CAJ | 학술논문

针对青东凹陷勘探程度较低、新生代地层发育特征尚不明晰的现状,从岩性、测井、地震、古生物化石等资料入手,结合区域地质背景,对凹陷新生代地层进行了构造层和岩石地层的多重划分,将其划分为古近系和新近系一第四系两个构造层,其中古近系构造层自下而上发育孔店组、沙四段、沙三段、沙二段,地层发育特征与东营凹陷相似,但垂向序列不完整,缺失沙一段和东营组.在此基础上结合钻井标定和地震剖面的解释,重点绘制了古近系四个构造亚层的残留地层等厚图,并对其展布特征进行了分析.结果表明,各构造亚层残留地层在厚度和展布方向上变化较大,且具有一定的规律性,体现了不同地质时期盆地沉积充填和构造演化的差异性.最后对青东凹陷缺失沙一段一东营组的可能原因进行了初步讨论,认为新生代地幔柱高点由渤海湾盆地南部迁移到渤海海域可能造成该地区在古近纪末期未接受沉积,而据垦东地区北部的物源在沙一一东营期来自南部也可推测该时期青东凹陷已抬升遭受剥蚀.
침대청동요함감탐정도교저、신생대지층발육특정상불명석적현상,종암성、측정、지진、고생물화석등자료입수,결합구역지질배경,대요함신생대지층진행료구조층화암석지층적다중화분,장기화분위고근계화신근계일제사계량개구조층,기중고근계구조층자하이상발육공점조、사사단、사삼단、사이단,지층발육특정여동영요함상사,단수향서렬불완정,결실사일단화동영조.재차기출상결합찬정표정화지진부면적해석,중점회제료고근계사개구조아층적잔류지층등후도,병대기전포특정진행료분석.결과표명,각구조아층잔류지층재후도화전포방향상변화교대,차구유일정적규률성,체현료불동지질시기분지침적충전화구조연화적차이성.최후대청동요함결실사일단일동영조적가능원인진행료초보토론,인위신생대지만주고점유발해만분지남부천이도발해해역가능조성해지구재고근기말기미접수침적,이거은동지구북부적물원재사일일동영기래자남부야가추측해시기청동요함이태승조수박식.
The present authors made multiple stratigraphic division of tectonic layers and lithostratigraphic study for the Cenozoic of the Qingdong Sag using the materials of lithology,well logging,seismdata,palaeobiology and regional geology.The Cenozoic in the studv area can be divided into two tectonic layers:the Paleogene and the Neogene to Quaternary.The Paleogene comprises Kongdian Formation,Sha-4 Member,Sha-3 Member,Sha-2 Member from bottom to top and without Sha-1 Memher and Dongying Formation.The development characteristics of strata in the Qingdong Sag are similar to the Dongying Sag except the incompleteness in vertical stratigraphie succession.Combining with drilling calibration and interpretation of seismic cross sections,remnant strata thickness isograms of four tectonic sub-layers in the Paleogene were drawn and the distribution characteristics of these strata were analyzed. The analysis shows that the thickness and distribution orientation of the remnant strata changed greatly and regularly which reflects the differences of basin sedimentary filling and tectonic evolution in different geological times. The possible causes of ahsence of Sha-1 Member and Dongying Formation in the Qingdong Sag were preliminarily discussed: The migration of the mantle plume high spot from the southem part of the Bohai Bay Basin towards the Bohai Sea in the Cenozoic might result in ahsence of sedimentation in this area in the late Paleogene. It could be proposed that the Qingdong Sag was uplifted and suhjected to erosion in the period of Sha-1 Member and Dongying Formation according to the fact that the material source in the northem part of the Kendong area was derived from the southem part during this period.