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碧口地块位于扬子板块西北缘，由北部变质沉积岩系及南部变质中基性火山岩组成。碧口地块北部岩石变质为千枚岩、云母石英片岩，南部岩石经历绿片岩蓝片岩相变质。由于对碧口地块变形特征及区域变质作用分析深度不够，缺少精确的变质时间限定，碧口地块变质杂岩系性质、区域变质年代及其大地构造属性始终处于争议之中，导致对西秦岭和龙门山造山过程的认识产生分歧。通过详细区域构造解析，将碧口地块划分为3期变形：D1期以紧闭褶皱、面理S1及矿物线理L1为特征；D2期形成于由北向南的正断拆离作用，显示韧性变形特征，D2期变形改造先期逆断层并形成半地堑盆地；D3期形成于喜山期逆冲走滑运动，以脆性变形为主要特征。本研究获得碧口变质岩中变形脉锆石UPb年龄（227.2±6.2） Ma，碧口地块已报道的D1期变形后期侵入体年龄为226~215 Ma，从而限定D1期碧口区域变质变形年龄为约220 Ma。因此推测D1期形成于三叠纪末华南华北板块碰撞，碧口地块区域变质主要形成于这一时期的俯冲碰撞作用；D2与D3期则与青藏高原的东向扩张有关。
Bikou block is located in the northwestern margin of the Yangtze plate, composed of northern metamorphic sedimentary rock and southern metamorphic basement volcanic rocks. The rocks in the northern part of the Bikou block have been metamorphosed into phyllite and mica quartz schist, while the southern rocks have undergone the metamorphism of the green schist and blue schist. Due to the lack of accurate analysis of the deformation characteristics and regional metamorphism of the Bikou block and the lack of precise metamorphic time limits, the nature of the metamorphic complex, the metamorphic age of the area and its tectonic attribute of the Bikou block have always been in dispute. As a result, The differences between the Qinling Mountains and the Longmen Mountains in the process of orogenic processes. By detailed regional tectonic analysis, the Bikou block is divided into three stages of deformation: the D1 stage is characterized by tight folds, surface S1 and mineral lineage L1; D2 stage is formed by the normal-decadal detachment from north to south, Ductile deformation characteristics, deformation of the D2 period reverse the fault and the formation of a half-graben basin; D3 period formed in the Himalayan thrust strike-slip movement, the brittle deformation as the main feature. In this study, the U-Pb dating of metamorphic rocks in Bikou was obtained (227.2 ± 6.2 Ma). The late stage of D1 deformation intrusion reported by Bikou Block has an age of 226-215 Ma, Metamorphosis deformation age of about 220 Ma. Therefore, it is speculated that Stage D1 was formed during the collision of the North China Plate in the southern part of Triassic. The metamorphism of the Bikou block formed mainly during this period of subduction collision. The D2 and D3 phases were related to the eastward expansion of the Tibetan Plateau.