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.

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.

Spatial distribution of U-Pb ages across a basement uplift in the Northern Andes and its implications for the interpretation of the detrital record in adjacent basins.

2020 ◽  
Author(s):  
Jose R. Sandoval ◽  
Nicolas Perez-Consuegra ◽  
Ricardo A. Gomez ◽  
Andres Mora ◽  
Mauricio Parra ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sedimentary Rocks ◽  
Foreland Basin ◽  
Heavy Mineral ◽  
Foreland Basins ◽  
Provenance Analysis ◽  
The North ◽  
Basement Rocks ◽  
Amazonian Craton

<p>Foreland basins represent a unique record of the evolution of mountain building processes in the adjacent hinterland. In the southern Colombian Andes and the adjacent foreland basin (i.e. Caguán-Putumayo Basin) no detrital U-Pb and heavy mineral studies have been conducted. This is due to the fact that the geochronological characterization of the basement rocks is poor, complicating the interpretation of source areas for provenance analysis.  Here we present a complete provenance study using U-Pb and Heavy mineral data. In order to gain a better understanding of the spatial distribution of the different potential basement sources we planned a characterization of the different basement provinces west of the Caguan-Putumayo basin. Here we present results from samples of active sediments (N=21), basements (N=16) and sedimentary rocks (N=4) older than Cretaceous. This characterization allowed the identification of eight (8) different domains with different age ranges. (1) The southern part of the Central Cordillera with populations of 150 - 250 m.y., (2) Southern part of the eastern flank of the Eastern Cordillera with ages around 150 - 180 m.y., (3) south of the Garzón Massif with age ranges between 1000 - 1150 m.y, (4) north of the Garzón Massif where rocks of 1500 m.y. dominate, (5) Paleozoic sedimentary rocks above the basement to the north of the Garzón Massif and the Serrania de la Macarena with a distinct population of 1300 m.y, (6). The basement of the Serrania de la Macarena with ages between 1650-1800 m, (7). The Serranía de Lindosa with ages around 500 m.y and (8). Amazonian Craton with ages between 1500 - 2000 m.y. Additionally, the relationship between Epidotes and Garnets displays a special behavior in each area. The provinces related to the Garzon Massif have a high amount of Garnets and low amount of Epidotes. On the other hand, the behavior of the areas away from the Garzon Massif is different. Based on the U-Pb detrital signal and the Epidote/Garnet relationship, we suggest that the stratigraphic intervals where we observe ages between 1000 and 1150 m.y. for the first time and high Garnet contents reflect uplift peaks of the Garzon Massif.</p>

Palaeophysiology : the organic origin of some minerals occurring in sedimentary rocks

1917 ◽  
Vol 18 (84) ◽  
pp. 87-98 ◽  
Author(s):  
J. V. Samoilov
Keyword(s):  
Field Study ◽  
Sedimentary Rocks ◽  
First Year ◽  
Geological Exploration ◽  
The Past ◽  
The North ◽  
North Eastern ◽  
The Government ◽  
North Eastern Part ◽  
Phosphate Deposits

During the last few years I have applied myself to the study of some minerals occurring in the sedimentary rocks of a definite geological horizon. The success of my investigations was greatly favoured by the fact that the mineralogical material was collected during the course of the systematic geological exploration of the phosphate deposits of Russia, which during the past eight years has been under my immediate supervision.The explorations just mentioned were begun in the north-eastern part of European Russia, and several occurrences of barite were found in the first year during the field study of the phosphate deposits in the government of Kostroma.

Sulphide remobilization in Archean volcano-sedimentary rocks and its significance in Proterozoic silver vein genesis, Cobalt, Ontario

1990 ◽  
Vol 27 (9) ◽  
pp. 1170-1181 ◽  
Author(s):  
Mark C. Smyk ◽  
David H. Watkinson
Keyword(s):  
Base Metal ◽  
Large Scale ◽  
Sedimentary Rocks ◽  
Hydrothermal Fluids ◽  
Fracture Zones ◽  
Sulphide Mineralization ◽  
Metal Sulphide ◽  
Basement Rocks ◽  
Sedimentary Succession ◽  
Archean Basement

The Archean volcano-sedimentary succession at Cobalt, Ontario, consists mainly of submarine andesitic flows and turbiditic interflow sedimentary rocks. Steeply dipping faults and large-scale, tight to isoclinar folds have developed in these basement rocks. The faults commonly host silver-vein-bearing structures that extend upward into overlying Proterozoic units. Synvolcanic and synsedimentary base metal sulphide deposits are ubiquitous in the Archean rocks. Epigenetic sulphide mineralization consists of remobilized and replacement sulphides and minor sulpharsenides. Epigenetic sulphides occur in permeable rocks and in fault and fracture zones, commonly in juxtaposition with silver veins.The coincidence of silver veins and structures containing remobilized sulphides suggests that sulphide remobilization from Archean basement rocks into Proterozoic vein-bearing structures predated or accompanied vein development. Sulphide remobilization may have also facilitated the mobilization (leaching) of metals from basement sulphides into the vein-forming hydrothermal fluids.

Gravity Anomalies in the Channel Islands

1959 ◽  
Vol 96 (2) ◽  
pp. 89-98 ◽  
Author(s):  
A. A. Day
Keyword(s):  
Coastal Area ◽  
Sedimentary Rocks ◽  
Gravity Anomalies ◽  
Great Depth ◽  
Bouguer Gravity ◽  
The North ◽  
Rock Types ◽  
North Eastern ◽  
Surface Geology ◽  
Gabbro Intrusion

AbstractBouguer gravity anomalies have been determined at seventy-nine stations on Alderney, Guernsey, and Jersey. On Alderney the anomalies are clearly dependent on the nature of the outcropping rock-types, and permit approximate values for the thickness of two outcropping rock masses to be obtained. On Guernsey the anomalies are not closely related to the surface geology, and suggest that the north-eastern coastal area is underlain by a body of dense rock, possibly of ultrabasic composition. The anomalies on Jersey indicate that the sedimentary rocks of western Jersey are underlain at no great depth by rock of density comparable to that of granite. In eastern Jersey the dominating feature of the anomalies is a pronounced “high” centred near Grande Charriére. It is shown that this feature is most reasonably considered to be the effect of a large buried gabbro intrusion.

Relations geometriques et chronologiques entre les series sedimentaires, les schistes lustres et le granite dans le Sud de la Corse alpine

1963 ◽  
Vol S7-V (3) ◽  
pp. 363-369
Author(s):  
Jean Paul Bloch
Keyword(s):  
Sedimentary Rocks ◽  
Basement Complex ◽  
The North ◽  
Basal Conglomerate ◽  
Tectonic Forces ◽  
Metamorphic Facies ◽  
The Relationship

Abstract Several localities in alpine Corsica were studied for the purpose of determining the age of the schistes lustres and their relationship with the sedimentary and granitic series. Since the Abatesco sedimentary series passes imperceptibly to the north into the schistes lustres, the relationship between the Abatesco and the granitic series and between the Abatesco and the Solaro formation is examined to determine the nature of the contacts. In places where the contact between the sedimentary series and the underlying granite is visible there was no evidence of the intrusion of the granite into the sedimentary rocks. On the contrary, the sedimentary series is transgressive on the granite as indicated by a basal conglomerate. The contact between the two dips slightly, leveling off to the north and overturning, placing the granite over the sedimentary series, and suggesting tectonic forces moving from west to east. The Eocene Abatesco and Solaro series are placed in the Fium' Orbo series which represents the detrital, somewhat metamorphic facies of the schistes lustres complex. The presence in the schistes lustres of black quartz--from the basement complex--makes it possible to assign a Paleozoic age to the series. The preferred theory is that the schistes lustres are Eocene, in part, and pass longitudinally into a sedimentary series well-rooted in the granite.

Discussion on “The grinding wheel and production” at the North-Eastern Section of the Institution

1942 ◽  
Vol 21 (8) ◽  
pp. 315
Author(s):  
Bowen ◽  
Vickery ◽  
Buchanan ◽  
Swallow ◽  
Perks ◽  
...  
Keyword(s):  
Grinding Wheel ◽  
The North ◽  
North Eastern
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