共查询到18条相似文献，搜索用时 78 毫秒
1.
裂变径迹技术以样品用量少、封闭温度低以及测年范围广等优势,被广泛应用于地质学研究中。完全退火或部分退火样品可有效记录岩体的冷却-剥露历史,限制构造活动起始时间,探讨上覆岩石的风化剥蚀历史与矿床保存变化之间的关系,定量化矿床隆升剥蚀量,实现找矿预测; 锆石裂变径迹封闭温度对应天然气生成温度区间,可运用于油气勘探研究计算中; 近年来结合元素含量分析的裂变径迹技术还可进行物源分析,LA-ICP-MS技术的引进为测量低U含量矿物的径迹带来了曙光。系统总结了磷灰石与锆石裂变径迹退火特性的研究成果,以及温度、化学成分、结晶各向异性及Dpar值等因素对磷灰石径迹退火特性数据解释可能产生的影响,锆石径迹热稳定性的降低主要受制于辐射损伤效应。实验室退火特性研究为了解繁杂的径迹退火化学动力机制提供了重要的理论参考,但在实际的数据解释中需结合地质背景,以获得更为清晰的地质热事件演化研究时间格架。结合径迹测年在矿床、山体隆升剥蚀、盆地热史等研究的典型案例分析,以期为裂变径迹应用的相关研究提供参考。 相似文献
2.
锆石裂变径迹长度是锆石裂变径迹热年代学研究的一个重要参数。基于不同热背景的沉积盆地样品实测数据,分析锆石裂变径迹的退火行为,探讨锆石裂变径迹长度的影响因素。研究表明,Sk1井样品的裂变径迹长度和径迹与结晶C轴夹角之间具有一定的负相关性,即夹角愈小,径迹长度愈长;反之,夹角愈大,径迹长度愈短。Sk1井样品径迹与结晶C轴夹角主要分布在10°～70°,整体分布较随机;而Ku1井样品多分布于高角度（60°～90°）,整体分布不随机。Sk1井锆石裂变径迹在沉积盆地开始退火温度为220℃,深层样品的平均径迹长度为5.02～5.55μm;Ku1井锆石裂变径迹在沉积盆地开始退火温度为170℃,深层样品的平均径迹长度为8.06～8.31μm,高温热背景下Sk1井的锆石裂变径迹开始受到沉积盆地影响的温度高于Ku1井。研究认为锆石裂变径迹在不同热背景下的开始退火温度和退火行为产生的差异是由盆地不同的增温速率导致的。Sk1井的中浅层样品平均径迹长度范围为5.85～8.36μm,Ku1井中浅层样品平均径迹长度为9.21～10.05μm。2口井中浅层样品的最小年龄大于地层年龄,表明未受到沉积盆地的影响,缩短的径迹... 相似文献
3.
阿尔泰造山带富蕴基性麻粒岩折返过程:来自裂变径迹热年代学的限定 总被引：1，自引：1，他引：0
论文在阿尔泰造山带富蕴县乌恰沟基性麻粒岩的锆石SHRIMP年代学、地球化学、变质温压条件和形成的大地构造背景研究基础上,利用麻粒岩、围岩片麻岩和侵入到麻粒岩的辉绿岩岩墙的裂变径迹热年代学探讨了麻粒岩从深部折返至地表的过程。裂变径迹年代学研究发现基性麻粒岩的锆石裂变径迹年龄为三叠纪,而麻粒岩、围岩片麻岩和侵入到麻粒岩的辉绿岩岩墙的磷灰石裂变径迹年龄均显示为晚白垩世至新生代早期。对磷灰石裂变径迹测试所得到的径迹长度和单颗粒年龄数据进行热史模拟表明,三叠纪时,基性麻粒岩抬升至约地表以下7.8km的上地壳,温度冷却至锆石裂变径迹的封闭温度;晚白垩世至新生代早期(约100～50Ma),麻粒岩、围岩片麻岩和辉绿岩抬升至约地表以下3.5km,温度冷却至磷灰石裂变径迹的封闭温度;约50～15Ma,三者滞留在约地表以下1.7km的磷灰石部分退火带;约15Ma以来,喜马拉雅运动使得它们被抬升剥蚀至地表。 相似文献
4.
据磷灰石裂变径迹具有在较低温度下能够退火的特征，以及锆石径迹封闭温度在７５０℃以上的特点，研究同一矿石中两种不同单矿物产生的裂变径迹与记录条件（径迹长度变化）。测定白云鄂博主矿成矿年龄数据属于海西中晚期，其值为３．３￣４亿年，是改造后形成的时代。 相似文献
5.
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 总被引：2，自引：0，他引：2
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 相似文献
6.
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。 相似文献
7.
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。 相似文献
8.
压力对磷灰石裂变径迹退火的影响初步探讨 总被引：1，自引：0，他引：1
磷灰石裂变径迹分析技术是确定岩石低温热历史的一种有效方法,其退火后径迹长度受多种因素影响,如温度、压力、磷灰石的化学成分、径迹与结晶C轴的夹角、蚀象直径（Dpar）以及年龄等,但压力的影响很少有文章论述.在调研大量国内外资料的基础上,通过将统计后的数据作图来阐明压力对径迹退火的影响.研究结果表明压力对径迹的退火具有重要影响,压力越大,退火后得到的径迹长度越短,且随着压力的增大,径迹变短的程度也在增大.当压力小于150 MPa时,压力的影响可以忽略,这时径迹退火主要受温度影响.压力和温度在磷灰石裂变径迹退火时起到相互弥补的作用,即高压、低温与低压、高温都能达到相同的退火程度. 相似文献
9.
一种约束盆地低温热历史的裂变径迹技术 总被引：1，自引：0，他引：1
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。 相似文献
10.
对采自中国南方十万大山盆地中生代地层的11个磷灰石样品和6个锆石样品进行了裂变径迹分析,所有磷灰石样品以及锆石样品SS-5、SW033、SW055的裂变径迹年龄数据均小于样品的地层年龄,表明这些样品在沉积后所经历的埋藏温度曾经大于最大退火温度。样品Shw-1、SW027、SW025的锆石裂变径迹年龄大于样品的地层年龄,反映的是源区的锆石年龄。根据磷灰石裂变径迹年龄数据进行的时间一温度历史模拟表明,十万大山地区的磷灰石样品基本反映了相同的低温段热演化史。各个样品在41～85Ma之间分别达到最大古地温值(介于98～175℃之间),此后各个样品的热演化史总体上呈冷却的趋势。自晚白垩世以来,盆地各地普遍遭受了抬升剥蚀过程,估算的地层剥蚀量在2281～4484m之间。 相似文献
11.
裂变径迹定年技术在构造演化研究中的应用 总被引：11，自引：0，他引：11
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。 相似文献
12.
Fission-track dating was conducted on zircons and apatites from 11 cores of the upper Xiaganchaigou Formation and lower Shangganchaigou Formation (northwestern Qaidam Basin). The obtained apatite fission-track age is 3.1–61.9 Ma, and the zircon fission-track age is 49.2–123.5 Ma. Although the average apatite age is consistent with ages predicted from the stratigraphy, nine of the 11 apatite fission-track ages have \(\hbox {P}(\upchi ^{2}) < 5\%\), indicating that the grains experienced heterogeneous annealing after sedimentation. The average zircon age is greater than that indicated by stratigraphy, and all eight zircon fission ages have \(\hbox {P}(\upchi ^{2})>5\%\), exhibiting consistent characteristics and indicating that zircons retain provenance age information after burial. From the zircon and apatite ages, the fission-track length distribution, and the geological setting, the northwestern Qaidam Basin has experienced two tectonothermal events since the Late Mesozoic, at \(39.1 \pm 9.3\) to \(133.7\,\pm \,6.6\,\hbox {Ma}\) and \(1.2 \pm 0.6\) to \(32.0\,\pm \,3.0\,\hbox {Ma}\). The earlier (39.1–133.7 Ma) tectonothermal event resulted from the initial collision of the Indian and Eurasian plates. As a consequence of the collision, the Altyn Tagh fault, which forms the northwestern boundary of the Qaidam Basin, began to develop. Subsequently, uplift of the Altyn Tagh mountains began and the northwestern depression of the Qaidam Basin started to form. The later (1.2–32.0 Ma) tectonothermal event resulted from further collision of the Indian and Eurasian plates along the Yarlung Tsangpo suture zone. Strata in the Qaidam Basin were further deformed by transpression in this period and this period played a crucial role in petroleum accumulation. 相似文献
13.
本文阐述了颗粒锆石裂变径迹法及双带源逐层蒸发法的方法原理，对取自美国菲什（Fish）峡谷凝灰岩中的锆石裂变径迹年龄国际标准样及取自香港花岗岩中锆石的两种年龄结果进行了对比，并分析了它们年龄差异的原因，认为铅年龄代表锆石的结晶年龄，而裂变径迹表观年龄代表岩体的冷却年龄或最后一次热事件的年代。开展不同方法的对比研究，可以得到更多的信息，以期更好地探讨研究区的演化历史。 相似文献
14.
Integration of zircon color and zircon fission-track zonation patterns in orogenic belts: application to the Southern Alps, New Zealand 总被引：2，自引：0，他引：2
An exhumed crustal section of the Mesozoic Torlesse terrane underlies the Southern Alps collision zone in New Zealand. Since the Late Miocene, oblique horizontal shortening has formed the northeastern–southwestern trending orogen and exhumed the crustal section within it. On the eastern side, rocks are zeolite- to prehnite–pumpellyite-grade greywacke; on the western side rocks, they have the same protolith, but are greenschist to amphibolite facies of the Alpine Schist. Zircon crystals from sediments in east-flowing rivers (hinterland) have pre-orogenic fission-track ages (>80 Ma) and are dominated by pink, radiation-damaged grains (up to 60%). These zircons are derived from the upper 10 km crustal section (unreset FT color zone) that includes the Late Cenozoic zircon partial annealing zone; both fission tracks and color remain intact and unaffected by orogenesis. Many zircon crystals from sediments in west-flowing rivers (foreland) have synorogenic FT ages, and about 80% are colorless due to thermal annealing. They have been derived from rocks that originally lay in the reset FT color zone and the underlying reset FT colorless zone. The reset FT color zone occurs between 250 and 400 °C. In this zone, zircon crystals have color but reset FT ages that reflect the timing of orogenesis. 相似文献
15.
Fission-track thermochronology has been applied to apatite, zircon and titanite from various depths of the Baltic Shield. Burial due to Sveconorwegian (Grenville) and Caledonian foreland sedimentation is revealed.
Titanite and zircon fission-track ages from surface samples (from eastern Sweden) do not vary significantly and average ∼ 850 Myr. It is suggested that Sveconorwegian sediments reached a thickness of at least 8 km in eastern Sweden. Exhumation of these sediments was succeeded by deposition of Lower Palaeozoic cover rocks. Apatite fission-track ages along a transect from SW to NE across the shield, increase from ∼ 300 Myr to ∼ 900 Myr and yield the Phanerozoic history of subsidence and exhumation. Apatite fission tracks, in the basement of the thickest parts of the foreland basin, were totally annealed. These results suggest a > 600 km wide Caledonian foreland basin filled by Devonian sediments that were > 2.5 km thick in southern and western Sweden, thinning to the east (in Finland). 相似文献
Titanite and zircon fission-track ages from surface samples (from eastern Sweden) do not vary significantly and average ∼ 850 Myr. It is suggested that Sveconorwegian sediments reached a thickness of at least 8 km in eastern Sweden. Exhumation of these sediments was succeeded by deposition of Lower Palaeozoic cover rocks. Apatite fission-track ages along a transect from SW to NE across the shield, increase from ∼ 300 Myr to ∼ 900 Myr and yield the Phanerozoic history of subsidence and exhumation. Apatite fission tracks, in the basement of the thickest parts of the foreland basin, were totally annealed. These results suggest a > 600 km wide Caledonian foreland basin filled by Devonian sediments that were > 2.5 km thick in southern and western Sweden, thinning to the east (in Finland). 相似文献
16.
Zircon and apatite fission-track analyses from Late Carboniferous felsic volcanic rocks of the NE German Basin (Halle area and Friedland drilling) reveal at least two major post-emplacement thermal events. After initial cooling at ca. 300 Ma, the volcanic pile underwent a major thermal event at ca. 200 Ma that reached in most places ca. 250-280 °C and led to the new growth of clay minerals. This event is recorded in the zircon fission-track data and can be related to Jurassic-Triassic rifting in Europe. Another thermal event is recorded in the apatite samples at ca. 100 Ma. A close correlation is observed between apatite fission-track age, texture, and sample alteration. Coarse-grained samples are stronger altered and have younger fission-track ages. Hydrothermal alteration coupled with advective heating probably caused these Upper Cretaceous fission-track ages. The latter event can be related to block faulting and inversion of the European plate during the early stages of the Alpine orogeny. 相似文献
17.
裂变径迹分析方法利用裂变径迹年龄及裂变径迹长度分布形态来反映随时间产生的裂变径迹积累及由温度控制的退火(裂变径迹缩短或消失)两种因素综合作用的结果。近几年来，有关磷灰石的退火特征进行了大量实验和野外研究，取得了较大进展。本文通过对80年代以来国内外裂变径迹研究状况的追踪调研结果，简要介绍裂变径迹定年方法的主要进展及应用情况。 相似文献
18.
The provenance of Cenomanian to Eocene flysch deposits accreted along the northern margin of the Eastern Alps has been investigated by means of zircon fission-track (FT) geochronology and zircon morphology. The Rhenodanubian flysch and Ybbsitz klippen zone comprise several nappes representing the Main flysch and Laab basins. The Laab basin received sediments of stable European provenance, indicated by pre-Variscan, Variscan, and Permian–Triassic zircon FT ages, and was thus located in the immediate south of the European margin. The Main flysch basin was supplied mainly from the evolving Eastern Alps and was therefore situated south of the Laab basin. Zircon populations with Permian to Jurassic cooling ages in the Main flysch basin are related to increased heat fluxes during the break-up of Pangaea and are probably derived from the northwestern part of the Eastern Alps. The dominant Cretaceous zircon FT cooling ages reflect Eoalpine metamorphism in the Austroalpine realm. 相似文献