CAJ | 학술논문

西昆仑北缘库斯拉甫一带寒武纪中酸性侵入岩广泛分布，据野外接触关系可分为前后两个序次。早序次岩石为浅灰-麻灰色似斑状石英(二长)闪长岩，具贫硅、中碱、高钙和过铝质等特征，岩石稀土总量较低，轻稀土元素富集((La/Yb)N平均15.56)，中等 Eu 负异常(δEu 为0.56～0.88，平均0.73)。晚序次岩石为灰白色似斑状粗粒(二长)花岗岩，具富硅、低钙、富钾和过铝质等特征，稀土元素总量较高，轻稀土元素富集((La/Yb)N平均13.39)，Eu负异常明显(δEu为0.25～0.57，平均0.40)。早序次岩体侵位规模大，出露广泛，为I型花岗岩；晚序次岩体规模小，以岩株、岩脉状穿插其中，属于S型花岗岩范畴。两序次岩石产出的大地构造环境均为岛弧，可能由昆仑洋的俯冲消减引起，不同之处在于早序次岩石产于活动大陆(西昆仑地块)边缘位置，而晚序次形成在俯冲消减带上，两序次岩石为消减洋壳上部不同源区地壳部分熔融的产物。
서곤륜북연고사랍보일대한무기중산성침입암엄범분포，거야외접촉관계가분위전후량개서차。조서차암석위천회-마회색사반상석영(이장)섬장암，구빈규、중감、고개화과려질등특정，암석희토총량교저，경희토원소부집((La/Yb)N평균15.56)，중등 Eu 부이상(δEu 위0.56～0.88，평균0.73)。만서차암석위회백색사반상조립(이장)화강암，구부규、저개、부갑화과려질등특정，희토원소총량교고，경희토원소부집((La/Yb)N평균13.39)，Eu부이상명현(δEu위0.25～0.57，평균0.40)。조서차암체침위규모대，출로엄범，위I형화강암；만서차암체규모소，이암주、암맥상천삽기중，속우S형화강암범주。량서차암석산출적대지구조배경균위도호，가능유곤륜양적부충소감인기，불동지처재우조서차암석산우활동대륙(서곤륜지괴)변연위치，이만서차형성재부충소감대상，량서차암석위소감양각상부불동원구지각부분용융적산물。
Cambrian intermediate-acid intrusive rocks (U-Pb age (511±29) Ma) distribute widely around the Kusilafu region at the north margin of the Western Kunlun. The intrusive rocks can be subdivided into early and later periods according to contact relationships. The early intrusion is greyish porphyritic quartz (monzonite) diorite, characterized by poor-SiO2 moderate-alkaline, high-Ca and strongly peraluminous, and is relatively low inΣREE with LREE enrichment ((La/Yb)N, 11.65 on average) and moderate negative Eu anomaly (δEu varied from 0.40 to 0.71, 0.73 on average). While the later is offwhite porphyritic coarse-grained (monzonite) granite characterized by rich-Si, low-Ca, rich-K and peraluminous, and is relatively enriched inΣREE with an enrichment of LREE ((La/Yb)N average at 10.19) and moderate negative Eu anomaly (δEu varied from 0.40 to 0.71, averaged at 0.73). The early intrusion is larger with widespread outcrops, and belongs to I-type granite, whereas the later is smaller, and belongs to S-type granite, which intruded into the early one. Both intrusions formed in an island arc tectonic setting likely associated with the Kunlun Ocean subduction. The difference is that the early one formed at the active continental (the Western Kunlun) margin while the later were formed in the subduction zone;they were both results of partial melting crust from different source regions of the upper subducting oceanic crust.