豫西地区中新生代差异构造变形

Mesozoic-Cenozoic different tectonic deformation in western Henan

受华北板块与秦岭造山带的构造联合、太平洋构造域的叠合作用,豫西地区中新生代构造边界复杂,发生多期次、多性质构造演化,致使构造变形时空差异显著。为揭示中新生代构造变形差异,通过构造精细解析以及平衡剖面恢复以阐明水平方向构造差异,并基于埋藏史模拟,展示垂向差异沉积与隆升剥露。分析显示,以中燕山期为关键构造变革期,豫西地区垂直方向构造变形形成两个构造层:印支-中燕山期挤压构造层与晚燕山-喜马拉雅期伸展构造层,并根据变形方式与变形强度,划分出南缘冲断-伸展构造带、渑池-伊川-汝州逆冲推覆-伸展构造带、北缘断块区、嵩山北斜坡-断陷区、嵩山-箕山隆起区等5个构造带。受制于水平构造变形差异,垂向上相应存在强烈隆升-断陷沉积、中等隆升-断陷沉积、中等隆升-断块剥蚀、轻微隆升-断块剥蚀4类沉积与隆升模式。

Due to the tectonic association of North China plate and Qinling orogenic belt,and the superposition of Pacific tectonic domain,the Mesozoic-Cenozoic in the boundary of West Henan structures are complex,as multi-period and multi-tectonic evolutions lead to the deformed structure of significant times and space differences.In order to reveal tectonic deformation difference in Mesozoic and Cenozoic,the vertical differential deposition and uplift exfoliation are demonstrated by balanced section restoration and fine structural analysis to clarify the horizontal structural difference.The analysis reveals that the central Yanshanian period is the key tectonic transformation period,and the horizontal structural deformation in West Henan formed two structure layers:the Indosinian to the Middle Yanshanian compressional tectonic layer and the late Yanshanian Himalayan extensional tectonic one.According to the deformation intensity and deformation mode,there are five structural zones:the southern margin thrust-extensional structural belt,Mianchi-Yichuan-Ruzhou thrust-nappe-extensional belt,the north margin fault block area,the north Songshan slope-fault depression area,and the Songshan-Jishan uplift zone.According to the horizontal tectonic deformation difference,four modes of uplift models and deposition are built.There are four types of uplift models and deposition:medium uplift-fault block denudation,slight uplift-fault block denudation and strong uplift-fault depression deposit,slight uplift-fault depression deposit.