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本区先经历了区域动力热流变质作用，后经受动力变质作用的迭加，主要表现为韧性剪切变质带的广泛出现．杂岩体呈现着良好的递增变质带，从低变质级到高变质级依次为黑云母带→石榴石带→十字石带→兰晶石带→矽线石带，属于中压变质相系．根据矿物化学研究了单斜辉石、角门石、石榴石、黑云母、白云母、斜长石等变质矿物的特征。利用平衡变质矿物组合的温度压力计定量计算了星子群杂岩的变质温压条件，其范围是温度４２０℃～５７０℃，压力５．３～５．７ＰＰａ．研究表明星子变质核杂岩组成一个自外围向中心变质温度逐渐升高的热穹窿，成为江南地区少有的递增变质带．显示出江南古陆在广泛分布的前寒武纪浅变质岩系之下存在着由中深变质岩系组成的变质基底，属于早元古亩成熟陆壳．
The region experienced thermal dynamic metamorphism of the region first and then experienced superposition of dynamic metamorphism, which is mainly manifested by the widespread occurrence of ductile shear metamorphic belt. The complex bodies show a good increasing metamorphic belt, ranging from low metamorphic grade to high metamorphic grade, followed by biotite band → garnet belt → cross belt → blue spinel belt → sillimanite belt, belonging to the medium-pressure metamorphic facies. The characteristics of metamorphic minerals such as clinopyroxene, corner stone, garnet, biotite, muscovite and plagioclase have been studied based on mineral chemistry. The metamorphic temperature and pressure conditions of the Xingzi Group Complex were quantitatively calculated by using the temperature and pressure gauge of the balanced metamorphic mineral assemblage. The range of the temperature and the pressure ranged from 420 ℃ to 570 ℃ and the pressure was 5.3 ~ 5.7Pa. The study shows that the Xingzi metamorphic core complex forms a thermal dome with a gradually increasing metamorphic temperature from the periphery to the center, becoming a rare increasing metamorphic belt in the southern part of the Yangtze River. It shows that there exists a metamorphic basement composed of middle-deep metamorphic rocks beneath the widely distributed Precambrian epimetamorphic rocks in the Jiangnan ancient land, which belongs to the early Proterozoic mature continental crust.