磷灰石裂变径迹方法研究沉积盆地古地温—以东营凹陷为例

介绍了应用磷灰石裂变径迹(AFTA)方法研究沉积盆地古地温的原理及研究现状,并以东营凹陷的具体数据为例进行了热史反演。研究表明东营凹陷的古地温梯度基本呈降低的趋势以及“马鞍形”的演变特点。从而表明磷灰石裂变径迹研究沉积盆地古地温是一种行之有效的方法,能够为古地温场的研究提供可靠的依据。     

用磷灰石裂变径迹研究西湖凹陷的古地温

对西湖凹陷HY14－1－1井的岩心和岩屑样品中的磷灰石进行了系统的裂变径迹测定,并对该井所代表的西湖凹陷地热史进行了分析和模拟。研究结果表明,西湖凹陷磷灰石裂变径迹退火带深度为2000－3900m,相应的古地温为70－125℃,古地温梯度为2．8℃／（100m)。西湖凹陷主要生油岩是下第三系暗色泥页岩,其大量生成油气的温度约为90℃,生油门限是2800m左右。西湖凹陷的磷灰石裂变径迹长度为单峰分布,说明此地区自第三纪以来仅经历了一次热事件作用,且与该地区大地构造活动一致。这说明此方法是可信的,值得进一步推广。     

基岩潜山油藏烃源岩的成烃特征

沉积盆地是一个巨大的低温热化学反应发生器,以辽河盆地大民屯凹陷曹台基岩潜山油藏为例,以其烃源岩在埋藏、压实、热力等因素作用下,达到成熟、生烃的动力学思路和方法为指导,探讨了曹台潜山原油的成因、来源及烃源岩的生烃过程。回剥反演了烃源岩的沉积埋藏史,磷灰石裂变径迹恢复了古地温,得出该油藏的原油是未发生降解的成熟型原油,潜山烃来源于西侧深凹陷的沙四段暗色泥岩。目前烃源岩还处于生烃高峰期,油藏尚处于油气充     

低温热年代学方法及其在叠合盆地构造-热演化研究中的应用

叠合盆地构造-热演化史是当前油气地质研究的重点和难点之一。近年来,低温热年代学测龄技术成为构造-热演化史研究的重要技术,多种测龄手段联用极大地拓宽了其应用范围。江汉平原区具有典型的叠合盆地特征,存在当阳复向斜等中新生代多旋回沉积埋藏区和京山地区等多期持续抬升区。在前一类地区,镜质体反射率记录、磷灰石裂变径迹和锆石裂变径迹等综合反映,该区具有"多段式"热历史,至少发生过2次地质事件,分别对应于侏罗纪-早白垩世后以及古近纪后的大规模构造抬升-地层剥蚀事件;在第二类地区,磷灰石裂变径迹、磷灰石和锆石(U-Th)/He测龄、裂变径迹和(U-Th)/He热史反演等综合反映,该区志留系在早白垩世以来先后经历了快-慢-较快的抬升冷却过程,分别对应于晚侏罗世末期-早白垩世地层大幅度抬升冷却、早白垩世-古近纪盆地拉张沉降和古近纪中期盆地内隆起抬升剥蚀事件。不同类型低温热年代学测龄指标可以有效反映沉积埋藏区地层沉降-古地温演化历史,再现多期持续剥蚀区地层冷却和构造抬升-剥蚀过程。     

用磷灰石裂变径迹研究西湖凹陷的古地温

对西湖凹陷HY1411井的岩心和岩屑样品中的磷灰石进行了系统的裂变径迹测定 ,并对该井所代表的西湖凹陷地热史进行了分析和模拟。研究结果表明 ,西湖凹陷磷灰石裂变径迹退火带深度为 2 0 0 0～ 390 0m ,相应的古地温为 70～ 12 5℃ ,古地温梯度为 2 .8℃ / (10 0m)。西湖凹陷主要生油岩是下第三系暗色泥页岩 ,其大量生成油气的温度约为 90℃ ,生油门限是 2 80 0m左右。西湖凹陷的磷灰石裂变径迹长度为单峰分布 ,说明此地区自第三纪以来仅经历了一次热事件作用 ,且与该地区大地构造活动一致。这说明此方法是可信的 ,值得进一步推广。     

晚中生代二连盆地吉尔嘎朗图凹陷地层和构造演化研究

二连盆地是中国东北重要的油气、煤炭和铀矿基地,吉尔嘎朗图凹陷是盆地最重要次级凹陷之一。吉尔嘎朗图凹陷的资源勘查工作已经持续了几十年,然而,至今凹陷形成和演化的过程仍缺少精细地刻画。通过磷灰石裂变径迹年代学分析、地震反射剖面分析,结合前人地层定年工作,对晚中生代吉尔嘎朗图凹陷地层和构造演化历史进行了研究。研究结果表明中侏罗世和早白垩世是凹陷的主要断陷期。但是,凹陷在晚中生代并不是始终处于伸展构造环境、凹陷至少在晚侏罗世晚期-早白垩世初(中侏罗统与阿尔善组沉积间歇期)、早白垩世中期(阿尔善组与腾格尔组沉积间歇期)、早白垩世中晚期(腾格尔组与赛汉组沉积间歇期)、早白垩世末-晚白垩世(赛汉组与新生界沉积间歇期)经历过短暂但强烈的挤压构造作用。     

磷灰石裂变径迹分析在焉耆盆地油气勘探中的应用

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。     

关于地层剥蚀厚度求取方法的讨论：以吐—哈盆地为例

以吐－哈油田为例，用镜质体反射率和磷灰石裂变径迹方法综合求取了地层剥蚀厚度。据此求得吐－哈盆地南部地区三叠系剥蚀厚度多小于５００ｍ；盆地北部的台北凹陷侏罗系剥蚀厚度介于６００ｍ到未剥蚀之间；台北凹陷北部山前带侏罗系剥蚀厚度多在１３００～１８００ｍ之间。     

渤海湾盆地剥蚀量恢复中的综合分析法

利用地震层速度法、镜质体反射率法、声波时差法、地质外推法等 ,确定渤海湾盆地中生界的剥蚀量 ,并建立起初步的埋藏史曲线 ,然后应用磷灰石裂变径迹长度分析技术 ,选定澳大利亚扇形模型 ,沿可能性最大的几种不同地质概念热史路径 ,对渤海湾盆地临清坳陷西部Q 5井等的白垩统地层的磷灰石裂变径迹长度分布进行了数值模拟 .通过与实测磷灰石裂变径迹长度分布的比较 ,确定了该井合理的、精确的地质演化历史 .模拟研究结果表明 ,Q 5井在距今 70Ma时 ,白垩系地层达到其演化历史上的最大埋深 (35 0 0m) ;之后发生构造抬升并遭受剥蚀 ,下白垩系地层的最大剥蚀量为 95 0m ,上白垩系地层的最大剥蚀量为 15 70m .研究过程证明 ,多种方法结合 ,比单纯用磷灰石裂变径迹热史分析法得出的结论可靠 .     

鄂尔多斯盆地中生代构造事件及其沉积响应特点

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.     

Meso-Cenozoic uplifting and exhumation on Yunkaidashan： Evidence from fission track thermochronology

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.     

Mesozoic-Cenozoic thermal history of Turpan-Hami Basin: apatite fission track constraints

Turpan HamiBasinisoneofthreekeyoil/gas bearingbasinsinXinjiang ,China .TheaeromagneticdatadisclosethatTurpan HamiBasinisofdoublebasements ,namelythePrecambriancrystalbasementandthePaleozoicfoldingbasementofvolcanicrockandclasticrock[1,2 ] .ThebasementevolutionstoppedattheendoftheCarboniferous .EarlyPermianwasaperiodofanimportanttectonictransitionintheTur pan HamiBasinthatunderwentatransformfromthebasementevolutiontothecoverevolutionstartingfromtheLatePermian[3] .Thebasinistotallyinlaidi…     

The tectonic uplift of the Hua Shan in the Cenozoic

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.     

Apatite fission track dating evidence for tectonic movement of Yarlung Zangbo Thrust Zone

Fission track geological chronology is an effective method of study on tectonic movement of fault zone. Apatite fission track (AFT) dating analyses of 9-apatite and 4-zircon samples collected from Lhasa to Langkazi, ~70-km-long in SN provide an understanding of the age and the uplifting of both sides of the Yarlung Zangbo Thrust Zone (YZTZ) in this work. The AFT ages range from ~37 to 14 Ma, indicating the time of major tectono-thermal events, i.e. the continent-continent collision along the YZTZ. Based on the relationship between the AFT ages and the sample elevations, there were two tectonic active periods: ~37—20 Ma and 20—14 Ma. In the first period the tectonic event did not bring on differential uplifting. Rapid differential uplifting with rapid cooling, resulting from thrusting, took place in the second period. The vertical displacement was ~1020 m and total ~2.9 km of overburden has been removed from the present-day surface since cooling below ~110℃ began. The maximum cooling and denudation occurred at a rate of ~7℃/Ma and ~207 m/Ma respectively since ~14 Ma. The zircon fission track analysis demonstrates that the temperature of tectono-thermal events did not exceed 310℃.     

磷灰石裂变径迹的分析在石油勘探中的初步应用

本文根据东濮凹陷文留地区的三口探井取得的13块岩芯,系统地做了磷灰石裂变径迹的测试。确定文留地区的磷灰石径迹衰退带的上限为2,000m,下限为3,500m。其温度范围为70℃～125℃。通过换算得到该区的古地温梯度,并取得区域的平均古大地热流值。根据测试资料,编制了径迹长度频谱图、绝对年龄与深度关系图。这些基础图对区域的古地温场的解释提供了较可靠的依据。     

Mesozoic-Cenozoic thermal history of Turpan-Hami Basin: apatite fission track constraints

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.     

蓬莱9-1潜山花岗岩油藏成藏时间的裂变径迹热年代学约束

油气藏成藏时间的确定一直是石油地质研究领域的难点。该文利用磷灰石裂变径迹测龄及温度-时间热史模拟技术探索了如何精确限定油气藏的成藏时间。从渤海蓬莱9-1潜山花岗岩储层裂缝带和基岩带分别获取2件磷灰石样品,根据磷灰石裂变径迹的长度、年龄和径迹分布,利用 AFT Solve 软件模拟获得了它们的温度-时间热史轨迹。2件样品相似的温度-时间热史轨迹表明,在3．8～2．6 Ma B．P．期间,由于受石油流体充注的影响,样品发生异常热扰动和温度突变,在3．2 Ma B．P．时期受扰动的温度达到最大。根据受异常热扰动的起始时间,确定蓬莱9-1潜山花岗岩石油充注时间为3．8～2．6 Ma B．P．,油气藏的主成藏期为3．2 Ma B．P．。     

Apatite fission track dating evidence on the tectonization of Gangdese block, south Qinghai-Tibetan Plateau

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.     

南天山新生代隆升和去顶作用过程

利用磷灰石裂变径迹技术并结合库车坳陷的沉积和变形特征，对南天山的隆升和去顶作用过程进行详细的研究。南天山在中新世早期就开始了现代天山形成的隆升事件，根据样品的磷灰石裂变径迹结果，其隆升年龄为17～25Ma；而且此隆升事件是一快速隆升事件，隆升速率达到138．8～198．8m/Ma。中新世南天山隆升的南部边界并不是前人所认为的北部古生代地层和南部中新生代地层之间的冲断层，而是在南部的中新生代地层中。在库车坳陷的阳霞地区，隆升的界线位于吐格尔明背斜核部的韧性剪切带。通过库车坳陷的新生代沉积和变形特征的分析，提出了天山中新世以来的隆升与库车坳陷的沉积和变形特征存在很好的耦合关系。