A study of mammalia and geology across the Cretaceous-Tertiary boundary in Garfield County,Montana: J. D. Archibald. 1982. University of California Publications in Geological Sciences,Volume 122, 286 pp     

S.G. Lucas 《Cretaceous Research》1983,4(2):217-219

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A look at global seismicity during 1999 in the longer-term time frame     

Vasile Marza  Juraci Carvalho  Lucas Barros  Cristiano Chimpliganond 《Journal of Seismology》2003,7(1):89-98

An analysis and discussion of the main features and effects of the 1999global seismicity based especially on the inferred patterns of strong(M_w 7) earthquakes using NEIC/USGS data is presented.Based on the above data and their statistical features (see also Table 1)one may state that from the point of view of occurrence rate (number/yr)the 1999 global seismicity was fairly regular, but from the moment (orenergy) release standpoint it is well under the long-term average. The spacepartition was again rather typical and time distribution was quasi-Poissonian,noteworthy, the 1999 worldwide seismicity had an anomalously high deathtoll, to be discussed later. Two main new insights are brought by ouranalysis: (i) a (mega)quiescence along the whole south American segmentof circum-Pacific earthquake belt, which was inferred and rated asanomalous while it was underway and which, in retrospect, ended with thegreat (M_w = 8.4 HRV) 2001 Arequipa (Peru) event; (ii) an intriguingmonotonous rate decrease within only magnitude class 5.0 to 5.9 duringthe analyzed period (i.e., 1990–1999).  相似文献   

The Images Used to “Sell” and Represent Retirement Communities     

Susan Lucas 《The Professional geographer》2004,56(4):449-459

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About the Special Issue: Collection of Achievements on Earth Resources from AUN/SEED-Net     

Akira Imai    Carla B. Dimalanta  Graciano P. Yumul  Jr.    Lucas Donny Setijadji  Koichiro Watanabe 《Resource Geology》2005,55(3):141-144

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On the Progress Design of Integrated Geologic Analysis System: Object-Relational Database Model and Visualization for Earth Resources     

Lucas Donny Setijadji  Koichiro Watanabe 《Resource Geology》2005,55(3):267-280

Abstract. An object-relational data model is an entry point and integral part of geologic analysis system, in which we can start geologic modeling inside a database. A conceptual data model named the Geoscience (Earth Resources) Data Model 3.0 has been developed based on the conceptual design of NADM-C1.0 and EGDM 812. Such adaptation makes this data model interoperable with data models from other geoscience fields. The focus of current data model is to effectively manage multi datasets related with the study of earth resources and to create relationship among data types.
The conceptual data model for earth resources is successfully implemented physically by integrating a GIS and relational data storage. The direct link between relational database and GIS makes the database contents highly visual and spatially enabling. Database contents are fully georeferenced through different types of georeferencing systems that enables data integration, visualization and analysis of multi geoscience datasets in 2D and 3D environment. A new way of geologic analysis through visualization of virtually all kinds of geoscience datasets is proposed.
The earth resources research and industry can take benefits on this system through better data management and effective geologic visualization that in turn accelerate a better understanding of earth resources. Meanwhile wider geoscience community will benefit from better interaction and data sharing among geoscience fields for accelerating a better understanding of our complex earth.  相似文献   

L'érosion chimique et l'érosion mécanique à long terme du substrat granitique (Vendée,France)     

Jean-Christophe Maurin  Françoise Gilbert  Michel Robert  Carine Churlaud 《Comptes Rendus Geoscience》2005,337(9):841-848

We calculate the chemical depletion fraction of the granitic bedrock by analysing the rock-soil enrichment of zirconium. In Vendée (France), chemical weathering rates account for 26% of the denudation rates. Such a chemical depletion fraction characterizes temperate regimes. It is three times lower than that of humid tropical regimes. To cite this article: J.-C. Maurin et al., C. R. Geoscience 337 (2005).  相似文献   

Imaging polarimetry of class I young stellar objects   总被引：1，自引：0，他引：1  

P. W. Lucas  & P. F. Roche 《Monthly notices of the Royal Astronomical Society》1998,299(3):699-722

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Palaeomagnetism and magnetostiatigraphy of Triassic strata in the Sangre de Cristo Mountains and Tucumcari Basin, New Mexico, USA     

Roberto S. Molina-Garza    John W. Geissman    Spencer G. Lucas  Rob Van der  Voo 《Geophysical Journal International》1996,124(3):935-953

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Sr and Ar isotope studies of detrital smectites from the Atlantic Ocean (D.S.D.P., Legs 43, 48 and 50)     

Norbert Clauer  Patrick Giblin  Jacques Lucas 《Chemical Geology》1984,46(2):141-151

Mineralogical, morphological and isotopic (RbSr and KAr) determinations were made on some detrital smectites of Palaeocene and Cenomanian ages from D.S.D.P. drillings in the Atlantic Ocean. These minerals are not inert in their depositional environment; authigenic laths grow on detrital sheets with sharp borders. This authigenesis could occur slightly after deposition in a closed system, for some of these smectites. It has been tentatively quantified by the RbSr and KAr isotopic methods, which seem also well suited to evaluate the chemical extent of this authigenesis. At least, no preferential loss of ⁴⁰Ar vs. ⁸⁷Sr could be detected in the minerals, even in those which are smaller than 0.2 μm.  相似文献   

Attenuation of a Mixed Chromium and Chlorinated Etjeme Ground Wate Plume in Estuarine Influenced Glaciated Sediments     

Lucas A. Hellerich  Matthew A. Poneiera  Nikolaos P. Nikolaidis  Barth F. Smets  Gregory M. Dobbs 《Ground Water Monitoring & Remediation》2003,23(3):74-84

The natural attenuation behavior of a ground water contaminant plume containing chromium and chlorinated ethenes in glaciated sediments was assessed using traditional and nontraditional methods. The mixed waste is transported through and attenuated within an estuarine influenced ground water aquifer of spatially varying redox character and organic carbon content. Contaminant fate and speciation were assessed as a function of geochemical conditions. Total, speciation-based, and sequential chemical extraction analyses were performed to determine contaminant partitioning and the redox capacity of the aquifer. Chromium speciation and partitioning were correlated with the reductive capacity and redox conditions of the aquifer sediments spatially distributed within the aquifer. Reductive dechlorination and partitioning of chlorinated ethenes were correlated with the organic carbon content and redox conditions of the aquifer sediments. The data showed that sharp redox gradients existed within the aquifer. Active reduction and retardation of both chromium and chlorinated ethenes was exhibited. The aqueous hexavalent chromium concentrations decreased to near nondetect levels in the vicinity of the receptor, whereas degradation products of higher-order chlorinated ethenes increased as a fraction of the total chlorinated ethene concentrations along the length of the plume. The potential for competition for reducing power under specific cases within the aquifer was suggested by the data, highlighting the need to include contaminant interactions in natural attenuation assessments.  相似文献