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通过大量岩相学和矿物化学研究,在北祁连和北阿尔金高压低温变质带中发现有含硬柱石的榴辉岩.硬柱石包裹在石榴子石中,并与绿辉石和多硅白云母共生.应用Grt-Omp-Phe矿物压力计和Grt-Omp矿物温度计,获得北祁连榴辉岩中含硬柱石共生组合的变质条件为420~510℃和2.1~2.4GPa,估算的温压条件处于硬柱石榴辉岩相稳定区域,据此推断榴辉岩形成的地温梯度为6~8℃/km,属于典型冷洋壳俯冲带变质产物.北祁连和北阿尔金均产出含硬柱石的榴辉岩,进一步证明了北阿尔金高压/低温变质带可能是北祁连高压/低温变质带的西延部分.
Through a large number of petrography and mineral chemistry research, there are eclogite-bearing eclogites found in the high-pressure and low-temperature metamorphic belt in the North Qilian and North Altyn Tales, which are surrounded by garnets and mixed with omphacite and polycrystalline silica Parental symbiosis.Using the Grt-Omp-Phe mineral pressure gauge and the Grt-Omp mineral thermometer, the metamorphic conditions for the inclusion of hard-pillared coals in the North Qilian eclogites were 420-510 ℃ and 2.1-2.4GPa, and the estimated conditions of temperature and pressure were Hard pluton facies stable area, infer that the eclogite formed geothermal gradient of 6 ~ 8 ℃ / km, belong to the typical cold oceanic crust subduction metamorphism products.North Qilian and North Altyn included the production of hard-feldspar Eclogite, further evidence that the North Altyn high pressure / low temperature metamorphic belt may be the North Qilian high pressure / low temperature metamorphic belt westward extension.