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1.
《新疆地质》2017,(3)
和什托洛盖盆地上石炭统太勒古拉组具有页岩气勘探潜力。为详细了解太勒古拉组泥页岩岩矿特征及其对页岩气勘探开发的影响,采用X射线衍射仪定量分析法,对其中的泥页岩岩矿特征进行了较全面的系统分析,结果表明太勒古拉组泥页岩具以下特征:(1)脆性矿物百分含量均值超过50%,表明可压裂性较好;(2)黏土矿物以伊利石和绿泥石为主,且随着伊利石含量的增多,伊/蒙间层含量大致呈相应降低的规律;(3)太三段泥页岩黏土矿物组合为高岭石+伊蒙混层+绿泥石+伊利石,加之其有机质镜质体反射率深部平均为1.15%,地表平均为1.20%,表明太三段已进入中成岩阶段;(4)黏土矿物、石英+长石及碳酸盐岩含量与井深相关性较差;盆地西南缘及东南缘脆性矿物含量略高于南缘,盆地北缘脆性矿物含量略低于盆地南缘,黏土矿物反之;(5)该组沉积于滨海环境,与川南筇竹寺组和龙马溪组海相泥页岩的形成环境不同。 相似文献
2.
以蒙脱石为初始材料,通过水热实验模拟在不同温度压力条件下蒙脱石的伊利石化过程。利用X射线粉末衍射及X射线荧光光谱、红外光谱和扫描电镜等方法对样品的矿物物相、化学成分、晶体结构与微观形貌等进行分析,其结果表明:(1)蒙脱石至伊利石的转化受温度和压力条件的控制;(2)随着温度和压力的增高,蒙脱石伊利石化沿着蒙脱石-无序伊蒙混层-有序伊蒙混层-伊利石的转化序列进行转化;(3)水热实验模拟表明蒙脱石至伊利石的转化以溶解重结晶机制为主。实验结果不仅有助于了解埋藏与低级变质作用中的蒙脱石伊利石化过程,同时为研究断层活动所致断层泥中黏土矿物的转化及反演断层形成时温度压力条件提供基本参数。 相似文献
3.
由于房屋建设开挖,浙江省江山市五家垄出露6条新鲜小断层,属于江绍断裂的次级组成部分.结合野外地质勘查,运用粉晶X射线衍射和穆斯堡尔谱技术对五家垄断层的3条小断层(F1、F2与F3)的断层泥和断层围岩进行矿物组成和铁元素化学种分布特征的对比分析与研究发现:断层围岩与断层泥的矿物成分主要为石英和黏土矿物,还含有少量钠长石和方解石,其中黏土矿物以伊利石、伊蒙混层和高蒙混层为主,还含有少量的绿泥石、高岭石和极少量的蒙脱石和蛭石;除采自F2断层的JS07样品外,断层围岩中造岩矿物含量高于断层泥,而断层泥黏土含量高于断层围岩;F1断层泥黏土矿物只有伊利石,显示断层带内为一个相对稳定的环境,F2与F3断层泥中伊利石含量低于断层围岩,蒙脱石、伊蒙混层含量高于断层围岩,指示其处于一个潮湿、强氧化环境;F1断层围岩高含量的还原性铁指示断层围岩形成的过程中有还原性物质的参与或者处于相对封闭的环境,F1、F3断层泥与F3上盘高含量的氧化铁亦说明F1、F3断层近期不活跃或者是块体内断层;断层带内黏土矿物的类型及组合与断层带内的氧化还原环境显示五家垄断层处于相对稳定的环境,但断层带内伊利石含量较高,有利于断层活动,五家垄断层的活动性与发震可能性应引起重视. 相似文献
4.
断裂带的变形行为和断层滑移机制是目前地震研究关注的热点,断裂带岩石特征、内部结构与物理化学性质是确定断层蠕滑或粘滑行为以及断层滑移机制的基础和关键。本文以鲜水河断裂带乾宁段地表出露的断裂岩为研究对象,通过野外地质调查、室内光学显微镜、扫描电镜、粒度统计、粉末X射线衍射分析（XRD）和薄片X射线荧光光谱分析（XRF）等多种研究方法,对鲜水河断裂带岩石特征、结构构造、物性、矿物成分及化学元素分布开展了详细的分析,并探讨了相关变形行为和滑移机制。分析表明：（1）断裂带核部主要由黑色断层泥、浅黄色及黄色断层角砾岩和灰色碎裂岩、灰色断层角砾岩组成,呈单核对称结构;（2）黑色断层泥厚3~5cm,具有快速滑动结构特征,表现为断层粘滑行为。断层泥可划分出13个滑移带,最窄滑移带厚约40μm,至少代表13期古地震事件;（3）断层泥主要由伊利石、高岭石和石英等矿物组成,其中边部伊蒙混层含量异常高,为最新一次古地震的主滑移带。由于伊利石和伊蒙混层（或蒙脱石）为主要黏土矿物的断层泥渗透率低、孔隙流体压力大,以及发现断层泥楔入脉,表明地震过程中断层滑动存在热增压弱化机制;（4）从断层泥不同滑动带中碎块蚀变程度和矿物分布特征来看,地震主滑动带有向碎裂岩方向迁移的趋势。推测断层在滑动过程中,更趋向于向弱矿物含量高（如伊利石、伊蒙混层）、强矿物含量低（如方解石、高岭石）的围岩一侧迁移。 相似文献
5.
《世界地质》2020,(2)
以水泉子沟—天山口断裂带杨树林剖面为研究对象,利用传统黏土矿物地质温度计讨论断层活动特征及断层活动导致温度小幅升高的可能。通过X—射线粉末衍射(XRD)及X—射线荧光光谱(XRF)测试,分析了断层泥及其中黏土矿物的物相及主量元素特征,同时,利用扫描电镜(SEM)对断层泥中分离出来的石英颗粒微形貌进行了表征。研究结果表明,杨树林剖面所在的断层主要经历了黏滑事件,断层活动性较弱且水岩反应程度较低;断层泥中的黏土矿物主要为伊蒙混层矿物,垂直于断层面方向上的蒙脱石伊利石化程度及黏土矿物含量变化趋势表明伊蒙混层矿物可能受到了同震摩擦升温效应的影响;利用黏土矿物地质温度计估算得知,断层泥中伊蒙混层矿物的形成温度为140℃～160℃;断层泥中伊蒙混层矿物形成温度上下限的差值为20℃,代表了同震摩擦造成的断层内部温度小幅升高情况。 相似文献
6.
探究断层泥力学行为是研究断裂带工程地质效应的基础,以延安神道沟断裂带断层泥为对象,借助颗粒分析、X射线衍射等微观测试手段研究了3种颜色断层泥的组构特征,并通过环剪试验分析了不同含水率条件下重塑断层泥的力学行为。研究结果表明:单峰型粒径曲线的断层泥级配明显优于双峰型,石英、云母和长石为主要的非黏土矿物,黏土矿物则以伊利石和高岭石为主,赤铁矿与绿泥石的相对含量是造成断层泥颜色差异的主要原因;受含水率和粗颗粒含量的影响,断层泥应变软化特征显著,应变软化随着含水率增大呈现先增强后减弱的变化规律,当含水率小于塑限含水率时,应变软化特征则随着粗颗粒含量升高而趋弱;内摩擦角是影响应变软化特征的主要力学指标,峰值内摩擦角和残余内摩擦角均与含水率呈负相关;矿物含量影响内摩擦角的变化,在5%和10%含水率条件下,内摩擦角随非黏土矿物含量的升高而增大。 相似文献
7.
断裂带的岩石组成、内部结构和地球化学特征是认识断裂活动性质和变形行为的关键,而断层泥作为断裂带核部的重要物质,不仅影响断裂带强度,而且控制断裂的滑移机制。本文以汶川地震的发震断裂龙门山映秀-北川断裂带北川段沙坝探槽中的断层泥为研究对象,通过对断层泥进行宏观与显微构造观察、粉末X射线衍射分析（XRD）、矿物自动化定量分析（TIMA）和薄片微区X射线荧光光谱分析（μXRF）等多种分析,探讨了其所蕴含的断裂变形行为和滑移机制。研究表明：北川段断裂带NW盘主要为寒武纪碳质泥页岩和板岩,SE盘由半固结的黄色砂质黏土层组成。断裂带核部由面理发育的黑色断层角砾岩和面理化的断层泥组成,断层泥厚约25cm,分为黄色断层泥、灰色断层泥和黑色断层泥,汶川地震滑移带沿灰色断层泥和黑色断层泥边界分布,在滑移带附近可见明显的拖曳构造与R1次级剪切破裂,指示了逆冲滑动的性质。断层泥中的碎块呈棱角状大小不均一,显示出地震快速滑动特征,表现为粘滑行为。黄色和灰色断层泥中黏土矿物含量（42%~52%）远高于黑色断层泥（19%~29%）,前者石英（36%~47%）、伊利石（18%~32%）和绿泥石（7%~15%）含量整体略高于后者中的含量,而长石含量整体低于后者,表明黄色和灰色断层泥中水-岩作用较强于黑色断层泥,推测前者断层泥的孔隙度高于后者;断层泥中含有较多的伊蒙混层,靠近滑移带Fe元素呈明显增加趋势,暗示了摩擦产生了大量的热,同时,黑色断层泥中发育有石墨,说明断层滑移具有热增压弱化机制。龙门山映秀-北川断裂带北段北川断裂在岩石组成和规模上与南段映秀断裂虹口段断裂带有着明显差异,但均存在断裂滑移的石墨化作用,这些研究对认识映秀-北川断裂带南北段的滑移行为具有重要的指示意义。 相似文献
8.
为了探讨伊利石对煤化作用和沉积环境的指示作用，以华北地区京西煤田侏罗纪煤层夹矸为研究对象，采用X射线衍射方法（XRD）和X射线荧光方法（XRF）分别测定煤层夹矸的矿物组成和化学组成，研究夹矸中伊利石矿物学特征及成因。结果表明，京西煤田侏罗纪煤层夹矸主要由伊利石、绿泥石和石英组成，其中，伊利石质量分数平均为62.92%。将XRD数据和XRF数据进行对比分析，计算得到伊利石平均化学式为（K0.37（NH4）0.03）Al2（Si3.60Al0.40O10）（OH）2。京西煤田煤层夹矸中伊利石主要由高岭石转化而来，伊利石的NH4+占层间阳离子的比例具有随沉积古盐度升高而逐渐升高的趋势，n（Si）/n（Al）Ⅳ具有随煤化程度升高而逐渐降低的趋势，这表明京西煤田侏罗纪煤层夹矸中的伊利石矿物学特征对沉积环境和煤化作用具有一定的指示作用。 相似文献
9.
10.
胶东半岛中生代金矿床具有重要的经济价值,其蚀变和矿化均受北东向断裂控制。例如,位于胶东半岛西北部的新立金矿床受区域三山岛-仓上断裂(F1)和次级断裂(F2)控制,其中F1广泛地控制蚀变和矿化,F2仅分割黄铁绢英岩化蚀变和钾化蚀变。本文选取新立金矿床F1和F2的断层泥为研究对象,通过显微观察,矿物组成测定,激光粒度分析等多种手段,探讨断层泥物质组成、矿物成因、演化阶段及其在成矿过程中的作用。矿物学分析表明F1断层泥主要成分为高岭石和石英,含少量黄铁矿、伊利石和石膏;F2断层泥含有大量的石英和绢云母以及少量高岭石和伊蒙混层。根据矿物共生关系和相图分析得出,高岭石是绢云母反应形成的,伊利石由高岭石转化所致,伊蒙混层是高岭石转化为伊利石的中间产物,这些矿物之间的转化反映了aK+或aK+/aH+连续减小。F1断层泥中黄铁矿和F2断层泥中石英和绢云母可能为围岩残留,石膏是次生风化的产物。F1断层泥的粒度分布曲线呈单峰型、复式双峰和三峰型,其粒度分布分维值为2.61~2.82;而F2断层泥仅呈简单双峰型,分维值为2.46~2.52,表明F1断层泥组份经历颗粒旋转磨蚀阶段,F2断层泥组份处于约束碾磨阶段。综上所述,水岩反应和构造磨蚀在断层泥的形成过程中扮演重要角色,两者在主断裂F1中更强烈、复杂。鉴于F2产出位置和断层泥特征,我们推断F2为成矿后构造。断层泥中大量的黏土矿物、高度分化的颗粒粒度以及定向的显微构造导致低的横向渗透性,使断层作为障碍层阻隔成矿流体并形成差异的蚀变矿化带。 相似文献
11.
Ronald K. Stoessell 《Geochimica et cosmochimica acta》1979,43(8):1151-1159
The dependence on the composition of the thermodynamic stability of an illite can be treated in terms of a regular solution site-mixing model. Four end-member micas (muscovite, pyrophyllite, phlogopite, and annite) were mixed to simulate an illite in this study. In the model, random mixing of cations was assumed over each given class of cation sites. Mixing over cation sites between different classes of cation sites was not allowed. The resulting free energy and chemical potential equations contain four site interaction parameters: three for octahedral site interactions and one for interlayer and tetrahedral site interactions. These parameters cannot presently be evaluated because of a lack of experimental data on Fe3+-free illites. The model does imply that the octahedral site interaction parameters must be significantly more positive than the interlayer and tetrahedral site interaction parameter to account for the dominant dioctahedral nature of most natural illites. This constraint is necessary to balance out the increase in stability due to the configurational entropy of an illite having a major trioctahedral component.The model can be extended to cover a wider range of illite compositions by the inclusion of an end-member mica containing Fe3+ ions in the octahedral sites. At present the thermodynamic properties of such an end-member are unknown. 相似文献
12.
Recurrent events on a Quaternary fault recorded in the mineralogy and micromorphology of a weathering profile, Yangsan Fault System, Korea 总被引：1，自引：0，他引：1
Recurrence characteristics of a Quaternary fault are generally investigated on the basis of field properties that are rapidly degraded by chemical weathering and erosion in warm humid climates. Here we show that in intense weathering environments, mineralogical and micromorphological investigations are valuable in paleoseismological reconstruction. A weathering profile developed in Late Quaternary marine terrace deposits along the southeastern coast of the Korean Peninsula was disturbed by tectonic movement that appears to be a simple one-time reverse faulting event based on field observations. A comparative analysis of the mineralogy, micromorphology, and chemistry of the weathering profile and fault gouge, however, reveals that both the microfissures in the deformed weathering profile and larger void spaces along the fault plane were filled with multi-stage accumulations of illuvial clay and silt minerals of detrital origin, suggesting a repetition of fissuring and subsequent sealing in the weathering profile as it underwent continuous mineralogical transformation and particle translocation. We reconstruct a sequence of multiple faulting events unrecognized in previous field surveys, which requires revision of the view that the Korean Peninsula was tectonically stable, during the Late Quaternary. 相似文献
13.
Gouges formed in north-northeast-striking fault zones of the Sydney region and associated host-rocks were investigated by XRD, SEM, TEM and optical microscopy in order to determine their mineralogy. XRD studies reveal that illite, illite–smectite, kaolinite, quartz and dickite are present in varying proportions. Kübler Indices (0.54–0.71) and low smectite contents in illite–smectite (<10% smectite) in most gouges and host-rocks, indicate the assemblages formed at temperatures between 120 and 150°C. Those at the Heathcote Road, Lucas Heights location formed at lower temperatures (<100°C). SEM images of the clays in host sublitharenites and gouges show a variety of sizes and habits that reflect variations in fluid temperature and rate of crystallisation. SEM studies also reveal that detrital quartz grains exhibit overgrowths and etch pits of varying density, size and shape that are more strongly developed in the gouges than in the host-rocks. These features are thought to be related to higher fluid/rock ratios brought about by major ingress of fluids into the fault zones. The mineral assemblage present and the features exhibited are believed to have formed in response to a thermal event associated with the early stages of the breakup of Gondwana. 相似文献
14.
Neoformed minerals in shallow fault rocks are increasingly recognized as key to the behavior of faults in the elasto-frictional regime, but neither the conditions nor the processes which wall-rock is transformed into clay minerals are well understood. Yet, understanding of these mineral transformations is required to predict the mechanical and seismogenic behavior of faults. We therefore present a systematic study of clay gouge mineralogy from 30 outcrops of 17 low-angle normal faults (LANF's) in the American Cordillera to demonstrate the range and type of clay transformations in natural fault gouges. The sampled faults juxtapose a wide and representative range of wall rock types, including sedimentary, metamorphic and igneous rocks under shallow-crustal conditions. Clay mineral transformations were observed in all but one of 28 faults; one fault contains only mechanically derived clay-rich gouge, which formed entirely by cataclasis.Clay mineral transformations observed in gouges show four general patterns: 1) growth of authigenic 1Md illite, either by transformation of fragmental 2M1 illite or muscovite, or growth after the dissolution of K-feldspar. Illitization of fragmental illite–smectite is observed in LANF gouges, but is less common than reported from faults with sedimentary wall rocks; 2) ‘retrograde diagenesis’ of an early mechanically derived chlorite-rich gouge to authigenic chlorite–smectite and saponite (Mg-rich tri-octahedral smectite); 3) reaction of mechanically derived chlorite-rich gouges with Mg-rich fluids at low temperatures (50–150 °C) to produce localized lenses of one of two assemblages: sepiolite + saponite + talc + lizardite or palygorskite +/− chlorite +/− quartz; and 4) growth of authigenic di-octahedral smectite from alteration of acidic volcanic wall rocks. These transformation groups are consistent with patterns observed in fault rocks elsewhere. The main controls for the type of neoformed clay in gouge appear to be wall-rock chemistry and fluid chemistry, and temperatures in the range of 60–180 °C. 相似文献
15.
四川汶川5.12大地震同震滑动断层泥的发现及意义 总被引：4，自引：0，他引：4
2008年汶川8.0级地震沿龙门山断裂带内的映秀—北川断裂和灌县—安县断裂产生了近300 km的同震地表破裂带。震后地质科学考察发现地表变形以逆冲为主,并伴有右旋走滑。地震地表破裂带大多沿古生代碳质泥岩、页岩和三叠系煤系地层内的滑动面出露地表,这些软弱地层为地震破裂带冲到地表提供了超低摩擦滑动带。我们发现在同震垂直和水平位错达6m左右的地表破裂带,地震的同震滑动发生在厚度约0.5~2cm 的狭窄滑动带内,以发育新鲜的灰色断层泥为特征,这些断层泥是地震断层快速滑动过程中岩石—流体相互作用的结果。 相似文献
16.
《Chemie der Erde / Geochemistry》2022,82(4):125919
Two stages of illite mineralization are recognized in the hydrothermal alteration zone of the Hoam granite. These illites are formed as a result of pervasive alteration by re-equilibration with high water/rock in a brittle environment below <2 km; the mineralization timing is middle Oligocene (26–27 Ma), coinciding with the timing of crustal deformation related to the opening of the East Sea (Sea of Japan). The mineralogical and geochemical characteristics of the clearly distinguished illites at each site indicate that they were mineralized from different fluid injections in distinct geological environments. Illites at the site-1 alteration zone are characterized by high-K content [K0.84 per O10(OH)2], 2M1 polytype of 99 %, hexagonal plate shape, and coexistence with pyrite. These observations indicate that the illites were formed in a slow cooling system (>250 °C), high fS2, and a relatively acidic environment. The pseudomorphic replacement combined with matrix-filling texture indicates that the illites at the site-1 alteration zone recorded the changes in fluid conditions from low to high water-rock ratio. In contrast, the illites at the site-2 alteration zone show the coexistence of polytypes (2M1, 1M, and 1Md), high-K illites [(K0.83 per O10(OH)2]/low-K illites [K0.63 per O10(OH)2], platy/hairy shapes, and presence of magnetite. Furthermore, this alteration zone no longer exhibits primary textures because of pervasive alteration induced by the dissolution-precipitation process. These results indicate that they were formed in a rapid cooling system and were continuously under conditions of high water-rock ratio, as well as in a less acidic and fS2 environment than that observed at the site-1 alteration zone. The behavior of trace elements for each illite primarily depends on the constituents of the hydrothermal fluid, which reflect different degrees of fluid evolution. The enrichment of high field strength elements (Nb and Ta), large ion lithophile elements (B, Be, and Cs), rare earth elements, and actinide elements (U and Th) in illite at the site-2 alteration zone shows that these elements formed by a more evolved fluid than that of the illite at the site-1 alteration zone. In addition, negative Ce anomalies at the site-2 alteration zone indicate that these crystallized in a reducing environment. Considering the mineralogical and geochemical properties of illites at the site-1 and site-2 alteration zones, the illite mineralization in the Hoam granite was likely generated by at least two episodes of hydrothermal illite mineralization, which originated from episodic injections of fluids, rather than continuously evolved fluids. 相似文献
17.
Supergene nickel deposits of New Caledonia that have been formed in the Neogene by weathering of obducted ultramafic rocks are controlled by fracture development. The relationship of tropical weathering and tectonic structures, faults and tension gashes, have been investigated in order to determine whether fractures play a passive role only, as previously thought; or alternatively, if brittle tectonics was acting together with alteration. Observation of time‐relationship, textures, and mineralogy of various fracture fills and fault gouges shows that active faulting has played a prominent role not only in facilitating drainage and providing room for synkinematic crystallization of supergene nickel silicate, but also in mobilizing already formed sparse nickel ore, producing the very high grade ore nicknamed “green gold”. 相似文献
18.
Dehydration of dioctahedral aluminous phyllosilicates: thermodynamic modelling and implications for thermobarometric estimates 总被引：1，自引：1，他引：0
Benoît Dubacq Olivier Vidal Vincent De Andrade 《Contributions to Mineralogy and Petrology》2010,159(2):159-174
We propose a solid-solution model for dioctahedral aluminous phyllosilicates accounting for the main compositional variations,
including hydration, observed in natural smectites, interlayered illite/smectite, illites, and phengites from diagenetic to
high-grade metamorphic conditions. The suggested formalism involves dehydrated micas and hydrated pyrophyllite-like thermodynamic
end-members. With these end-members, the equilibrium conditions of quartz + water + K-bearing mica-like phyllosilicates of
fixed 2:1 composition are represented by a line in P–T space along which the interlayer water content varies. The relevant thermodynamic properties required for the calculation
of equilibrium conditions were derived using a set of 250 natural data of known maximal temperature and pressure conditions,
which covers a range between 25°C and few MPa to 800°C and 5 GPa. The temperatures calculated at fixed pressure with our model
are in fair agreement with those reported in the literature for the 250 natural data. At low temperature and pressure, the
amount of interlayer water in K-deficient phengite and illite is predicted to reach 100% of the apparent vacancies, which
is consistent with previous values reported in the literature. Although the amount of interlayer water is predicted to decrease
with pressure and temperature, it is calculated to be significant in K-deficient phengite from LT–HP pelites metamorphosed
at about 350°C, 10 kbar. The presence of molecular water in the interlayer site of such phengites has been confirmed by FTIR
mapping. Its implications for P–T estimates are discussed. 相似文献
19.
Inclined K–Ar illite age spectra in brittle fault gouges: effects of fault reactivation and wall‐rock contamination 
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下载免费PDF全文 K–Ar clay fraction ages of brittle faults often vary with grain size, decreasing in the finer size fractions, producing an inclined age–grain‐size spectrum. K–Ar ages and mineralogical characterization of gouges from two normal faults in the Kongsberg silver mines, southern Norway, suggest that inclined spectra derived from brittle fault rocks reflect the mixing of inherited components with authigenic mineral phases. The ages of the coarsest and finest fractions constrain faulting at c. 260–270 Ma and reactivation around 200–210 Ma, respectively. This study demonstrates how wall‐rock contamination influences the K–Ar age of the coarsest size fractions and that authigenic illite and K‐feldspar can crystallize synkinematically under equivalent conditions and thus yield the same K–Ar ages. 相似文献
20.
Walter Kurz Andreas Wölfler Robert Rabitsch Johann Genser 《Swiss Journal of Geoscience》2011,104(2):323-343
The Lavanttal Fault Zone (LFZ) is generally considered to be related to Miocene orogen-parallel escape tectonics in the Eastern
Alps. By applying thermochronological methods with retention temperatures ranging from ~450 to ~40°C we have investigated
the thermochronological evolution of the LFZ and the adjacent Koralm Complex (Eastern Alps). 40Ar/39Ar dating on white mica and zircon fission track (ZFT) thermochronology were carried out on host rocks (HRs) and fault-related
rocks (cataclasites and fault gouges) directly adjacent to the unfaulted protolith. These data are interpreted together with
recently published apatite fission track (AFT) and apatite (U-Th)/He ages. Sample material was taken from three drill cores
transecting the LFZ. Ar release spectra in cataclastic shear zones partly show strongly rejuvenated incremental ages, indicating
lattice distortion during cataclastic shearing or hydrothermal alteration. Integrated plateau ages from fault rocks (~76 Ma)
are in parts slightly younger than plateau ages from HRs (>80 Ma). Incremental ages from fault rock samples are in part highly
reduced (~43 Ma). ZFT ages within fault gouges (~65 Ma) are slightly reduced compared to the ages from HRs, and fission tracks
show reduced lengths. Combining these results with AFT and apatite (U-Th)/He ages from fault rocks of the same fault zone
allows the recognition of distinct faulting events along the LFZ from Miocene to Pliocene times. Contemporaneous with this
faulting, the Koralm Complex experienced accelerated cooling in Late Miocene times. Late-Cretaceous to Palaeogene movement
on the LFZ cannot be clearly proven. 40Ar/39Ar muscovite and ZFT ages were probably partly thermally affected along the LFZ during Miocene times. 相似文献