CAJ | 학술논문

伸展系数是张性盆地运动学分析的关键参数之一,对其计算可采用定义法、平衡剖面法和构造热演化模拟法.该文介绍了用这3种方法求取伸展系数的原理,并对苏北盆地晚白垩世伸展拉张以来的伸展系数进行了计算,综合分析后认为:定义法在获取了区域地壳厚度的基础上便能勾画出平面上的伸展系数分布图,便于区域比较,但对多期拉张的盆地而言,难以准确计算各期次具体的伸展系数;平衡剖面法能够恢复多期拉张的伸展系数,但因其自身难以做到真正的平衡,且没有考虑到地壳下部的热沉降,因而计算结果常需辅以其他手段加以对比分析;构造热演化模拟法在研究盆地构造形变的同时,综合考虑了深部构造热沉降,并且能读取不同时期任一点的地壳厚度,因而较定义法和平衡剖面法更为精确和方便.
신전계수시장성분지운동학분석적관건삼수지일,대기계산가채용정의법、평형부면법화구조열연화모의법.해문개소료용저3충방법구취신전계수적원리,병대소북분지만백성세신전랍장이래적신전계수진행료계산,종합분석후인위:정의법재획취료구역지각후도적기출상편능구화출평면상적신전계수분포도,편우구역비교,단대다기랍장적분지이언,난이준학계산각기차구체적신전계수;평형부면법능구회복다기랍장적신전계수,단인기자신난이주도진정적평형,차몰유고필도지각하부적열침강,인이계산결과상수보이기타수단가이대비분석;구조열연화모의법재연구분지구조형변적동시,종합고필료심부구조열침강,병차능독취불동시기임일점적지각후도,인이교정의법화평형부면법경위정학화방편.
@@@@Basin stretching factor is a key parameter of extensional basin study and it was normally calculated from definition, balanced cross-section and tectonic -thermal modeling. The principles of traditional methods were briefly introduced in this paper, and the stretching factor of extension rifting in the Northern Jiangsu Basin after the late Cretaceous was also calculated. Basin stretching factor can be acquired by definition based on crust thickness, and it can be easily compared in different regions. For multi-phases stretch basin, it is hard to deter-mine the stretching factor in different phases. The balanced cross-section method can reconstruct the basin stretching factor of multi-phases stretch, but the real equilibrium is actually hard to reach while the tectonic-thermal sub-sidence of the lower crust is not taken into consideration, thus other methods are needed for better comparison. The tectonic-thermal modeling method considers tectonic-thermal subsidence, and can also read curst thickness in any period. As a result, the tectonic-thermal modeling method is regarded as the more precise and convenient approach to calculate basin stretching factor.