Nouvelles observations sur la serie de la Gara Sayada (bordure nord-est de l'Eglab, Sahara occidental)

1961 ◽  
Vol S7-III (2) ◽  
pp. 127-132
Author(s):  
Pierre Dourthe ◽  
O. Serra
Keyword(s):  
Western Sahara ◽  
Eastern Margin ◽  
The North ◽  
North Eastern

Abstract A subhorizontal sandy series, the Gara Sayada series, some hundreds of meters thick, overlies a folded sandstone-shale series, more than 1,000 meters thick, on the north-eastern margin of the Eglab massif (Algeria) in the western Sahara. The intra-Caradocian (Ordovician) unconformity already known at several other localities in the Sahara is thus also represented in this region.

Petroleum system of the North-Eastern margin of the Pechora Platform

1996 ◽  
Author(s):  
V. Martirosyan ◽  
A. Simonov ◽  
L. Popova ◽  
F. Kevorkov ◽  
L. Tichomirova
Keyword(s):  
Petroleum System ◽  
Eastern Margin ◽  
The North ◽  
North Eastern

scholarly journals Notes on the Permian to Recent Geology of the Kruger National Park

Koedoe ◽  
1986 ◽  
Vol 29 (1) ◽  
Author(s):  
J.W. Bristow ◽  
F.J. Venter
Keyword(s):  
National Park ◽  
Kruger National Park ◽  
Eastern Margin ◽  
The North ◽  
North Eastern ◽  
Extreme North

Permian to Recent rocks form narrow, roughly north- south and east-south-east trending belts in the north-eastern Transvaal. The rocks consist of a thin succession of Karoo sediments, a thick overlying succession of mafic and felsic volcanics referred to as the Lebombo Group, isolated outcrops of Cretaceous sediments and fairly extensive Tertiary-Recent Gravels and sediments. These rocks are in general well exposed along the eastern margin of the Kruger National Park and also crop out in the extreme north. Emplacement of the Lebombo volcanics and subsequent deposition of the Cretaceous rocks was intimately associated with the fragmentation of Gondwanaland.

scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2011 ◽  
pp. 28-36
Author(s):  
G.P. Yarotskiy ◽  
Keyword(s):  
Seismic Events ◽  
The South ◽  
Strong Earthquakes ◽  
Eastern Margin ◽  
The North ◽  
South West ◽  
North Eastern

Earthquakes on the south-west of Koryak highlands are connected with a block-key tectonics of lithosphere of marine transital of north-eastern margin of Eurasia and the block-key structure of its strata. The cloud of shocks of three strong earthquakes: Koryak`s (13.10.1988), Khailin`s (8.03.1991) and Olutor`s (20.04.2006) is located over the downfold of lithosphere bottom with drop of depths equal to 15-20 km. Preparation for the seismic events evolution to the north-eastward is possible.

Spatial variability of modern tectonic stress fields in the north‐eastern margin of Tibetan Plateau

2020 ◽  
Vol 55 (11) ◽  
pp. 7167-7192
Author(s):  
Liming Li ◽  
Xianrui Li ◽  
Mingtao Li ◽  
Zhirong Liang ◽  
Jingxiong Tian ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Spatial Variability ◽  
Tectonic Stress ◽  
Stress Fields ◽  
Eastern Margin ◽  
The North ◽  
North Eastern

scholarly journals PETROGRAPHY AND GEOCHEMISTRY OF SOME PALEOPROTEROZOIC GRANITOIDS AT THE NORTH-EASTERN MARGIN OF THE KUMASI BASIN IN GHANA

2020 ◽  
Vol 4 (2) ◽  
pp. 118-126
Author(s):  
Blestmond A. Brako ◽  
Gordon Foli ◽  
Kofi Adomako- Ansah ◽  
Derrick Aikins ◽  
Solomon Dery ◽  
...  
Keyword(s):  
Continental Crust ◽  
Fractional Crystallization ◽  
Distribution Patterns ◽  
Quartz Diorite ◽  
Geodynamic Setting ◽  
Petrographic Analysis ◽  
Eastern Margin ◽  
The North ◽  
North Eastern ◽  
Water Saturated

This study investigates basin-type granitoid samples from the north-eastern margin of the Kumasi Basin in Ghana to establish their source and geodynamic setting. Petrographic analysis, TAS and A/NK-A/CNK plots classify the granitoids as metaluminous quartz diorite, metaluminous granodiorite, and peraluminous monzogranite; and exhibiting I-type signatures. These rocks are formed by magma differentiation and/or partial melting at various stages. Distribution patterns of incompatible elements and the positive Eu/Eu* anomalies of 1.15 and 1.47 exhibited by quartz diorite and granodiorite, respectively, the values suggest the rocks crystallized from melts formed in a water-saturated environment. The negative Eu/Eu* anomaly exhibited by monzogranite indicate fractionation of plagioclase in the final stages of the magma evolution. The water-rich environment is probably due to dewatering of the basin’s foreland volcaniclastic sediments during regional subsidence, burial and metamorphism. K2O enrichments and wide variations suggest that the granodiorite and monzogranite are formed from fractional crystallization and/or crustal assimilation of the continental crust by under-plating dioritic magma. The higher Al2O3/TiO2 enrichment and the shift from metaluminous to peraluminous in the monzogranite suggest a longer residence time within the continental crust, during which fractional crystallization and the assimilation of pre-existing crustal components into the dioritic magma that resulted in the formation of the monzogranite. The study requires replication at other areas within the basin to generate enough data to enhance metallogenic studies in the terrain.

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