地质学报
地質學報
지질학보
ACTA GEOLOGICA SINICA
2014年
2期
285-298
,共14页
袁桂邦%胥勤勉%王艳%杨吉龙%秦雅飞%杜东
袁桂邦%胥勤勉%王豔%楊吉龍%秦雅飛%杜東
원계방%서근면%왕염%양길룡%진아비%두동
渤海湾北岸%磁性地层%沉积速率%构造运动
渤海灣北岸%磁性地層%沉積速率%構造運動
발해만북안%자성지층%침적속솔%구조운동
the northern coast of Bohai bay%magnetostratigraphy%sedimentation rate%tectonics
对渤海湾北岸孔深600m的Bg10孔进行了详细的沉积学和古地磁研究,划分了39个沉积单元;基于516个样品(60个交变样品,456个热退样品)分离出的特征剩磁,建立了钻孔的磁性地层,并与标准极性年表相对比,确定正极性 N1、N2、N3、N4、N5、N6和 N7分别对应 C1n、C1r.1n、C2n、C2r.1n、C2An.1n、C2An.2n 和C2An.3n,R1、R2、R3、R4、R5和R6分别对应C1r.1r、C1r.2r+C1r.3r、C2r.1r、C2r.2r、C2An.1r和C2An.2r。钻孔B/M界限埋深162.3m,M/G界限埋深为475.8m,钻孔底部位于C2An.3n内,其年龄应小于3.596Ma。Bg10孔包括3个沉积阶段:Ⅰ阶段为3.3~3.6Ma,沉积速率略大于130m/Ma,为构造活动期,唐县期夷平面结束后,盆地沉降和山体隆升的差异增大,并与西部地区的青藏运动A 幕相对应;Ⅱ阶段为1.9~3.3Ma,沉积速率为112m/Ma,为盆地的填充过程,气候变化控制沉积过程,但沧县隆起和黄骅坳陷之间沉降仍有差异。Ⅲ阶段为0~1.9 Ma ,沉积速率为202m/Ma,约在1.0~1.2Ma发生一期构造活动,与西部地区的昆黄运动时代大体相当。1.0Ma以来,沉积过程受构造和气候变化双重影响,沧县隆起和黄骅坳陷之间仍有差异沉降。唐山-邢台断裂带可能在1.9 Ma之后活动性增强,并和张家口-蓬莱断裂带在沧县隆起上的交汇区域形成一个次级凹陷。
對渤海灣北岸孔深600m的Bg10孔進行瞭詳細的沉積學和古地磁研究,劃分瞭39箇沉積單元;基于516箇樣品(60箇交變樣品,456箇熱退樣品)分離齣的特徵剩磁,建立瞭鑽孔的磁性地層,併與標準極性年錶相對比,確定正極性 N1、N2、N3、N4、N5、N6和 N7分彆對應 C1n、C1r.1n、C2n、C2r.1n、C2An.1n、C2An.2n 和C2An.3n,R1、R2、R3、R4、R5和R6分彆對應C1r.1r、C1r.2r+C1r.3r、C2r.1r、C2r.2r、C2An.1r和C2An.2r。鑽孔B/M界限埋深162.3m,M/G界限埋深為475.8m,鑽孔底部位于C2An.3n內,其年齡應小于3.596Ma。Bg10孔包括3箇沉積階段:Ⅰ階段為3.3~3.6Ma,沉積速率略大于130m/Ma,為構造活動期,唐縣期夷平麵結束後,盆地沉降和山體隆升的差異增大,併與西部地區的青藏運動A 幕相對應;Ⅱ階段為1.9~3.3Ma,沉積速率為112m/Ma,為盆地的填充過程,氣候變化控製沉積過程,但滄縣隆起和黃驊坳陷之間沉降仍有差異。Ⅲ階段為0~1.9 Ma ,沉積速率為202m/Ma,約在1.0~1.2Ma髮生一期構造活動,與西部地區的昆黃運動時代大體相噹。1.0Ma以來,沉積過程受構造和氣候變化雙重影響,滄縣隆起和黃驊坳陷之間仍有差異沉降。唐山-邢檯斷裂帶可能在1.9 Ma之後活動性增彊,併和張傢口-蓬萊斷裂帶在滄縣隆起上的交彙區域形成一箇次級凹陷。
대발해만북안공심600m적Bg10공진행료상세적침적학화고지자연구,화분료39개침적단원;기우516개양품(60개교변양품,456개열퇴양품)분리출적특정잉자,건립료찬공적자성지층,병여표준겁성년표상대비,학정정겁성 N1、N2、N3、N4、N5、N6화 N7분별대응 C1n、C1r.1n、C2n、C2r.1n、C2An.1n、C2An.2n 화C2An.3n,R1、R2、R3、R4、R5화R6분별대응C1r.1r、C1r.2r+C1r.3r、C2r.1r、C2r.2r、C2An.1r화C2An.2r。찬공B/M계한매심162.3m,M/G계한매심위475.8m,찬공저부위우C2An.3n내,기년령응소우3.596Ma。Bg10공포괄3개침적계단:Ⅰ계단위3.3~3.6Ma,침적속솔략대우130m/Ma,위구조활동기,당현기이평면결속후,분지침강화산체륭승적차이증대,병여서부지구적청장운동A 막상대응;Ⅱ계단위1.9~3.3Ma,침적속솔위112m/Ma,위분지적전충과정,기후변화공제침적과정,단창현륭기화황화요함지간침강잉유차이。Ⅲ계단위0~1.9 Ma ,침적속솔위202m/Ma,약재1.0~1.2Ma발생일기구조활동,여서부지구적곤황운동시대대체상당。1.0Ma이래,침적과정수구조화기후변화쌍중영향,창현륭기화황화요함지간잉유차이침강。당산-형태단렬대가능재1.9 Ma지후활동성증강,병화장가구-봉래단렬대재창현륭기상적교회구역형성일개차급요함。
Based on detailedsedimentological and magnetostratigraphic study of Bg10 borehole (600m)in the northern coast of Bohai bay,there are 39 sedimentary units and 8 normal magnetozones and 7 reverse magnetozones according on 516 specimens (456 specimens subjected to progressive thermal demagnetization and 60 specimens subjected to alternating field demagnetization ) calculated the characteristic remanent magnetization (ChRM)directions.Thinking about sedimentation rates of different magnetozones,Comparing to the geomagnetic polarity timescale (Cande et al.,1995;Gradstein et al., 2004),the normal magnetozones N1,N2,N3,N4,N5,N6 and N7 can be correlated with C1n,C1r.1n, C2n,C2r.1n,C2An.1n,C2An.2n and C2An.3n,the reverse magnetozones R1,R2,R3,R4,R5 and R6 can be collated with C1r.1r,C1r.2r+C1r.3r,C2r.1r,C2r.2r,C2An.1r and C2An.2r.The B-M and M-G boundary of borehole are located in 162.3m and 475.8m respectively,and the age of the bottom is less than 3.596Ma.There have been three sedimentation phases.The Ⅰphase which age was 3.3~3.5Ma and sedimentation rate was more than 130m/Ma was tectonic active period and could be correlated with the phase A of Qingzang movement.The Ⅱ phase which age was 1 .9~3 .3 Ma and sedimentation rate was 112m/Ma was tectonic silent period,and the sedimentary process could be controlled by climate change, but there had the different subsidence rate between Huanghua depression and Cangxian uplift.There was a tectonic active period aged 1 .0~1 .2 Ma in the Ⅲ phase which age was 0~1 .9 Ma and sedimentation rate was 202m/Ma,which could be correlated with Kunhuang movement.The sedimentary process should be controlled by tectonics and climate and the subsidence rates of Huanghua depression and Cangxian uplift have been different since 1.0Ma.Tangshan-Xingtai fault could be formed at 1.9Ma,and has developed one sag at the intersection with Zhangjiakou-Penglai fault.