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大陆伸展构造体系具有两种端元特征,即裂谷环境和强烈的伸展地体。这些不同的构造样式形成并被记录在不同的伸展盆地中,陆内的裂陷作用通常出现在具有正常地壳厚度和热均衡的地区(如东非裂谷和贝加尔湖)。裂陷沉降普遍伴随着碱性-拉斑玄武岩岩浆活动,具有大倾角的边界断层(45°~60°),小于1mm/a的滑移速率,以及小幅度伸展特征(1%~25%)。在典型情况下,其总的伸展作用时间大于25Ma。这种裂陷盆地的断裂,以及控制沉积特征的内部低级序盆地单元几何形态是一种具有高角度边界断层的半地堑。其相应盆地深陷,而且其沉积作用以盆地轴向或来自上盘的径向物源占优势,不均衡沉降导致沉积中心沿活动性盆地边界陡崖分布。强烈伸展的大陆地体[如科罗拉多(ColoradoRiver)伸展走廊和赛克莱岛(Cyclade)]代表了与之不同的另一伸展构造端元。这类盆地形成于弧后地区,那里的地壳在伸展作用之前一直经受着明显的增厚过程,而且已变形的地壳往往再度活化。与这类伸展作用相伴生的火山岩县有典型的钙碱性,并且达到其总伸展量的80%~90%,所需要的时间甚小(小于10Ma)。这类盆地的边界断层往往呈低角度(15°~25°),并同时具有较高的滑移速率(通常大于2mm/a)和体积伸展量(通常大于100%)
The continental extensional tectonic system has two kinds of endmember characteristics, that is, the rift environment and the intense extension of the earth. These different tectonic patterns are formed and recorded in different extensional basins, and intracontinental rifting usually occurs in areas with normal crustal thickness and thermal balance (eg, the East African Rift and Lake Baikal). The rift subsidence is generally accompanied by alkaline-tholeiitic magmatic activity, large-angle boundary faults (45 ° -60 °), slip velocities less than 1 mm / a, and small extensional features (1% -25%) . Under typical conditions, its total stretching time is greater than 25Ma. The ruptures of such rifted basins, as well as the internal low-order basins unit geometry that control sedimentary features, are semi-graben with high-angle boundary faults. The corresponding basins are deep-seated, and their sedimentary functions are dominated by the radial source of the basins in the basin or from the upper plate. The unbalanced sedimentation leads to the distribution of sedimentary centers along the cliffs of the active basin boundary. Strongly extended continental bodies [such as the ColoradoRiver Extension Corridor and Cyclade] represent yet another stretch of structural tectonic elements. Such basins are formed in the backarc area where the crust has undergone significant thickening prior to extension and the deformed crust often reactivates. Volcanic rocks associated with this type of extension have typical calc-alkaline properties and reach 80% to 90% of their total extension, requiring very little time (less than 10 Ma). The boundary faults in these basins tend to be low-angle (15 ° -25 °) and have high slip rates (typically> 2 mm / a) and volumetric stretch (typically> 100%)