Structure of the earth's crust of epi-continental seas: Caspian, Black, and Mediterranean

1968 ◽  
Vol 5 (4) ◽  
pp. 1037-1043 ◽  
Author(s):  
Yu. P. Neprochnov
Keyword(s):  
Crustal Structure ◽  
Earth’S Crust ◽  
Deep Basin ◽  
Smooth Interface ◽  
Tectonic Development ◽  
Earth's Crust ◽  
Granitic Layer ◽  
Different Parts ◽  
Sedimentary Layer

Comparison of crustal structure of the deep basins of the Caspian, Black, and Mediterranean Seas indicates the similarities of the main characteristics: great Bouger anomalies, the absence of a 'granitic' layer, a thick sedimentary layer with a relatively smooth interface, aseismicity. However, each of the above-mentioned basins (or even different parts of one deep basin) has its peculiarities, which indicates a very complicated tectonic development of the entire Caspian–Mediterranean zone.

Peculiarities of the Earth’s crust sedimentary layer structure in the Falkland Basin

Oceanology ◽  
2010 ◽  
Vol 50 (6) ◽  
pp. 961-970
Author(s):  
A. A. Schreider ◽  
E. L. Mazo ◽  
A. A. Bulychev ◽  
M. P. Kulikova ◽  
D. A. Gilod ◽  
...  
Keyword(s):  
Layer Structure ◽  
Earth’S Crust ◽  
Earth's Crust ◽  
Sedimentary Layer

A study of the calc-gneisses, scapolite-gneisses, and cordierite-garnet-sillimanite-rocks of Coimbatore, Madras Presidency; with comparison to other similar occurrences in India

1929 ◽  
Vol 22 (126) ◽  
pp. 121-135 ◽  
Author(s):  
L. A. Narayana Iyer
Keyword(s):  
Central India ◽  
Earth’S Crust ◽  
Indian Shield ◽  
Indian Peninsula ◽  
Stable Part ◽  
Earth's Crust ◽  
Different Parts

The Indian peninsula, though considered to be a very stable part the earth's crust and hence called the 'Indian Shield', shows in different parts evidence of formerly having sustained epicontinental basins, in which sedimentation occurred. These sediments are now found in detached prisms as crystalline gneisses and schists in different parts of India, e.g. in the Madras Presidency, Bihar and Orissa, Central Provinces, Central India, and Rajputana. They have been found overlying the ancient gneigses (Archaean), and belong to a division known in Indian geology as the Dharwar System.

ON GEODYNAMIC CONDITIONS AND UNDERWATER-LANDSLIDE DEFORMATIONS IN THE ULUTAU FORMATION

2020 ◽  
Vol 0 (4) ◽  
pp. 46-52
Author(s):  
T.T. KAZANTSEVA ◽  
Keyword(s):  
Structural Characteristics ◽  
Research Area ◽  
Earth’S Crust ◽  
The West ◽  
Clastic Rocks ◽  
Underwater Landslide ◽  
Tectonic Development ◽  
Earth's Crust ◽  
Folded Structures ◽  
The Village

To understand the features of geodynamics during the accumulation of the systems of geological matter in the Earth's crust at the formation level of the Paleozoic Urals, this paper presents the author's factual materials on structural characteristics of clastic rocks of the flysch sequence of the Ulutau Formation (Middle Devonian Givetian) within the mapping area of the Urtazym zone of the Magnitogorsk Synclinorium. Here, to the west of the village of Tash-Tugay, rhythmites are developed in the lower reaches of the Tanalyk River that show very informative underwater interlayer dislocations: cross-bedding, spherical and folded structures serving as a decisive marker for the synchronism of sedimentation and dislocation. They characterize the deformation period in the tectonic development of the folded region, according to the main points of the thrust-nappe theory of the formation of the Earth's crust and the scientific research area «structural factor in theoretical geology».

A study of the Earth's crust near Gauribidanur in Southern India

1971 ◽  
Vol 61 (3) ◽  
pp. 671-683
Author(s):  
S. K. Arora
Keyword(s):  
Epicentral Distance ◽  
Earth’S Crust ◽  
Seismic Events ◽  
Travel Times ◽  
Geological Features ◽  
Local Earthquake ◽  
First Arrival ◽  
Earth's Crust ◽  
Relative Differences ◽  
Granitic Layer

abstract A hypothetical two-layered model has been evolved for the Earth's crust near Gauribidanur. The model is found to be consistent with the local earthquake and rockburst data obtained at Gauribidanur seismographic array. Sixty-seven well-recorded seismic events have been studied for this purpose. First arrival conditions for some of the phases in a “near-source” (epicentral distance Δ ≦ 10°) seismogram have been derived and subsequently made use of in establishing the nature of the first arriving phases pertaining to the available data. Thickness of the top granitic layer and the depth of Moho below this layer are found to be about 16 km and 19 km, respectively. Observed velocities are 5.67, 6.51 and 7.98 km/sec for P phases, and 3.46, 3.96 and 4.61 km/sec for the corresponding S phases. Values of the crustal parameters given by this study have been used in estimating the relative differences in travel times corresponding to various observed phases. These travel times may improve the precision with which earthquakes in this region could be located. Typical geographical and geological features of the region are also briefly described.

scholarly journals The role of geodynamic stress in the formation of oil and gas structures in the Caspian Sea (on the example of the Shah Deniz, Umid, Babek, Bulla Deniz fields)

2021 ◽  
Author(s):  
Г.О. Велиев
Keyword(s):  
Mantle Plume ◽  
Caspian Sea ◽  
Oil And Gas ◽  
Heat Removal ◽  
Earth’S Crust ◽  
Caspian Basin ◽  
Depth Range ◽  
The Caspian Sea ◽  
Earth's Crust ◽  
Sedimentary Layer

В статье рассматривается геодинамическое напряжение в формировании нефтегазовых структур в пределах Каспийского моря (на примере нефтяных месторождений Шахдениз, Умид, Бабек и Булла Дениз). Цель работы. Была предложена теория формирования Каспийского бассейна на основе модели формирования мантийных плюмов. Метод работы. В данной методике предполагается, что в пределах мантийных плюмов происходит подъём вещества и вынос тепла из мантийных глубин. Считается также, что в головной части мантийного плюма происходит частичное плавление мантийного вещества и образуется магмогенерирующая об­ласть. Магма, формирующаяся в головной части, обычно имеет щёлочно-базальтовый состав. При достижении мантийного плюма подошвы литосферы над ним проявляется плюмовый магматизм: про­исходит внедрение интрузий в земную кору и вдоль границы земной коры и мантии. В статье отмечено, что в области, охватываемой Палео-Каспием, магма переместилась из мантийного слоя на поверхность Земли, изменила свою структуру вблизи поверхности Земли, а область, очерченная локальными аномальными полями в гравитации и магнитных полях, соответствовала палеокаспийской морфологии. Зоны сейсмической активности и круговые региональные разломы, в условиях геодинамического напряжения современного Каспийского бассейна считаются признаками плюмового процесса. Результаты работы. Установлено, что сильные землетрясения с относительной магнитудой M≥6–8 происходят в диапазоне глубин 7–20 км. В северной дуге Южного Каспия, где активность плюма все еще присутствует в интервале 55–65 км в базальтовом слое, в этом интервале наблюдаются признаки деформации в соответствии с характерными очагами землетрясения. Геодинамическое напряжение, накопленное в результате горизонтальных, вертикальных и круговых движений, создаваемых плюмом в мантии, повлияло на динамику осадочного слоя до глубины 25 км, границы Конрада 20–32 км 40–53 км, и границы Мохо до глубины 40–53 км, где постоянно менялась морфоструктура осадочного слоя. Процесс осаждения в бассейне Каспийского моря начался до мезозоя, и в течение юрского периода земная кора продолжала снижаться и примерно с такой же тенденцией происходило формирование бассейна. В результате вихревого движения, созданного магматическим шлейфом в Каспийском бассейне, выстроились кольцевые спиральные антиклинальные структуры (Бахар, Шах-Дениз, Абшерон, Шафаг, Машал, Бабек, Умид, Булла-Дениз, Асиман, Зафар и др.), где было накоплено большое количество углеводородного потенциала страны. Проанализированы стратиграфическо-литологические особенности отложений в структуре Умид и показано, что там запасы нефти и газа очень велики The article considers the geodynamic stress in the formation of oil and gas structures within the Caspian Sea (on the example of the Shah Deniz, Umid, Babek, Bulla Deniz fields). Aim. A theory for the formation of the Caspian basin was proposed based on the “mantle plume” model. Methods. In this technique, it is assumed that within the mantle plumes there is an uplift of matter and heat removal from the mantle depths. It is also believed that in the head of the mantle plume there is a partial melting of the mantle material and a magma-generating area is formed. The magma that is formed in the head is usually alkaline-basalticcomposition. When the mantle plume reaches the base of the lithosphere, plume magmatism appears above it: intrusions are introduced into the earth's crust and along the border of the earth's crust and mantle. It is noted that in the area covered by the Paleo-Caspian, magma moved from the mantle layer to the Earth's surface. Thus, it changed its structure near the Earth's surface, and the area outlined by local anomalous fields in gravity and magnetic fields corresponded to the paleocaspian morphology. Zones of seismic activity and circular regional faults, under the geodynamic stress of the modern Caspian basin, are considered signs of a plume process. Results. It has been established that strong earthquakes with a relative magnitude of M≥6–8 occur in the depth range of 7–20 km. In the northern arc of the South Caspian, where plume activity is still present in the 55–65 km interval in the basalt layer, there are signs of deformation in this interval in accordance with the characteristic earthquake sources. Geodynamic stress accumulated as a result of horizontal, vertical and circular motions created by the plume in the mantle influenced the dynamics of the sedimentary layer to a depth of 25 km, the Conrad boundaries 20–32 km 40–53 km, and the Moho boundaries to a depth of 40–53 km.There the morphostructure of the sedimentary layer was constantly changing. The deposition process in the basin of the Caspian Sea began before the Mesozoic, and during the Jurassic period the earth's crust continued to decline and the formation of the basin took place with approximately the same tendency. As a result of the vortex movement created by the magmatic plume in the Caspian basin, the circular spiral anticlinal structures (Bahar, ShahDeniz, Absheron, Shafag, Mashal, Babek, Umid, BullaDeniz, Asiman, Zafar, etc.) were built. There was accumulated the large amount of the country's hydrocarbon potential. The stratigraphic and lithological features of deposits in the structure ofUmidare analyzed and it is shown that there are very large reserves of oil and gas.

Sign in / Sign up

Export Citation Format

Share Document