Pilot Point Optimization of Mining Boundaries for Lateritic Metal Deposits: Finding the Trade-off Between Dilution and Ore Loss     

Dagasan  Yasin  Renard  Philippe  Straubhaar  Julien  Erten  Oktay  Topal  Erkan 《Natural Resources Research》2019,28(1):153-171

Natural Resources Research - Geological contacts in lateritic metal deposits (footwall topographies) often delineate the orebody boundaries. Spatial variations seen in such contacts are frequently...  相似文献   

Integrating hydropower and intermittent climate‐related renewable energies: a call for hydrology          下载免费PDF全文

B. François  M. Borga  S. Anquetin  J. D. Creutin  K. Engeland  A. C. Favre  B. Hingray  M. H. Ramos  D. Raynaud  B. Renard  E. Sauquet  J. F. Sauterleute  J. P. Vidal  G. Warland 《水文研究》2014,28(21):5465-5468

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Can shallow open-loop hydrothermal well-doublets help remediate seawater intrusion?     

François De Keuleneer  Philippe Renard 《Hydrogeology Journal》2015,23(4):619-629

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Prediction-Focused Subsurface Modeling: Investigating the Need for Accuracy in Flow-Based Inverse Modeling   总被引：1，自引：1，他引：0  

Céline Scheidt  Philippe Renard  Jef Caers 《Mathematical Geosciences》2015,47(2):173-191

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Stress sensitivity of stylolite morphology   总被引：1，自引：0，他引：1  

Marcus Ebner  Daniel Koehn  Renaud Toussaint  François Renard  Jean Schmittbuhl 《Earth and Planetary Science Letters》2009,277(3-4):394-398

Stylolites are rough surfaces that form by localized stress-induced dissolution. Using a set of limestone rock samples collected at different depths from a vertical section in Cirque de Navacelles (France), we study the influence of the lithostatic stress on the stylolites morphology on the basis of a recent morphogenesis model. We measured the roughness of a series of bedding-parallel stylolites and show that their morphology exhibits a scaling invariance with two self-affine scaling regimes separated by a crossover-length (L) at the millimeter scale consistent with previous studies. The importance of the present contribution is to estimate the stylolite formation stress σ from the sample position in the stratigraphic series and compare it to the crossover-length L using the expected relationship: L ～ σ ^?2. We obtained a successful prediction of the crossover behavior and reasonable absolute stress magnitude estimates using relevant parameters: depth of stylolite formation between 300 to 600 m with corresponding normal stress in the range of 10–18 MPa. Accordingly, the stylolite morphology contains a signature of the stress field during formation and we thus suggest that stylolites could be used as paleo-stress gauges of deformation processes in the upper crust.  相似文献   

Expression of the Early Toarcian negative carbon-isotope excursion in separated carbonate microfractions (Jurassic,Paris Basin)     

Michaël Hermoso  Laurence Le Callonnec  Fabrice Minoletti  Maurice Renard  Stephen P. Hesselbo 《Earth and Planetary Science Letters》2009,277(1-2):194-203

The causes of the pronounced negative excursion in carbon-isotope values that was recorded during the Early Toarcian Oceanic Anoxic Event (T-OAE) are still under debate, particularly with regard to the local versus global pattern of the excursion, and the extent to which recorded signals are under a diagenetic control. In this study we employ a novel microseparation technique in order to investigate the isotopic and mineralogical characteristics of different size fractions of the carbonate content from a Toarcian section recovered from the Sancerre–Couy borehole, southern Paris Basin. Beyond the recognition of a ? 6‰ δ¹³C excursion in the bulk carbonate content, our data also demonstrate that biogenic particles (such as coccoliths) and inorganic grains precipitated as early diagenetic phases (including dolomite) both record the excursion with the same magnitude. Although several black shales occur through the Paris Basin Toarcian section, it is only that associated with the onset of the OAE that coincides with a large negative carbon-isotope excursion. Taken together these observations indicate that during this event, the entire water column was characterized by homogeneous carbon-isotope values; such a pattern is incompatible with the idea that the negative excursion was generated simply through the upwelling of bottom waters enriched in re-mineralized organic carbon (cf. “the Küspert model”), since this would have required a strong vertical gradient in the water column. Additionally, the Paris Basin data show that the decrease in carbonate δ¹³C values during the OAE occurred in several discrete steps (each of some ? 2‰), as has previously been found for organic carbon substrates in other European sections. The stepped nature of the isotopic profile, which is part of a stratigraphic signature previously ascribed to Milankovitch forcing, is compatible with regular pulsed input of light carbon into the whole atmosphere–ocean system from a climatically sensitive source such as gas hydrate, or from thermal methanogenesis of organic-rich sediments in the Karoo–Ferrar large igneous province. Contrasts in the amplitude of the negative carbon-isotope excursion on a regional scale remain an important unexplained aspect of the Toarcian record.  相似文献   

Generation of 3D Spatially Variable Anisotropy for Groundwater Flow Simulations          下载免费PDF全文

Andrea Borghi  Philippe Renard  Gabriel Courrioux 《Ground water》2015,53(6):955-958

Sedimentary units generally present anisotropy in their hydraulic properties, with higher hydraulic conductivity along bedding planes, rather than perpendicular to them. This common property leads to a modeling challenge if the sedimentary structure is folded. In this paper, we show that the gradient of the geological potential used by implicit geological modeling techniques can be used to compute full hydraulic conductivity tensors varying in space according to the geological orientation. For that purpose, the gradient of the potential, a vector normal to the bedding, is used to construct a rotation matrix that allows the estimation of the 3D hydraulic conductivity tensor in a single matrix operation. A synthetic 2D cross section example is used to illustrate the method and show that flow simulations performed in such a folded environment are highly influenced by this rotating anisotropy. When using the proposed method, the streamlines follow very closely the folded formation. This is not the case with an isotropic model.  相似文献   

Issues in characterizing heterogeneity and connectivity in non-multiGaussian media     

Jaouher Kerrou  Philippe Renard  Harrie-Jan Hendricks Franssen  Ivan Lunati 《Advances in water resources》2008

The performances of kriging, stochastic simulations and sequential self-calibration inversion are assessed when characterizing a non-multiGaussian synthetic 2D braided channel aquifer. The comparison is based on a series of criteria such as the reproduction of the original reference transmissivity or head fields, but also in terms of accuracy of flow and transport (capture zone) forecasts when the flow conditions are modified. We observe that the errors remain large even for a dense data network. In addition some unexpected behaviours are observed when large transmissivity datasets are used. In particular, we observe an increase of the bias with the number of transmissivity data and an increasing uncertainty with the number of head data. This is interpreted as a consequence of the use of an inadequate multiGaussian stochastic model that is not able to reproduce the connectivity of the original field.  相似文献   

Special Issue on 20 Years of Multiple-Point Statistics: Part 1   总被引：1，自引：1，他引：0  

Philippe Renard  Grégoire Mariethoz 《Mathematical Geosciences》2014,46(2):129-131

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Interstitial water chemistry of villefranche bay sediments: Trace metal diagenesis   总被引：1，自引：0，他引：1  

J.-F Gaillard  C Jeandel  G Michard  E Nicolas  D Renard 《Marine Chemistry》1986,18(2-4)

Pore water aliquots were taken with an in situ close interval sampler: the “Peeper”.We report here the pore water concentration profiles of TCO₂, SO₄, TH₂S, Ca and the trace metals Mn, Cu, Pb, Cd and Cr from sediments of a relatively polluted area, the Villefranche Bay, on the French Riviera (close to Nice).We investigated the major ion concentrations in order to establish geochemical mass balances of organic matter oxidation. ΔTCO₂/ΔSO₄ was <−2.0, reflecting the precipitation of calcite as confirmed by the calcium profile. Reduction of sulfate led to increasing sulfide concentrations with depth.Trace metal interstitial water concentrations decreased from 63 to 5 nM, 18 to 4 nM and 6.6 to less than 2 nM for Cu, Pb and Cr, respectively. Cd showed a different pattern with top and deep values of 0.7 nM and a minimum of 0.27 nM.Thermodynamic calculations were performed which suggest the potential formation of mineral phases such as sulfides.  相似文献