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1.
A Study on the Surface Wettability of Clastic Rocks with Potential Application for CO2 Storage Sites
Umar Bappah Adamu Gholami Raoof Raza Arshad Downey William Samuel Sarmadivaleh Mohammad Shah Afroz A. Nayak Prasanta 《Natural Resources Research》2020,29(3):2051-2061
Natural Resources Research - There have been many studies carried out in the past decades attempting to develop strategies for a safe injection of CO2 into storage sites without leakage and... 相似文献
2.
Owen M. Weller Simon Jackson William G. R. Miller Marc R. St-Onge Nicole Rayner 《Journal of Metamorphic Geology》2020,38(8):853-880
Texturally complex monazite grains contained in two granulite-facies pelitic migmatites from southern Baffin Island, Arctic Canada, were mapped by laser ablation-inductively coupled plasma-mass spectrometry (using spot sizes ≤5 µm) to quantitatively determine the spatial variation in trace element chemistry (with up to 1,883 analyses per grain). The maps highlight the chemical complexity of monazite grains that have experienced multiple episodes of growth, resorption and chemical modification by dissolution–precipitation during high-grade metamorphism. Following detailed chemical characterization of monazite compositional zones, a related U–Pb data set is re-interpreted, allowing petrologically significant ages to be extracted from a continuum of concordant data. Synthesis of these data with pseudosection modelling of prograde and peak conditions allows for the temporal evolution of monazite trace element chemistry to be placed in the context of the evolving P–T conditions and major phase assemblage. This approach enables a critical evaluation of three commonly used petrochronological indicators: linking Y to garnet abundance, the Eu anomaly to feldspar content and Th/U to anatectic processes. Europium anomalies and Th/U behave in a relatively systematic fashion, suggesting that they are reliable petrochronological witnesses. However, Y systematics are variable, both within domains interpreted to have grown in a single event, between grains interpreted to be part of the same age population, and between samples that experienced similar metamorphic conditions and mineral assemblages. These observations caution against generalized petrological interpretations on the basis of Y content, as it suggests Y concentrations in monazite are controlled by domainal equilibria. The results reveal a c. 45 Myr interval between prograde metamorphism and retrograde melt crystallization in the study area, emphasizing the long-lived nature of heat flow in high-grade metamorphic terranes. Such long timescales of metamorphism would be assisted by the growth, retention and dominance of high-Th suprasolidus monazite, as observed in this study, contributing to the radiogenic heating budget of mid- to lower-crustal environments. Careful characterization of monazite grains suggests that continuum-style U–Pb data sets can be decoded to provide insights into the duration of metamorphic processes. 相似文献
3.
Natural Hazards - Indo-Gangetic plains are seismically most vulnerable due to the proximity of adjacent great Himalayan earthquakes and thick alluvium deposits of the Ganga River system. As the... 相似文献
4.
Subsurface flow measurements using passive flux meters in variably-saturated cold-regions landscapes
To date, passive flux meters have predominantly been applied in temperate environments for tracking the movement of contaminants in groundwater. This study applies these instruments to reduce uncertainty in (typically instantaneous) flux measurements made in a low-gradient, wetland dominated, discontinuous permafrost environment. This method supports improved estimation of unsaturated and over-winter subsurface flows which are very difficult to quantify using hydraulic gradient-based approaches. Improved subsurface flow estimates can play a key role in understanding the water budget of this landscape. 相似文献
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Acta Geotechnica - The hypoplastic model for sands proposed by Wolffersdorff (Mech Cohes Frict Mater 1: 251–271, 1996) combined with the intergranular strain anisotropy by Fuentes and... 相似文献
7.
William B. Meyer 《Geographical review》2019,109(1):131-145
The phenomenon of urban primacy has been much studied in the social sciences since Mark Jefferson introduced the term in 1939. It is less well recognized that many European and American writers of stature from the late seventeenth century onward had discussed the same phenomenon under other names, often that of a “capital” or its cognates in other languages. Their work attests to the wide currency that the concept enjoyed and offered many important suggestions regarding urban primacy's causes and consequences. Jefferson nonetheless remains a central figure in the history of the idea for having inaugurated the coordinated academic study of the topic. 相似文献
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Creating an isotopically similar Earth–Moon system with correct angular momentum from a giant impact
Bryant M. Wyatt Jonathan M. Petz William J. Sumpter Ty R. Turner Edward L. Smith Baylor G. Fain Taylor J. Hutyra Scott A. Cook John H. Gresham Michael F. Hibbs Shaukat N. Goderya 《Journal of Astrophysics and Astronomy》2018,39(2):26
The giant impact hypothesis is the dominant theory explaining the formation of our Moon. However, the inability to produce an isotopically similar Earth–Moon system with correct angular momentum has cast a shadow on its validity. Computer-generated impacts have been successful in producing virtual systems that possess many of the observed physical properties. However, addressing the isotopic similarities between the Earth and Moon coupled with correct angular momentum has proven to be challenging. Equilibration and evection resonance have been proposed as means of reconciling the models. In the summer of 2013, the Royal Society called a meeting solely to discuss the formation of the Moon. In this meeting, evection resonance and equilibration were both questioned as viable means of removing the deficiencies from giant impact models. The main concerns were that models were multi-staged and too complex. We present here initial impact conditions that produce an isotopically similar Earth–Moon system with correct angular momentum. This is done in a single-staged simulation. The initial parameters are straightforward and the results evolve solely from the impact. This was accomplished by colliding two roughly half-Earth-sized impactors, rotating in approximately the same plane in a high-energy, off-centered impact, where both impactors spin into the collision. 相似文献
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