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1.
为厘定松辽盆地深部断陷层系地层的地质时代,解决不同断陷间断陷层系地层横向对比难度大的问题,笔者整理了松辽盆地及其周边露头断陷层系火山岩(火山灰)锆石U-Pb测年数据,选择有断代地质意义的有效年龄数据,并结合国际标准地层年代表对松辽盆地白垩系断陷层系年龄的限定,建立了松辽盆地断陷层系年代地层时间框架。确定了断陷层系地层年龄范围为登娄库组105.5~100.5 Ma、营城组118.0~105.5 Ma、沙河子组124.0~118.0 Ma、火石岭组135.0~124.0 Ma。该研究成果为松辽盆地开展断陷层系区域地层划分对比研究提供了时间标尺,为其他早白垩世断陷盆地的地层划分对比研究提供了参考。  相似文献   

2.
为了确定鄂尔多斯盆地苏里格气田的成藏年代,通过提取砂岩储层中的黏土质填隙物,分离分级成 < 0.5、0.5~1.0、1.0~2.0μm的分样品,进行伊利石激光阶段加热40Ar-39Ar定年.等时线年龄是自生伊利石与碎屑伊利石的混合年龄.通过趋势分析和回归分析分别获得极小的趋势年龄和极小的回归年龄,该年龄比较接近自生伊利石年龄.测试结果表明,伊利石的等时线年龄介于160.9~232.0 Ma之间,为自生伊利石与碎屑伊利石的混合年龄.采用数理统计方法获得极小趋势年龄和极小回归年龄分别为151.7 Ma和152.4 Ma,该年龄比较接近自生伊利石年龄,代表了热流体活动和油气成藏时间.   相似文献   

3.
对巢湖北部地区以碳酸盐岩为主的寒武系—下三叠统海相地层的黏土矿物分析及伊利石结晶度测定的结果表明:伊利石是本区海相地层的主体矿物,平均体积分数为73%。黏土矿物的成岩转化特征表现为蒙皂石的伊利石化。按照伊利石结晶度的成岩-浅变质程度划分,本区寒武系—下三叠统的成岩作用已达到最高成岩阶段。伊利石结晶度的纵向变化总体上可分为上、下两部分:下部寒武系至志留系的结晶度为0.41~0.60°Δ2θ,结晶度与埋深具有一定的相关性,成岩作用是下部地层黏土矿物特征的主控因素;上部泥盆系至下三叠统的结晶度为0.45~0.77°Δ2θ,呈波动变化,蒙皂石连续出现,地层没有被显著埋藏,沉积因素是上部地层黏土矿物特征的主控因素。下三叠统地层中蒙皂石的分布特征以及上泥盆统五通组顶部高岭石的普遍富集具有重要的古气候研究意义。  相似文献   

4.
胡振铎  朱杰辰 《铀矿地质》1998,14(4):218-226
笔者对沧参1井石炭、二叠纪地层中的粘土矿物特征进行研究,并对不同深度的粘土矿物进行了K-Ar、40Ar-39Ar及Rb-Sr法同位素地质年龄测定,得出至少存在三期伊利石的结论;碎屑伊利石,年龄为400Ma左右,在235—243Ma时受到热扰动;海西期末一印支早期形成的高温伊利石,其年龄为214—234Ma,在145Ma时经受一次热扰动;早侏罗世时期形成的伊利石,年龄为180Ma左右,分布比较普遍。这一研究结果无疑将有助于深入探讨区域地热场的演化,以及进一步研究有关地层的生、储油气能力。  相似文献   

5.
松辽盆地层序地层特征及油气聚集规律   总被引:22,自引:9,他引:13  
根据野外露头、钻井岩心、测井和地震资料,建立松辽盆地各级层序的识别标志和层序地层格架,将松辽盆地地层划分为白垩纪裂谷盆地巨层序和第三纪裂谷盆地巨层序,并将白垩纪裂谷盆地巨层序进一步划分为3个超层序组,7个超层序和19个层序.松辽盆地构造演化经历了断陷期、坳陷期和萎缩期3个阶段,断陷湖盆与坳陷湖盆成因机制不同.因此,层序地层内部特征及充填序列有较大差别.通过对层序地层格架内各体系域生储盖层发育特征、组合规律和油气聚集规律研究认为:水退体系域是储集砂体最发育、油气资源量最多的层段,其次为低水位和水进体系域,高水位体系域含油气较差.  相似文献   

6.
松辽盆地断陷期白垩纪营城组的时代归属   总被引:19,自引:1,他引:18  
本文结合生物地层,同位素年代学,古地磁及地层序列的最新研究成果,探讨了松辽盆地断陷期营城组的时代归属。营城组孢粉组合多繁盛于白垩纪早—中期的Hauterivian期—Albian期;营城组同位素年龄分布表现出两个峰值135 ~ 120Ma和115 ~ 110Ma,结合采样层位及地层序列特征认为135~130Ma代表营城组下段中基性火山岩的年龄,130 ~ 120Ma代表营城组一段酸性火山岩的年龄,115~110Ma代表营城组三段基性火山岩及顶部酸性火山岩的年龄;古地磁研究表明在Hauterivian期底界偏上的135Ma发生过磁性的倒转以及松辽盆地的快速北移。这些特征表明营城组的时代为Hauterivian期—Albian早期,同位素年龄为135 ~ 110Ma。  相似文献   

7.
对松辽盆地北部黑富地3井所钻遇的侵入岩进行同位素U-Pb年代学分析,以探讨其形成期次和构造演化特征,并对所侵入的地层进行时代约束.测试分析结果显示,锆石206Pb/238U年龄的加权平均值为245.5±1.9 Ma,表明侵入岩的结晶年龄为早中三叠世,指示松辽盆地北部发育早中三叠世岩浆热事件.同时存在两组捕获的锆石年龄,...  相似文献   

8.
松辽盆地西南隆起区高力板镇西南首次发现晚白垩世叶肢介化石4属6种,包括:EstheritesEuestherites)cf.pulcherrimus Zhang et Chen、EstheritesEuestherites)sp.、Estherites sp.、Halysestheria biformis Zhang et Chen、Glyptostracus sp.、Dictyestheria sp.,确定这套地层为嫩江组.该地区嫩江组的发现,为建立松辽盆地西南隆起区地层系列奠定了基础,为下一步开展松辽盆地油气地质调查研究提供了有力支撑.  相似文献   

9.
自生伊利石40Ar/39Ar法定年技术及气藏成藏期的确定   总被引:19,自引:1,他引:18  
为了确定天然气藏的成藏期,进行了自生伊利石的^40Ar/^39Ar法同位素定年实验.实验重点解决了自生伊利石的^40Ar/^39Ar法定年的几个技术难题:第一,粘土矿物的提纯,避免伊利石以外的含K矿物混入;第二,自生伊利石与碎屑伊利石的分离;第三,克服核反冲造成的Ar原子丢失.利用冷冻一加热循环碎样技术获得高纯度的粘土矿物;通过阶段加热得到的年龄谱可以区分自生伊利石与碎屑伊利石;利用“显微包裹”技术有效克服了核照射反冲问题.对鄂尔多斯盆地北部苏里格气田研究发现。二叠系储层中的伊利石有2种年龄图谱:一种只有自生伊利石的坪年龄;另一种图谱既有自生伊利石的坪年龄,也有碎屑伊利石的年龄,形成二阶式的图谱.通过自生伊利石的形成时间推断,天然气的最早充注时间晚于169~189Ma.实验的结果表明,冷冻加热循环碎样技术可以有效地避免伊利石以外的含K矿物混入.是获得高纯度粘土矿物的关键技术;自生伊利石^40Ar/^39Ar法定年技术可以用于确定天然气藏的成藏期.  相似文献   

10.
松辽盆地西南隆起区发现晚白垩世嫩江组叶肢介化石   总被引:1,自引:0,他引:1  
松辽盆地西南隆起区高力板镇西南首次发现晚白垩世叶肢介化石4属6种,包括:EstheritesEuestherites)cf.pulcherrimus Zhang et Chen、EstheritesEuestherites)sp.、Estherites sp.、Halysestheria biformis Zhang et Chen、Glyptostracus sp.、Dictyestheria sp.,确定这套地层为嫩江组.该地区嫩江组的发现,为建立松辽盆地西南隆起区地层系列奠定了基础,为下一步开展松辽盆地油气地质调查研究提供了有力支撑.  相似文献   

11.
通过对凤凰山铜矿床新屋里岩体的黑云母、斜长石单矿物进行阶段加热法40Ar-39Ar 定年,获得石英二长闪长岩中黑
云母及斜长石坪年龄分别为(152.1±1.7)Ma 和(135±1)Ma,花岗闪长岩中黑云母及斜长石坪年龄分别为(143.8±0.9)
Ma 和(140.4±0.9)Ma,反映了长江中下游地区燕山期岩浆活动的一个重要阶段。石英二长闪长岩中黑云母的40Ar-39Ar年
龄显著高于前人的锆石U-Pb 年龄,可能为含过剩Ar 的结果。结合已知年龄资料,作出新屋里岩体不同单元的冷却曲线,
显示新屋里岩体在晚侏罗世的冷却速率很大,暗示当时处于一种伸展的构造背景之下,其形成可能与中国东部中生代晚期
的岩石圈减薄事件有关。  相似文献   

12.
The Songliao Basin in northeast China is an intra-continental fossil rift basin mainly developed from the latest Jurassic and throughout the Cretaceous. The Daqing oil field in the basin is one of the largest hydrocarbon exploitation areas in China. A fission track (FT) study has been carried out on sandstone well samples in the Songliao Basin to constrain the depositional ages of Cretaceous strata and to ascertain their source region. FT dating also has been carried out on welded tuffs in the Dahinganling Mountains to determine their eruption ages. The detrital zircon FT age suggests that the depositional age of the middle Quantou Formation is younger than 109 Ma. Zircon FT ages for Cretaceous strata (from the Nenjiang Formation to the Quantou Formation) suggest that the source region has a fairly homogeneous cooling history at ~120-100 Ma. Eruption ages of welded tuffs in the Dahinganling Mountains show an age range from 110 to 92 Ma. The regional geology and FT data suggest that volcanic rocks in the Dahinganling Mountains were eroded soon after their deposition and were reworked toward the Songliao basin.  相似文献   

13.
The South China Sea began to outspread in the Oligocene. A great quantity of terraneous detritus was deposited in the northern continental shelf of the sea, mostly in Pearl River Mouth Basin, which constituted the main paleo-Pearl River Delta. The delta developed for a long geological time and formed a superimposed area. Almost all the oil and gas fields of detrital rock reservoir distribute in this delta. Thirty-three oil sandstone core samples in the Zhujiang Formation, lower Miocene (23–16 Ma), were collected from nine wells. The illite samples with detrital K feldspar (Kfs) separated from these sandstone cores in four sub-structural belts were analysed by the high-precision 40Ar/39Ar laser stepwise heating technique. All 33 illite 40Ar/39Ar data consistently yielded gradually rising age spectra at the low-temperature steps until reaching age plateaus at mid-high temperature steps. The youngest ages corresponding to the beginning steps were interpreted as the hydrocarbon accumulation ages and the plateau ages in mid-high temperature steps as the contributions of the detrital feldspar representing the ages of the granitic parent rocks in the provenances. The ages of the detrital feldspar from the Zhujiang Formation in the four sub-structural belts were different: (1) the late Cretaceous ages in the Lufeng 13 fault structural belt; (2) the late Cretaceous and early Cretaceous-Jurassic ages in the Huizhou 21 buried hill-fault belt; (3) the Jurassic and Triassic ages in the Xijiang 24 buried hill-fault belt; and (4) the early Cretaceous – late Jurassic ages in the Panyu 4 oil area. These detrital feldspar 40Ar/39Ar ages become younger and younger from west to east, corresponding to the age distribution of the granites in the adjacent Guangdong Province, Southern China.  相似文献   

14.
Six samples of a single carbonate-rich unit of the Swiss Préalpes, progressively metamorphosed from diagenesis to deep anchizone, yield 40Ar/39Ar spectra with variably developed staircase patterns, consistent with mixtures of detrital mica and neocrystallized mixed-layer illite/smectite. The lowest temperature heating steps for different size fractions (2–6?μm and 6–20?μm) converge to ~40?Ma providing an imprecise, maximum age of regional metamorphism. A method is described for distinguishing and quantifying the amount of pre-existing detrital mica versus neoformed illite layer in the illite/smectite formed during Tertiary Alpine metamorphism by comparison of X-ray diffraction patterns with Newmod© simulations. In the least metamorphosed samples the illite/smectite contains ~65% neoformed illite, and this illite accounts for approximately 17% of all dioctahedral phyllosilicate minerals in the rock (e.g., detrital mica and illite/smectite). In contrast, the illite/smectite from the more strongly metamorphosed samples contains >97% neoformed illite, which accounts for ~70% to >90% of all dioctahedral phyllosilicate minerals. Phyllosilicate morphologies viewed by scanning electron microscopy are consistent with these estimates. A process of dissolution/reprecipitation is inferred as a mechanism for the growth of the neoformed phyllosilicates. A plot of neoformed illite content versus 40Ar/39Ar total fusion age yields a near-linear curve with an extrapolated age of 27?Ma for 100% neoformed dioctahedral phyllosilicates. This age is interpreted as the time of incipient metamorphism and is consistent with independent biostratigraphic constraints. Model 40Ar/39Ar age spectra constructed with the XRD simulation results correspond well to the experimental data and illustrate the changes in degassing properties of progressively metamorphosed mixtures of detrital mica and neoformed illite.  相似文献   

15.
喻顺  陈文  孙敬博  尹继元  张彦  刘新宇  袁霞  马勋 《地质学报》2016,90(8):1874-1885
沉积盆地碎屑岩记录了相邻造山带构造演化及隆升剥蚀的重要信息。本文对库车盆地白垩系砂岩中的白云母进行了电子探针及~(40)Ar/~(39)Ar定年分析,并与天山造山带的数据对比研究表明:库车盆地白垩系砂岩中白云母为多硅白云母,硅原子数小于西南天山蓝片岩及榴辉岩中的多硅白云母,形成时的压力低于目前保留在西南天山蓝片岩中多硅白云母;白垩系砂岩多硅白云母~(40)Ar/~(39)Ar年龄为396.6 Ma,与在低温高压变质带中获得的多硅白云母~(40)Ar/~(39)Ar年龄419~310Ma一致,表明了在白垩纪西南天山低温高压变质岩带已抬升至地表遭受剥蚀,为库车盆地提供大量的物质,也表明了在白垩纪西南天山低温高压变质岩带高度(海拔)高于其南部的哈尔克山,而现今天山地貌形态显示低温高压变质岩海拔低于哈尔克山,这可能是由于新生代天山地区差异隆升剥蚀引起的。  相似文献   

16.
为了更清晰地理解优质烃源岩和优质储层的耦合关系在致密油气成藏过程中的控制作用,本文应用地化测试、恒速压汞、常规压汞、含烃流体包裹体等多种资料,对比了松辽盆地南部致密油和松辽盆地北部致密气的成藏条件。研究表明:1)优质源岩生、排烃中心基本吻合超压高值区,超压到达的边界就是致密油气富集边界。2)孔喉结构约束下的松南泉四段优质储层渗透率下限为0.10×10-3 μm2,松北沙河子组优质储层的渗透率下限为0.05×10-3 μm2。3)时间上,形成致密油气藏的前提条件是源储之间应具备"先致密后成藏"的匹配关系,这是决定其成藏机理的根本;空间上,2个研究区的"甜点区"均发育在近源、强压、高渗的优质源储叠合部位,其展布特征受控于优质源储的空间耦合关系。  相似文献   

17.
40Ar/39Ar step-heating data were collected from micron to submicron grain-sizes of correlative illite- and muscovite-rich Cambrian pelitic rocks from the western United States that range in metamorphic grade from the shallow diagenetic zone (zeolite facies) to the epizone (greenschist facies). With increasing metamorphic grade, maximum ages from 40Ar/39Ar release spectra decrease, as do total gas ages and retention ages. Previous studies have explained similar results as arising dominantly or entirely from the dissolution of detrital muscovite and precipitation/recrystallization of neo-formed illite. While recognizing the importance of these processes in evaluating our results, we suggest that the inverse correlation between apparent age and metamorphic grade is controlled, primarily, by thermally activated volume diffusion, analogous to the decrease in apparent ages with depth observed for many thermochronometers in borehole experiments. Our results suggest that complete resetting of the illite/muscovite Ar thermochronometer occurs between the high anchizone and epizone, or at roughly 300 °C. This empirical result is in agreement with previous calculations based on muscovite diffusion parameters, which indicate that muscovite grains with radii of 0.05–2 μm should have closure temperatures between 250 and 350 °C. At high anchizone conditions, we observe a reversal in the age/grain-size relationship (the finest grain-size produces the oldest apparent age), which may mark the stage in prograde subgreenschist facies metamorphism of pelitic rocks at which neo-formed illite/muscovite crystallites typically surpass the size of detrital muscovite grains. It is also approximately the stage at which neo-formed illite/muscovite crystallites develop sufficient Ar retentivity to produce geologically meaningful 40Ar/39Ar ages. Results from our sampling transect of Cambrian strata establish a framework for interpreting illite/muscovite 40Ar/39Ar age spectra at different stages of low-grade metamorphism and also illuminate the transformation of illite to muscovite. At Frenchman Mtn., NV, where the Cambrian Bright Angel Formation is at zeolite facies conditions, illite/muscovite 40Ar/39Ar data suggest a detrital muscovite component with an apparent age ≥967 Ma. The correlative Carrara Fm. is at anchizone conditions in the Panamint and Resting Spring Ranges of eastern California, and in these locations, illite/muscovite 40Ar/39Ar data suggest an early Permian episode of subgreenschist facies metamorphism. The same type of data from equivalent strata at epizone conditions (greenschist facies) in the footwall of the Bullfrog/Fluorspar Canyon detachment in southern Nevada reveals a period of slow-to-moderate Late Cretaceous cooling.  相似文献   

18.
对佳木斯隆起周缘的勃利盆地和鸡西盆地中的早白垩世穆棱组和滴道组砂岩样品进行了系统的碎屑锆石U-Pb同位素年代学和碎屑白云母40Ar/39Ar同位素年代学研究。结果表明,滴道组和穆棱组沉积时期,没有500Ma或大于500Ma的来自佳木斯地块基底的年龄纪录,暗示佳木斯隆起在早白垩世穆棱组沉积时期尚未隆起。黑龙江东部盆地群为统一的原型盆地,结合对该区白垩纪砂岩的矿物组成和砾石统计的研究成果,认为早白垩世末东山组沉积以后佳木斯隆起开始隆升,猴石沟组沉积时期佳木斯隆起已经隆升到一定高度并为其周缘盆地提供物源,同时随着佳木斯隆起的隆升,原来早白垩世的统一盆地遭到分割破坏,形成诸多相对独立的盆地。  相似文献   

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