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1.
福州盆地埋藏晚第四纪沉积地层划分   总被引:1,自引:0,他引:1       下载免费PDF全文
文中以14个钻孔地层编录为基础,结合前人研究资料,初步总结了福州盆地埋藏第四纪地层的沉积特征。福州盆地沉积始于晚更新世中期(约56.5ka BP),由砾石、砂、黏土、淤泥组成,总体表现为从下至上粒度变细的沉积序列,地层岩性横向变化较大;盆地内发育3层淤泥,第1,2层淤泥发育于全新世中晚期,时代为1.44~7.86ka BP,为“长乐海侵”的产物,第3层淤泥发育于晚更新世晚期,时代约为44~20ka BP,为“福州海侵”的产物;盆地埋藏晚第四纪地层可划分为上更新统和全新统,分为4个组,从老至新分别为龙海组(Q3pl)、东山组(Qhd)、长乐组(Qhc)与江田组(Qhj)。龙海组归属上更新统,划分为3段,其余3个组归属全新统  相似文献   

2.
鹤庆盆地是青藏滇缅印尼巨型歹字型构造与川滇经向构造带复合部位的一个山间盆地,它的形成与南北向断裂密切有关,东西向冲断层及基性岩脉也相当发育。在晚近地质时期,它们都在强烈活动,因此,本区是构造的强化地带。 笔者在开展滇西北红河断裂带新活动的研究工作中,发现了鹤庆盆地一起古地震事件,古地震遗迹保留在盆地西部山麓的缓坡带上,主要表现为: 1.地震断层(照1、2):在南半榜洗马池水库北侧及鹤云寺西缓山坡上均有发现。两处均由中更新世及晚更新世河湖相亚粘土、亚砂土、中—细砂层及砂砾石层组成。断层断开了最新的晚更新世地层。在剖面  相似文献   

3.
罗云山山前断裂带阶地调查研究及其构造意义   总被引:2,自引:1,他引:1  
罗云山山前断裂带位于山西临汾盆地西侧,控制着盆地的西界.对罗云山山前断裂带8条冲沟的阶地测量资料的研究表明:该断裂带冲沟发育T1~T5五级阶地.T1 阶地拔沟3m左右,T2 阶地拔沟8~10m,T3 阶地拔沟20m左右,T4 阶地拔沟30m左右,T5 阶地拔沟40~50m.阶地测年数据及断错地貌调查表明:罗云山山前断裂带在晚第四纪以来有过多次活动.晚更新世中晚期以来阶地的抬升速率为0.41 mm/a,全新世以来抬升速率为0.75mm/a.罗云山山前断裂带冲沟阶地从晚更新世中晚期到全新世抬升速率有逐渐增大的趋势,反映该断裂带自晚第四纪以来构造抬升作用逐渐加强,这与临汾盆地从晚更新世晚期到全新世沉降速率也有增大的趋势比较一致.  相似文献   

4.
尹功明  高钧成 《地震地质》1996,18(4):358-360
北京延庆盆地是一个小型的新生代断陷盆地,第四纪时期曾发育多期湖相层,而对这些湖相层的时代有着不同的认识。应用电子自旋共振(ESR)测年方法对采自北京延庆盆地地表湖相沉积层的6个钙质样品作了年龄测定,结果表明,延庆盆地地表出露的较老湖相层的时代属于中更新世  相似文献   

5.
系统解读了山西晚新生代古地理古环境特征,结合近年来笔者的研究给出了各时代古地理分布图。上新世的构造运动和地理环境演化奠定了现今地理环境的基础,尤其是奠定了现今地貌、水系的轮廓。早更新世地理环境最突出的事件是各断陷盆地中的湖泊广泛发育,出现淹没整个盆地的大湖景观;黄土广泛发育,但主要堆积于吕梁山分水岭以西;黄河在早更新世已经发育,并形成5级阶地。中更新世古地理的主要事件是湖泊的衰退,黄土堆积范围几乎遍布全省,厚可达200 m左右,表明气候较早更新世进一步明显变干。晚更新世古地理的主要特征是湖泊消亡,其地理环境更加接近现代。最后,笔者预测未来山西断陷盆地将持续断陷,各盆地内水系不再外流,形成贯通的大湖景观,类似现今的贝加尔湖。  相似文献   

6.
罗云山山前断裂中段土门-贾朱村晚第四纪断错地貌特征   总被引:2,自引:0,他引:2  
罗云山山前断裂位于山西临汾盆地西侧,控制着盆地的西界。通过对该断裂1∶ 5万地质填图、对河流冲沟阶地及山前断错地貌的调查,介绍了罗云山山前断裂中段土门-贾朱村晚第四纪断错地貌特征。罗云山山前发育D1、D2、D3 等3 级洪积扇,罗云山山前断裂上升盘冲沟发育T1 ~ T5 等5 级阶地。D1 洪积扇与T1、T2 阶地形成于全新世早中期;D2 洪积扇与T3 阶地形成于晚更新世中晚期;D3 洪积扇与T4、T5 阶地形成于中更新世中晚期。罗云山山前断裂中段不同部位断错地貌特征差异较大,D1 洪积扇的断错在席坊沟一带断距约2. 9m;在金殿镇峪口村南西山前断错约3m。D2 洪积扇的断错在土门镇南西堡子村约2. 5m;在杨家庄村西山前断错约4m;在景村西山前断错约6m;在襄陵镇浪泉沟南西侧山前断错约7. 7m。罗云山山前断裂中段山前断错地貌明显,其最新活动时代为全新世。其中,土门段最新活动时代为全新世早期,龙祠段最新活动时代为全新世中晚期。罗云山山前断裂中段晚更新世中晚期以来活动速率为0. 18~ 0. 54mm / a,由北向南活动呈增强趋势;全新世早中期以来活动速率为0. 4 ~ 0. 9mm / a,断裂活动主要集中于席坊沟-峪口一带。罗云山山前断裂中段从晚更新世中晚期到全新世活动速率有增大的趋势,这与该断裂上升盘冲沟阶地从晚更新世中晚期到全新世抬升速率有增大的趋势以及临汾盆地从晚更新世晚期到全新世沉降速率也有增大的趋势具有较好的一致性。  相似文献   

7.
依据盆地第四系沉积特点,结合高密度、CSAMT(可控源音频大地电磁)、浅层地震及钻孔磁化率探测结果,剖析隐伏断裂在盆地的几何形态特征及活动性。结果表明:延矾盆地北缘断裂南段(隐伏端)沿窑湾村-桑园南堡村展布,由2条SE倾的阶梯状正断层组成,切割第四系上更新统泥河湾组地层,上断点埋深40m,断距约35m;断裂在早-中更新世有过活动,晚更新世断裂活动性较强,全新世以后断裂活动性具逐渐减弱趋势;施庄断裂北隐伏段经施庄向SE145°方向展布,切割第四系泥河湾组地层,上断点埋深70m,断裂早-中更新世有过活动,晚更新世断裂活动性较强。综合分析认为,延怀盆地隐伏断裂在晚更新世时期活动性强,而全新世以来,各断裂活动性减弱。  相似文献   

8.
山西省大同市城区位于大同断陷盆地西北隅,东、西、北三面环山,中部为倾斜平原,其上发育有御河及十里河,主要有侵蚀-堆积河谷、剥蚀-堆积台原、侵蚀-堆积倾斜平原3种地貌类型,大同市城区主要位于剥蚀-堆积台原,组成台原的物质为中更新世的冲积-湖积物,岩土由不同粒度的卵石、砾砂、中细砂及黏性土互层组成,沉积韵律发育,为典型的河湖相沉积,厚度30 m~80 m.  相似文献   

9.
柴达木盆地早更新世湖相非冰川碎屑纹泥的初步研究   总被引:1,自引:0,他引:1  
汪永进 《湖泊科学》1995,7(3):203-212
柴达木盆地东部三湖地区早更新世湖相沉积层中,阶段性地发育了具季节性韵律层理的钙质泥岩和泥灰岩。组构、粒度、矿物成分、氧碳同位素及沉积相等研究表明:这是一种成因上与湖水年季节性分层相关的非冰川碎屑纹泥。冬季泥质层中粘土矿物和泥晶碳酸盐矿物的混合沉积呼应于总体气候干旱背景。纹泥的发育与大幅度湖侵的同步性反映了区域构造运动对湖相纹泥形成的宏观控制;纹泥的物质组成、厚度等差异则指示了细微的环境变化。  相似文献   

10.
晚更新世以来地层的形成受气候、构造活动的影响,并记录其过程。因此,建立晚更新世以来的地层序列,对于气候变化、活动构造、地貌成因等研究十分重要。若尔盖盆地位于青藏高原的东部边缘,中国季风区和青藏高原区的交会地带,对气候变化敏感,构造活动也很强烈,建立盆地晚更新世以来的地层序列可以促进气候变化、构造活动研究。根据若尔盖盆地的湖相钻孔、泥炭矿、河流阶地和探槽等揭露的26个典型地层剖面,结合14C和OSL等测年方法获得的200多个同位素年龄,对晚更新世以来的地层进行对比和划分,得到地层综合柱状。晚更新世中期以来划分6个沉积韵律(75~55kaBP,55~33kaBP,33~20kaBP,20~11kaBP,11~4kaBP,4~0kaBP)和6个标志层(75~55kaBP和22~20kaBP的粉细砂层,13~9kaBP的青灰色粉细砂或灰—青灰色砾石沉积,5~4kaBP、3.5~2kaBP、0.5~0.3kaBP的黑色含炭质砂质黏土沉积)。沉积序列和构造-气候关系紧密,一方面沉积韵律与气候旋回基本吻合,与深海氧同位素阶段有较好的对应关系;另一方面,沉积层岩性特征也受到北侧的东昆仑断裂带和西侧的龙日坝断裂带新构造期持续活动的影响,沉积过程主要受气候控制,地层厚度及其空间分布的差异也受到构造活动影响。  相似文献   

11.
福建深沪湾地区晚更新世中晚期以来的地壳运动   总被引:6,自引:1,他引:6       下载免费PDF全文
研究表明 ,深沪湾地区晚更新世早中期地壳运动以下沉为主 ,沉积了冲洪积含砾砂粘土层。晚更新世中晚期以来地壳先升后降 ,近 15 0 0aB .P .以来地壳较为稳定。在 (2 5 5 80± 2 4 90 )~15 4 6 0aB .P .期间 ,该区地壳与水动型海平面大致同步升高 ,上升幅度为 8m左右 ,速率达 0 .78mm/a ,深沪湾内生长了古牡蛎。 15 4 6 0~ 110 0 0aB .P .期间 ,该区地壳快速上升 ,上升幅度超过 10m ,速率超过 2mm/a ,形成多个由晚更新世含砾砂粘土构成的低凹洼地 ,古牡蛎滩成为台地。其后地壳稳定 ,在低凹洼地内生长了古森林。 70 0 0aB .P .深沪湾发生了由强古地震导致的地壳快速下沉 ,古森林生长的凹陷洼地变成泻湖环境 ,古牡蛎滩台地与海面很接近。 2 0 0 0aB .P .左右 ,深沪湾又一次发生由强古地震导致的地壳快速下沉 ,古森林下沉到更深的海底 ,古牡蛎滩回到潮间带海域  相似文献   

12.
洱海湖盆晚第四纪地层的14C年龄测定及洱海的演变   总被引:2,自引:0,他引:2       下载免费PDF全文
彭贵  焦文强 《地震地质》1991,13(2):179-183
从大理洱海湖盆西部平原湖沼相地层的分布和相关的14C年龄测定以及文物考古资料,阐述了晚更新世中期以来洱海的演变。研究表明,距今5万年以来洱海西部古湖岸线是从西向东迁移的。期间曾有过几次摆动。引起洱海古湖岸线变迁的主导因素是点苍山断块的间歇性抬升和洱海湖盆的下沉,地质历史时期的气候干湿演变也起了重要作用  相似文献   

13.
延庆盆地是一个位于燕山山及脉南京的晚新生代形成的小型断陷盆地,通过对延庆盆地系统的野外调查,根据延庆分协的地貌,只物,断裂活动等特征,初步认为延就分协在过去约50万年曾发生守三次对盆地地貌和沉积环境演化发生过重要升改变盆地演经过程的重大构造事件。  相似文献   

14.
尹金辉  计凤桔 《地震地质》2000,22(2):195-199
应用1 4 C测年法和热释光方法对采自永定河上游晚更新世晚期以来形成的堆积阶地样品进行了年代测定。研究结果表明 ,永定河上游三条一级支流的低阶地形成时代具有一定的同时性 ,第三级阶地的下切时间大约在 30 0 0 0aB .P .;第二级阶地的下切时间大约在 10 0 0 0aB .P .;第一级阶地的下切时间大约在 4 0 0 0aB .P .。气候变暖对第二级阶地形成起主导作用 ,构造作用对最新阶地形成有一定的影响  相似文献   

15.
The interaction between the continental-continental collision of the Indian-Eurasian plate and the westward underthrusting of Pacific plate is generally considered to be the cause of the destruction of North China Craton. At present, there are still doubts in the researches worldwide about the dynamic mechanism of the formation and evolution of the Ordos peripheral fault-depression system and the contemporary tectonic stress field.
The Hetao Basin is a Cenozoic fault basin located between the Ordos block and the Yinshan Mountains. Due to the effect of uplift of the Tibet Plateau and the continuous subduction of the Pacific plate, graben faulting of different intensities occurred in different periods of Cenozoic around the Ordos block. Late Quaternary lacustrine facies sedimentary strata are widely developed in Hetao Basin. The Haolaigou profile, Bianqianhao profile and the Langshan profile in this study are all located in Hetao Basin. According to the lithology and structural analysis of the upper Pleistocene series in the three profiles, angular unconformities of phase 1-2 are recorded in the lacustrine facies sediments with a thickness of about 10m. The dating results of the Haolaigou profile, Bianqianhao profile and Langshan profile show that the formation time of both unconformities is 80ka BP.
Using the tectonic geology, Quaternary geology, stratigraphy, sedimentology and a variety of dating methods, we also carry out a comprehensive study and obtain the following results:
(1)The analysis of lithological and structural features of Haolaigou profile, Bianqianghao profile and Langshan profile in the Hetao Basin shows that multi-phase angular unconformities events are recorded in the lacustrine strata of a thickness of nearly 10m. These unconformities represent the tectonic movement in the late Pleistocene period since the 80ka BP and they may be widely distributed in the North China region. They are probably the direct products of the latest tectonic movement in the Quaternary period.
(2)The present tectonic movement initiates at about 80ka BP. It not only causes multiple angular unconformity events, but also leads to the disappearance of the Hetao ancient lake. The rapid regional epeirogenetic uplifting of the Ordos block since 76.4ka BP should also be the specific manifestation of this tectonic movement. Because of the influence of the accelerated uplifting and eastward spreading of the Qinghai-Tibet plateau in the late Quaternary, the NEE thrusting effect of the Ordos block is enhanced and affected.  相似文献   

16.
Since stratigraphic formation is influenced by tectonic activities and climate since late Pleistocene,it is important to build the stratigraphic sequence to improve the research of active tectonics,climatic change and landform factors.Zoige Basin is located in the eastern edge of Tibet Plateau where the tectonic is active and the Chinese monsoon is strong.The research of stratigraphic sequence is closely related to the tectonic activities and climate changes.Based on 26 typical stratum profiles revealed by lacustrine boreholes,terraces,peat deposits and trenching,203 isotope dating data were obtained by AMS and OSL methods.We conduct a stratigraphic correlation and classification in Zoige Basin since the Late Pleistocene.Sedimentary cycles are divided into six sedimentary rhythms (75~42ka,42~37ka,37~20ka,16~11ka,11~4ka and 4~0ka) and six marker beds (fine sand of 75~55ka and 22~20ka,gray silt deposit or gravel deposit of 13~9ka,black sandy clay containing carbonaceous deposits of 4ka,2ka and 0.3ka).There is a close relation between strata and tectonic-climate.On the one hand,sedimentary cycles coincide with climate change and have a good correspondence with ocean oxygen isotope.On the other hand,sedimentation characteristics is influenced by the persistent activities in neotectonic period of the east Kunlun fault zone on the north side and the Longrize fault zone on the west side.Marker beds and sedimentary cycles are compared with the strata in adjacent areas.It shows that climate change is the main factor affecting sedimentary cycle.The difference of stratum thickness and its spatial distribution is also affected by tectonic activity.  相似文献   

17.
武威盆地晚更新世河流阶地变形与新构造活动   总被引:20,自引:4,他引:16       下载免费PDF全文
根据武威盆地 7条河流的阶地测量资料和测年数据探讨了河流阶地变形与新构造活动的关系。河流阶地的变形特征反映出新构造活动的方式 ,断层活动以逆冲为主 ,河流阶地的错断状况表明活动断层活动的次数 ,盆地西部活动至少有 7次 ,东部活动至少有 5次 ;同时可表明断层活动的幅度与强度 ,以及不同时期活动强烈区具有迁移变化的特点。武威盆地晚更新世以来发育的第四纪断层主要有 3条 ,各条断裂活动次数、强度不尽相同 ,以山前断裂活动最为强烈 ,至今活动仍未停息。 6 0ka前后西部活动强烈 ,2 0ka以来东强西弱  相似文献   

18.
焉耆盆地北缘和静逆断裂-褶皱带第四纪变形   总被引:5,自引:5,他引:0       下载免费PDF全文
焉耆盆地是塔里木盆地东北缘天山山间的重要坳陷区,盆地北缘发育的和静逆断裂-褶皱带是一条现今活动强烈的逆断裂-褶皱带,对其第四纪以来缩短量和隆升量的计算有利于分析该区域的构造活动情况,对缩短速率和隆升速率的估计可以与天山造山带其他区域的活动速率进行横向对比,从而反映出焉耆盆地在天山晚新生代构造变形的作用。在深部资料不足的情况下,对背斜形态完整、构造样式简单的和静逆断裂-褶皱带,利用地表可获得的地层和断层产状,通过恢复褶皱几何形态,计算褶皱的缩短量、隆升量和断层滑动量,得到逆断裂-褶皱带早更新世晚期(1.8Ma)、中更新世(780ka)和晚更新世中期(80ka)以来的缩短量分别为1.79km、0.88km和26m,初步估计的缩短速率分别为0.99mm/a、1.13mm/a和0.33mm/a。显示和静逆断裂-褶皱带自开始形成以来构造活动强度并不一致。与地壳形变观测结果对比,作为南天山东段最主要的坳陷区,焉耆盆地吸收了这一区域(86°~88°E)的大部分地壳缩短,且主要表现为盆地北缘新生逆断裂-褶皱带的强烈变形。  相似文献   

19.
Based on the 1︰50000 active fault geological mapping, combining with high-precision remote imaging, field geological investigation and dating technique, the paper investigates the stratum, topography and faulted landforms of the Huashan Piedmont Fault. Research shows that the Huashan Piedmont Fault can be divided into Lantian to Huaxian section (the west section), Huaxian to Huayin section (the middle section) and Huayin to Lingbao section (the east section) according to the respective different fault activity. The fault in Lantian to Huaxian section is mainly contacted by loess and bedrock. Bedrock fault plane has already become unsmooth and mirror surfaces or striations can not be seen due to the erosion of running water and wind. 10~20m high fault scarps can be seen ahead of mountain in the north section near Mayu gully and Qiaoyu gully, and we can see Malan loess faulted profiles in some gully walls. In this section terraces are mainly composed of T1 and T2 which formed in the early stage of Holocene and late Pleistocene respectively. Field investigation shows that T1 is continuous and T2 is dislocated across the fault. These indicate that in this section the fault has been active in the late Pleistocene and its activity becomes weaker or no longer active after that. In the section between Huaxian and Huayin, neotectonics is very obvious, fault triangular facets are clearly visible and fault scarps are in linear distribution. Terrace T1, T2 and T3 develop well on both sides of most gullies. Dating data shows that T1 forms in 2~3ka BP, T2 forms in 6~7ka BP, and T3 forms in 60~70ka BP. All terraces are faulted in this section, combing with average ages and scarp heights of terraces, we calculate the average vertical slip rates during the period of T3 to T2, T2 to T1 and since the formation of T1, which are 0.4mm/a, 1.1mm/a and 1.6mm/a, and among them, 1.1mm/a can roughly represent as the average vertical slip rate since the middle stage of Holocene. Fault has been active several times since the late period of late Pleistocene according to fault profiles, in addition, Tanyu west trench also reveals the dislocation of the culture layer of(0.31~0.27)a BP. 1~2m high scarps of floodplains which formed in(400~600)a BP can be seen at Shidiyu gully and Gouyu gully. In contrast with historical earthquake data, we consider that the faulted culture layer exposed by Tanyu west trench and the scarps of floodplains are the remains of Huanxian MS8½ earthquake. The fault in Huayin to Lingbao section is also mainly contacted by loess and mountain bedrock. Malan loess faulted profiles can be seen at many river outlets of mountains. Terrace geomorphic feature is similar with that in the west section, T1 is covered by thin incompact Holocene sand loam, and T2 is covered by Malan loess. OSL dating shows that T2 formed in the early to middle stage of late Pleistocene. Field investigation shows that T1 is continuous and T2 is dislocated across the fault. These also indicate that in this section fault was active in the late Pleistocene and its activity becomes weaker or no longer active since Holocene. According to this study combined with former researches, we incline to the view that the seismogenic structure of Huanxian MS8½ earthquake is the Huashan Piedmont Fault and the Northern Margin Fault of Weinan Loess, as for whether there are other faults or not awaits further study.  相似文献   

20.
程绍平  杨桂枝 《地震地质》1994,16(4):346-354
通过1个探槽记录、3个地质学剖面、7个晚更新世沉积物表面断层崖形态学剖面和15个放射性测年数据,论述了延庆盆地北缘断裂带蚕房营段的晚更新世晚期断层作用。这些资料显示出该时期内的两次断层作用事件:最近的一次发生在9870±130~11800±1100aB.P.之间,最早不超过13200±l100aB.P.;较早一次的发生时间为19850±1550aB.P.。一次事件的位移量3.34~3.64m,两次事件之间的重复间隔9980a。大约自21050±1600aB.P.以来的垂直位移速度计算为0.31~0.34mm/a。蚕房营段的晚更新世晚期的断层作用,以较大的表面位移量和较长的重复间隔为特征。全新世没有类似的断层作用事件  相似文献   

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