التفاصيل البيبلوغرافية
| العنوان: |
柴北缘锡铁山一带榴辉岩的岩石学特征及其退变PT轨迹 ; Petrology and calculation of retrograde PT path of eclogites from Xitieshan, North Qaidam, China |
| المؤلفون: |
张聪, 张立飞, 张贵宾, 宋述光 |
| المساهمون: |
北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室 |
| المصدر: |
万方 ; 知网 ; SCI |
| بيانات النشر: |
岩石学报 |
| سنة النشر: |
2009 |
| المجموعة: |
Peking University Institutional Repository (PKU IR) / 北京大学机构知识库 |
| مصطلحات موضوعية: |
柴北缘, 锡铁山, 榴辉岩, PT视剖面图, 退变PT轨迹, North Qaidam, Xitieshan, Eclogite, PT pseudosection, Retrograde PT paths |
| الوصف: |
柴北缘锡铁山地区榴辉岩以透镜体的形式存在于花岗质片麻岩和副变质片麻岩中。根据矿物组合的不同,可以分为多硅白云母榴辉岩和角闪石榴辉岩。在多硅白云母榴辉岩中首次发现了柯石英假象.利用榴辉岩中Grt-Cpx-Phn矿物温压计,结合绿辉石中存在柯石英假象包体的现象,得到锡铁山榴辉岩的峰期温压条件为751～791℃,2.71～3.17GPa,证明了锡铁山地区与柴北缘其他地块一样,也经历了超高压变质作用。通过PT视剖面图计算了榴辉岩退变的PT轨迹具有2个阶段演化特征:即先等温降压,然后再降温降压的PT轨迹。详细的岩石学研究探讨了榴辉岩在退变过程中,各矿物的成分和结构的改变过程。石榴石在等温降压过程中成分变. ; Eclogite from Xitieshan area Occurs as lenses within granitic gneiss and pelitic gneiss. According to the characteristic minerals, these eclogites can be divided into two types, i.e., phengite eclogite and hornblend eclogtie. Coesite pseudomorph inclusion in omphacite is found in the phengite eclogite. Using garnet-omphacite-phengite the peak P-T conditions of Xitieshan eclogites are P = 2.71 similar to 3.17GPa and T = 751 similar to 791 degrees C which is consistent with the presence of coesite pseudomorph inclusion in omphacite. Therefore, we infer that some of eclogites in XitieShan have undergone UHP metamorphism as the other blocks such as Dulan eclogites in North Qadam. Based on the PT pseudosections calculation by the Thriak/domino programme, two stages of retrograde MetaloOrphic evolution have been simulated, i.e, the erly isothermal decompression process followed by a late process of decreasing temperature and pressure. The mineral compositions and texture changed it lot during retrograde, metamorphic evolution. The composition of garnet made little changes during the ITD ( Isothermal Decomprcssion) process, however, pyrope contents decreased obviously in the rim of the garnet when amphibole appeared, and then formed the pargasite + plagioclace coronas around garnet. Jadeide contents of omphacite decreased in the presents of active fluid during retrograde metamorphism. The appearance of Di + All + Amp symplectites around omphacite indicated a fluid absent condition. Phengite decomposed into the assefuhlage of muscovites+biotites and a little K-feldspar + quartz. Amphibole changed from magnesiokatophorite to pargasite, Which indicawd a transform from calcic-sodic to calcic amphibole. ... |
| نوع الوثيقة: |
journal/newspaper |
| اللغة: |
Chinese |
| تدمد: |
1000-0569 |
| Relation: |
岩石学报.2009,(09),2247-2259.; 927999; http://hdl.handle.net/20.500.11897/50141; WOS:000270044500017 |
| الاتاحة: |
https://hdl.handle.net/20.500.11897/50141 |
| رقم الانضمام: |
edsbas.32110BC2 |
| قاعدة البيانات: |
BASE |