火山岩地区勘探地下水过程中自然电位异常的解释

当利用自然电位法（ＳＰ法）在火山岩地区勘探地下水时，发现负的自电异常大小与地下非饱和区厚度之间存在一个线性关系，从理论上对该经验关系进行了探讨，并提出对这一水文地质问题的自电测量解释方法，最后给出法国中央高原ＬａＣｈａｉｎｅｄｅｓＰｕｙｓ地区的勘探结果。     

沉积地层中坠石的成因及其研究意义

坠石是沉积时落入水体底部沉积物中的单个或集群状外来碎屑，按其搬运载体不同可分为：（１）冰筏成因坠石：冰山作用形成的坠石和季节性冰体形成的坠石；（２）非冰筏成因坠石；动物植成因坠石和其它成因坠石。坠石是寒冷气候的标志，其形成时的气候具有多解性。     

福建省地层多重划分,对比研究（续）

福建省地层多重划分、对比研究（续）李兼海，王国平，郑铁藩，梁诗经（福建省区域地质调查队，三明，３６５００１）３晚三叠世一新第三纪印支运动后，福建地壳发生了重大变革，全境由海转变成陆地。晚三叠世一中佛罗世，除闽西南局部地区有海湾泻湖相沉积外，皆为河流一...     

Paleoceanographic changes at the Jurassic–Cretaceous boundary in the Western Tethys, northeastern Mexico

Mexico is usually considered to have formed the western end of the Tethys during Late Jurassic and Early Cretaceous times. The circumstances of the opening of the Gulf of Mexico Basin towards the Tethys and the exact stratigraphic timing, however, are not clear. Four sections covering this time interval, located in northeastern Mexico, have been measured and sampled in detail, in order to clarify their stratigraphic position during the Late Jurassic to Early Cretaceous time interval and the paleogeographic and oceanographic changes that accompanied this opening. Our studies include microfacies, micro- and macropaleontology, whole rock and clay-mineral x-ray diffraction and stable isotopes analyses. Our data indicate that the Jurassic-Cretaceous boundary, as defined by the Lyon-Neuchâtel Colloquium of 1973, cannot be determined precisely in northeastern Mexico due to the near-absence of calpionellids and endemism of ammonite taxa. In the lower and upper Berriasian sediments, we detected Mediterranean ammonite taxa so far unknown from Mexico, corresponding to the appearance of typical calpionellid-rich facies. These faunas allow direct biostratigraphic correlation with European ammonite and calpionellid zones.We propose that a major oceanographic change occurred in the upper part of calpionellid Zone B of the Early Berriasian. At this time, sediments in northeastern Mexico present increasingly pelagic facies, a dramatic appearance of Tethyan microfossils (calpionellids) and ammonites, changes in stable isotopic values, whole rock and clay-mineral mineralogy. We suggest that these changes are due to a global sea-level rise that connected directly northeastern Mexico to the European Tethys and ended the endemic, semi-restricted and anoxic environment of the Late Jurassic La Casita and equivalent La Caja and La Pimienta Formations.     

亚洲夏季风活动激发的北半球大气环流遥相关型

亚洲季风区是全球热力变化最为显著的区域，亚洲夏季风活动必定会对其它环流系统产生影响。本文通过夏季风指数与北半球环流的相关计算以及强、弱季风候北半球环流异常合成的分析发现，亚洲夏季风的活动会激发北半球夏季大气环流遥相关型，其主要相关中心均出现在季风区的下游地区，即从亚洲经太平洋至北美洲一带，除了表现出正负中心交替出现的波列状结构外，该遥相关型在太平洋地区还表现为一对南北向的偶极子异常型，我们将这一遥相关型称为亚洲太平洋北美（ＡＰＮ）型。     

新的核线相关算法——跨接法

本文研究与讨论了一种新的核线相关算法——跨接法。它是基于特征匹配的算法,即将两个“特征”连接起来构成匹配窗。由于此算法能预先消除匹配窗口之几何变形,然后再判断其灰度分布之相似性,因而它能有效地考虑由于地形起伏等原因引起的变形,提高了影象相关的可靠性。     

Recent environmental changes inferred from the sediments of small lakes in Yellowstone's northern range (Engstromet al., 1991)

Sedimentation rate data of Engstromet al. (1991) were analyzed in relation to the elevation of the eight ponds studied. The ... asynchroneity of the stratigraphic changes among the lakes ... that they noted was transformed into a pattern of time-transgressive change of sedimentation rate with elevation. Sediment units representing increasing (and decreasing) sedimentation rate and accelerating (and decelerating) sediment accumulation were correlated from pond to pond, suggesting that the sediment-producing condition somehow moved upslope over time at a rate of 3.4 to >5 m yr^–1. Climatic data appear not to explain this monotonic pattern, but dendrochronological data and elk population numbers suggest that ungulate foraging patterns might. Engstromet al. (1991) concluded that ...the lake-sediment records in the northern range do not convincingly show systematic direct or indirect effects of ungulate grazing during the history of the Park. Reinterpretation of these sediment data suggests that detailed reanalysis might lead to a different conclusion.     

概率成像方法对地下球体定位的应用研究

概率成像方法是一种新颖的成像方法。它是利用测量的地面电场函数与电场扫描函数进行归一化的互相关运算，从而对地下电荷进行定位。本文对电法勘探中，地下球体进行了概率成像研究，给出了理论模型和成像结果，从而也证明概率成像方法确实是一种行之有效、计算简便的方法。     

Late Quaternary stratigraphic development in the lower Luni,Mahi and Sabarmati river basins,western India

This study reviews the Quaternary alluvial stratigraphy in three semi-arid river basins of western India i.e., lower Luni (Rajasthan), and Mahi and Sabarmati (Gujarat alluvial plains). On the basis of OSL chronologies, it is shown that the existing intra-valley lithostratigraphic correlations require a revision. The sand, gravel and mud facies are present during various times in the three basins, however, the fluvial response to climate change, and the resulting facies associations, was different in the Thar desert as compared to that at the desert margin; this makes purely lithostratigraphic correlations unviable. It is further shown that the rivers in the Thar desert were more sensitive to climate change and had small response times and geomorphic thresholds as compared to the desert-margin rivers. This is illustrated during the early OIS 1, when the Luni river in the Thar desert was dynamic and showed frequent variations in fluvial styles such as gravel bedload braided streams, sand-bed ephemeral streams and meandering streams, all followed by incision during the early Holocene. The coeval deposits in Sabarmati, however, only show a meandering, floodplain-dominated river. Late Quaternary alluvial deposits in these basins unconformably overlie some older deposits that lack any absolute chronology. Based on the facies types and their associations, and the composition and architecture of the multistoried gravel sheets in the studied sections, it is suggested that older deposits are of pre-Quaternary age. This hypothesis implies the presence of a large hiatus incorporating much of the Quaternary period in the exposed sections     

Correlation between the seismicity parameters

Though the forecast and prediction of earthquakes is a commonly accepted difficult problem in science, the step towards the exploration and knowledge of the generation and occurrence of earthquakes has never stopped. It has strong scientific exploration nature and great social efficacy in disaster reduction. For this reason, it has always been the object and motivation pursued assiduously by earthquake researchers. It is beyond doubt that the study of seismicity is still one of the important information sources that have historical records of the longest time and most abundant earthquake cases that can be testified. For many years, with the progress of study in this aspect and the unceasing increase of study methods, there have been not less than tens of methods that can be used to describe theseismicity characteristics from different angles. It is of great importance to determine from the numerous methods those ones that are relatively independent and to understand how many dimensions are there to restrict the complexsystem of earthquake generation and occurrence. Taking these as a referential basis, we would be able to identify the quantities that restrict the study of the seismogenic system, to raise the scientific value and rigorousness of prediction and forecast, and to get rid of the trouble of repeated information superposition.