Etude tectonique du secteur Pradoluengo-Alarcia, Sierra de la Demanda (chaines iberiques, Espagne)

1963 ◽  
Vol S7-V (7) ◽  
pp. 1068-1075
Author(s):  
Michel Colchen
Keyword(s):  
Basement Complex ◽  
Direction Parallel ◽  
The North ◽  
Basement Rocks ◽  
Northern Border ◽  
Tectonic Study

Abstract A tectonic study of the area northwest of Sierra de la Demanda (Spain) revealed Tertiary orogenic phases represented by overlaps and overturnings. Towards the northern border, the Cambrian overrides Carboniferous, Triassic and Jurassic formations; the Carboniferous-Triassic units appear overturned under the Cambrian; and the Jurassic formations are affected locally by a system of dislodged slices of nappes associated with imbricate basement rocks. Two major directions of deformation suggest the presence of two successive orogenic phases. The first phase, older than the Oligocene conglomerates, folded the units above the basement in a NW-SE direction, parallel to the north oriented horst in the basement complex. In the post-Oligocene phase NE-SW imbrication affected the conglomerates as well as the basement and overlying units.

X.—The Pre-Devonian Basement Complex of Central Spitsbergen

1922 ◽  
Vol 53 (1) ◽  
pp. 209-229 ◽  
Author(s):  
G. W. Tyrrell
Keyword(s):  
Sedimentary Rocks ◽  
Basement Complex ◽  
East Central ◽  
Mountain Ranges ◽  
The North ◽  
Basement Rocks ◽  
North Eastern ◽  
Sedimentary Succession

The more or less flat-lying sedimentary rocks that build up the plateau country of the northern, central, and eastern parts of Spitsbergen range in age from Downtonian to Tertiary. The rocks with which it is proposed to deal in this paper constitute the basement underlying this sedimentary succession in the east central part of Spitsbergen, in the region at the head, and to the east, of Klaas Billen Bay, the north-eastern branch of the Ice Fiord (Map, fig. I). An extension of these basement rocks is to be found in the mountains east of Wijde Bay, and similar rocks are to be found in other parts of Spitsbergen, notably in the western mountain ranges. Formations up to the Tertiary, as well as the Pre-Devonian, are involved in the folding of these western ranges; but the rocks dealt with in this paper may be designated as older than the oldest unfolded rocks in the country.

Subsurface stratigraphy and basin-fill architecture of the late Paleozoic eastern Taos trough, northern New Mexico, U.S.A.

2020 ◽  
Vol 57 (3) ◽  
pp. 149-176
Author(s):  
Nur Uddin Md Khaled Chowdhury ◽  
Dustin E. Sweet
Keyword(s):  
New Mexico ◽  
Sediment Accumulation ◽  
Late Paleozoic ◽  
North Central ◽  
The North ◽  
Basement Rocks ◽  
Basin Geometry ◽  
Deformation Event ◽  
Thrust System ◽  
Basin Fill

The greater Taos trough located in north-central New Mexico represents one of numerous late Paleozoic basins that formed during the Ancestral Rocky Mountains deformation event. The late Paleozoic stratigraphy and basin geometry of the eastern portion of the greater Taos trough, also called the Rainsville trough, is little known because the strata are all in the subsurface. Numerous wells drilled through the late Paleozoic strata provide a scope for investigating subsurface stratigraphy and basin-fill architecture of the Rainsville trough. Lithologic data obtained predominantly from petrophysical well logs combined with available biostratigraphic data from the greater Taos trough allows construction of a chronostratigraphic framework of the basin fill. Isopach- and structure-maps indicate that the sediment depocenter was just east of the El Oro-Rincon uplift and a westerly thickening wedge-shaped basin-fill geometry existed during the Pennsylvanian. These relationships imply that the thrust system on the east side of the Precambrian-cored El Oro-Rincon uplift was active during the Pennsylvanian and segmented the greater Taos trough into the eastern Rainsville trough and the western Taos trough. During the Permian, sediment depocenter(s) shifted more southerly and easterly and strata onlap Precambrian basement rocks of the Sierra Grande uplift to the east and Cimarron arch to the north of the Rainsville trough. Permian strata appear to demonstrate minimal influence by faults that were active during the Pennsylvanian and sediment accumulation occurred both in the basinal area as well as on previous positive-relief highlands. A general Permian decrease in eustatic sea level and cessation of local-fault-controlled subsidence indicates that regional subsidence must have affected the region in the early Permian.

scholarly journals Studies on the onshore hydrocarbon potential in East Greenland 1986-87: field work from 72° to 74°N

1987 ◽  
Vol 135 ◽  
pp. 72-81
Author(s):  
C Marcussen ◽  
F.G Christiansen ◽  
P.-H Larsen ◽  
H Olsen ◽  
S Piasecki ◽  
...  
Keyword(s):  
Thermal History ◽  
Sedimentary Basins ◽  
Field Work ◽  
Source Rocks ◽  
Hydrocarbon Potential ◽  
East Greenland ◽  
The North ◽  
Hydrocarbon Traps ◽  
Subsidence History ◽  
Tectonic Study

A study of the onshore hydrocarbon potential of central and northem East Greenland was initiated in 1986. Field work was carried out from early July to mid August covering the region between Kong Oscar Fjord and Kejser Franz Joseph Fjord (fig. 1). In 1987 field activities will continue further to the north, eventually reaching Danmarkshavn (77°N). The programme is a continuation of the 1982-83 investigations in Jameson Land (Surlyk, 1983; Surlyk et al., 1984a) and is part of a regional programme comprising petroleum geological studies of all sedimentary basins in Greenland (Larsen & Marcussen, 1985; Larsen, 1986). The aim of the two-year field study followed by laboratory analyses is: (1) to study the presence and distribution of potential hydrocarbon source rocks in the region; (2) to evaluate the thermal history and maturity pattern of the region including the thermal effect of Tertiary intrusions and volcanics; (3) to make a stratigraphic, sedimentological and tectonic study of the region with special emphasis on subsidence history, reservoir formation and potential hydrocarbon traps.

Age and Geochemical Studies of the Snyder Breccia, Coastal Labrador

1975 ◽  
Vol 12 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Jackson M. Barton Jr. ◽  
Erika S. Barton
Keyword(s):  
Trace Element ◽  
North Atlantic ◽  
Layered Intrusion ◽  
Basement Complex ◽  
Fine Grained ◽  
The North ◽  
Isotopic Analyses ◽  
The Matrix ◽  
The North Atlantic ◽  
Geochemical Studies

The Snyder breccia is composed of angular to subrounded xenoliths of migmatites and amphibolites in a very fine grained matrix. It is apparently intrusive into the metasediments of the Snyder Group exposed at Snyder Bay, Labrador. The Snyder Group unconformably overlies a migmatitic and amphibolitic basement complex and is intruded by the Kiglapait layered intrusion. K–Ar ages indicate that the basement complex is Archean in age (> 2600 m.y. old) and that the Kiglapait layered intrusion was emplaced prior to 1280 m.y. ago. Major and trace element analyses of the matrix of the Snyder breccia indicate that while it was originally of tonalitic composition, later it locally underwent alteration characterized by loss of sodium and strontium and gain of potassium, rubidium and barium. Rb–Sr isotopic analyses show that this alteration occurred about 1842 m.y. ago, most probably contemporaneously with emplacement of the breccia. The Snyder Group thus was deposited sometime between 2600 and 1842 m.y. ago and may be correlative with other Aphebian successions preserved on the North Atlantic Archean craton.

Lower Palaeozoic and Precambrian igneous rocks from eastern England, and their bearing on late Ordovician closure of the Tornquist Sea: constraints from U-Pb and Nd isotopes

1993 ◽  
Vol 130 (6) ◽  
pp. 835-846 ◽  
Author(s):  
S. R. Noble ◽  
R. D. Tucker ◽  
T. C. Pharaoh
Keyword(s):  
Volcanic Rocks ◽  
Igneous Rocks ◽  
Calc Alkaline ◽  
Nd Isotopes ◽  
Nd Isotope ◽  
Magmatic Arc ◽  
The North ◽  
Basement Rocks ◽  
Continental Arc ◽  
Lower Palaeozoic

AbstractThe U-Pb isotope ages and Nd isotope characteristics of asuite of igneous rocks from the basement of eastern England show that Ordovician calc-alkaline igneous rocks are tectonically interleaved with late Precambrian volcanic rocks distinct from Precambrian rocks exposed in southern Britain. New U-Pb ages for the North Creake tuff (zircon, 449±13 Ma), Moorby Microgranite (zircon, 457 ± 20 Ma), and the Nuneaton lamprophyre (zircon and baddeleyite, 442 ± 3 Ma) confirm the presence ofan Ordovician magmatic arc. Tectonically interleaved Precambrian volcanic rocks within this arc are verified by new U-Pb zircon ages for tuffs at Glinton (612 ± 21 Ma) and Orton (616 ± 6 Ma). Initial εNd values for these basement rocks range from +4 to - 6, consistent with generation of both c. 615 Ma and c. 450 Ma groups of rocksin continental arc settings. The U-Pb and Sm-Nd isotope data support arguments for an Ordovician fold/thrust belt extending from England to Belgium, and that the Ordovician calc-alkaline rocks formed in response to subductionof Tornquist Sea oceanic crust beneath Avalonia.

Le synclinal danien-eocene de La Mourotte (Var)

1962 ◽  
Vol S7-IV (1) ◽  
pp. 87-91 ◽  
Author(s):  
Fernand Touraine
Keyword(s):  
Upper Jurassic ◽  
The South ◽  
Northern Limit ◽  
Southern Limit ◽  
The North ◽  
Bird Eggs ◽  
Tectonic Study ◽  
Dinosaur Eggs

Abstract Results of a stratigraphic and tectonic study of the Mourotte syncline, Provence, France, divide the structure into three parts. The northern part is composed of Hauterivian littoral beds containing Danian dinosaur eggs. The Danian limestone-sandstone series disappears at La Neuve while the marly upper Danian beds continue to the extreme northern limit of the syncline. In the central part the Hauterivian wedges out, and toward its southern limit the substratum is entirely upper Jurassic. In the southern part, the Danian limestones are only visible on the northeast border. Bird eggs collected in the area assign the southern part of the syncline to the Thanetian. Overturning is less noticeable in the north, becoming acute toward the south where the syncline is tightly overturned.

Injected drugs consumption in Mexico: notes for the last two decades / El consumo de drogas inyectadas en México: apuntes de las últimas dos décadas

2003 ◽  
Vol 3 (2) ◽  
Author(s):  
Nivaldo Linares Pérez
Keyword(s):  
Sources Of Information ◽  
The North ◽  
Northern Border ◽  
The Family ◽  
Careful Revision ◽  
Bibliographic Search ◽  
The Subject ◽  
The Individual ◽  
Windows 2000 ◽  
Different Sources

Objetivo: Revisar los aspectos epidemiológicos relevantes de investigaciones nacionales sobre consumo de heroína y cocaína en las dos últimas décadas, haciendo énfasis en la frontera norte de México. Material y Método: Se realizó una consulta automatizada, previo diseño teórico de búsqueda bibliográfica de trabajos sobre el tema. Se encontraron 72 materiales y tras una cuidadosa selección, quedaron 59, recuperando 83% de ellos. Para su análisis se diseñó una matriz de variables cualitativas y cuantitativas y se procesó en Excel para Windows 2000. Resultados: Sin ser un fenómeno reciente, el consumo de heroína esta alcanzando en últimas fechas proporciones considerables y diversas fuentes de información marcan esta tendencia, sobre todo en el norte del país. Asimismo el consumo de cocaína es cada vez mayor y se extiende por todo el territorio nacional en proporciones cada vez mayores según lo muestran diferentes indicadores. Comentarios: El panorama epidemiológico del consumo de heroína y cocaína es alarmante por sus repercusiones en lo individual, familiar y social y representa un reto principalmente para la planificación y funcionamiento de los servicios de salud en México. AbstractObjective: To review the relevant epidemiological aspects of national research regarding consumption of heroin and cocaine over the last two decades, with emphasis on the northern border of Mexico. Materials and Method: An automated consultation was carried out after the theoretical design of a bibliographic search for works related to the subject. 72 papers were found of which 59 were chosen after a careful revision representing 83%. For the analysis a matrix of qualitative and quantitative variables was designed and processed with Excel, Windows 2000. Results: Although the consumption of heroin is not a recent phenomenon, over the last few years it has reached such high proportions, especially in the north of the country, as many different sources of information indicate. Likewise, the consumption of cocaine is ever-growing and spreading throughout the country the same proportions, as show by several indicators. Observations: The consumption prevalence of both heroin and cocaine is alarming because its tremendous impact on the individual, the family and the society and it represents a challenge for the Mexican Health Services, particularly in planning and management. 

Contribution a l'etude petrographique et tectonique de la bordure nord du massif de Mayenne

1944 ◽  
Vol S5-XIV (1-3) ◽  
pp. 45-65
Author(s):  
Raoul Giret
Keyword(s):  
Special Reference ◽  
Border Region ◽  
The North ◽  
Mylonite Zone ◽  
Tectonic Study

Abstract A petrographic and tectonic study of the north border region of the Mayenne massif, Normandy, France, with special reference to the granites of the mylonite zone which separates the massif from other structures of the region, microgranite veins, and the Cambro-Ordovician complex at the base of the adjoining Villaines Paleozoic syncline.

Stratigraphic and tectonic study of Larderello-Travale basement rocks and its geothermal implications

Geothermics ◽  
1977 ◽  
Vol 6 (1-2) ◽  
pp. 83-93 ◽  
Author(s):  
M. Puxeddu ◽  
P. Squarci ◽  
A. Rau ◽  
M. Tongiorgi ◽  
P.D. Burgassi
Keyword(s):  
Basement Rocks ◽  
Tectonic Study

AN ATTEMPT TO DEFINE THE CURIE POINT ISOTHERM IN NORTHERN AND CENTRAL ARIZONA

Geophysics ◽  
1977 ◽  
Vol 42 (7) ◽  
pp. 1394-1400 ◽  
Author(s):  
P. E. Byerly ◽  
R. H. Stolt
Keyword(s):  
Curie Point ◽  
The State ◽  
Regional Variations ◽  
The North ◽  
Curie Depth ◽  
Northern Border ◽  
Central Arizona ◽  
North And South

Magnetic total intensity anomalies in northern and central Arizona have been analyzed to locate the bases of the polarized source bodies. The base of the magnetic crust is interpreted as the position of the Curie point isotherm. Results indicate a zone of shallow Curie depth (∼10 km) in a belt, about 60 km wide, running through the center of the state. This zone, near the northern border of the Basin‐Range province, is flanked on the north and south by areas of greater Curie depth (∼20 km). The results are in agreement with regional variations in [Formula: see text] velocity in Arizona.

Sign in / Sign up

Export Citation Format

Share Document