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1.
攀西地区早白垩世以来地壳抬升运动的裂变径迹年龄研究   总被引:1,自引:0,他引:1  
通过对扬于板块西缘攀枝花一西昌地区麻粒岩中锆石和磷灰石的裂变径迹(FT)年龄测定,首次研究和报道了该区中一新生代地壳的低温热历史和抬升运动过程,分析显示,锆石FT年龄为143.8—68.4Ma;磷灰石FT年龄为24.1—12.8Ma.磷灰石FT平均长度的变化范围在10.54—13.20μm.研究表明,攀西地区从早白垩世到白垩纪末期地壳抬升是十分缓慢的,抬升速率仅为46—51m/Ma;但从第三纪开始地壳抬升运动明显加快,抬升速率达208-391m/Ma.这可能是印度板块与欧亚板块碰撞效应.  相似文献   

2.
通过酒泉盆地新生代地层裂变径迹年龄分析,对新生代以来酒泉盆地构造过程进行了探讨。研究表明,酒泉盆地源区祁连造山带在54.3M a、41.5M a、39.2M a、33.8M a~37M a有4次快速蚀顶作用,酒泉盆地约26.4M a和13~19M a2次快速构造抬升。  相似文献   

3.
取自天山南侧库车盆地北缘欧西达坂花岗体的锆石、磷灰石裂变径迹年龄给出了初步结果;中新生代天山板内造山带早白垩世发生了明显快速隆升,平均隆升速率为0.13mm/a(130m/Ma);而从晚白垩世到现在,天山板内造山带的平均隆升速率为0.03mm/a(31.9m/Ma)。  相似文献   

4.
吐鲁番-哈密盆地中新生代热历史:磷灰石裂变径迹证据   总被引:7,自引:0,他引:7  
对吐鲁番-哈密盆地中部连木沁剖面和南北山前带的9个样品进行磷灰石裂变径迹测年发现,7个侏罗系样品的中心年龄皆小于地层沉积年龄,而2个白垩系样品的中心年龄则大于或等于地层沉积年龄,表明侏罗系样品经历过退火或部分退火,而白垩系样品则未退火.进一步的热模拟研究表明,在晚白垩世120~100Ma,吐哈盆地发生构造抬升,地层快速冷却剥露,岩层在新生代二次埋藏加热,至10~8Ma又再次剥露.  相似文献   

5.
鄂尔多斯盆地南缘渭北隆起中新生代构造抬升及演化   总被引:3,自引:0,他引:3  
应用磷灰石裂变径迹定年技术研究鄂尔多斯盆地南缘渭北隆起抬升期次及演化过程.对渭北隆起不同地区磷灰石裂变径迹年龄分析结果表明,渭北地区主要经历了3期主要抬升过程,主要发生在146~ 125 Ma,107~83.8 Ma和40 ~ 27.3 Ma.结合前人对该地区原型盆地、构造变形特征等研究成果认为,早白垩世末之前渭北隆起应为大型鄂尔多斯盆地的一部分,整体以沉降沉积为主,此时尚未隆起;渭北隆起的形成和演化可分为晚白垩世整体抬升阶段和始新世~渐新世以来的断块翘倾两大阶段.晚白垩世渭北地区整体抬升主要受控于秦岭造山带中晚燕山期的抬升过程;始新世-渐新世以来的断块敲倾作用阶段,与秦岭造山带始新世以来的快速隆升,以及渭河盆地新生代的快速断陷作用有关.  相似文献   

6.
研究了博南 1井和焉参 1井侏罗系碎屑岩 6个样品的磷灰石裂变径迹测试结果 ,得出北部凹陷中生界埋深普遍 >2 0 0 0 m ,属新生代补偿型地温场分区 ,最大古地温发生在新生代以来的挽近时期 ,中下侏罗统经历的最大古地温约为 70~ 1 1 0℃ ;南部凹陷中生界埋深普遍<1 5 0 0 m,属新生代欠补偿型地温场分区 ,最大古地温发生在侏罗系沉积末 ,下侏罗统—中侏罗统下部经历的最大古地温大约为 80~ 1 1 0℃ ,中侏罗统上部经历的最大古地温低于 70℃。磷灰石裂变径迹年龄特征表明 ,焉耆盆地最显著的抬升降温事件主要发生在白垩纪 ,因此盆地的主构造活动期为中、晚燕山期。南部凹陷和北部凹陷两区侏罗系裂变径迹年龄对比分析结果进一步表明 ,燕山期抬升变形南部 (早白垩世为主 )略早于北部 (晚白垩世为主 ) ,说明抬升变形的序次是由南向北扩展的。  相似文献   

7.
取自天山南侧库车盆地北缘欧西达坂花岗岩体的锆石、磷灰石裂变径迹年龄给出了初步结果:中 新生代天山板内造山带在早白垩世(134Ma~109Ma)发生了明显快速隆升,平均隆升速率为0.13mm/a(130m/Ma);而从晚白垩世到现在,天山板内造山带的平均隆升速率为0.03mm/a(31.9m/Ma)。在晚新生代天山板内造山带再次发生了快速隆升。现有的同位素研究成果表明中新生代天山造山带至少发生了两次幕式快速隆升。  相似文献   

8.
应用磷灰石裂变径迹研究沉积盆地的热史   总被引:5,自引:0,他引:5  
磷灰石裂变径迹是研究沉积盆地地热史的强有力工具。胜利油区东营凹陷磷灰石裂变径迹分析表明该盆地的古热作用比现今热作用强。盆地形成初期经历的热事件使其具有较高的热流,随后热流缓慢衰减;3号样品径迹长度的混和型分布说明东营组(Ed)和馆陶组(Ng)之间的沉积间断曾引起了盆地古地温的降低。东营凹陷磷灰石裂变径迹退火带位置在2000~3400m左右,和生油窗是一致的。  相似文献   

9.
鲁西隆起蒙山晚白垩世-新生代抬升的裂变径迹证据   总被引:3,自引:0,他引:3  
 研究晚白垩世以来蒙山的抬升对全面认识鲁西隆起区的构造演化具有重要的意义。对采自蒙山山脉的6个岩石样品进行了磷灰石/锆石裂变径迹测年及热历史模拟分析。分析结果表明蒙山自晚白垩世开始快速抬升,经历了70~43 Ma和32~20 Ma两个快速抬升阶段,并且蒙山的抬升表现出加速抬升的特征。晚白垩世以来蒙山的快速抬升与其毗邻的泰山有着较好的对应关系,蒙山的整体抬升略早于泰山,并且鲁西隆起的抬升表现出由南向北的抬升序列。蒙山的两期快速抬升事件很好地对应了济阳坳陷在这两个时期经历的构造沉降和区域隆升过程,表明新生代蒙山的快速抬升与济阳坳陷的构造演化有着良好的隆拗耦合关系。  相似文献   

10.
元谋盆地元谋组地层的裂变径迹年代数据   总被引:3,自引:0,他引:3  
元谋盆地元谋组地层的裂变径迹年代数据张虎才,钱方,陈怀录(兰州大学地理科学系,兰州,730000)自1965年在云南元谋盆地新生界元谋组地层中发现“元谋人”化石以来,对元谋盆地新构造运动、地貌演出、古气候演变、地层学及古地磁地层年代学、动植物及微体化...  相似文献   

11.
青藏高原东缘及四川盆地晚中生代以来隆升作用对比研究   总被引:11,自引:0,他引:11  
通过系统对比磷灰石裂变径迹数据,从整体上探讨了青藏高原东缘地区与四川盆地各地质单元在晚中生代、新生代抬升冷却特征.它们的构造活动在空同上具有分区性和连续性特征,在时间上具有幕武性特点.构造活动的空间上分区性表现在各地质单元隆升特征的差异性,主要为四川盆地川东北一川西南地区及其相邻两侧单元对比的差异和松潘一甘孜造山带南北地区的差异.空同上的连续性表现在中生代一新生代构造活动具有由北向南逐渐迁移的趋势,即由北向南磷灰石裂交径迹年龄减小和径迹长度增大的趋势.构造活动时间的幕式性表现在阶段性的快速冷却(埋深)及其相问的缓慢冷却过程.青藏高原东缘和四川盆地各地质构造单元径迹年龄值及年龄交化范围具有由西向东逐渐增大、径连长度逐渐减小的趋势,它们在晓中生代一新生代共处于统一的、递进的挤压变形动力学体制下,从西向东构筑成一个有机联系的挤压-抬升体系,其新生代构造抬升运动主要受控于喜马拉雅构造运动,同时也受中央造山带和扬子板块的重要影响.青藏高原东缘新近纪龙门山遣山带隆升速率最快(大干600 m/Ma),隆升幅度大于3 km,甚至超过6 km.  相似文献   

12.
13.
Apatite fission track dating is carried out on nine samples collected from the central part (Lianmuqin section) and from both northern and southern margins of Turpan-Hami Basin. The fission-track ages of seven Jurassic samples are distinctly younger than depositional ages. In contrast, the fission-track ages of two Cretaceous samples are older than, or as old as depositional ages. These observations indicate that the Jurassic samples have been annealed or partially annealed, whereas the Cretaceous samples have not been annealed.The further thermal modelling results show that Turpan-Hami Basin experienced a Late Cretaceous period (120-100 Ma) of tectonic uplift with rapid cooling and exhumation of sediments. The samples underwent a Cenozoic period of reburial and re-heating and were exhumed again at 10-8 Ma.  相似文献   

14.
The tectonic uplift of the Hua Shan in the Cenozoic   总被引:5,自引:0,他引:5  
Six granite samples were collected from six difference elevation locations at the Hua Shan in a main ridge of the Qinling Mountain. Apatite and zircon separated from these six samples were dated by the fission track technique. An assessment of the Cenozoic uplift or exhumation rate was obtained from the altitude difference of sampling samples dated by fission track, and from the difference of fission track dates of both apatite and zircon for a sample. The preliminary results suggest that the beginning of uplift of the Hua Shan was as early as 68.2 MaBP and the uplift rates for different periods are 0.02–0.19 mm/a (from the elevation difference) or 0.12–0.16 mm/a (from two mineral fission track dates). The average uplift rate is 0.12 mm/a (from the elevation difference) or 0.14 mm/a (from two mineral fission track dates). The uplift of the Hua Shan might accelerate since (17.8±2.0) MaBP, and the average uplift rate is about 0.19 mm/a.  相似文献   

15.
鄂尔多斯盆地中生代构造事件及其沉积响应特点   总被引:9,自引:0,他引:9  
以鄂尔多斯盆地中新生代构造演化的区域动力学环境分析为基础,重点通过锆石和磷灰石裂变径迹年龄数据的统计分析,提供了鄂尔多斯盆地中新生代构造事件的年代学约束,并结合地层不整合关系和沉积建造特征讨论了中生代构造事件的沉积响应特点.讨论结果表明:印支期构造事件主要发生在230~190Ma,在盆地西南缘发育晚三叠世粗碎屑类磨拉石建造.燕山期构造事件主要发生在燕山中晚期的150~85Ma,包含145Ma±、120Ma±和95Ma±三个峰值年龄组,锆石和磷灰石裂变径迹年龄叠合分布的峰值年龄(140~150Ma±,平均145Ma±),指示了鄂尔多斯盆地中新生代构造演化过程中最为关键的一次构造变革事件,并在盆地西南缘发育上侏罗统芬芳河组和下白垩统志丹群等多套粗碎屑类磨拉石建造.  相似文献   

16.
鄂尔多斯盆地南部渭北隆起发育时限及其演化   总被引:8,自引:0,他引:8  
通过对渭北隆起残存地层展布、沉积特征及构造变形等研究,结合磷灰石裂变径迹测试分析,认为渭北隆起后期经历了明显的改造,在早白垩世末以前应为鄂尔多斯盆地的一部分,总体以沉降接受沉积为主,此时隆起并未发育;而其整体作为正向构造单元应始于早白垩世末以来(约114~83 Ma),大致与鄂尔多斯盆地的消亡时间同步,且经历了早白垩世末—古新世的整体抬升剥蚀和始新世以来的断块翘倾剥蚀两大演化阶段.  相似文献   

17.
Yunkaidashan, located at the southern South China block (SCB) and closely adjacent to the Indochina block, is an ideal region for better understanding the temporal and spatial framework of tectonothermal overprinting at the southern SCB since Mesozoic. Apatite and zircon fission track thermochronology of various-type rocks from Yunkaidashan is presented in this paper. The results show, no matter what rocks are, the apparent ages of zircon fission track range from 97.4 to 133.0 Ma, and those of apatite fission track from 43.2 to 68.4 Ma. The length of apatite fission track yields an average confined track length of -13 μm andshows normal distribution of unimodal frequency. It is inferred that the uplifting amplitude has been more than 5 km in Yunkaidashan since late Mesozoic. The difference of fission track apparent ages at different locations in Yunkaidashan suggests a paleophysiognomic scenario of the heterogeneous uplift/denudation. These data of the fission track thermochronology provide new constraints for better understanding the tectonophysiognomic pattern of the SCB sincelate Mesozoic.  相似文献   

18.
Fission track (FT) ages of apatite and zircon from four granite batholiths from Lhasa and Shannan areas are measured.The FT ages of apatite range from 3.2±8.3 Ma, corresponding to the uplift rates of 0.12±0.20 mm·a~(-1) during this period. The upliftheight is 580m, showing that there is not large-scale rapid uplifting in southern Tibet from 3.2 to 8.3 Ma. The zircon FT ages of Lhasabatholith are 25.9±1.7 and 32.7±2.8 Ma, yielding an uplift rate of 0.08 mm·a~(-1) between 26 and 33 Ma. Combining this work withother studies, it is suggested that the average uplift rate in southern Tibet is low from the time of collision between India and Asian conti-nents to ~3Ma. The uplift of Tibetan Plateau seems to have finished in multi-stage processes with varied rates.  相似文献   

19.
This work makes the quantitative constrain on tectonizations of the Gangdese block, south Qinghai-Tibetan Plateau. Apatite fission track (AFT) dating analyses of 15 samples collected across the Gangdese block show that the Gangdese block went through two periods of tectonizations, during ~37.2 - 18.5 Ma and 18.5 - 8.0 Ma in the south Gangdese block, and during ~47.6 - 5.3 Ma and 5.3 - 0 Ma in the middle Gangdese block. Different upliftings did not take place in the first period and rapid uplifting occurred in the late period. Meantime, there are some differences between the south and middle Gangdese block. Their uplifting rate is 180 m/Ma and 70 m/Ma respectively. The rapid uplifting time in the middle Gangdese block lagged behind the time in the south Gangdese block. It is Chala-Jiacuo-Riduo fault zone that is similar to the Yarlung Zangbo fault zone in control of the tectonization.  相似文献   

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