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埃达克质火成岩在中国东部,包括燕山带是很常见的,一般认为它们是下地壳不均匀的镁铁质岩石及/或富集的上地幔岩石在高压(≥1.5 GPa)下部分熔融的结果。在燕山带内埃达克岩浆的形成有一个很长的时间(约190～80 Ma),然而岩浆活动的峰期却与约170～130 Ma间有基底岩石卷入的陆壳收缩期相一致。尽管埃达克质岩浆活动的历史很长,但那种把岩浆活动与岩石圈的拆沉效应相联系的模式似乎是不适当的。在该带内,埃达克质与非埃达克质岩浆活动有一部分是同时的,而且在地理分布上也是相间的,这说明了在下地壳和上地幔岩石的部分熔融中成分是相当不均匀的。侏罗纪及白垩纪熔融作用的热源应当是与古太平洋板块俯冲相关的中生代板底垫托的玄武岩浆。除了局部例外,在燕山带,埃达克质岩浆活动的终结和碱性岩浆活动的开始约在130～120 Ma,在此时期收缩作用使东亚大达200万km~2以上的地区发生了NW—SE向的区域性伸展作用。强烈的地壳伸展仅局限于华北克拉通北缘分布的少数几个变质核杂岩中。陆壳的伸展减薄合理地解释了130～120 Ma间发生高压埃达克质熔融条件的终结,尽管还有局部年轻的埃达克火山活动(约120～80Ma)可以在伸展规模有限而厚的地壳依然存在的地区继续出现。燕山区早白垩世的碱性侵入体中的锆石不存在前寒武纪?
Adakitic igneous rocks are common in eastern China, including the Yanshan belt, and are generally considered to be partially melted under high pressure (≥1.5 GPa) for mafic rocks and / or enriched upper mantle rocks with heterogeneous lower crust result. The formation of the Adak magma within the Yanshan zone lasted for a long time (about 190-80 Ma), whereas the peak period of magmatism coincided with that of the continental crust with basement rocks ca. 170-130 Ma . Although the history of the adakitic magmatism is long, it seems inappropriate to model the association of magmatism with the delamination effect of the lithosphere. Within this zone, some of the adakitic and non-adakitic magmatic activities are simultaneous and geographically interdependent, indicating that the composition of the rocks in the lower crust and the upper mantle is rather heterogeneous in composition of. The heat source for the Jurassic and Cretaceous melting should be Mesozoic mats of Mesozoic paddyplants associated with the subduction of the Paleo-Pacific plate. With the exception of local exceptions, in the Yanshan belt, the onset of adakitic magmatic activity and the onset of alkaline magmatic activity ranged from 130 to 120 Ma, during which time the contraction caused a NW of over 2 million km 2 in East Asia Regional extension of the SE. Strong crustal extension is limited to a few metamorphic core complexes distributed in the northern margin of North China Craton. The extension and thinning of the continental crust rationally explained the end of high-pressure adakitic melting conditions between 130-120 Ma, although there are also some young adakitic volcanic activities (about 120- 80 Ma) that can be extended and limited in scale Areas where the crust still exists continue to appear. There is no Precambrian zircon in the Early Cretaceous alkaline intrusions in the Yanshan area?