论文部分内容阅读
二连盆地白音查干凹陷下白垩统钻井取芯中发现有变形和开裂两类特殊地质现象。同沉积塑性变形和碟状构造属于变形,微断层、网状裂缝、砂岩岩脉、角砾岩为开裂。这些地质现象具有震积岩的特征,多由外界振动引发。变形多发生在沉积物未固结—半固结阶段,开裂发生在沉积物成岩后。微断层、网状裂缝和砂岩岩脉形成于拉张应力作用下。这些特殊地质现象多出现在腾格尔组和都红木组一段,而且从下往上,由开裂向变形演化。这与当时区域伸展构造背景和地震、构造活动有关,地震、构造活动较为强烈时容易产生开裂现象,地震、构造活动较为微弱时容易产生变形。
Two special geological phenomena of deformation and cracking are found in the core-drilling of the Lower Cretaceous in the Baiyinchagan Sag, Erlian Basin. The same plastic deformation and disc-shaped structure belong to deformation, micro-faults, reticular fractures, sandstone dikes, breccias for cracking. These geological phenomena have the characteristics of seismites, mostly caused by external vibration. Deformation occurred in the sediment unconsolidated - semi-consolidation stage, cracking occurred in sediment after diagenesis. Microfacies, reticular fractures and sandstone dikes are formed under tensile stress. These special geological phenomena mostly occur in the Tengger group and in the mahogany group, and from bottom to top, from cracking to deformation evolution. This is related to the regional tectonic extensional structure and the earthquake and tectonic activities at the time, and the cracking and tectonism are prone to occur when the earthquakes and tectonic activities are intense. The earthquakes and tectonic activities tend to deform when the tectonic activities are relatively weak.