scholarly journals Stratigraphy of amethyst geode-bearing lavas and fault-block structures of the Entre Rios mining district, Paraná volcanic province, southern Brazil

2013 ◽  
Vol 86 (1) ◽  
pp. 187-198 ◽  
Author(s):  
LÉO A. HARTMANN ◽  
LUCAS M. ANTUNES ◽  
LEONARDO M. ROSENSTENGEL
Keyword(s):  
Block Structure ◽  
Underground Mines ◽  
Mining District ◽  
Volcanic Province ◽  
Fault Block ◽  
River Bed ◽  
World Class ◽  
Entre Rios ◽  
Block Structures

The Entre Rios mining district produces a large volume of amethyst geodes in underground mines and is part of the world class deposits in the Paraná volcanic province of South America. Two producing basalt flows are numbered 4 and 5 in the lava stratigraphy. A total of seven basalt flows and one rhyodacite flow are present in the district. At the base of the stratigraphy, beginning at the Chapecó river bed, two basalt flows are Esmeralda, low-Ti type. The third flow in the sequence is a rhyodacite, Chapecó type, Guarapuava subtype. Above the rhyodacite flow, four basalt flows are Pitanga, high-Ti type including the two mineralized flows; only the topmost basalt in the stratigraphy is a Paranapanema, intermediate-Ti type. Each individual flow is uniquely identified from its geochemical and gamma-spectrometric properties. The study of several sections in the district allowed for the identification of a fault-block structure. Blocks are elongated NW and the block on the west side of the fault was downthrown. This important structural characterization of the mining district will have significant consequences in the search for new amethyst geode deposits and in the understanding of the evolution of the Paraná volcanic province.

Structural Characterization of Diene Block Copolymers by GPC and Ozonolysis—GPC Measurements

1987 ◽  
Vol 60 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Yasuyuki Tanaka ◽  
Hisaya Sato ◽  
Junichi Adachi
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Block Copolymers ◽  
Block Structure ◽  
Triblock Copolymers ◽  
Thermoplastic Elastomer ◽  
Chemical Composition Distribution ◽  
Block Structures ◽  
Styrene Butadiene

Abstract The sequence distribution and block structure of styrene units in commercial styrene—butadiene and styrene-isoprene copolymers were analyzed by GPC measurements on the original copolymers and on ozonolysis products. Tapered-block structures are clearly differentiated by ozonolysis—GPC measurements. The content of large block styrene sequences in S-B-S type block copolymers was found to be 77 to 99% or more. S-B and S sequences in addition to the S-B-S sequence were observed for most of the triblock copolymers. A star-shaped S-B-S copolymer was distinguished from a linear copolymer by comparison of the molecular weight and chemical composition of the main and shoulder peaks by GPC and also by reference to the molecular weight of the block styrene sequence determined by ozonolysis—GPC measurements. A mixture of block copolymers was estimated for a high-styrene thermoplastic elastomer by GPC and ozonolysis—GPC measurements together with the measurement of chemical composition distribution. In a similar way the block structure was analyzed for S-I-S triblock copolymers.

scholarly journals Synthesis and Characterization of Polyphosphazenes Modified with Hydroxyethyl Methacrylate and Lactic Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Room Temperature ◽  
Block Structure ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Poly Lactic Acid ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.

scholarly journals Surface and Underground Geomechanical Characterization of an Area Affected by Instability Phenomena in Zaruma Mining Zone (Ecuador)

2021 ◽  
Vol 13 (6) ◽  
pp. 3272
Author(s):  
Paúl Carrión-Mero ◽  
Maribel Aguilar-Aguilar ◽  
Fernando Morante-Carballo ◽  
María José Domínguez-Cuesta ◽  
Cristhian Sánchez-Padilla ◽  
...  
Keyword(s):  
Mass Movement ◽  
Mining Activity ◽  
Mining District ◽  
Mean Values ◽  
Surface Areas ◽  
Definition Of ◽  
Action Measures ◽  
Geomechanical Characterization ◽  
The City

In the last decade, in the mining district of Zaruma-Portovelo, there has been significant land subsidence related to uncontrolled mining activity. The purpose of this work was to carry out a surface and underground geomechanical characterization of a mining sector north of the city of Zaruma that allows the definition of potentially unstable areas susceptible to the mass movement. The methodology used consists of the following stages: (i) compilation of previous studies; (ii) surface and underground characterization of rocky material to establish its susceptibility to mass movement; (iii) interpretation of results; and (iv) proposal of action measures. Among the most relevant results, it stands out that 26.1% of the 23 stations characterized on the surface present conditions that vary from potentially unstable to unstable. In underground galleries, the studied mean values of the 17 stations indicate that the rock has a medium to good quality, representing a medium susceptibility to gallery destabilization. The results obtained for the surface areas (depths up to 50 m, where altered materials predominate) and the underground areas (depths > 50 m, where the alterations are specific) can be used to identify the areas with a more significant potential for instability. For both cases, it has been possible to define specific monitoring, control, and planning actions for sensitive areas.

scholarly journals Features of ground inflow testing in the areas of double porosity aquifer development

2021 ◽  
Vol 44 (2) ◽  
pp. 116-124
Author(s):  
L. I. Auzinaa ◽  
Yu. K. Lankin
Keyword(s):  
Free Water ◽  
Double Porosity ◽  
Rift System ◽  
Eastern Siberia ◽  
Geological Exploration ◽  
Tectonic Structures ◽  
Fault Block ◽  
Study Results ◽  
Exploration Drilling ◽  
Block Structures

The purpose of the study is optimization of geological exploration at the groundwater deposits of the upper hydrodynamic zone formed in the fault-block structure conditions in Eastern Siberia. The authors analyze the structural and tectonic features of the areas under investigation, the results of areal geophysics studies, exploration drilling and the use of the author's methodology in carrying out of the ground inflow testing. The objects of research are groundwater deposits located in various tectonic structures of Eastern Siberia. The analysis of field study results involving researches of groundwater deposits located in various tectonic structures of Eastern Siberia made it possible to identify the double porosity in the aquifers of free water exchange in the region, which is due to the stresses arising during the inland Baikal rift system formation. As a result, the optimization of geological exploration work, methodology and processing methods of ground inflow testing in the areas of fault-block structures development were introduced on the basis of the features of structural-tectonic and hydrogeological conditions.

scholarly journals Stability Analysis and Monitoring Method for the Key Block Structure of the Basic Roof of Noncoal Pillar Mining with Automatically Formed Gob-Side Entry

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jianning Liu ◽  
Manchao He ◽  
Yajun Wang ◽  
Ruifeng Huang ◽  
Jun Yang ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Coal Mine ◽  
Block Structure ◽  
Monitoring Method ◽  
Roof Caving ◽  
Pillar Mining ◽  
Key Block ◽  
The Stability ◽  
Block Structures ◽  
Basic Roof

The key block of the basic roof is the main contributor to the structural stability of a roadway. Research on the stability of the key block structure is of great significance for the promotion of noncoal pillar mining with automatically formed gob-side entry (GEFANM) technology. This paper is set in the engineering context of the GEFANM experiment at the Ningtiaota Coal Mine. The study fully considered the differences in the gob roof caving on the roof-cutting-line side, and the range of rotation angles to maintain a stable key block was determined. Based on this range of rotation angles, the range of safe bulking coefficients of gangue was calculated. The bulking coefficient of the gangue on the gravel side of the roadway was used as the metric in a new monitoring method and in the calculation of the field parameters. The range of safe bulking coefficients was determined to be 1.40–1.37. Field monitoring was conducted to obtain the gangue bulking coefficient on the gravel side. Combining the roof and floor convergence data, when the bulking coefficient fell within the safe range, the convergence was 95–113 mm. In this stage, the key block structure was stable. When the gangue bulking coefficient fell outside the safe range, the convergence was larger, and cracks were observed. The key block may be vulnerable to instability. The results affirmed that the gangue bulking coefficient can be used as a monitoring metric to study the stability of key block structures.

The Elgin, Franklin, Glenelg and West Franklin fields, Blocks 22/30b, 22/30c, 29/4d, 29/5b and 29/5c, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 436-446 ◽  
Author(s):  
A. D. Irving ◽  
K. F. Raphael ◽  
P. M. Rennison ◽  
R. Lewis ◽  
C. D. Cruickshank ◽  
...  
Keyword(s):  
Initial Pressure ◽  
Upper Jurassic ◽  
Central Process ◽  
Fault Block ◽  
High Pressure High Temperature ◽  
Temperature Development ◽  
Production Wells ◽  
Cumulative Production ◽  
The Uk ◽  
Block Structures

AbstractThe Elgin, Franklin, Glenelg and West Franklin fields lie approximately 240 km (150 miles) east of Aberdeen in Blocks 22/30b, 22/30c, 29/4d, 29/5b and 29/5c of the UK Central Graben. Franklin was discovered in 1985, Elgin in 1991, Glenelg in 1999 and West Franklin in 2003. Elgin is a complex faulted anticline comprising four panels, while the others are simpler, tilted fault block structures. The main reservoir is the Upper Jurassic Fulmar Formation shoreface sandstone, although the Middle Jurassic Pentland and Triassic Skagerrak formations have also been produced on Franklin. Initial pressure was c. 1100 bar (16 000 psi), with a reservoir temperature of around 190°C (375°F). Production wells are drilled from four wellhead platforms; all connected to a central process, utilities and quarters facility above Elgin. Gas and condensate production started in 2001 from six wells on each of Elgin and Franklin, with the plateau being extended by satellite and infill wells. The project remains the world's largest high-pressure–high-temperature development, requiring continued innovations in geoscience, drilling, completion and operations. Cumulative production at end 2017 is 886 Mboe, with estimated ultimate recovery around 1300 Mboe.

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