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Experiment of the40Ar/39Ar dating of diagenetic illite in gas reservoirs
Longzhang Wang,Tongmo Dai,Ping’an Peng
Chinese Science Bulletin , 2004, DOI: 10.1007/BF02890459
Abstract: 40Ar/39Ar dating of diagenetic illite has been performed to investigate gas reservoirs in the Sulige Gas Field of the northern Ordos Basin. A series of technical challenges were confronted, including illite purification, Ar recoil loss, and separation of diagenetic illite from detrital illite. Mineral growth ages for diagenetic illite were obtained by this experiment, from which the age of gas emplacement was deduced to be later than 169 Ma.
Paleomagnetism, structure and 40Ar/39Ar geochronology of the Cerro Mercado pluton, Coahuila: Implications for the timing of the Laramide orogeny in northern Mexico
Molina-Garza, Roberto S.;Chávez-Cabello, Gabriel;Iriondo, Alexander;Porras-Vázquez, Mario Alberto;Terrazas-Calderón, Guillermo Daniel;
Revista mexicana de ciencias geológicas , 2008,
Abstract: the cerro mercado pluton, emplaced in the coahuila fold belt, contains magmatic, ductile, and brittle fabrics that suggest local and regional deformation during igneous emplacement, later affected by regional deformation in the area. the cerro mercado pluton intruded, deformed and uplifted upper cretaceous strata in the southern edge of the central depression of the sabinas basin. a hornblende mineral separate from the pluton yielded a 40ar/39ar plateau age of 44.29 ± 0.19ma (1σ), interpreted as an approximation to the crystallization age of the monzonite. a younger biotite total fusion age of 41.23 ± 0.21 ma (1σ) from a different rock sample is interpreted to represent slow cooling (80°c/ma) of the cerro mercado pluton. paleomagnetic analyses of the pluton yieldwell defined remanent magnetizations of nearly uniform reverse polarity, with a grand mean of d=178.2° and i=-61.7° (n=9 acceptable sites; k=57.5, α.95 = 6.8°). these data are discordant with respect to the eocene reference direction, indicating apparent clockwise rotation (8°) and inclination steepening (21°). the simplest interpretation of the discordance is that northwestward tilting of the pluton occurred during basin inversion within a weakly right lateral transpressive regime with nnw directed contraction. the strain field is consistent with contraction during the laramide orogeny. also, remanence acquisition is contemporaneous with both tectonic and magmatic fabrics in the pluton indicating that it is syntectonic. this suggests - in agreement with stratigraphic data - that the laramide orogeny in central coahuila ended some time after about 44 ma. we propose that reactivation of the san marcos fault and other basement faults in the sabinas basin represents the last manifestation of shortening produced by the laramide orogeny. this was a short episode of deformation that ended by the time of emplacement of younger plutons of the candela-monclova magmatic belt ca. 41 ma. this indicates that culmination
40Ar/39Ar geochronology constraints on hydrocarbon accumulation and destruction periods in the Bankeng paleo-reservoir in the southern margin of the middle Yangtze block
ZhaoQian Liu,LianFu Mei,HuaNing Qiu,ChuanBo Shen,JiGuang Tang,JianBing Yun
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4625-6
Abstract: The exact determination of isotopic ages of hydrocarbon accumulation, reconstruction and destruction periods using traditional isotopic dating methods is complex because of the small numbers of minerals that correlate with hydrocarbons. The quantitative and direct study of hydrocarbon geochronology is therefore an important scientific problem for isotope geochronology and petroleum geology. This study obtains two isotopic ages from a quartz vein sample associated with bitumen in a reverse fault located in the Bankeng paleo-reservoir on the southern margin of the middle Yangtze block (the northern margin of the Jiangnan-Xuefeng uplift) by inclusion 40Ar/39Ar stepwise crushing in a vacuum. Two different and good linear inverse isochrons that correspond to two age plateaus were determined. The two ages correspond to primary inclusions of about 228 Ma and secondary inclusions of about 149 Ma. These inclusion groups represent two distinct kinds of fluids. Quartz veins associated with bitumen in faulted paleo-reservoirs, which have a strict response relationship with tectonization and hydrocarbon accumulation, are the unified products of tectonic processes, hydrocarbon accumulation and reconstruction. Therefore, they can be used to constrain the hydrocarbon accumulation, reconstruction and destruction periods that are controlled by multiphase and complicated tectonic actions. The evolutionary processes of hydrocarbon accumulation can be divided into two periods consisting of a primary oil and gas reservoir formation period in the late Indosinian epoch (about 228 Ma) and a period of oil and gas reservoir reconstruction in the early Yanshan epoch (about 149 Ma). This study quantitatively reconstructs the hydrocarbon accumulation and destruction chronological framework of a giant hydrocarbon accumulation belt along the southern margin of the middle Yangtze block (the northern margin of the Jiangnan-Xuefeng uplift) controlled by multiphase and complicated tectonism. The two ages associated with hydrocarbons here correspond to the special controlling actions of continental tectonics in the Jiangnan-Xuefeng uplift that affected the timeline of reconstruction and destruction in this giant marine hydrocarbon accumulation. This study shows the feasibility and usefulness of dating inclusions with the 40Ar/39Ar technique for hydrocarbon geochronology, especially in the marine hydrocarbon accumulation region of southern China within a geological setting of old strata, high thermal evolution hydrocarbons, and complex, multiphase and multicycle tectonization.
40Ar/39Ar age and geochemical features of mugearite from the Qingshankou Formation: Significances for basin formation, hydrocarbon generation and petroleum accumulation of the Songliao Basin in Cretaceous
松辽盆地青山口组橄榄粗安岩:40Ar/39Ar年龄、地球化学及其成盆、成烃和成藏意义

WANG PuJun,GAO YouFeng,REN YanGuang,LIU WanZhu,ZHANG JianGuang,
王璞珺
,高有峰,任延广,刘万洙,张建光

岩石学报 , 2009,
Abstract: 在松辽盆地上白垩统青山口组二段湖相泥岩中识别出橄榄粗安岩夹层,高精度40Ar/39Ar坪年龄tp=88.0±0.3Ma,属晚白垩世Coniacian阶。岩石具玻基少斑斑状结构,斑晶为橄榄石、辉石和斜长石。岩石富钠、富铝、富轻稀土(∑LREE/∑HREE=8.0~9.7)和U、Th、Pb、Rb、Sr、Ba等不相容的大离子亲石元素,Rb/Sr比高、Sm/Nd比低,δEu =0.95~1.36,高镁(Mg#=0.61~0.64),高氧化度(Oxo=0.62~0.68),低分异指数(MDI=3.4~5.3)。MgO/Al2O3和标准矿物压力计算得到岩浆源区深度大于60km。岩浆源于富集型地幔,属板内火山岩,是成盆过程中裂谷作用发育到最大深切割期的产物。火山活动热效应及其高区域地温场有利于成烃,造成局部类礁相环境形成的大量生物灰岩沉积是重要烃源岩,火山岩之下的牵引构造、之上的差异压实局部高部位以及其周围的浊积体是成藏有利部位。
应用UV激光显微探针技术测定金云母的40Ar/39Ar年龄剖面  [PDF]
贺怀宇,王非,桑海清,王英兰,A.,Boven,朱日祥
科学通报 , 2004,
Abstract: UV激光40Ar/39Ar显微探针技术能对含钾矿物进行微区分析,测定其年龄剖面,真实地反映Ar同位素在矿物晶体内的分布,拓展了常规40Ar/39Ar年代学的应用领域.本文对新疆皮山煌斑岩中金云母进行了常规40Ar/39Ar阶段升温和UV激光40Ar/39Ar微区分析对比,结果显示金云母内Ar同位素分布均匀,激光微区分析结果与阶段升温结果一致.使用激光微区分析系统能准确测定矿物颗粒内的年龄剖面,为经历复杂热历史的样品提供了一种新的40Ar/39Ar微区年代学研究方法.
海绿石K-Ar、40Ar/39Ar年代学研究  [PDF]
李明荣,王松山,裘冀
地球学报 , 1994,
Abstract: 海绿石是与沉积岩同时形成的高钾层状硅酸盐自生矿物,其K-Ar、40Ar/39Ar年龄存在失真现象。笔者认为,引起年龄失真的主要原因是由于该矿物结构中含有可膨胀层。通过测量可膨胀层含量及中子活化过程中39Ar的丢失率,使可对海绿石常规K-Ar、40Ar/39Ar年龄进行校正,得到其年龄校正公式。
岩石微区激光探针质谱40Ar/39Ar定年研究  [PDF]
胡世玲,郑祥身,戴樟谟,蒲志平
地球学报 , 1997,
Abstract: 采用连续激光40Ar/39Ar测年技术,在岩石光片上成功地对贵州绿豆岩、南极地区3块火山岩及江西德兴钠长花岗岩进行了多点微区等时年龄测定;消除了过剩Ar的影响,部分样品作了40Ar/39Ar坪年龄谱测定,取得了满意的结果。
风化矿物黄钾铁矾40Ar/39Ar测年的基本方法――从样品采集到年龄测试  [PDF]
杨静,郑德文,陈文,武颖,李洁,张彦
地质通报 , 2015,
Abstract: 由于40Ar/39Ar定年方法在技术上极具复杂性,目前,国内在开展干旱区研究中很少使用风化矿物定年研究手段。重点介绍黄钾铁矾矿物40Ar/39Ar定年法的基本流程,并针对该方法的技术问题初步探讨了解决办法。研究表明,科学的野外采集样品、仔细的挑选矿物并综合采用多种测试手段(X衍射、扫描电镜、电子探针)进行监测可以获得纯净的风化矿物,并结合精细的40Ar/39Ar阶段加热技术,能够获得比较可靠的风化矿物40Ar/39Ar年龄。
Crushing modes of aluminium tubes under axial compression  [PDF]
Florent Henri Marc Rémy Pled,Wenyi Yan,Cui'E Wen
Physics , 2014,
Abstract: A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results would assist the design of crashworthy tube components with the preferred crushing mode with the maximum energy absorption.
40Ar/39Ar ages of lunar impact glasses: Relationships among Ar diffusivity, chemical composition, shape, and size  [PDF]
N. E. B. Zellner,J. W. Delano
Physics , 2015, DOI: 10.1016/j.gca.2015.04.013
Abstract: Lunar impact glasses, quenched melts produced during cratering events on the Moon, have the potential to provide not only compositional information about both the local and regional geology of the Moon but also information about the impact flux over time. We present in this paper the results of 73 new 40Ar/39Ar analyses of well-characterized, inclusion-free lunar impact glasses and demonstrate that size, shape, chemical composition, fraction of radiogenic 40Ar retained, and cosmic ray exposure (CRE) ages are important for 40Ar/39Ar investigations of these samples. Specifically, analyses of lunar impact glasses from the Apollo 14, 16, and 17 landing sites indicate that retention of radiogenic 40Ar is a strong function of post-formation thermal history in the lunar regolith, size, and chemical composition. Based on the relationships presented in this paper, lunar impact glasses with compositions and sizes sufficient to have retained 90% of their radiogenic Ar during 750 Ma of cosmic ray exposure at time-integrated temperatures of up to 290 K have been identified and are likely to have yielded reliable 40Ar/39Ar ages of formation. Additionally, ~50% of the identified impact glass spheres have formation ages of <500 Ma, while ~75% of the identified lunar impact glass shards and spheres have ages of formation <2000 Ma. The observed age-frequency distribution of lunar impact glasses may reflect two processes: (i) diminished preservation due to spontaneous shattering with age; and (ii) preservation of a remnant population of impact glasses from the tail end of the terminal lunar bombardment having 40Ar/39Ar ages up to 3800 Ma. A protocol is described for selecting and analyzing lunar impact glasses.
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