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哈尔里克奥姆尔塔格碱性花岗岩(OMAG)侵入于小铺东二长花岗岩中。该岩体岩性较均一,呈灰紫色,主要矿物组合为石英、钾长石、钠长石、碱性角闪石和霓石;化学成分上富硅、碱,贫钙、镁,低铝;富Rb、Th、U和Zr,Ga/Al比值大(3.18×10~4～3.56×10~4),贫Ba、Sr,岩石中Co、Cr、V和Ni等过渡元素显著亏损,U、Hf、Zr和Nb等高场强元素的含量高;稀土总量较高,配分模式右倾,并具有显著的负铕异常;LA-ICP-MS锆石~(206)Pb/~(238)U加权平均年龄为287.6±2.1Ma;具有正的ε_(Nd)(t)值(+4.96),较低的(~(87)Sr/~(86)Sr),值(0.70159)。同样侵入于小铺东二长花岗岩中的恰干昆多沟含角闪石石英正长岩(QGQS)也呈灰紫色,其结构和构造与OMAG非常相似。两个岩体在主量元素和REE图解上均呈现有规律的分布和一致的演化趋势。从QGQS到OMAG,SiO_2含量增加(从64.71%～64.83%到71.23%～74.31%)、全碱含量降低(从11.72%～11.79%到8.49%～9.87%)和Al_2O_3含量减少(从16.09%～16.19%到11.44%～13.34%)、稀土总量减少(从592.3×10~(-6)～656.0×10~(-6)到273.9×10~(-6)～405.9×10~(-6))、轻/重稀土比值降低(从18.2～20.1到4.4～6.0)、稀土配分曲线从平滑到Eu显著亏损。基于OMAG的岩相学、矿物学、地球化学、锆石年代学和与QGQS的对比研究,笔者认为奥姆尔塔格碱性花岗岩可能是由石英正长岩母岩浆经过分离结晶作用演化的产物,且这种石英正长岩岩浆起源于亏损地幔;根据哈尔里克造山带地质演化历史的分析,这两个岩体均形成于紧随主碰撞后的挤压-伸展转折阶段。
Haerke Aumortag alkaline granite (OMAG) invaded the Xiaopu East granite. The rock is more homogeneous and gray purple in color, and the main mineral assemblages are quartz, potash feldspar, albite, basic amphibole and aegirine. The chemical composition is rich in silicon, alkali, calcium, magnesium and low aluminum. Cr, V, Ni and other transition elements are significantly depleted in the lean Ba, Sr, while the ratios of Ga / Al are large (3.18 × 10 ~ 4 ~ 3.56 × 10 ~ 4) The contents of Hf, Zr and Nb high field elements are high; the total amount of REEs is high and the distribution pattern is right-inclined with significant negative Eu anomaly; LA-ICP-MS zircon 206 Pb / 238 U The weighted average age was 287.6 ± 2.1Ma, with a positive ε_ (Nd) (t) value of +4.96 and a low (87 Sr / 86 Sr) value of 0.70159. QGQS, also intruded into the Xiaodian eastern monzonite granite, is also pale purple in color and has a very similar structure and structure to OMAG. Both of the rock masses show regular distribution and consistent evolution trend in the main elements and REE diagrams. From QGQS to OMAG, the content of SiO 2 increased from 64.71% to 64.83% to 71.23% to 74.31%, the content of total alkali decreased (from 11.72% to 11.79% to 8.49% to 9.87%) and the content of Al 2 O 3 decreased from 16.09% (From 16.19% to 11.44% to 13.34%), and the total rare earth content decreased from 592.3 × 10 -6 to 656.0 × 10 -6 to 273.9 × 10 -6 to 405.9 × 10 -6 )), The ratio of light / heavy rare earth decreased (from 18.2-20.1 to 4.4-6.0), and the rare earth distribution curve decreased significantly from smooth to Eu. Based on the OMAG petrography, mineralogy, geochemistry, zircon geochronology and comparative studies with QGQS, the authors believe that Olm’Thaga alkaline granites may be the product of the evolution of quartz syenite magmatic magma after separation and crystallization , And this quartz syenite magma originated from a depleted mantle. According to the analysis of the geological evolution of the Halrick orogen, both of these mafic rocks formed during the compression-extension transition immediately after the main collision.