共查询到19条相似文献，搜索用时 125 毫秒
1.
山东东营凹陷渐新统东营组的天文地层研究 总被引：4，自引：2，他引：2
XU Dao-yi ) YAO Yi-min ) ZHANG Hai-feng ) HAN Yan-ben ) YIN Zhi-qiang ) HE Qing-fang ) BIAN Xue-mei ) ) Institute of Geology China Earthquake Administration Beijing ) Geological Scientific Research Institute of Shengli Oilfield Company SINOPEC Dongying ) National Astronomical Observatories Chinese Academy of Sciences Beijing 《地层学杂志》2007,(Z2)
选定东营凹陷牛38、郝科1和利1等3口井东营组进行天文地层研究。以牛38井沙河街组一段顶界31.8Ma作为东营组底界年龄,得到3口井各段的年龄平均值为:东二段底28.406Ma,东一段底25.385Ma和顶界24.467Ma。东营组底界(31.829Ma)大致相当于"中国区域地层表"提出的32Ma的渐新统底年龄,但是与"国际地层表"提出的渐新世鲁培尔阶底界(33.9Ma)相差1.9Myr。东三段底界、顶界的平均年龄分别为31.829Ma、28.406Ma大致可与中国的乌兰布拉格阶或国际的鲁培尔阶中上部相当;东二段底界至东一段顶界的平均年龄大致相当于塔本布鲁克阶或夏特阶。根据东营组岩石地层与天文地层研究认为,在三角洲沉积过程中,东营组各段界线是穿时的,如东三与东二段界线的年龄相差可达1.4Myr。根据偏心率理论曲线和小波分析,夏特阶底界(28.4Ma)附近的变化可能与偏心率100ka左右理论周期的特殊变化有关。 相似文献
2.
认识偏心率周期的地层古气候意义 总被引：15，自引：0，他引：15
介绍了偏心率周期在地层和古气候研究方面的新发展.现有地球轨道模式对250Ma以来的轨道运算误差能控制在0.2%之内, 使基于偏心率周期来划分地层年代成为可能.新的国际标准地层年代表以405ka长偏心率周期为基础来划分主要地层界线.新生代将包括E1-E162偏心率长周期, 底界年龄(65.5±0.3) Ma.这一地层年代表的建立, 标志着轨道地层学时代的到来.偏心率的100ka短周期和405ka长周期在诸多地质记录中都有反映, 特别是来自深海钻孔的物理化学古气候指标.很多古气候重大事件往往发生在偏心率周期的弱振幅时期, 表明弱振幅时期易受其他因素的干扰影响, 这些因素包括碳储库、冰盖和海平面变化、电磁场, 以及区域构造重组等等.越来越多的研究发现碳同位素在偏心率周期上与地球轨道驱动相关, 且常领先于氧同位素的变化, 表明热带碳循环过程是影响全球气候变化的关键因素之一. 相似文献
3.
为建立西沙地区与邻近琼东南盆地深水区之间可对比的地层格架及明确二者之间碳酸盐岩—生物礁群的发育规律,基于岩芯暴露面、生物地层、古地磁及化学地层的分析与相互印证,开展了西科1井的综合地层研究。研究认为该井0～214.89 m为乐东组,底界年龄约2.0 Ma; 214.89～288.43 m为莺歌海组一段,底界年龄约3.2 Ma; 288.43～374.95 m为莺歌海组二段,底界年龄约5.3Ma; 374.95～470.1m为黄流组一段,底界年龄约7.2 Ma; 470.1～576.5 m为黄流组二段,底界年龄约11.6 Ma; 576.5～758.4 m为梅山组一段,底界年龄约13.8 Ma;758.4～1032.46m为梅山组二段,底界年龄约16Ma;1032.46～1179.69m为三亚组一段,底界年龄约21Ma;1179.69～1257.52 m为三亚组二段,底界年龄约23 Ma。 相似文献
4.
山东济阳坳陷始新统-渐新统天文地层界线年龄分析 总被引：2，自引：2，他引：0
YAO Yi-min ) XU Dao-yi ) HAN Yan-ben ) YIN Zhi-qiang ) ZHANG Hai-feng ) ) Geological Scientific Research Institute of Shengli Oilfield Company SINOPEC Dongying ) Institute of Geology China Earthquake Administration Beijing ) National Astronomical Observatories Chinese Academy of Sciences Beijing 《地层学杂志》2007,(Z2)
山东济阳坳陷沙河街组上部天文地层研究是以牛38井沙三段中亚段顶界年龄34.892Ma作为标定,分析和计算出沙二段下亚段底年龄为33.799Ma、沙段二段上亚段底为33.338Ma、沙一段底为32.940Ma和东营组底为31.829Ma。从天文地层界线年龄分析,沙三段-沙二段界线的年龄大致可对比为"国际地层表(2004)"始新统-渐新统界线年龄33.90Ma,而沙二段下亚段-上亚段界线年龄比国际始新统-渐新统界线的滞后大约600ka。在"中国区域地层表"始新统-渐新统界线年龄(32Ma)和"国际地层表"的始新统-渐新统界线年龄(33.9Ma)之差的1.9Myr,大致相当于本区计算的沙一、二段的持续时间。SP数据的小波分析表明,在沙二段-沙三上亚段界线附近,即约33.8Ma之后,约405ka周期开始变得不明显、不规则,幅度亦下降,剧烈突变发生时间在33.4Ma左右。上述界线对应偏心率周期的理论值突变的时间。因此推论始新世-渐新世转折期是偏心率多个理论周期重迭而导致的一个特殊的时期,也是本区沙二段下亚段这段地层形成不整合面的时间,大约在33.8—33.4Ma期间。 相似文献
5.
通过对山西榆社地区新近纪地层的野外地质调查和实测剖面,对分布于该区的新近纪地层进行了详细的研究和划分,提供了新的ESR测年数据,并结合古地磁年龄、生物地层序列确定了该区新近纪地层顺序为:新近系上新统上部麻则沟组(Naa m)、新近系上新统下部高庄组(N12 g)和中新统马会组(N1m).根据实测剖面,可将这3个组的河湖相地层划分为37层,总厚度达446.5 m.ESR测年结果表明,麻则沟组的形成时间为2.50～3.04 Ma,属新近纪上新世晚期;高庄组形成时间为3.25～5.25 Ma,属新近纪上新世早期;马会组形成时间为5.30～13.10 Ma,属新近纪中新世晚期. 相似文献
6.
根据湖南地层发育情况，依国际地层划分标准和中国地层指南要求，将湖南省境内原震旦纪早世划归新元古代南华纪，地层系统可分为3个相区。综合已有同位素测年数据，初步建立起南华纪年代构造格架，确立南华纪底界年龄为800Ma左右，顶界年龄为700Ma左右． 相似文献
7.
在研究了黔西南及邻区中—晚三叠世地层的层序界面特征、地层结构和堆叠型式之后 ,将其划分为 5个沉积层序 ,并描述了层序内各体系域的特点 ,在此基础上 ,通过综合研究已取得的生物地层资料 ,将其与Haq等列出的三叠纪生物地层时带进行对比 ,初步标定了各沉积层序及体系域的界面年龄 (层序 1底界年龄 2 39.4Ma;层序 2底界年龄 2 38Ma;层序 3底界年龄 2 33Ma;层序 4底界年龄 2 2 7Ma,顶界年龄 2 2 3Ma) ,从而建立了本区分辨率较高的中—晚三叠世地层格架。格架中层序地层的组合样式 ,在 2级海平面缓慢下降的背景下 ,受盆地构造沉降的影响较大。当层序处于构造沉降的加速期时 ,呈退积型组合方式 (如层序 1和层序 3) ;而当层序处于构造沉降的平缓期时 ,则呈进积型组合方式 (如层序 2和层序 4 )。 相似文献
8.
国际地层委员会最新表决通过第四系为系级年代地层单位,它位于新近系之上,底界由意大利西西里岛的Monte San Nicola"金钉子"定义,也就是由定义格拉斯阶底界的"金钉子"来定义,年龄值约为2.59Ma;更新统的底界也下移到这个位置,格拉斯阶划归更新统,长期争论的第四系的地位和定义问题有望得到解决。 相似文献
9.
10.
东营凹陷明化镇组（狭义）相当于渤海湾地区明化镇组（广义）的上段。选取东营凹陷华8、郝科1等5口井的测井数据（SP、GR）进行了明化镇组天文地层研究。把本区东辛2-4井明化镇组顶界年龄值（2.588 Ma BP）作为5口井明化镇组顶界年龄值,根据频谱、数字滤波和小波分析结果,得出明化镇组各段的堆积速率、延续时间,并得出明下段底界平均年龄为10.794 Ma BP;明上段底界平均年龄为5.121Ma BP。东营凹陷明化镇组下段与国际地层表的中新世晚期及中国区域地层表的保德阶相当;明上段的底界可对比为上新世的底界（5.332 Ma BP）,明上段相当于中国的高庄阶和麻则沟阶。在大约11—5 Ma BP期间中,曾有过几次环境突变：较强的突变大约发生在 10.873 Ma BP,较弱的是在 8.9 Ma BP,次强的是在7 Ma BP,最后发生的相当强的突变是在5.11 Ma BP前后。根据天文地层、天文周期、地球构造气候旋回等研究成果,在11—2.6 Ma BP期间,地球上可能存在过大约2Ma间隔的突变,并与区域或全球性的地层变化界线大体一致。 相似文献
11.
The Hanjiang Formation of Langhian age(middle Miocene) in the Pearl River Mouth Basin (PRMB),South China Sea consists of deltaic siliciclastic and neritic shelf carbonate rhythmic alternations,which form one of the potential reservoirs of the basin.To improve stratigraphic resolutions for hydrocarbon prospecting and exploration in the basin,the present study undertakes spectral analysis of high-resolution natural gamma-ray(NCR) well-logging record to determine the dominant frequency components and test whether Milankovitch orbital signals are recorded in rhythmic successions.Analytical results indicate the orbital cycles of precession(～19 ka and～23 ka), obliquity(～41 ka),and eccentricity(～100 ka and～405 ka),which provide the strong evidence for astronomically driven climate changes in the rhythmic alternation successions.Within biochronological constraint,a high-resolution astronomical timescale was constructed through the astronomical tuning of the NGR record to recent astronomically calculated variation of Earth’s orbit. The astronomically tuned timescale can be applied to calculate astronomical ages for the geological events and bioevents recognized throughout the period.The first downhole occurrences of foraminifers Globorotalia peripheroronda and Globigerinoides sicanus are dated at 14.546 Ma and 14.919 Ma,respectively,which are slightly different from earlier estimates in the South China Sea. When compared with the global sea-level change chart,the astronomical estimate for the sequences recognized based on microfossil distributions have the same end time but the different initiation time. This is probably due to the local or regional tectonic activities superimposed on eustatic rise which postponed the effect of global sea-level rising.Astronomical timescale also resolves the depositional evolution history for the Langhian Stage(middle Miocene) with a variation that strongly resembles that of Earth’s orbital eccentricity predicted from 13.65 Ma to 15.97 Ma.We infer that the main factor controlling the variability of the sedimentation rate in the Hanjiang Formation is related to the～405-ka-period eccentricity. 相似文献
12.
Sedimentary deposits of the Lower Cretaceous Xiagou Formation form the most significant potential hydrocarbon reservoirs in the Qingxi Sag, Jiuquan Basin(NW China). Zircon U-Pb ages of the dated basalts at the top of the Xiagou Formation give an isochron age of 115.6 Ma, and the sedimentation interval of the Xiagou Formation was speculated to range from about 125/124 Ma to 115 Ma based on paleontological research and stratigraphic correlation analysis. Here we use GR logging data as a palaeoenvironmental and palaeoclimatic proxy to conduct a detailed cyclostratigraphic study of five selected wells. Power spectra, evolutionary fast Fourier transformation and wavelet analysis all reveal significant sedimentary cycles in the Xiagou Formation. The ratios of cycle wavelengths in these stratigraphic units are 33.82 m : 7.91 m : 3.06 m : 1.79 m, which is similar to the ratio of orbital targets of 20 : 5 : 2 : 1. The ratio of 20 : 5 : 2 : 1 is interpreted as Milankovitch cycles of 405 kyr long eccentricity,100 kyr short eccentricity, 37 kyr obliquity, and 22 kyr precession cycles respectively. A high-resolution astronomical time scale is constructed by tuning the stratigraphy into target curves of orbital cycles respectively. Based on the astronomical time scale, the absolute ages of 55 samples were estimated,which are used for subsequent stable carbon and oxygen isotope stratigraphy analysis. The analysis results of the five studied wells in the Qingxi Sag indicate:(1) a negative trend of δ~(13)C values upwards in the Xiagou Formation, and(2) negative δ~(18)O values with a positive trend upwards. Both relatively heavy values and pronounced covariances of δ~(13)C values and δ~(18)O values indicate an arid-evaporationcontrolled climate during the sedimentary period of the Lower Cretaceous Xiagou Formation, Qingxi Sag, Jiuquan Basin. Moreover, positive covariances of SQK_1g_(2+3) indicate extremely high temperature, and negative covariances of SQK_1g_1 indicate a relatively low temperature. 相似文献
13.
旋回地层学的研究对象由海相地层逐渐转移到陆相深水地层.为了探究通过旋回地层学研究方法在陆相浅水湖盆建立高频层序格架的可能,采用频谱分析、天文调谐、“米氏”沉积速率拾取等手段对东海陆架盆地西湖凹陷黄岩区渐新统坳陷湖盆的岩相敏感曲线-GR数据开展研究.频谱分析结果显示黄岩区花港组受405 ka长偏心率周期（E）、121 ka和97 ka短偏心率周期（e）、28 ka斜率周期（O）以及约22 ka岁差周期（P）的调控.在浅水湖泊环境的富泥区,以La2004天文解决方案给出的65°N平均日照序列为参照进行天文调谐,建立了浮动天文年代标尺;在浅水三角洲环境的富砂区,通过滑动窗口频谱分析得到“米氏”沉积速率曲线,结合锆石铀铅测年资料的校验和岩石组合类型联合约束,完成高频层序格架划分.研究表明:黄岩区花港组持续时间约为10.9 Ma,可识别出27个405 ka长偏心率周期,根据偏心率滤波曲线和日照量各级次包络面的对应关系共划分11个四级层序,27个五级层序,分别对应着0.8~1.6 Ma和0.4 Ma的基准面旋回,每个旋回在沉积速率曲线上表现为高?低?高的特征.本次研究提供了一种利用“米氏”沉积速率进行高频层序格架搭建及层序?时间单元拾取的新方法,拓宽了旋回地层学的应用范围. 相似文献
14.
冀中中奥陶统高频率旋回层序的基本特征 总被引：2，自引：0，他引：2
王立峰 《沉积与特提斯地质》1994,(6)
通过野外实测剖面及路线观察，河北中部中奥陶统马家沟群的高频率旋回可划分为三个级别，并与层序地层学术语可以对比，由低到高为；六级旋回──韵律层；五级旋回──准层序；四级旋回──准层序组。这些由米兰柯维奇驱动力所控制的旋回层序在不同的沉积环境中具有不同岩石组合特征，反映了高频率旋回的沉积模式。 相似文献
15.
《地学前缘(英文版)》2020,11(4):1345-1352
One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sedimentation signals,high resolution astronomical time scale(ATS) can be obtained.Paleoclimate proxies are widely used to extract astronomical cycles.However different proxies may respond differently to astronomical signals and nonastronomical noises including tectonics,diagenesis,and measurement error among others.Astronomical time scale constructed based on a single proxy where its signal-to-noise ratio is low may have uncertainty that is difficult to evaluate but can be revealed by utilizing other proxies.Here,we test eight astronomical age models using two astrochro no logical methods from four paleoclimate proxies(i.e.,color reflection L~* and b~*,natural gamma radiation,and bulk density) from the Turonian to the Coniacian of the Cretaceous Period at the Demerara Rise in the equatorial Atlantic.The two astrochronological methods are time calibration using long eccentricity bandpass filtering(E1 bandpass) and tracking the long eccentricity from evolutive harmonic analysis(tracking EHA).The statistical mean and standard deviation of four age models from the four proxies are calculated to construct one integrated age model with age uncertainty in each method.Results demonstrate that extracting astronomical signals from multiple paleoclimate proxies is a valid method to estimate age model uncertainties.Anchored at the Cenomanian/Turonian boundary with an age of 93.9 ± 0.15 Ma from biostratigraphy,the ages for CC11/CC12(calcareous nannofossil zones),Turonian/Coniacian(CC12/CC13),CC13/CC14,and Coniacian/Santonian boundaries are 91.25±0.20 Ma,89.87±0.20 Ma,86.36±0.33 Ma,and 86.03±0.32 Ma in E1 bandpass method,compared with 91.17±0.36 Ma,89.74±0.38 Ma,86.13±1.31 Ma,and 85.80±1.33 Ma respectively in tracking EHA method.These results are consistent with previous studies within error and provide a reliable estimation of uncertainties of the ages. 相似文献
16.
旋回地层学是提高地质年代标尺精度的一种重要方法。特提斯海相沉积是旋回地层学研究的良好对象,与西特提斯比较,东特提斯的旋回地层学研究程度较低,第四纪之前的研究精确度有待进一步的提高。西藏南部广泛出露海相白垩系,其中定日贡扎剖面出露的上白垩统尤为连续和完整。在对贡扎剖面野外观察及其层束厚度测量的基础上,通过快速傅立叶变换(FFT),分析该地层蕴含的地球轨道周期,得到了与理论值较为接近的结果:偏心率周期,4092 ka/周期(E1),1279 ka/周期(E2),93 ka/周期(E5);斜率周期,512 ka/周期(O1),409 ka/周期(O2),389 ka/周期(O2)。在功率谱分析过程中,利用层束和超层束组的关系进行了调谐的处理,并比较调谐前后结果,来确定调谐的重要性,证明该地层沉积速率的变化:地层由老至新,其沉积速率的变化趋势整体为由小变大,变化范围为086～253 cm/ka。进一步对比东西特提斯和其他地区研究结果,证明东西特提斯海相沉积在外形、成因和所蕴含的轨道周期的一致性,地球轨道周期变长与理论值变化的一致性。最后给出了下一步工作的建议。
关键词：藏南; 定日; 晚白垩世; Coniacian阶; 旋回地层学 相似文献
17.
Sea-level change, carbon cycling and palaeoclimate during the Late Cenomanian of northwest Europe; an integrated palaeoenvironmental analysis 总被引：3，自引：1，他引：3
A new high resolution sea-level curve for the Late Cenomanian M. geslinianum Zone has been generated using sequence stratigraphic analysis on transects through the margins of the Anglo-Paris Basin in the UK and Saxony Basin in Germany. Transgressive sediments that bury a rocky shoreline in the Dresden area have proved particularly useful in determining both the absolute amount of sea-level change and the rate of rise. After a brief fall at the base of the M. geslinianum Zone, sea level rose rapidly through the higher part of the zone, resulting in an overall short term eustatic rise of 22–28 m. Biostratigraphy and carbon isotope stratigraphy have enabled detailed correlations to be made between marginal locations and thick, relatively complete, basinal successions. The basinal successions at Eastbourne, UK, and Gröbern, Germany, provide both geochemical proxies for palaeoenvironmental change, including oxygen and carbon isotope records, and an orbital timescale graduated in precession and eccentricity cycles. Integration of the sea-level history with palaeoclimate evolution, palaeoceanography and changes in carbon cycling allows a detailed reconstruction of events during the Late Cenomanian. Orbital forcing on long eccentricity maxima provides the underlying drive for these changes, but amplification by tectonic events and feedback mechanisms augmented the orbital effects and made the Cenomanian/Turonian Boundary Event distinctive. In particular, variations in atmospheric CO2 caused by oceanic drawdown and a brief period of intense volcanic outgassing resulted respectively in short term cooling and warming events. The magnitude and high rates (up to 1 m/1 kyr) of sea-level rise are diagnostic of glacioeustasy, however improbable this may appear at the height of the Cretaceous greenhouse. 相似文献
18.
南海ODP1143站上新世至更新世天文年代标尺的建立 总被引：8，自引：3，他引：5
基于底栖有孔虫δ18O的精确的年代标尺是古海洋学研究的基础, 特别是长度超过5 Ma, 分辨率小于5 ka的连续δ18O记录在全球大洋深海记录中更是凤毛麟角.在大西洋和东太平洋已经建立起了类似的代表性剖面, 如大西洋ODP659站和东太平洋ODP846站, 但在对全球气候有着重要影响的“西太平洋暖池区”还没有建立起这样的剖面.以南海大洋钻探184航次1143站底栖有孔虫的δ18O为材料, 建立了西太平洋地区跨越5 Ma、分辨率达2~ 3 ka的天文年代标尺.天文调谐的基本原理参照Imbrie et al.(1984), 并将斜率周期上8 ka的相位差和岁差周期上5 ka的相位差从晚更新世扩展到5 Ma; 调谐目标选用Laskar(1990)的斜率和岁差; 调谐方法采用了有别于ODP659站和ODP846站的自动轨道调谐方法(Yu and Ding, 1998).调谐结果显示, 1143站190.77 m、191个冰期、间冰期的深海沉积记录了5.02 Ma的南海古海洋学历史; 1143站布容/松山磁性反转事件的年龄为0.78 Ma, 与前人研究结果一致; 15个识别出的浮游有孔虫生物事件年龄部分与已经发表过的年龄相吻合, 部分为该生物事件在南沙海区的新年龄.由年代标尺推导出的南海沉积特征显示, 2.9 Ma是沉积速率的一个转折点, 在此之前, 平均线性沉积速率只有39.5 m/Ma, 冰期、间冰期平均波动幅度为50 m/Ma; 2.9 Ma以后, 平均线性沉积速率猛然上升到65.4 m/Ma, 冰期、间冰期平均波动幅度为200 m/Ma.此外, 南海的沉积速率还显示出冰期或间冰期中的亚冰阶沉积速率高, 而相邻的间冰期或亚间冰阶的沉积速率低, 这种特点在更新世尤为典型.这可能与全球冰量变化带来的冰期、间冰期差异性风化剥蚀和搬运有关. 相似文献
19.
地球公转轨道偏心率变化的构造运动响应 总被引：5，自引：0，他引：5
最近3Ma发生的主要构造运动和气候变化事件,在准0.4Ma周期上与地球轨道偏心率变化存在一致性。据黄土高原地层记录划分的构造气候旋回界限,日历年龄分别为0.07、0.46、0.83、1.32、1.70、2.08、2.74MaBP,对应于偏心率曲线波动幅度由大变小时段的特定转折位置。文中分析了地球公转运动变速的基本数据及其对地球自转运动和圈层相互作用的可能影响,探讨了轨道偏心率变化对构造运动的驱动机制,并指出了构造气候旋回研究可为地质力学理论发展展示良好的前景。 相似文献