scholarly journals Early Tertiary volcanic rocks from eastern Disko and south-eastern Nûgssuaq

1987 ◽  
Vol 135 ◽  
pp. 11-17
Author(s):  
A.K Pedersen ◽  
L.M Larsen
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Stratigraphy ◽  
South Eastern ◽  
Early Tertiary ◽  
Clastic Sediments ◽  
Greenland Basin ◽  
Geological Map ◽  
Volcanic Facies ◽  
Volcanic Succession ◽  
Basalt Plateau

As part of an integrated study of the interaction between sedimentary and volcanic facies in the Cretaceous-Tertiary West Greenland basin, early Tertiary extrusive and intrusive basic igneous rocks have been investigated in eastern Disko and south-eastern Nûgssuaq (fig. 1). The volcanic activity started in the early Tertiary. It was centred in the western regions of Disko and Nûgssuaq and west of the present land areas, and consequently western Disko and western Nûgssuaq have a thick and complete volcanic succession, the Vaigat and Maligât Formations (Hald & Pedersen, 1975; Pedersen, 1975a, 1985). The coeval deposits in the eastern part of the basin are clastic sediments of the Upper Atanikerdluk Formation (Koch, 1959). With time, the volcanic deposits prograded eastwards, and eventually the whole area was covered by a coherent basalt plateau. The present study attempts to extend the established volcanic stratigraphy from western Disko and the geological map sheets 1:100 000 Qutdligssat (published in 1976) and Mellemfjord (published in 1987) into eastern Disko and eastern Nûgssuaq where volcanic rocks and sediments interfinger.

scholarly journals Investigations of Tertiary volcanic rocks along the south coast of Nûgssuaq and in eastern Disko, 1987

1988 ◽  
Vol 140 ◽  
pp. 28-32
Author(s):  
L.M Larsen ◽  
A.K Pedersen
Keyword(s):  
Volcanic Rocks ◽  
Field Work ◽  
South Coast ◽  
The West ◽  
West Greenland ◽  
Early Tertiary ◽  
Composite Section ◽  
Greenland Basin ◽  
Volcanic Facies ◽  
Integrated Study

As a continuation of an integrated study of sedimentary and volcanic facies in the Cretaceous to Tertiary West Greenland basin (G. K.Pedersen, 1987; A. K. Pedersen & Larsen, 1987) early Tertiary volcanic rocks were studied in 1987 along a NW-SE trending composite section, about 120 km in length; on Niigssuaq and Disko. The study attempts to establish and describe lithostratigraphic volcanic units in the Tertiary volcanic formations, and through a combination of field mapping, photogrammetry and geochemistry to establish chronostratigraphic horizons through the early Tertiary deposits of the region. In this respect it is essential to identify the same eruptive units as subaeriallava facies and as subaqueous lava or hyaloclastite facies, and to trace subaerial tufts throughout the area. In the first part of the season localities along the Vaigat coast of Nûgssuaq from Kugssinerssuaq in the east to Nûssap qâqarssua in the west were investigated. In the second part of the season very poorly known areas in the western and southem part ofthe Kvandalen region on east Disko were investigated. The field work was supported by the Arctie Station in Godhavn and its cutter Porsild as well as by GGU's cutter J. F. Johnstrup.

scholarly journals Understanding the offshore flood basalt sequence using onshore volcanic facies analogues: an example from the Faroe–Shetland basin

2009 ◽  
Vol 146 (3) ◽  
pp. 353-367 ◽  
Author(s):  
DOUGAL A. JERRAM ◽  
RICHARD T. SINGLE ◽  
RICHARD W. HOBBS ◽  
CATHERINE E. NELSON
Keyword(s):  
Volcanic Rocks ◽  
Flood Basalt ◽  
Reflection Seismology ◽  
Flood Basalts ◽  
Geological Interpretation ◽  
Seismic Modelling ◽  
The North ◽  
Volcanic Facies ◽  
Volcanic Succession ◽  
Simple Flows

AbstractFlood basalts in associated volcanic rifted margins, such as the North Atlantic Igneous Province, have a significant component of lavas which are preserved in the present day in an offshore setting. A close inspection of the internal facies architecture of flood basalts onshore provides a framework to interpret the offshore sequences imaged by remote techniques such as reflection seismology. A geological interpretation of the offshore lava sequences in the Faroe–Shetland Basin, using constraints from onshore analogues such as the Faroe Islands, allows for the identification of a series of lava sequences which have characteristic properties so that they can be grouped. These are tabular simple flows, compound-braided flows, and sub-aqueously deposited hyaloclastite facies. The succession of volcanic rocks calculated in this study has a maximum thickness in excess of 6800 m. Down to the top of the sub-volcanic sediments, the offshore volcanic succession has a thickness of about 2700 m where it can be clearly identified across much of the area, with a further 2700 m or more of volcanic rock estimated from the combined gravity and seismic modelling to the north and west of the region. A large palaeo-waterbody is identified on the basis of a hyaloclastite front/apron consisting of a series of clinoforms prograding towards the eastern part of the basin. This body was > 500 m deep, must have been present at the onset of volcanism into this region, and parts of the water body would have been present during the continued stages of volcanism as indicated by the distribution of the hyaloclastite apron.

XXVIII.—Geological Observations in South-eastern and Central Iceland

1949 ◽  
Vol 61 (3) ◽  
pp. 779-791 ◽  
Author(s):  
F. W. Anderson
Keyword(s):  
Volcanic Rocks ◽  
Glacial Deposits ◽  
South Eastern ◽  
Group 3 ◽  
East And West ◽  
Group 2 ◽  
Basalt Plateau ◽  
Basaltic Lavas ◽  
Group 1

The volcanic rocks of Iceland have been grouped by Tyrrell and Peacock (1928) into:3. The Recent, Post-Glacial and Late Interglacial Eruptives.2. The Early Glacial Breccia or Palagonite Formation.1. The Pre-Glacial Kainozoic Basalt Plateau.Group 1 consists of nearly 10,000 feet of basalts with lignite beds, acid extrusives and acid and basic intrusions. In the east and west of Iceland the old plateau is exposed, but centrally it is down-faulted and covered with more recent tuffs and lavas.Group 2 contains a varied assemblage of deposits comprising tuffs, breccias and lavas, moraines, boulder clays and fluvioglacial sediments (Nielsen and Noe-Nygaard, 1936 a). The lower part of this formation consists of over 2000 feet of basaltic lavas with interbedded glacial and fossiliferous deposits, and the upper part of glacial and fluvio-glacial deposits with doleritic lavas.Group 3 is made up mainly of basaltic lavas but with occasional acid phases. In the ice-covered highlands the volcanoes have continued to produce tuffs and breccias.

Volcanic stratigraphy and structure in the Hunter Creek Fault area, Rouyn–Noranda, Quebec

1990 ◽  
Vol 27 (10) ◽  
pp. 1348-1358 ◽  
Author(s):  
G. Camiré ◽  
D. H. Watkinson
Keyword(s):  
Volcanic Rocks ◽  
Drill Hole ◽  
Volcanic Complex ◽  
Calc Alkaline ◽  
Volcanic Stratigraphy ◽  
The Past ◽  
The North ◽  
Northern Side ◽  
Volcanic Facies ◽  
Geochemical Studies

The Hunter Creek Fault (HCF) has been considered in the past as a major synvolcanic fault marked by a change in volcanic facies and separating two geologically distinct blocks within the Noranda volcanic complex: the North Mine and the Central Mine sequences. Detailed mapping in the HCF area, in conjunction with petrographic and geochemical studies, has revealed that most of the volcanic units defined south of the fault zone also occur on its northern side. Field and drill-hole correlations indicate that the rocks are cut by a N240–N250 reverse-slip fault dipping approximately 70° toward the northwest. Major- and trace-element data suggest that least-altered volcanic rocks are of tholeiitic affinity and that there is no calc-alkaline unit in the HCF area.

scholarly journals Lithostratigraphy of the early Tertiary volcanic rocks of central West Greenland

1975 ◽  
Vol 69 ◽  
pp. 17-24
Author(s):  
N Hald ◽  
A.K Pedersen
Keyword(s):  
Marine Sediments ◽  
Volcanic Rocks ◽  
Igneous Rocks ◽  
Metamorphic Rocks ◽  
Flood Basalts ◽  
West Greenland ◽  
Early Tertiary ◽  
Volcanic Sequence ◽  
Geological Map

A sequence of flood basalts, in places more than 8-10 km thick, was erupted during the Early Tertiary in the central part of West Greenland between latitudes 69° and 73°N. The volcanic rocks rest on Precambrian metamorphic rocks and non-marine and marine sediments from the Cretaceous and Paleocene. The lower part of the volcanic sequence is dominated by tholeiitic olivinerich basalts and picrite basalts, whereas the upper part is characterized by tholeiitic basalts with plagioclase as the dominant phenocryst mineral; transitional and alkaline lavas and tuffs are found, especially in the upper part of the sequence. The geology of the Tertiary igneous rocks has been summarized by Munck & Noe-Nygaard (1957), Rosenkrantz & Pulvertaft (1969) and Clarke & Pedersen (in press). However, until now no formal lithostratigraphy has been established. A geological map at scale 1:100 000 covering the greater part of Nugssuaq (sheet Agatdal-70 V. 1 Nord) has been published by GGU.

Petrogenesis of the peralkaline Flowers River Igneous Suite and its significance to the development of the southern Nain Batholith

2021 ◽  
pp. 1-26
Author(s):  
Taylor A. Ducharme ◽  
Christopher R.M. McFarlane ◽  
Deanne van Rooyen ◽  
David Corrigan
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Second Phase ◽  
Discrete Events ◽  
Volcanic Event ◽  
Volcanic Succession ◽  
Intrusive Suite ◽  
Tectonic Boundaries ◽  
Host Rocks ◽  
Nain Plutonic Suite

Abstract The Flowers River Igneous Suite of north-central Labrador comprises several discrete peralkaline granite ring intrusions and their coeval volcanic succession. The Flowers River Granite was emplaced into Mesoproterozoic-age anorthosite–mangerite–charnockite–granite (AMCG) -affinity rocks at the southernmost extent of the Nain Plutonic Suite coastal lineament batholith. New U–Pb zircon geochronology is presented to clarify the timing and relationships among the igneous associations exposed in the region. Fayalite-bearing AMCG granitoids in the region record ages of 1290 ± 3 Ma, whereas the Flowers River Granite yields an age of 1281 ± 3 Ma. Volcanism occurred in three discrete events, two of which coincided with emplacement of the AMCG and Flowers River suites, respectively. Shared geochemical affinities suggest that each generation of volcanic rocks was derived from its coeval intrusive suite. The third volcanic event occurred at 1271 ± 3 Ma, and its products bear a broad geochemical resemblance to the second phase of volcanism. The surrounding AMCG-affinity ferrodiorites and fayalite-bearing granitoids display moderately enriched major- and trace-element signatures relative to equivalent lithologies found elsewhere in the Nain Plutonic Suite. Trace-element compositions also support a relationship between the Flowers River Granite and its AMCG-affinity host rocks, most likely via delayed partial melting of residual parental material in the lower crust. Enrichment manifested only in the southernmost part of the Nain Plutonic Suite as a result of its relative proximity to multiple Palaeoproterozoic tectonic boundaries. Repeated exposure to subduction-derived metasomatic fluids created a persistent region of enrichment in the underlying lithospheric mantle that was tapped during later melt generation, producing multiple successive moderately to strongly enriched magmatic episodes.

Implication of dating of Early Tertiary volcanic rocks from the north-Chilean Precordillera

1992 ◽  
Vol 202 (1) ◽  
pp. 55-81 ◽  
Author(s):  
K. Hammerschmidt ◽  
R. Döbel ◽  
H. Friedrichsen
Keyword(s):  
Volcanic Rocks ◽  
The North ◽  
Early Tertiary

Geochemistry and tectonic environment of the Şarkışla area volcanic rocks in central Anatolia, Turkey

1987 ◽  
Vol 51 (362) ◽  
pp. 553-559 ◽  
Author(s):  
E. Gökten ◽  
P. A. Floyd
Keyword(s):  
Upper Cretaceous ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Central Anatolia ◽  
Magmatic Arc ◽  
Early Tertiary ◽  
Tectonic Environment ◽  
Geochemical Study ◽  
Lithological Composition ◽  
Back Arc

AbstractThe volcanic rocks of the Şarkışla area in northeastern central Anatolia are associated with volcaniclastics, turbiditic limestones and pelagic-hemipelagic shales of Upper Cretaceous-Palaeocene age. A preliminary geochemical study was undertaken to constrain local tectonic models, and due to the variable altered nature of the volcanics, determine the lithological composition and magma type. Chemically the volcanics are an andesite-dominated suite of calc-alkali lavas, probably developed adjacent to an active continental margin in a local (ensialic back-arc?) basinal area. The volcanic activity was probably related to a postulated magmatic arc just south of the area during the early Tertiary.

The control of preexisting faults on the distribution, morphology, and volume of monogenetic volcanism in the Michoacán-Guanajuato Volcanic Field

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2455-2474 ◽  
Author(s):  
Martha Gabriela Gómez-Vasconcelos ◽  
José Luis Macías ◽  
Denis Ramón Avellán ◽  
Giovanni Sosa-Ceballos ◽  
Víctor Hugo Garduño-Monroy ◽  
...  
Keyword(s):  
Hanging Wall ◽  
Temporal Distribution ◽  
Volcanic Field ◽  
Fault System ◽  
Volcanic Stratigraphy ◽  
Listric Fault ◽  
Tectonic Processes ◽  
State Of Stress ◽  
Geological Map ◽  
Scoria Cones

Abstract Interactions between volcanic and tectonic processes affect the distribution, morphology, and volume of eruptive products in space and time. The Queréndaro area in the eastern Michoacán-Guanajuato Volcanic Field affords an exceptional opportunity to understand these relationships. Here, a Pleistocene lava plateau and 20 monogenetic volcanoes are vented from an active ENE-striking segment of the Morelia-Acambay fault system. Thirteen scoria cones are aligned along this structure, vented from an extensional gap in between two rotated hanging wall blocks of a listric fault. A new geological map, volcanic stratigraphy, and 40Ar/39Ar dating indicate that this lava plateau and volcanic cluster were emplaced from 0.81 to 0.25 Ma by 11 intermittent eruptive epochs separated by ca. 0.05 Ma, emplacing a total magma volume of 5 km3. Petrography and chemistry of rocks suggest that all volcanic structures were fed by three different magma batches but vented from independent feeder dikes. Our results indicate that preexisting faults exert a strong influence on volcanic spatial and temporal distribution, volcanic morphology, magma volume, and eruptive dynamics in this area. ENE-breached and ENE-elongated scoria cones indicate parallel subsurface fissure and feeder dikes. Additionally, points of maximum fault dilation at depth related to a transtensive state of stress coincide with less fragmented deposits and larger magma volumes. Furthermore, this study raises important questions on the geodynamics of volcano-tectonic interactions possible in similar monogenetic volcanic alignments worldwide.

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