Abstract: Jianping metamorphic Complex, the lowest section of the Archaean terrain from the Western Liaoning Province, is composed of discontinuous supra-crustal rocks, an amount of TTG rocks and some other plutons. Single zircon ages for TTG series and some other plutons obtained by the Pb evaporation method show that intrusion of TTG series began at 2521Ma and reached a peak at about 2500Ma. This was followed by high-grade metamorphic and deformed event, transforming the above assemblages into graulites, charnockites and enderbites some 2483-2490Ma. The intrusion of post tectonic granites in 2472Ma associated with regional retrogression ends the evolution of this area. A likely tectonic setting in which the Jianping metamorphic Complex was formed is an active continental margin that is involved in continental collision and crustal thickening shortly after its formation.

Key words: Zircon age, TTG suite, Jianping metamorphic Complex, western Liaoning Province

摘要： 建平变质杂岩是辽宁西都太古代最下部地质单元，是华北地台北缘麻粒岩相带的重要组成部分。它由少量连续性很差的表壳岩及大量的TTG岩石和其他深成侵入体组成。采用单颗粒锆石Pb蒸发法对其中的TTG岩石及其他侵入岩进行了年龄测定。结果表明：本区TTG花岗质岩浆约于2521Ma开始活动，并于2500Ma左右达到高峰，形成了大量的TTG质侵入体(包括部分喷出岩)；紧随其后，本区发生强烈的高级变质变形事件，此事件约于2483～2490Ma达到高峰，使得已形成的岩石变成麻粒岩、紫苏花岗岩及斜长紫苏花岗岩等；于2472Ma就位的与退变质作用有关的后构造花岗岩标志着本区高级变质变形事件的结束。据此，可以推测建平变质杂岩可能形成于陆块形成后不久即发生大陆碰撞和地壳加厚的晚太古活动大陆边缘的环境中。

关键词: 锆石年龄, TTG岩石, 建平变质杂岩, 辽西