نتایج جستجو برای: crustal contamination

تعداد نتایج: 61183  

Journal: :international journal of environmental research 0
v.o. ajibola department of chemistry, faculty of science, ahmadu bello university, zaria, nigeria m.k. ladipo department of polymer & textile technology, yaba college of technology, lagos, nigeria

concentrations of eight metals namely, cr, mn, fe, co, ni, cu, zn and pb were examined in the surface sediments of discharge channels of six industries in lagos using x-ray fluorescence spectrometry.these channels drain into the isolo canal which empties into the lagos lagoon and eventually into the atlantic ocean. this study was conducted to detect any contamination levels within the sediments...

2009
M. B. Channon

Introduction: Martian (SNC) meteorites are igneous rocks that range from a reduced, trace-element depleted end member to an oxidized, trace-element enriched end member [1-3] (Figure 1). One interpretation of this trend is that relatively reduced, depleted magmas are partial melts of a reduced peridotitic mantle, whereas more oxidized, enriched magmas are mantle-derived magmas contaminated by ox...

1998
MICHAEL O. GARCIA EMI ITO JOHN M. EILER AARON J. PIETRUSZKA

Oceanic island basalts have a large range in dO values (4·5– INTRODUCTION 7·5‰) compared with the assumed primordial mantle values A 1996 conference on ‘shallow level processes in ocean (5·5–6·0‰) and with mid-ocean ridge basalts (5·7 ± 0·2‰). island magmatism’ drew attention to the controversy that Some Hawaiian tholeiitic basalts have low O values (4·6–5·2‰), is developing on the possible ext...

Journal: :Computers & Geosciences 2016
Liang-feng Zhu Xin Pan Jian-zhong Sun

Global crustal models, such as CRUST 5.1 and its descendants, are very useful in a broad range of geoscience applications. The current method for representing the existing global crustal models relies heavily on dedicated computer programs to read and work with those models. Therefore, it is not suited to visualize and disseminate global crustal information to non-geological users. This shortco...

2009
Shijie Zhong

Introduction: The two most striking surface features on Mars are the crustal dichotomy and the Tharsis Rise [1]. While it is generally accepted that the Tharsis Rise is formed as a result of plume related volcanism [2], the formation mechanism for the crustal dichotomy is controversial with two main competing proposals: endogenic (mantle convection and flow) [3-5] and exo-genic (mega-impact) me...

1999
Rebecca Ghent Vicki Hansen

Crustal plateaus on Venus constitute one of that planet’s most intriguing tectonic features. They host so-called “tessera” terrain, or deformed crust exhibiting two or more sets of intersecting tectonic lineaments, which comprises ∼8% of Venus’ surface. Major questions surrounding crustal plateaus and tessera terrain include: (1) What is the nature of crustal plateau deformation? What structure...

2016
H L Viswanath

Environment checking is utilized to distinguish crustal developments, approaching tidal waves, contamination (global warming), an Earth-wide temperature boost, and numerous different truths that are committed to influence human lives. Sensor networks for environment observing can comprise of segment and/or floor sensors, conceivably associated with berthed floats giving integration back to the ...

2001
B. E. HOBBS

One of the characteristic features of Ordovician tectonism in the east Lachlan Fold Belt is the occurrence of calcalkaline to shoshonitic basalts, which have been recognised as part of an intraoceanic arc environment (Glen et al. 1998), consistent with early tectonic interpretations (Oversby 1971; Scheibner 1973). Aside from typical traceelement abundances of intraoceanic arcs, critical evidenc...

Journal: :Science 2008
Sabine Stanley Linda Elkins-Tanton Maria T Zuber E Marc Parmentier

Mars' crustal magnetic field was most likely generated by dynamo action in the planet's early history. Unexplained characteristics of the field include its strength, concentration in the southern hemisphere, and lack of correlation with any surface features except for the hemispheric crustal dichotomy. We used numerical dynamo modeling to demonstrate that the mechanisms proposed to explain crus...

Journal: :فیزیک زمین و فضا 0
علیرضا آزموده اردلان دانش آموختة کارشناس ارشد هیدروگرافی مهندسی نقشه برداری، قطب علمی مهندسی نقشه برداری در مقابله با سوانح طبیعی، پردیس دانشکده های فنی بهنام حضرتی صومعه دانش آموختة کارشناس ارشد هیدروگرافی مهندسی نقشه برداری، قطب علمی مهندسی نقشه برداری در مقابله با سوانح طبیعی، پردیس دانشکده های فنی

using tidal potential, the effect of tide on the gravity field, crustal deformation due to tidal force, and gravity variations resulted from the crustal deformation are presented. tidal potential is divided into constant and periodic (diurnal and semi-diurnal) constituents, and for each constituents crustal displacements in radial, south-north, and east-west directions are computed. the aforeme...

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