Evaluation of the relative roles of global versus local sedimentary controls on Middle to Late Pleistocene formation of continental margin strata,Canterbury Basin,New Zealand          下载免费PDF全文

Tania Villaseñor  John M. Jaeger  Kathleen M. Marsaglia  Greg H. Browne 《Sedimentology》2015,62(4):1118-1148

Determining the relative influence of eustasy versus local sedimentary processes on strata formation is a fundamental challenge in the study of continental margin stratigraphy. In this paper, the relative contribution of these factors on continental margin evolution during the Middle to Late Pleistocene is evaluated using samples from Integrated Ocean Drilling Program Expedition 317. Core‐logging, biostratigraphy and quantitative X‐ray diffraction mineralogy are used to delineate continental shelf sedimentary systems. Major lithological unconformities bound stratigraphic sequences that contain recurring compositional patterns and that resemble other examples of Middle to Upper Pleistocene sequences. However, a preliminary chronology suggests that sequence boundary formation cannot be linked ‘one to one’ with eustatic cycles and therefore these sequences can contain multiple ca 100 ka eustatic cycles. Smaller amplitude, higher frequency transitions in sediment composition are interpreted as stratigraphic sequences driven by more rapid perturbations in the interplay of accommodation and sediment supply; their stratigraphy is variable in time and across the shelf, suggesting a strong influence of local sedimentary forcing in their formation. Changes in sediment composition after the Middle Pleistocene Transition indicate that sediment transfer from onshore sources in the glaciated Southern Alps to the middle‐shelf occurred over a single 100 ka glacio‐eustatic cycle, with an additional 100 ka lag before the mineralogical signal was preserved on the outer‐shelf. This phenomenon is coincident with rapid shelf progradation in this basin, suggesting a causal relation between across‐shelf sediment transport and margin progradation. This is one of very few studies that provide insights at the core scale into the processes driving continental margin evolution during the Middle to Late Pleistocene. This work shows that compositional changes in mud‐dominated successions can lead to a sequence stratigraphic interpretation and the identification of high‐frequency sequences, which may not be possible using a conventional stratigraphic approach.  相似文献   

基于ETM~+数据和GIS技术的缅甸铜金矿成矿预测     

独文惠  王功文  陈永清  郭娜娜  郝应龙  冯源 《地质通报》2015,34(4):786-791

在利用遥感数据和地理信息系统(GIS)技术的矿产资源勘查与评价中,矿化蚀变信息提取和构造信息提取起着至关重要的作用。以缅甸铜金矿为例,利用ETM+遥感图像,采用比值法、阈值分割和主成分分析(PCA)提取羟基蚀变信息;利用数字高程模型和遥感数据提取与铜金矿化有关的线环构造,结合地质资料和上述信息,利用证据权和分形方法进行整合,确定该研究区的成矿远景区。结果发现,已知铜金矿均分布于成矿靶区中,综合信息可为下一步的矿产资源勘探工作提供决策依据。  相似文献   

Improving Statistical Downscaling of General Circulation Models     

Matthew Lee Titus  Jinyu Sheng  Richard J. Greatbatch  Ian Folkins 《大气与海洋》2013,51(2):213-225

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THE FREE-WILSON PARADIGM REDUX:SIGNIFICANCE OF THE FREE-WILSON COEFFICIENTS,INSIGNIFICANCE OF COEFFICIENT ‘UNCERTAINTIES’ AND STATISTICAL SINS     

DAVID LEE DUEWER 《地理学报(英文版)》1990,(4)

The Free-Wilson paradigm is an established and powerful tool for quantitatively relating activity withchemical structure.Current implementations of the paradigm,however,are flawed both conceptually andin execution.As part of an attempt to more fully realize the promise of the paradigm,it was necessaryto examine these limitations in detail.This report introduces a robust,theory-founded Free-Wilson implementation:stepwise principalcomponents regression analysis(SPCRA).SPCRA is computationally superior to previousimplementations but does not in itself correct their conceptual flaws.The development of SPCRA did,however,facilitate derivation of a simple and chemically significantinterpretation of the Free-Wilson structure-activity model.A number of statistical aspects of this modelcommonly misused in previous applications are discussed at length.These discussions provide criticalbackground for the development of an alternative implementation of the Free-Wilson paradigm.  相似文献   

Detecting subtle hydrochemical anomalies with multivariate statistics: an example from ‘homogeneous’ groundwaters in the Great Artesian Basin,Australia     

Bethany O'Shea  Jerzy Jankowski 《水文研究》2006,20(20):4317-4333

The major ion composition of Great Artesian Basin groundwater in the lower Namoi River valley is relatively homogeneous in chemical composition. Traditional graphical techniques have been combined with multivariate statistical methods to determine whether subtle differences in the chemical composition of these waters can be delineated. Hierarchical cluster analysis and principal components analysis were successful in delineating minor variations within the groundwaters of the study area that were not visually identified in the graphical techniques applied. Hydrochemical interpretation allowed geochemical processes to be identified in each statistically defined water type and illustrated how these groundwaters differ from one another. Three main geochemical processes were identified in the groundwaters: ion exchange, precipitation, and mixing between waters from different sources. Both statistical methods delineated an anomalous sample suspected of being influenced by magmatic CO₂ input. The use of statistical methods to complement traditional graphical techniques for waters appearing homogeneous is emphasized for all investigations of this type. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Statistical approach to determine the salinized ground water flow path and hydrogeochemical features around the underground LPG cavern,Korea     

Jeongho Lee  Ji‐Hoon Kim  Hun‐Mi Kim  Ho‐Wan Chang 《水文研究》2007,21(26):3615-3626

The ground water flow path of the coastal area in the Yellow Sea, Korea, was interpreted using both the cross‐correlation analysis of hydraulic properties and the principal component analysis (PCA) of ground water chemistry. Data was obtained from observation wells in the underground liquefied petroleum gas (LPG) cavern constructed in the coastal area of Pyeongtaek. Cross‐correlation results showed that the operating pressure became more influenced on artificial factors for the variation of the groundwater level of the study area (45–66% of correlation coefficient) even though its affecting area was limited to the region with fractures or faults, and also showed that the delay time from the variation of operating pressure to the fluctuation of ground water level were relatively long periods (28–31 days). Three hydrogeochemical events (encrusted cement dissolution, host rock dissolution, and seawater intrusion), which were dominantly influenced on ground water quality, could be induced from the result of PCA. Quantitative evaluation for these events using the mixed equation with principal component scores suggest that the dissolution of encrusted cement materials was the predominant factor (39·0% of the total mixed proportion) to change the chemical composition of the seepage water during the ground water flow from the observation wells to the cavern. Integration of the statistical results also imply that ground water flow and hydrogeochemistry were predominantly affected by artificial factors such as cavern operation pressure and dissolution of encrusted cement materials, which were interdependent factors on the observation wells with high cross‐correlation coefficients and pH. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

PRINCIPAL COMPONENTS REGRESSION FOR ROUTINE MULTICOMPONENT UV DETERMINATIONS: A VALIDATION PROTOCOL     

PAULJ.GEMPERLINE  ALGER SALT 《地理学报(英文版)》1989,(1)

A validation protocol for multicomponent spectroscopic assays based on principal componentsregression is described. Factorial design and hypothesis tests are used to establish the linearity andabsence of interaction between components in the regression model. Testing considers multiple responsevariables simultaneously so that correlation between residuals is properly treated. Assay reproducibilityand sensitivity to related substances are evaluated.  相似文献   

MULTIVARIATE RESPONSE SURFACE MODELLING BY PRINCIPAL COMPONENTS ANALYSIS     

N.BRATCHELL 《地理学报(英文版)》1989,(3)

Analysis of multivariate response data by modelling the principal components of the response has beenapplied to two sets of data. In both cases principal components analysis revealed the relationships amongthe response variables and exploited them to simplify the problem of modelling and optimizing themultivariate response. The models and optima obtained from the principal components comparedfavourably with the individual models and simultaneous optima.  相似文献   

地理信息系统发展趋势   总被引：10，自引：0，他引：10  

黄杏元  陈丙咸 《地理学报》1989,44(2):230-236

本文根据国内外在地理信息系统方面的进展，就地理信息系统的科学概念、基本构成和它的以下一些发展趋势作了讨论：（1）地理信息系统是构成地理学日臻完善的技术体系的重要部分；（2）空间分析功能是系统研究和应用的主要目标；（3）系统最重要的技术问题是管理和存储大量空间数据的数据结构；（4）综合性的发展特色日益明显；（5）标准化和智能型的发展方向已引起关注。  相似文献   

攀枝花市大气污染物降水清除机制的研究     

唐士豹 《成都信息工程学院学报》1989,(4)

本文采用了主成份分析及因子分析的方法,研究了影响降水pH值的主要源及其贡献和这些源被降水清除的机制。分析结果表明:大气中一次污染物是影响降水pH及各种成分浓度的主要因素。人为污染源包括高排放源、低排放源和汽车源,它们的排放物以碱性物质为主;自然污染源包括输送物、腐烂物、自然NOx等,它们的排放物主要是酸性物质;在一般情况下,降水的pH值取决于高、低排放源排放的碱性物质的多寡;降水量越大,清除的污染物越多,在雨季各测点降水平均pH值为6.31～7.10。在高排放源影响小的地方,对持续时间长的大雨,降水后期的pH能反映自然源的影响,其值小于5.60。可见,攀枝花市酸雨几率极低甚至降水呈碱性,  相似文献