A three-dimensional geophysical model of the Earth’s crust in the central part of the Karelian Craton

2015 ◽  
Vol 463 (2) ◽  
pp. 808-812 ◽  
Author(s):  
I. K. Pashkevich ◽  
A. S. Savchenko ◽  
V. I. Starostenko ◽  
N. V. Sharov
Keyword(s):  
Three Dimensional ◽  
Earth’S Crust ◽  
Karelian Craton ◽  
Geophysical Model ◽  
Earth's Crust

Stability of a Penny-Shaped Geothermal Reservoir in the Earth’s Crust

1982 ◽  
Vol 104 (2) ◽  
pp. 93-95 ◽  
Author(s):  
H. Abe´ ◽  
H. Sekine ◽  
S. Kitada
Keyword(s):  
Critical Pressure ◽  
Three Dimensional ◽  
Tectonic Stress ◽  
Theory Of Elasticity ◽  
Surrounding Rock ◽  
Geothermal Reservoir ◽  
Earth’S Crust ◽  
Dimensional Theory ◽  
Opening Mode ◽  
Earth's Crust

The theoretical analysis of a penny-shaped geothermal reservoir in the earth’s crust subject to linear tectonic stress gradients has been made on the basis of the three-dimensional theory of elasticity. The condition for stability of a reservoir requires K1 < Kc, where K1 and Kc are, respectively, the stress intensity factor for the opening mode and the fracture toughness of the surrounding rock. From this condition the upper critical pressure being necessary for the reservoir stability is obtained and is shown graphically.

scholarly journals THREE-DIMENSIONAL DENSITY MODEL OF THE EARTH’S CRUST OF THE TERRITORY OF THE REPUBLIC OF NIGER

2021 ◽  
pp. 6-21
Author(s):  
V.N. Glaznev ◽  
◽  
M.V. Mints ◽  
I.A. Yakuba ◽  
◽  
...  
Keyword(s):  
Gravity Field ◽  
Three Dimensional ◽  
Earth’S Crust ◽  
Density Model ◽  
Weight Functions ◽  
Rift System ◽  
Data Set ◽  
Anomalous Gravity ◽  
The Republic ◽  
Earth's Crust

The paper considers the results of calculation of the three-dimensional density model of the Earth’s crust for the territory of the Republic of Niger in conditions of incomplete initial geological and geophysical information. A brief description of the geological structure of the research region is given and the task of the study is formulated. The initial data set of density modeling is described, including: the anomalous gravity field, the initial model of the medium, the constraints on the desired solution, and the weight functions of redistribution of field incompatibilities. Inversion of the anomalous gravity field was performed in a three-dimensional formulation for a regular grid with a 25×25 km spacing in the plan and 14 layers of irregular vertical grid. The density model of the crystalline crust obtained by solving the inverse problem was combined with a priori data on the density of the upper mantle layer and the previously constructed layered model of the sedimentary cover of the region. The main features of the density model of the Earth’s crust are considered and its density heterogeneities are compared with the regional geological and tectonic data. The leading role of young structures of the West African rift System and their relationship with density inhomogeneities in the lower and middle crust of the territory of the Republic of Niger was noted.

scholarly journals Microscopy and Microanalysis of Magmatic and Metamorphic Minerals—Part 2: Feldspar

2010 ◽  
Vol 18 (3) ◽  
pp. 18-24 ◽  
Author(s):  
Robert Sturm
Keyword(s):  
Solid Solutions ◽  
Three Dimensional ◽  
Alkali Feldspar ◽  
Major Elements ◽  
Potassium Feldspar ◽  
Earth’S Crust ◽  
Mineral Species ◽  
Oxygen Ions ◽  
Dimensional Network ◽  
Earth's Crust

Feldspar is the name for a mineral group consisting of nearly 20 triclinic or monoclinic mineral species, of which only nine are well documented and widely distributed in the Earth's crust. Single members of the feldspar group belong to the so-called framework—or tectosilicates, where SiO4- and AlO4-tetrahedra share all their oxygen ions, resulting in an infinite three-dimensional network . Feldspar crystals include the major elements K, Na, Ca, Al, as well as Si and thus may be attributed to one of the following three endmembers: potassium-feldspar (K-feldspar) KAlSi3O8, albite NaAlSi3O8, or anorthite CaAl2Si2O8 (Table 1). Solid solutions occur between K-feldspar and albite, forming what is commonly known as alkali feldspar, and between albite and anorthite, forming plagioclase. The alkali feldspar group consists of orthoclase, microcline, sanidine, and anorthoclase, whereas the plagioclase group includes albite, oligoclase, andesine, labradorite, bytownite, and anorthite .

Three-dimensional Earth’s crust density model of the central part of the Golovanevsk suture zone of the Ukrainian Shield

2018 ◽  
Vol 40 (3) ◽  
pp. 27-53
Author(s):  
V. I. Starostenko ◽  
P. Ya. Kuprienko ◽  
I. B. Makarenko ◽  
A. S. Savchenko ◽  
O. V. Legostaeva
Keyword(s):  
Three Dimensional ◽  
Suture Zone ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Density Model ◽  
Earth's Crust
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