵位时限基本一致。综合分析本次研究结果与前人资料，认为黄陵杂岩主要形成于863~794 Ma，为新元古代早期岩浆活动的产物。通过综述区域地质和地球化学研究资料，认为黄陵杂岩形成于新元古代早期活动大陆边缘的构造环境，提出扬子板块北缘在新元古代早期经历了长期的俯冲- 增生造山过程。  相似文献   

2.
鄂西黄陵花岗岩基同位素年龄谱   总被引：14，自引：0，他引：14  
采用Isoplot程序重新计算了鄂西黄陵花岗岩基主要岩套的Rb-Sr等时线年龄和锆石U-Pb一致曲线年龄,测定了各种类型脉岩的侵入年龄,最后获得该岩基岩浆活动的年龄谱是主体太平溪英云闪长岩岩套和黄陵庙花岗闪长岩岩套的侵位年龄分别是(833±29)Ma和(819±7)Ma,大老岭石英二长花岗岩岩套是(786±54)Ma,脉岩套侵入年龄从花岗闪长斑岩的813 Ma开始,到770Ma的辉绿岩和772Ma的石英脉侵入,整个岩基抬升作用完成,岩浆活动基本结束.在印支期(217±7)Ma时,岩基上NNW和NNE向大断裂发生了强烈的再次活动.Nd,Sr同位素证据表明,除大老岭岩套外,其他三个岩套的岩浆演化是连续的,这些岩浆起源于晋宁期扬子板块北缘发生的大洋板块消减作用.  相似文献   

3.
本文报道分别位于扬子克拉通核部和北缘的黄陵及汉南新元古代侵入杂岩体的惰性气体激光剥蚀-等离子体质谱(ELA-ICPMS)锆石U-Pb年代学研究及其构造意义分析.定年数据显示,黄陵地区的三斗坪、大老岭岩套分别形成于794±7和795±8Ma;晓峰浅成岩岩套形成于744±22Ma,不仅与震旦系莲沱组底部火山岩年龄相同,且同期热事件普遍记录于杂岩体内其它岩套.汉南杂岩体中五堵门岩体形成于789±10Ma,在分析误差范围内与三斗坪、大老岭岩套相同;天平河岩形成于863±10Ma,这是在扬子北缘首次识别出这期岩浆作用.在扬子陆核和北缘侵入杂岩中还分别发现了≈860Ma和945～931Ma的捕获锆石.此外,740Ma的后期热事件同样记录于汉南杂岩体,表明扬子陆块内部和北缘共同经历了790Ma的峰期中酸性岩浆作用和≈740Ma的后期强烈热改造事件,即事件具有克拉通范围的性质.与天平河岩体岩性相似、年龄相同的侵入岩体已在攀西多处地区发现,说明空间上860Ma岩浆作用在扬子北缘和西缘可能具延续性.作者认为,"晋宁期"具造山性质的构造运动开始的时间应以830Ma为限,于≈790Ma达到了以壳内物质重熔为主的大规模岩浆侵入事件的峰期,并在≈740Ma以短期内地壳运动由剧烈抬升向快速沉降的构造转换为造山作用结束的标志.本次研究成果为探讨扬子克拉通新元古代大规模岩浆作用与同期全球构造事件的相互关系提供了重要的同位素年代学约束.  相似文献   

4.
黄陵断隆北部太古界花岗岩-绿岩地体的发现   总被引：8，自引：0，他引：8  
属于扬子地台基底的黄陵断隆北部太古界混合奥长花岗岩及其残留围岩——王家湾群所组成的地体,是一个遭受了斜长角闪岩相变质的花岗岩-绿岩地体。本区上太古界酸性侵入岩体是白岗岩-奥长花岗岩套(AT岩套)。绿岩带中的超镁铁质岩是含SiO_2稍高的辉岩质科马提岩。  相似文献   

5.
对黄陵花岗岩基英云闪长岩的黑云母、角闪石单矿物进行阶段加热法~(40)Ar-~(39)Ar定年,获得黑云母和角闪石坪年龄分别为837.3±4.2～838.7±4.0Ma和844.0±4.2Ma,属于晋宁运动晚期事件。结合黄陵花岗岩基已有的年龄资料作出英云闪长岩的冷却曲线,显示英云闪长岩经历了850Ma～800Ma的一个岩浆活动时期,并在840Ma～830Ma之间存在一个快速冷却的过程,指示当时处于一种伸展的构造背景下,这一事件可能与位于华南的约825Ma的地幔柱上隆导致的Rodinia超级大陆的裂解事件相互响应,之后岩体经历了一个长期的演化过程,到≈800Ma该期岩浆活动基本结束。  相似文献   

6.
扬子陆核黄陵地区发育较为完整的太古宙—古元古代片麻岩、表壳岩组合(即崆岭杂岩),前人调查研究认为南北黄陵Ar-Pt1具有一致的物质组成和地质演化过程。笔者分别对南北黄陵太古宙花岗质片麻岩进行锆石年代学研究发现,北黄陵2件样品(HL013-1、HL013-2)均存在大量锆石发育岩浆核-变质边结构,都获得～2.8 Ga原岩结晶年龄和～2.0 Ga变质年龄;而南黄陵1件样品(HL005-3)以具振荡环带结构的岩浆锆石为主,仅获得～2.9 Ga原岩结晶年龄。结合前人研究成果发现,～2.0 Ga的变质年龄在北黄陵太古宙—古元古代的花岗片麻岩、表壳岩中广泛发育,而在南黄陵相似建造中均未获得,一定程度上说明北黄陵地区广泛遭受～2.0 Ga的区域变质作用而南黄陵不发育,南北黄陵在古元古代可能处在不同地块或者同一地块不同部位。2.1～1.6 Ga的构造岩浆事件的分布特点说明扬子陆块可能存在多条古元古代造山带,扬子陆块古元古代以多块体拼贴为特点,广泛记录2.1～1.6 Ga的构造岩浆事件说明扬子陆块是全球哥伦比亚超大陆的重要组成部分。  相似文献   

7.
崆岭杂岩中斜长角闪岩包体的锆石年龄和Hf 同位素组成   总被引：3，自引：0，他引：3  
采用激光剥蚀- 等离子质谱（LA-ICP-MS）分析技术,测定崆岭杂岩中斜长角闪岩包体的锆石U-Pb 年龄和Hf同位 素组成,以探讨黄陵结晶基底的形成及演化。崆岭杂岩主要由太古代TTG片麻岩和早元古代孔兹岩系组成,TTG片麻岩中 存在少量斜长角闪岩包体。该包体中的锆石可分为岩浆结晶锆石、变质改造锆石和变质新生锆石三类。（1）第一类原生岩 浆结晶锆石的U-Pb 年龄为（3000±24）Ma,MSWD=2.4,代表斜长角闪岩的原岩- 拉斑玄武岩的成岩时间,指示崆岭杂岩 中以包体形式存在的斜长角闪岩（3.0 Ga）,是黄陵结晶基底和扬子克拉通中出露的最古老岩石。（2）第二类变质改造锆石 的U-Pb 年龄为（2715±9）Ma,MSWD=1.4,代表黄陵地区第Ⅰ期角闪岩相变质事件的时间。第Ⅰ期（2.75~2.7 Ga）角闪 岩相变质作用,使TTG花岗岩及其拉斑玄武质岩石包体,变质为TTG 片麻岩及其斜长角闪岩包体。（3）第三类变质新生锆 石的U-Pb 年龄为（2558±40）Ma,MSWD=0.93,代表黄陵地区第Ⅱ期角闪岩相变质事件的时间。第Ⅱ期构造热事件（2.6~2.5 Ga）与“水月寺运动”相关,造成黄陵地区太古代与元古代之间的不整合面。总之,黄陵地区第Ⅰ期和第Ⅱ期变质事件的 共同作用,将黄陵花岗岩- 绿岩型地体转变为晚太古代稳定陆块,并从此开始了长达500 Ma 的克拉通化。（4）斜长角闪岩 包体中锆石的平均εHf（t ）为-11.59~-3.98、平均亏损地幔模式年龄t DM2 为3.4 Ga,表明黄陵地区存在比崆岭群更古老（>3.2 Ga）的地壳。  相似文献   

8.
对北大巴山地区岚皋－镇坪一带的区域地质构造演化及其与早古生代碱基性火山杂岩的成岩关系进行了综合分析，指出本区曾经历了裂陷－愈合－再裂陷－愈合的地质发展和演化。早古生代时期本区是一个在已固结愈合的中－晚元古代的裂陷的扬子地台北缘构造软弱带的基础上重新活化的大陆边缘陆内断陷构造带。它不仅控制了区内该时期碱基性火山杂岩的产出位置、岩浆脉动活动特征，而且还影响到岩浆物质来源的深度。在此基础上，笔者探讨了与  相似文献   

9.
撮科杂岩是最近在滇中地区发现的早前寒武纪基底杂岩，对深入探究扬子陆块早期演化具有重要意义.报道了4件代表性岩石样品的锆石U-Pb年代学和Hf同位素新数据.奥长花岗质片麻岩样品的结晶年龄为2 845±33 Ma，具有正的锆石εHf（t）值（1.7~4.6）和相对年轻的亏损地幔二阶段（TDM2）模式年龄（2.97~3.12 Ga），表明其形成于新生地壳的重熔.变二长花岗岩和片麻状花岗岩样品的结晶年龄分别为2 401±15 Ma和2 320±16 Ma，显示负的锆石εHf（t）值（-6.2~-0.8）和明显老的TDM2模式年龄（2.90~3.11 Ga），指示其来自古老地壳物质的重熔.斜长黑云碎粒岩的变质锆石的年龄为1 948±16 Ma，结合已有变质年龄揭示一期1.96~1.95 Ga区域变质作用.扬子陆块西南缘存在太古代结晶基底，并保留了与Nuna超大陆聚合有关的多期构造-岩浆事件的记录.   相似文献   

10.
具有特殊晶洞构造的镶黄旗南钾长花岗岩杂岩,位于中亚造山带华北地台北缘东段。获得其黑云钾长花岗岩锆石LA-ICP-MS U-Pb年龄为(262.7±2.0)Ma;杂岩体为准铝质、弱过铝质到过铝质,钙碱性到高钾钙碱性,I型和A型花岗岩。从组成杂岩体的石英二长岩、钾长花岗斑岩到具有晶洞构造的黑云钾长花岗岩,SiO2、全碱含量及δEu负异常值逐渐升高,基性组分逐渐降低;并随岩浆结晶演化,Al2O3、TFeO、TiO2、CaO、P2O5、Na2O含量呈线性逐渐降低,K2O含量逐渐升高;相似的微量、稀土元素配分模式暗示,组成杂岩体的各组分为同源岩浆不同演化阶段的产物。根据较低的镁指数值(Mg#:0.03～0.37),Rb/Sr比值(0.58～5.73、0.23～0.48、0.20～0.27)和Hf同位素组成(εHf(t)=-2.65～2.38)及εHf(t)模式年龄(1 220.80～957.97 Ma)暗示,杂岩体位于中亚造山带向华北克拉通过渡范围,源岩来自于新增生的弧增生杂岩基底壳源熔融。具有俯冲消减带组分(SZC)特征的钾长花岗岩杂岩,由具有弧岩浆性质的基底控制;镶黄旗南钾长花岗岩可能与华北地台北缘西段乌梁亚斯太A型花岗岩组成一条代表古亚洲洋最终缝合的A型花岗岩带,其具有西部形成早于东部的特征。  相似文献   

11.
Many elongated, lenticular plutons of porphyritic granitoids are distributed mainly near the southern and northern margin of the Chhotanagpur Gneissic Complex （CGC） which belongs to the EW to ENE-WSW tending 1500 km long Proterozoic orogenic belt amalgamat ng the North and South Indian cratonic blocks. The late Grenvillian （1071 ±64 Ma） Raghunathpur porphyritic granitoid gneiss （PGG） batholith comprising alkali feldspar granite, granite, granodiorite, tonalite, quartz syenite and quartz monzonite intruded into the granitoid gneisses of southeastern part of CGC in the Purulia district, West Bengal and is aligned with ENE-WSW trending North Purulia sr~ear zone, Mineral chemistry, geochemistry, physical condition of crystallization and petrogenetic model of Raghunathpur PGG have been discussed for the first time. The petrographic and geochemical features （including major and trace- elements, mineral chemistry and S7Sr/S6Sr ratio） suggest these granitoids to be classified as the shosh- onitic type. Raghunathpur batholith was emplaced at around 800 ~C and at 6 kbar pressure tectonic discrimination diagrams reveal a post-collision tectonic setting while structural studies reveal its emplacement in the extensional fissure of North Purulia shear zone. l＇he Raghunathpur granitoid is compared with some similar granitoids of Europe and China to draw its petrogenetic model. Hybridi- zation of mantle-generated enriched mafic magma and crustal magma at lower crust and later fractional crystallization is proposed for the petrogenesis of this PGG. Mafic magma generated in a post-collisional extension possibly because of delamination of subducting slab. Raghunathpur batholith had emplaced in the CGC during the final amalgamation （~ 1.0 Ga） of the North and South Indian cratonic blocks. Granitoid magma, after its generation at depth, was transported to its present level along megadyke channel, ways within shear zones.  相似文献   

12.
The Late Paleozoic intrusive rocks, mostly granitoids, totally occupy more than 200,000 km2 on the territory of Transbaikalia. Isotopic U-Pb zircon dating (about 30 samples from the most typical plutons) shows that the Late Paleozoic magmatic cycle lasted for 55–60 m.y., from ~330 Ma to ~275 Ma. During this time span, five intrusive suites were emplaced throughout the region. The earliest are high-K calc-alkaline granites (330–310 Ma) making up the Angara–Vitim batholith of 150,000 km2 in area. At later stages, formation of geochemically distinct intrusive suites occurred with total or partial overlap in time. In the interval of 305–285 Ma two suites were emplaced: calc-alkaline granitoids with decreased SiO2 content (the Chivyrkui suite of quartz monzonite and granodiorite) and the Zaza suite comprising transitional from calc-alkaline to alkaline granite and quartz syenite. At the next stage, in the interval of 285–278 Ma the shoshonitic Low Selenga suite made up of monzonite, syenite and alkali rich microgabbro was formed; this suite was followed, with significant overlap in time (281–276 Ma), by emplacement of Early Kunalei suite of alkaline (alkali feldspar) and peralkaline syenite and granite. Concurrent emplacement of distinct plutonic suites suggests simultaneous magma generation at different depth and, possibly, from different sources. Despite complex sequence of formation of Late Paleozoic intrusive suites, a general trend from high-K calc-alkaline to alkaline and peralkaline granitoids, is clearly recognized. New data on the isotopic U-Pb zircon age support the Rb-Sr isotope data suggesting that emplacement of large volumes of peralkaline and alkaline (alkali feldspar) syenites and granites occurred in two separate stages: Early Permian (281–278 Ma) and Late Triassic (230–210 Ma). Large volumes and specific compositions of granitoids suggest that the Late Paleozoic magmatism in Transbaikalia occurred successively in the post-collisional (330–310 Ma), transitional (305–285 Ma) and intraplate (285–275 Ma) setting.  相似文献   

13.
The southern Sinai Peninsula, underlain by the northernmost extension of the Arabian-Nubian Shield, exposes post-collisional calc-alkaline and alkaline granites that represent the youngest phase of late Neoproterozoic igneous activity. We report a petrographic, mineralogical and geochemical investigation of post-collisional plutons of alkaline and, in some cases, peralkaline granite. These granites intrude metamorphosed country rocks as well as syn- and post-collisional calc-alkaline granitoids. The alkaline and peralkaline granites of the southern tip of Sinai divide into three subgroups: syenogranite, alkali feldspar granite and riebeckite granite. The rocks of these subgroups essentially consist of alkali feldspar and quartz with variable amounts of plagioclase and mafic minerals. The syenogranite and alkali feldspar granite contain small amounts of calcic amphibole and biotite, often less than 3%, while the riebeckite granite is distinguished by sodic amphibole (5–10%). These plutons have geochemical signatures typical of post-collisional A-type granites and were most likely emplaced during a transition between orogenic and anorogenic settings. The parental mafic magma may be linked to lithospheric delamination and upwelling of asthenospheric mantle material. Differentiation of the underplated basaltic magma with contributions from the juvenile crust eventually yielded the post-collisional alkaline granites. Petrogenetic modelling of the studied granitic suite shows that pure fractional crystallization cannot quantitatively explain chemical variations with the observed suite, with both major oxides and several trace elements displaying trends opposite to those required by the equilibrium phase assemblage. Instead, we show that compositional variation from syenogranite through alkali feldspar granite to riebeckite granite is dominated by mixing between a low-SiO2 liquid as primitive or more primitive than the lowest-SiO2 syenogranite and an evolved, high-SiO2 liquid that might be a high-degree partial melt of lower crust.  相似文献   

14.
The Egyptian older and younger granitic rocks emplaced during pre- and post-collision stages of Neoproterozoic Pan-African orogeny, respectively, are widely distributed in the southern Sinai Peninsula, constituting 70% of the basement outcrops. The Wadi El-Akhder, southwestern Sinai, is a mountainous terrain exposing two granitoid suites, namely the Wadi El-Akhder Older Granites (AOG) and the Homra Younger Granites (HYG). The AOG (granodiorites with subordinate tonalite compositions) have geochemical characteristics of medium-K calc-alkaline, metaluminous to mildly peraluminous granitoids formed in an island-arc environment, which are conformable with well-known Egyptian older granitoids rocks, whereas the HYG display calc-alkaline to slightly alkaline nature, peraluminous syeno-, monzogranites and alkali feldspar granites matching well those of the Egyptian younger granites. With respect to the AOG granitoids, the HYG granites contain lower Al2O3, FeO*, MgO, MnO, CaO, TiO2, Sr, Ba, and V, but higher Na2O, K2O, Nb, Zr, Th, and Rb. The AOG are generally characterized by enrichment in LILE and LREE and depletion in HFSE relative to N-MORB values (e.g., negative Nb and Ta anomalies). The geochemical features of the AOG follow assimilation-fractional crystallization (AFC) trends indicative of extensive crustal contamination of magma derived from a mantle source. The chemical characteristics of the AOG are remarkably similar to those of subduction-related granitoids from the Arabian-Nubian Shield (ANS). The compositional variations from monzogranites through syenogranites to alkali feldspar granite within HYG could not be explained by fractional crystallization solely. Correlating the whole-rock composition of the HYG to melts generated by experimental dehydration melting of meta-sedimentary and magmatic rocks reveals that they appear to be derived by extended melting of psammitic and pelitic metasediments, which is similar to the most of younger granitic suites in the ANS.  相似文献   

15.
新疆西准噶尔花岗岩类的时代及其成因   总被引：40，自引：0，他引：40       下载免费PDF全文
在西准噶尔地区存在两期不同成因的花岗岩类,一期为与弧后盆地封闭有关的海西中期(305—320Ma)、以小岩体产出的花岗闪长岩-石英闪长岩;另一期为后造山的海西晚期(240—280Ma)的以巨大岩基形式产出的碱长花岗岩。  相似文献   

16.
临沧花岗岩基中段花岗闪长岩类研究   总被引：11，自引：0，他引：11  
临沧花岗岩基中段花岗闪长岩类属残留岩基，岩石学特征与临沧花岗岩基其它花岗岩明显不同。地球化学特征与二长花岗岩类相近，两类花岗岩之稀土特征与大勐龙岩群(Pt2d．)基本一致。加之花岗闪长岩类中含镁铁质微粒包体(MME)，认为花岗闪长岩类存在岩浆混合作用，岩浆向上运移过程中未发生同化混染和分离结晶作用。结合同位素测年结果及其它地质事件，确定是在二叠纪侵位于活动陆缘，是区内古特提斯洋向东俯冲消减作用的产物。  相似文献   

17.
The Batouri gold mining area in southeastern Cameroon is part of the Adamawa–Yadé Domain of the Central African Fold Belt (Pan-African). It is underlain by a variety of granitic rocks, including alkali-feldspar granite, syeno-monzogranite, granodiorite, and tonalite. Geochemical data suggest that these rocks formed by differentiation of I-type tonalitic magma under oxidizing conditions in a continental volcanic arc setting. U–Pb dating of zircons from gold-associated monzogranite-granodiorite at Kambélé gave concordant ages of 619 ± 2 and 624 ± 2 Ma, while Ar–Ar dating of alkali-feldspar granite yielded a non-plateau maximum age of 640–620 Ma. These ages imply that the Batouri granitoids were emplaced during the collision of the West African Craton and the Congo Craton.

The geochemical characteristics of the Batouri granitoids as well as their oxidized state (magnetite series) are typical of gold-associated felsic rocks in subduction settings elsewhere. The similarities in age, composition, and geochemical affinities of these granitoids with those reported from other localities in the Adamawa–Yadé Domain reinforce the earlier assumption that the granitic rocks of this domain represent parts of a regional-scale batholith, with commonly small-scale, high-grade auriferous quartz veins in structurally favourable sites. The spatial and temporal association of gold mineralization and the Batouri granitoids may suggest potential for regional-scale, high-tonnage, granite-related gold ore.  相似文献   

18.
We present the geochemistry and intrusion pressures of granitoids from the Kohistan batholith, which represents, together with the intruded volcanic and sedimentary units, the middle and upper arc crust of the Kohistan paleo-island arc. Based on Al-in-hornblende barometry, the batholith records intrusion pressures from ~0.2 GPa in the north (where the volcano-sedimentary cover is intruded) to max. ~0.9 GPa in the southeast. The Al-in-hornblende barometry demonstrates that the Kohistan batholith represents a complete cross section across an arc batholith, reaching from the top at ~8–9 km depth (north) to its bottom at 25–35 km (south-central to southeast). Despite the complete outcropping and accessibility of the entire batholith, there is no observable compositional stratification across the batholith. The geochemical characteristics of the granitoids define three groups. Group 1 is characterized by strongly enriched incompatible elements and unfractionated middle rare earth elements (MREE)/heavy rare earth element patterns (HREE); Group 2 has enriched incompatible element concentrations similar to Group 1 but strongly fractionated MREE/HREE. Group 3 is characterized by only a limited incompatible element enrichment and unfractionated MREE/HREE. The origin of the different groups can be modeled through a relatively hydrous (Group 1 and 2) and of a less hydrous (Group 3) fractional crystallization line from a primitive basaltic parent at different pressures. Appropriate mafic/ultramafic cumulates that explain the chemical characteristics of each group are preserved at the base of the arc. The Kohistan batholith strengthens the conclusion that hydrous fractionation is the most important mechanism to form volumetrically significant amounts of granitoids in arcs. The Kohistan Group 2 granitoids have essentially identical trace element characteristics as Archean tonalite–trondhjemite–granodiorite (TTG) suites. Based on these observations, it is most likely that similar to the Group 2 rocks in the Kohistan arc, TTG gneisses were to a large part formed by hydrous high-pressure differentiation of primitive arc magmas in subduction zones.  相似文献   

19.

The Uromia–Dokhtar Magmatic Arc (UDMA) is a northwest–southeast trending magmatic belt which is formed due to oblique subduction of Neotethys underneath Central Iran and dominantly comprises magmatic rocks. The Jebal-e-Barez Plutonic Complex (JBPC) is located southeast of the UDMA and composed of quartz diorite, granodiorite, granite, and alkali granite. Magmatic enclaves, ranging in composition from felsic to mafic, are abundant in the studied rocks. Based on the whole rock and mineral chemistry study, the granitoids are typically medium-high K calc-alkaline and metaluminous to peraluminous that show characteristics of I-type granitoids. The high field strength (HFS) and large ionic radius lithophile (LIL) element geochemistry suggests fractional crystallization as a major process in the evolution of the JBPC. The tectonomagmatic setting of the granitoids is compatible with the arc-related granitic suite, a pre-plate collision granitic suite, and a syncollision granitic suite. Field observations and petrographic and geochemical studies suggest that the rocks in this area are I-type granitoids and continental collision granitoids (CCG), continental arc granitoids (CAG), and island arc granitoid (IAG) subsections. The geothermobarometry based on the electron probe microanalysis of amphibole, feldspars, and biotite from selected rocks of JBPC implies that the complex formed at high-level depths (i.e., 9–12 km; upper continental crust) and at temperatures ranging from 650 to 750 °C under oxidation conditions. It seems that JBPC is located within a shear zone period, and structural setting of JBPC is extensional shear fractures which are product of transpression tectonic regime. All available data suggested that these granitoids may be derived from a magmatic arc that was formed by northeastern ward subduction of the Neotethyan oceanic crust beneath the Central Iran in Paleogene and subsequent collision between the Arabian and Iranian plates in Miocene.

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