基于辐射损伤的磷灰石裂变径迹退火行为研究

目前裂变径迹低温热年代学的理论基础是建立在温度是导致径迹退火的唯一诱因之上的。然而，辐射损伤是否能够促进裂变径迹退火尚处于争论中。文章采用云南临沧四块花岗岩样品的磷灰石裂变径迹测试分析方法，对辐射损伤与裂变径迹退火行为之间的关系进行了研究。云南临沧磷灰石单颗粒年龄71～15 Ma，封闭径迹长度9～16μm, U含量24～290μg/g。统计分析结果表明，磷灰石封闭径迹长度以及单颗粒年龄分别随相应U含量增加而减小。综合分析认为，这种变化趋势初步表明了辐射损伤能够促进裂变径迹退火，是导致裂变径迹退火的另一诱因，为辐射损伤诱发裂变径迹退火行为研究提供了新证据。     

磷灰石裂变径迹分析（AFTA）——一种研究含油气盆地古热构造史的新方法

磷灰石裂变径迹分析近年来广泛地被用来研究含油气盆地古热定史与古构造史及指导油气勘探，这主要是根据磷灰石裂变径迹退火是时间和温度的函数，而烃的生成与热成熟同是也是和温度的函数，而且磷灰石裂变径迹退火温度范围与石油的生成门限相吻合，退火除受温度、时间影响外、还受化学成分，取向因素控制。ＡＦＴＡ包括裂变径迹年龄分析和裂变径迹长度分析，通过前者可获得退火方面信息，通过后者可获得最大古地温及其随时间的变化及     

利用磷灰石裂变径迹计算隆升速率的一些问题

主要讨论了利用磷灰石理解变径迹年龄－－地形高差法计算隆升速率存在的一些问题，介绍了近年来国外在磷灰石裂变径迹退火方面取得的新进展及其在研究隆升速率问题上的应用，并分析了利用磷灰石裂变径迹研究隆升速率应当注意的问题，强调了加强径迹长度分析的研究。     

磷灰石裂变径迹热年代学研究的进展与展望

综述了磷灰石裂变径迹热年代学研究在退火模型及模拟方法、造山带及造山后剥露历史、构造热成像及地形演变和成矿作用等方面的一些理论和应用成果,分析了目前在磷灰石裂变径迹退火机理、数据解释和应用等方面研究中存在的主要问题,指出了磷灰石裂变径迹热年代学研究今后会朝着深层次退火机理、新的应用领域、自动化技术和可操作性等方向发展.     

磷灰石裂变径迹退火影响因素研究进展

磷灰石裂变径迹退火是一个繁杂的化学动力学过程,清楚地了解其退火的影响因素对于该技术的应用十分重要。文章概述了磷灰石裂变径迹退火动力学模型的发展史,并结合以往对其退火影响因素的研究,将磷灰石裂变径迹退火影响因素分为自身和外部环境两方面:自身影响因素包括化学成分、晶体结构、径迹长度与半径、径迹与结晶轴的方位关系,其中化学成分对退火起到主导作用;外部环境影响中,温度是主导因素,压力和蚀刻条件的改变也会影响退火。研究成果有利于完善磷灰石裂变径迹的实验室退火模型,提高其作为热历史记录器的精度。     

锆石裂变径迹(ZFT)年代学:进展与应用

裂变径迹技术是解决各种与时间-温度相关的地质问题的一种低温年代学手段.与磷灰石相比,锆石裂变径迹具有较高的封闭温度和退火区间,有其特定的地质意义和应用.自20世纪90年代以来,开展了大量锆石裂变径迹退火的研究,包括退火特性、径迹测量、退火模型,以及来自露头和钻孔样品的退火研究.首先介绍了锆石裂变径迹的分析程序、测量标准...     

裂变径迹法原理及其在盆地分析中的应用

裂变径迹法对于研究盆地热史有着不可替代的作用,它可以通过对于年龄和温度的确定,将地热的发展史揭露出来。从裂变径迹的发展历史入手,分析裂变径迹的成因和退火产生的影响。由于裂变径迹具有温度和长度双重特征,就可以对于盆地热史或盆地边缘山体隆升情况进行具体恢复。因此通过具体实例,说明裂变径迹法在盆地热史分析以及如何研究盆地热发展史和成矿、断裂的作用。概述了磷灰石裂变径迹的加强机制研究,建立标准,多方法结合,自动化技术发展趋势。     

裂变径迹退火动力学及其研究进展

裂变径迹定年是６０年代开始兴起的一种新的同位素年代学方法。人们一开始就注意到了它的退火特性,例如使用总体定年时,先把样品分成两份,其中一份经高温退火,退去所有的自发裂变径迹,再送反应堆辐射,用来测诱发裂变径迹密度。但直到８０年代初,裂变径迹分析方法还...     

磷灰石裂变径迹的退火作用及其在沉积盆地油气勘探中的应用：？…

以研究沉积盆地热历史具有独特优越性的新技术方法－裂变径迹法为主要研究手段,通过对东濮凹陷不同区带钻井样品中磷灰石裂变径迹分析,从磷灰石裂变径退火特征所确定的古地渐及古地温梯度,磷灰石裂变径迹表现年龄及退火范围,以及它们与“石油窗”的关系出发,分析了东濮凹陷内油气形成的有利地段,预测了油气远景区,为油田进一步勘探开发提供了理论依据。     

磷灰石裂变径迹与结晶C轴的夹角对模拟热历史的影响

磷灰石裂变径迹退火行为是磷灰石裂变径迹技术模拟热历史的基础,退火程度的不同会导致径迹的长度不同,其中退火的各向异性（与结晶C轴夹角不同退火行为不同）是导致长度差异的重要因素。首先利用C轴投影模型将任意夹角的径迹转化成与C轴平行的径迹,以此消除分布方位的影响,进而探讨实际测量长度相同而分布方位不同的径迹模拟的热历史之间的差异。研究结果表明,磷灰石裂变径迹与结晶 C轴夹角不同揭示的最高古地温之间最大差异为15℃,用来研究剥蚀量和年轻造山带冷却抬升速率引起的最大差异可分别达到430 m及1.5℃/Ma,揭示构造抬升事件的初始抬升时间最大可相差2Ma。因此,在实际模拟热历史时应注意该参数的影响,准确测量磷灰石裂变径迹与结晶C轴的夹角将有助于提高模拟热历史的精度。     

裂变径迹定年技术在构造演化研究中的应用

裂变径迹技术是一种以磷灰石和锆石等矿物为定年对象的低温热年代学方法,特别适用于研究上地壳岩石冷却剥露的时间和过程。该技术在地学中的应用早期以定年为主,随着对裂变径迹长度分布特征与裂变径迹退火特性的深入研究,这种方法得到更广泛的应用,在此基础上综述了裂变径迹技术在下列构造演化问题中的应用和进展,包括：（1）造山带隆升时代及隆升速率的研究;（2）造山带热演化历史的研究;（3）快速蚀顶或冷却事件的年代确定;（4）盆地反转时代的确认;（5）盆地基底岩系构造热历史的研究;（6）盆山耦合过程的研究。     

The Cretaceous and younger thermal history of the KTB site (Germany): apatite fission-track data from the Vorbohrung

A detailed fission-track analysis was carried out on 41 apatite samples from the 4001-m-deep pilot hole of the German Continental Deep Drilling Program (KTB). The investigations include dating by the population method and length measurements of horizontal confined tracks. Age and length information indicate that all samples above the present-day partial annealing zone cooled from temperatures above 120?°C in the Cretaceous. The top two kilometres of the profile show less variation of age with depth than was expected. Modelling of the profile indicates that the distribution of fission track ages with depth requires that the profile was disturbed during or after cooling through the partial annealing zone. Modelling of individual samples reveals that at least the upper 2?km experienced reverse faulting, effectively thickening the upper part of the rock column by up to 1000?m in the Tertiary. A present-day partial annealing zone for apatite was observed between 2000 and 4000?m (～60–110?°C). This confirms earlier in situ observations of the position of the partial annealing zone.     

伊犁盆地南缘隆升剥蚀及其盆地南部的沉积响应——利用磷灰石裂变径迹分析

分析了伊犁盆地南缘蚀源区14件磷灰石样品,其中南缘中西部10件,东部4件。磷灰石裂变径迹表观年龄及其与高程的关系、单颗粒年龄、封闭径迹分布特征表明,伊犁盆地南缘样品均遭受了不同程度的退火,但没有发生明显的区域性热事件。通过封闭径迹正演热史模拟得出,伊犁盆地南缘中新生代构造演化经历了三叠纪-侏罗纪晚期快速隆升,白垩纪-古近纪相对稳定和新构造快速隆升三个阶段。东西两段略有不同,西段隆升时间较早,样品所在地在早三叠世就开始强烈隆升,说明当时该处离原型盆地边界较近,而东段此时样品所在位置还可能接受沉积,直至中侏罗世末期才开始隆升剥蚀。侏罗纪原型盆地南部边界至少跨过大板煤矿,因为在该处出露中侏罗世西山窑组残留地层。相应的稳定阶段东段要滞后一些,稳定时间相对较短,西段该时段长达100Ma,而东段多在50～60Ma。新构造运动强烈活动的时间东段相对较早,局部地段在38Ma就开始隆升。盆地南缘沉积相带的发育特征和新近纪（或第四纪）内给出的电子自旋共振年龄（ESR）均说明,沉积对构造具明显的响应,盆缘快速隆升阶段其盆地内相应的沉积物较粗,相对稳定阶段对应的沉积较细或缺失。     

一种约束盆地低温热历史的裂变径迹技术

裂变径迹(FT)技术是根据矿物中铀裂变产生的辐射损伤特性进行分析的低温热年代技术。随着对FT退火行为和实验退火模型研究的深入,使得这一技术成为约束沉积盆地低温热历史的重要手段。Laslett等、Crowley等和Ketcham等先后提出3个重要的磷灰石FT实验退火模型,其中以Ketcham等的退火模型研究最为深入,它分析了磷灰石类型、时间、温度和化学成分对其径迹退火的影响,使用c轴投射径迹长度和Dpar等参数,形成了描述磷灰石FT多元动力学退火的数学模型。锆石FT与U-Th/He技术、Ro值、地表温度和地层年龄等,均是约束磷灰石FT热历史重建的重要约束条件,HeFTy(2009)是进行低温热历史模拟的主要软件之一。     

伊犁盆地白垩纪剥露事件的裂变径迹证据

本文利用砂岩中磷灰石的裂变径迹方法, 研究了伊犁盆地中生代抬升-剥露事件。根据磷灰石裂变径迹测年结果, 开展了温度-时间热模拟反演研究, 结果揭示出伊犁盆地在115~95Ma期间存在一期重要的抬升-剥露冷却事件, 剥蚀量至少可达1.8km, 剥蚀速率至少为0.09mm/a。区域资料对比分析表明中晚白垩世的抬升剥露事件, 在天山地区乃至整个新疆的造山带普遍存在。      

裂变径迹法在研究造山带隆升过程中的应用介绍

介绍了４种类型的造山带隆升－冷却模式,不同模式对应不同的磷灰石裂变径年龄－－高程图特征;了不同构造造背景下的热历史特征一裂变径迹年龄序列。裂变径变宅遮挡同统计分布型式对应于不同的热历史,具有不同的年代学意义。     

Electrodynamic Disaggregation: Does it Affect Apatite Fission-Track and (U-Th)/He Analyses?

Apatite fission-track and (U-Th)/He analyses require the liberation of intact idiomorphic apatite grains from rock samples. While routinely being carried out by mechanical methods, electrodynamic disaggregation (ED) offers an alternative approach. The high-voltage discharges produced during the ED process create localised temperature peaks (10000 K) along a narrow plasma channel. In apatite, such high temperatures could potentially reduce the length of fission tracks, which start to anneal at temperatures > 60 °C, and could also enhance He diffusion, which becomes significant at 30–40 °C over geological time scales. A comparison of fission-track analyses and (U-Th)/He ages of apatites prepared both by mechanical (jaw crusher, disk mill) and ED processing provides a way of determining whether heating during the latter method has any significant effect. Apatites from three samples of different geological settings (an orthogneiss from Madagascar, the Fish Canyon Tuff, and a muscovite-gneiss from Greece) yielded statistically identical track length distributions compared to samples prepared mechanically. Additionally, (U-Th)/He ages of apatites from a leucogranite from Morocco prepared by both methods were indistinguishable. These first results indicated that during electrodynamic disaggregation apatite crystals were not heated enough to partially anneal the fission tracks or induce significant diffusive loss of He.     

Confined fission track lengths in apatite: a diagnostic tool for thermal history analysis

Fission-track ages in apatite are generally accepted as giving a measure of the time over which a sample has been exposed to temperatures below approximately 100° C. A compilation of the lengths of confined fission tracks in a wide variety of apatites from different geological environments has shown that the distribution of confined track lengths can provide unique thermal history information in the temperature range below about 150° C over times of the order of 10⁶ to 10⁹ years. The distribution of confined lengths of freshly produced induced tracks is characterised by a narrow, symmetrical distribution with a mean length of around 16.3 m and a standard deviation of the distribution of approximately 0.9 m. In volcanic and related rocks which have cooled very rapidly, and never been reheated above about 50° C, the distribution is also narrow and symmetric, but with a shorter mean of 14.5 to 15 m, and a standard deviation of the distribution of approximately 1.0 m. In granitic basement terrains which are thought never to have been significantly disturbed thermally, since their original post-emplacement cooling, the distribution becomes negatively skewed, with a mean around 12 or 13 m and a standard deviation between 1.2 and 2 m.This distribution is thought to characterise slow continuous cooling from temperatures in excess of 120° C, to ambient surface temperatures. More complex thermal histories produce correspondingly complex distributions of confined tracks. The continuous production of tracks through time, coupled with the fact that the length of each track shrinks to a value characteristic of the maximum temperature it has experienced, gives a final length distribution which directly reflects the nature of the variation of temperature with time. Most distinctive of the myriad possible forms of the final distribution are the bimodal distributions, which give clear evidence of a two-stage history, including high and low temperature phases. The study of confined length distributions therefore offers invaluable evidence on the meaning of any fission-track age, and bears the potential of providing rigorous constraints on thermal history in the temperature regime below about 150° C. The results of this study strongly suggest that any apatite fission-track age determination should be supported by a confined track length distribution.     

Age and Thermal History of the East Ore Section,Bayan,Obo Deposit—A Fission Track Study

Considerable attention has been paid in recent years to the study of geothermal history by using spontaneous fission tracks of 238U recorded in minerals.Apatite and zircon were used for fission track study in this paper because apatitie has been widely used as a natural geothermometer(Wang Shicheng et al., 1994) to reveal the thermal evolution of sedimentary rocks based on its low annealing temperature of fission tracks and zircon is characterized by a closing temperature above 700℃,The samples were collected from ferruginous,siliceous slate wall rock at the upper levels of the orebody and Nb-REE-Fe ores from deep tunnels.The age and thermal evolution of the orebody were discussed in terms of fission track characters and their length variations observed in the coexisting apatite and zircon in the same specimen.