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巴西东北部新法曾达-雅皮甘加山脉深成杂岩体在300～500MPa压力下侵位于新元古代角闪岩相变质岩中,主要由三类岩石组成:(1)粗粒花岗岩,(2)斑状花岗岩,(3)闪长岩到石英二长岩。后两类岩石构成新法曾达岩基,它位于走向北东的新法曾达左旋剪切带之北西侧,剪切带向北东倾伏的拉伸线理暗示该岩基是杂岩体深部抬升上来的一岩块。杂岩体的构造反映其在岩浆室的分层:斑状花岗岩在闪长岩之上而在粗粒花岗岩之下。 斑状花岗岩具有一致的成分,其镁铁矿物、石英和主要元素的含量都介于粗粒花岗岩与闪长岩之间,且不舍不平衡矿物组合,与上覆粗粒花岗岩局部显示过渡接触。大多数元素在哈克田上与SiO_2呈线性相关。这些特征表明它是由几乎无晶体的长英质岩浆与中性岩浆混合所成。 闪长岩含熔蚀的钾长石巨晶,其SiO_2含量从低到较高,部分与斑状花岗岩重叠,这表明在斑状花岗岩结晶过程中出现了一次新的岩浆混合事件,产生一种含捕虏晶的不均匀闪长质混染岩。斑状花岗岩中有丰富的闪长岩包体,一般无冷凝边,因而在花岗岩结晶历史中形成较早。它们被认为是从不均匀混染岩浆中分离出来的液体小滴,并通过对流流动加入到正在结晶的花岗岩岩浆中。 其后,在斑状花岗岩结晶过程中,镁铁质岩浆可能在新法曾达剪切带的帮助下继续供给岩基
The Neoproterozoic-Yapigagan Mountains deep-craton complex in the northeastern Brazil invaded the Neoproterozoic amphibolite facies metamorphic rocks under the pressure of 300-500 MPa and consisted mainly of three types of rocks: (1) coarse-grained granites, (2) porphyritic granite, (3) diorite to quartz monzonite. The latter two types of rocks form a new Fa Zengda basement, which is located on the north west side of the newly discovered Zhada Zengda uplift to the northeast. The stretching line to the NE plunge in the shear zone implies that the rock foundation is a deep uplifted complex A rock block up. The structure of the complex body reflects its stratification in the magma chamber: porphyritic granite is above the diorite and below the coarse-grained granite. The porphyritic granite has a consistent composition, and its contents of mafic minerals, quartz and major elements are between coarse granite and diorite, and disregard the unbalanced mineral assemblages, and show the transitional contact with the overlying coarse-grained granite partially . Most elements are linearly related to SiO 2 in Haqtian. These characteristics indicate that it is a mixture of almost amorphous feldspar magma and neutral magma. The calcareous feldspar giant gneiss, which has a low content of SiO 2 and partially overlaps with porphyritic granite, indicates that a new magmatic mixing event occurred during the crystallization of the porphyritic granite, resulting in a magma- Inhomogeneous diorite mixed with contaminated rock. The porphyritic granite is rich in diorite inclusions, generally without condensation, and thus formed early in the granite crystallization history. They are considered as liquid droplets separated from inhomogeneous magma and added to the crystallizing granite magma by convective flow. Later on, the mafic magma may continue to supply the rock foundation with the help of the new Fa Zeda shear zone during the crystallization of porphyritic granites