scholarly journals Evidence of Hydrocarbon-Rich Fluid Interaction with Clays: Clay Mineralogy and Boron Isotope Data from Gulf of Cádiz Mud Volcano Sediments

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 651
Author(s):  
Rubén Martos-Villa ◽  
M. Pilar Mata ◽  
Lynda B. Williams ◽  
Fernando Nieto ◽  
Xabier Arroyo Rey ◽  
...  
Keyword(s):  
Density Functional ◽  
Clay Mineralogy ◽  
Great Depth ◽  
Gulf Of Cadiz ◽  
Dft Methods ◽  
Methane Generation ◽  
Tetrahedral Sites ◽  
Gulf Of Cádiz ◽  
Fluid Interaction

Clay dehydration at great depth generates fluids and overpressures in organic-rich sediments that can release isotopically light boron from mature organic matter, producing 10B-rich fluids. The B can be incorporated into the tetrahedral sites of authigenic illite during the illitization of smectite. Therefore, the crystal-chemical and geochemical characterization of illite, smectite or interlayered illite–smectite clay minerals can be an indicator of depth (temperature) and reactions with the basin fluids. The aim of this study was to determine the detailed clay mineralogy, B-content and isotopic composition in illite–smectite rich samples of mud volcanoes from the Gulf of Cádiz, in order to evaluate interactions of hydrocarbon-rich fluids with clays. Molecular modeling of the illite structure was performed, using electron density functional theory (DFT) methods to examine the phenomenon of B incorporation into illite at the atomic level. We found that it is energetically preferable for B to reside in the tetrahedral sites replacing Si atoms than in the interlayer of expandable clays. The B abundances in this study are high and consistent with previous results of B data on interstitial fluids, suggesting that hydrocarbon-related fluids approaching temperatures of methane generation (150 °C) are the likely source of B-rich illite in the studied samples.

scholarly journals Multidisciplinary characterization of Quaternary mass movement deposits in the Portimão Bank (Gulf of Cadiz, SW Iberia)

2020 ◽  
Vol 420 ◽  
pp. 106086
Author(s):  
P.F. Silva ◽  
C. Roque ◽  
T. Drago ◽  
A. Belén ◽  
B. Henry ◽  
...  
Keyword(s):  
Mass Movement ◽  
Gulf Of Cadiz ◽  
Gulf Of Cádiz

Spatial characterization of megabenthic epifauna of soft bottoms around mud volcanoes in the Gulf of Cádiz

2013 ◽  
Vol 47 (25-28) ◽  
pp. 1803-1831 ◽  
Author(s):  
Marina Delgado ◽  
José Luis Rueda ◽  
Juan Gil ◽  
Candelaria Burgos ◽  
Ignacio Sobrino
Keyword(s):  
Mud Volcanoes ◽  
Gulf Of Cadiz ◽  
Spatial Characterization ◽  
Gulf Of Cádiz ◽  
Soft Bottoms

scholarly journals Heterometallic boride clusters: synthesis and characterization of butterfly and square pyramidal boride clusters*

2018 ◽  
Vol 90 (4) ◽  
pp. 665-675 ◽  
Author(s):  
Ranjit Bag ◽  
Bijan Mondal ◽  
K. Bakthavachalam ◽  
Thierry Roisnel ◽  
Sundargopal Ghosh
Keyword(s):  
Boron Atom ◽  
Density Functional ◽  
Chemical Shifts ◽  
Dft Methods ◽  
Functional Theory ◽  
Pyramidal Geometry ◽  
Valence Electrons ◽  
Square Pyramidal Geometry ◽  
Optimized Geometries

AbstractA number of heterometallic boride clusters have been synthesized and structurally characterized using various spectroscopic and crystallographic analyses. Thermolysis of [Ru3(CO)12] with [Cp*WH3(B4H8)] (1) yielded [{Cp*W(CO)2}2(μ4-B){Ru(CO)3}2(μ-H)] (2), [{Cp*W(CO)2}2(μ5-B){Ru(CO)3}2{Ru(CO)2}(μ-H)] (3), [{Cp*W(CO)2}(μ5-B){Ru(CO)3}4] (4) and a ditungstaborane cluster [(Cp*W)2B4H8Ru(CO)3] (5) (Cp*=η5-C5Me5). Compound2contains 62 cluster valence-electrons, in which the boron atom occupies the semi-interstitial position of a M4-butterfly core, composed of two tungsten and two ruthenium atoms. Compounds3and4can be described as hetero-metallic boride clusters that contain 74-cluster valence electrons (cve), in which the boron atom is at the basal position of the M5-square pyramidal geometry. Cluster5is analogous to known [(Cp*W)2B5H9] where one of the BH vertices has been replaced by isolobal {Ru(CO)3} fragment. Computational studies with density functional theory (DFT) methods at the B3LYP level have been used to analyze the bonding of the synthesized molecules. The optimized geometries and computed11B NMR chemical shifts satisfactorily corroborate with the experimental data. All the compounds have been characterized by mass spectrometry, IR,1H,11B and13C NMR spectroscopy, and the structural architectures were unequivocally established by crystallographic analyses of clusters2–5.

Characterization of storm events along the Gulf of Cadiz (eastern central Atlantic Ocean)

2015 ◽  
Vol 36 (11) ◽  
pp. 3690-3707 ◽  
Author(s):  
G. Anfuso ◽  
N. Rangel-Buitrago ◽  
C. Cortés-Useche ◽  
B. Iglesias Castillo ◽  
F.J. Gracia
Keyword(s):  
Atlantic Ocean ◽  
Storm Events ◽  
Gulf Of Cadiz ◽  
Gulf Of Cádiz ◽  
Central Atlantic

BAND NN: A Deep Learning Framework For Energy Prediction and Geometry Optimization of Organic Small Molecules

2019 ◽  
Author(s):  
Siddhartha Laghuvarapu ◽  
Yashaswi Pathak ◽  
U. Deva Priyakumar
Keyword(s):  
Machine Learning ◽  
Density Functional ◽  
Computational Cost ◽  
Geometry Optimization ◽  
Dft Methods ◽  
Energy Prediction ◽  
Machine Learning Model ◽  
Equilibrium Structures ◽  
High Level ◽  
Non Equilibrium

Recent advances in artificial intelligence along with development of large datasets of energies calculated using quantum mechanical (QM)/density functional theory (DFT) methods have enabled prediction of accurate molecular energies at reasonably low computational cost. However, machine learning models that have been reported so far requires the atomic positions obtained from geometry optimizations using high level QM/DFT methods as input in order to predict the energies, and do not allow for geometry optimization. In this paper, a transferable and molecule-size independent machine learning model (BAND NN) based on a chemically intuitive representation inspired by molecular mechanics force fields is presented. The model predicts the atomization energies of equilibrium and non-equilibrium structures as sum of energy contributions from bonds (B), angles (A), nonbonds (N) and dihedrals (D) at remarkable accuracy. The robustness of the proposed model is further validated by calculations that span over the conformational, configurational and reaction space. The transferability of this model on systems larger than the ones in the dataset is demonstrated by performing calculations on select large molecules. Importantly, employing the BAND NN model, it is possible to perform geometry optimizations starting from non-equilibrium structures along with predicting their energies.

FORMATION HISTORY AND OCEANOGRAPHIC CONTROL OF LATE HOLOCENE MUD DEPOCENTERS IN THE NORTHEASTERN GULF OF CADIZ, SOUTHERN SPAIN

2016 ◽  
Author(s):  
Mary Lee King ◽  
◽  
Till J.J. Hanebuth ◽  
Francisco Lobo ◽  
Hendrik Lantzsch ◽  
...  
Keyword(s):  
Late Holocene ◽  
Southern Spain ◽  
Gulf Of Cadiz ◽  
Formation History ◽  
Gulf Of Cádiz

Biogeochemistry of surface sediments in mud volcanoes of the Gulf of Cádiz

2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Dolores Jiménez-López ◽  
Ana Sierra ◽  
Teodora Ortega ◽  
Sandra Manzano-Medina ◽  
M. Carmen Fernández-Puga ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Mud Volcanoes ◽  
Gulf Of Cadiz ◽  
Gulf Of Cádiz
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