The application of computer-assisted photogrammetric methods in the structural analysis of part of the North Greenland Fold Belt

1981 ◽  
Vol 3 (3) ◽  
pp. 253-264 ◽  
Author(s):  
Stig A. Schack Pedersen
Keyword(s):  
Structural Analysis ◽  
Computer Assisted ◽  
Fold Belt ◽  
The North ◽  
North Greenland

scholarly journals Structural analysis of the Rio Preto fold belt (northwestern Bahia / southern Piauí), a doubly-vergent asymmetric fan developed during the Brasiliano Orogeny

2014 ◽  
Vol 86 (3) ◽  
pp. 1101-1113 ◽  
Author(s):  
FABRÍCIO A. CAXITO ◽  
ALEXANDRE UHLEIN ◽  
LUIZ F.G. MORALES ◽  
MARCOS EGYDIO-SILVA ◽  
JULIO C.D. SANGLARD ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Structural Evolution ◽  
Shear Zones ◽  
Central Compartment ◽  
Strike Slip ◽  
Fold Belt ◽  
Main Structure ◽  
The North ◽  
Brasiliano Orogeny ◽  
Analog Models

The Rio Preto fold belt borders the northwestern São Francisco craton and shows an exquisite kilometric doubly-vergent asymmetric fan structure, of polyphasic structural evolution attributed exclusively to the Brasiliano Orogeny (∼600-540 Ma). The fold belt can be subdivided into three structural compartments: The Northern and Southern compartments showing a general NE-SW trend, separated by the Central Compartment which shows a roughly E-W trend. The change of dip of S2, a tight crenulation foliation which is the main structure of the fold belt, between the three compartments, characterizes the fan structure. The Central Compartment is characterized by sub-vertical mylonitic quartzites, which materialize a system of low-T strike slip shear zones (Malhadinha – Rio Preto Shear Zone) crosscutting the central portion of the fold belt. In comparison to published analog models, we consider that the unique structure of the Rio Preto fold belt was generated by the oblique, dextral-sense interaction between the Cristalândia do Piauí block to the north and the São Francisco craton to the south.

scholarly journals Volcanic centres between Frigg Fjord and Midtkap, eastern North Greenland

1981 ◽  
Vol 106 ◽  
pp. 69-75
Author(s):  
I Parsons
Keyword(s):  
Fault Zone ◽  
Fold Belt ◽  
The South ◽  
The North ◽  
Rock Types ◽  
South West ◽  
North Greenland

A series of smal! volcanic centres cut Ordovician turbidites of Formation A in the southem part of Johannes V. Jensen Land between Midtkap and Frigg Fjord (Map 2). Their general location and main rock types were described by Soper et al. (1980) and their nomenclature is adopted here for fig. 22 with the addition of the small pipe B2. A further small intrusion, south-west of Frigg Fjord, was described by Pedersen (1980). The centres lie 5-10 km south of, and parallel to, the important Harder Fjord fault zone (fig. 22) which traverses the southern part of the North Greenland fold belt and shows substantial downthrow to the south (Higgins et al., this report).

scholarly journals Structural and stratigraphic framework of the North Greenland fold belt in Johannes V. Jensen Land, Peary Land

1979 ◽  
Vol 93 ◽  
pp. 1-40
Author(s):  
P.R Dawes ◽  
N.J Soper
Keyword(s):  
Northern Coast ◽  
Structural Detail ◽  
Fold Belt ◽  
The North ◽  
Stratigraphic Framework ◽  
Mineral Assemblages ◽  
Lower Palaeozoic ◽  
Main Deformation ◽  
Basin Margin ◽  
North Greenland

Structural and stratigraphic detaiIs collected during reconnaissance fjeld work in northern Peary Land in 1969 are presented to substantiate the rather general accounts of the North Greenland fold belt hitherto published. The structural detail, largely in the form of graphic profiles sketched in the fieid, is referred to a structural frarnework in which three main deformation phases are recognised. The fold belt displays a roughly E-W zonation based on the progressive northerly increasing intensity of deformation and metamorphic effects that culminate along the northern coast in amphibolite-facies mineral assemblages in complexly folded schist lithologies. It is stressed that, while the conspicuous structural character of the fold belt is its northerly vergence seen particularly in the northernmost part, the detailed structural make-up of the fold belt is complex. Fold style and vergence vary considerably and the southern margin of the fold belt, autochthonous with respect to the platform, is characterised by south-verging folds. Some stratigraphical data is presented particularly from the Lower Palaeozoic sequence at the southern part of the fold belt that iIIustrates the basinal clastic facies at the sheIf-basin margin.

scholarly journals Preliminary Rb-Sr age determinations from the North Greenland fold belt, Johannes V Jensen Land, with comments on the metamorphic grade

1981 ◽  
Vol 106 ◽  
pp. 77-84
Author(s):  
N Springer
Keyword(s):  
Sedimentary Rocks ◽  
Metamorphic Grade ◽  
Low Grade ◽  
Fold Belt ◽  
Isotopic Dating ◽  
Field Mapping ◽  
Sedimentary Structures ◽  
The North ◽  
North Greenland ◽  
Age Determinations

This report presents the first Rb-Sr age determinations obtained on low-grade metasediments within the eastern part of the North Greenland fold belt. Samples were collected during the 1979 field mapping in eastem Johannes V. Jensen Land, the results ofwhich have been published elsewhere (Soper et al., 1980). Material selected for this study was taken from moderately folded rocks of the Polkorridoren Group and from the northem part of the fold belt where deformation is intense and sedimentary structures are rarely preserved (fig. 23). The principles and methods of isotopic dating of sedimentary rocks applied in this study have been treated in a recent paper by Clauer (1979).

scholarly journals A Late Permian flora of Pechora affinity in North Greenland

1982 ◽  
Vol 108 ◽  
pp. 5-13
Author(s):  
R.H Wagner ◽  
N.J Soper ◽  
A.K Higgins
Keyword(s):  
Eastern China ◽  
Late Permian ◽  
Fold Belt ◽  
The North ◽  
North Eastern ◽  
Warm Temperate ◽  
North Greenland

Late Permian plant impressions comprising six taxa have been obtained from the North Greenland fold belt. Rhipidopsis, a probable ginkgophyte, occurs together with the fems Prynadaeopteris venusta Radczenko and Pecopteris (Asterotheca?) cf. P. (A?) helenaeana Zalessky, the sphenophyte Sphenophyllum cf. S. biarnicum Zalessky the cordaitean Cordaites cf. C. sylovaensis (Neuburg) Meyen and a possibie conifer branch fragment. The assemblage invites comparison with the Pechora flora of the northem Pre-Urals, and also with that of Mongolia and north-eastern China. These may be warm temperate floras on approximately the same palaeolatitude.

scholarly journals The North Greenland fold belt in eastern Johannes V Jensen Land

1980 ◽  
Vol 99 ◽  
pp. 89-98
Author(s):  
N.J Soper ◽  
A.K Higgins ◽  
J.D Friderichsen
Keyword(s):  
Metamorphic Grade ◽  
Fold Belt ◽  
The North ◽  
Lower Palaeozoic ◽  
North Greenland ◽  
Dividing Line

This report concerns that part of the North Greenland fold belt in north Peary Land (Johannes V. Jensen Land) which lies east of Polkorridoren (the glacier filled depression between Frigg Fjord and Sands Fjord) and north of the Harder Fjord fault (fig. 40). The rocks forming the fold belt are mainly Lower Palaeozoic quartzites, carbonates, arkoses and shales, which are an extension of the Hazen Trough that stretched through the Queen Elizabeth Islands of Canada and across northern Greenland. Because of the northward increase in deformation and metamorphic grade, it is convenient to subdivide the region into a southerly, less deformed, area in which a stratigraphical sequence ean be established, and a northerly area in which only lithological units can be mapped. The dividing line corresponds to that, north of which, 'way-up' criteria cannot be used owing to the masking of the sedimentation structures by a pervasive schistosity. This line runs approximately from the northern end of Paradisfjeld to Bliss Bugt.

scholarly journals Late Silurian and early Devonian graptolites from North Greenland

1974 ◽  
Vol 65 ◽  
pp. 11-13
Author(s):  
W.B.N Berry ◽  
A.J Boucot ◽  
P.R Dawes ◽  
J.S Peel
Keyword(s):  
Field Work ◽  
Fold Belt ◽  
The South ◽  
Early Devonian ◽  
The North ◽  
The Subject ◽  
North Greenland

The precise age of the youngest part of the geosynclinal fill of the North Greenland fold belt has been the subject of important discussion, particularly with regard to the problem of dating the Palaeozoic diastrophism (Kerr, 1967; Dawes, 1971). Since Lauge Koch's field work between 1916 and 1923 it has been known that strata bearing Monograptus priodon were involved in the folding (Koch, 1920), indicating the presence of Silurian of Llandovery-Wenlock age. In addition, Poulsen (1934) identified Cyrtograptus cf. C. multiramus and Monograptus bohemicus in collections made by Koch from unfolded shales on the platform, to the south of the fold belt, which demonstrated that the section included Wenlock and early Ludlow strata.

scholarly journals Geology of central and eastern North Greenland

1986 ◽  
Vol 128 ◽  
pp. 37-54
Author(s):  
A.K Higgins
Keyword(s):  
Historical Review ◽  
Convincing Evidence ◽  
Fold Belt ◽  
Sedimentary Sequences ◽  
The North ◽  
Middle Carboniferous ◽  
Lower Palaeozoic ◽  
Dyke Swarms ◽  
Grade Increase ◽  
North Greenland

A historical review of geological research in North Greenland is followed by a summary of the main results of the 1978-80 GGU expeditions to the region. New outcrops of Archaean and early Proterozoic crystalline rocks are recorded only as xenoliths in dykes and volcanic centres. A revised stratigraphy is applied to the middle Proterozoic Independence Fjord Group sandstones, while petrographic and isotopic studies have been made of the cross-cutting Midsommersø dolerites and the overlying Zig-Zag Dal Basalt Formation. No convincing evidence has been found of a Carolinidian orogenic episode separating these units from succeeding late Proterozoic sedimentary sequences. Lower Palaeozoic sediments dominate North Greenland and are divided into southern shelf and northern trough successions; new or revised stratigraphies are now applied in both settings. The shelf-trough boundary can be shown to have moved south with time, and a major early Silurian expansion of the trough is related to shelf subsidence and a new phase of turbidite deposition derived from the rising East Greenland Caledonian mountains. Devonian - Middle Carboniferous (Ellesmerian) deformation brought deposition to a close and created the North Greenland fold belt, in which deformation intensity and metamorphic grade increase northwards. Thin-skinned thrusting in association with west or south-facing folds is important in southern areas; this is one of the main differences in interpretation compared to earlier work in the fold belt. New outcrops of post-ElIesmerian sediments (Wandel Sea Basin) have mainly been recorded as fault or thrust bounded sequences; a new stratigraphy is applied to the Wandel Sea Basin succession. Cretaceous - Tertiary events include a suite of volcanic centres, dyke swarms, the Kap Washington Group volcanics, and faults and thrusts of Tertiary (Eurekan) age; all have been studied anew, as have the Quaternary deposits.

scholarly journals An occurrence of Tertiary shales from the Harder Fjord Fault, North Greenland fold belt, Peary Land

1980 ◽  
Vol 101 ◽  
pp. 61-64
Author(s):  
C.A Croxton ◽  
P.R Dawes ◽  
N.J Soper ◽  
E Thomsen
Keyword(s):  
Fault Zone ◽  
Fold Belt ◽  
The North ◽  
Early Tertiary ◽  
Age Range ◽  
North Greenland

A shale outcrop from the Harder Fjord Fault zone in eastern Peary Land, North Greenland, is dated on palynological evidence as early Tertiary. The Harder Fjord Fault traverses the North Greenland fold belt and the shale occurrence extends the age range of strata known to be trapped in this important fault zone. The occurrence represents the most northerly record of Tertiary pollen.

scholarly journals Rb/Sr age of the Kap Washington Group, North Greenland, and its geotectonic implications

1978 ◽  
Vol 90 ◽  
pp. 115-119
Author(s):  
O Larsen ◽  
P.R Dawes ◽  
N.J Soper
Keyword(s):  
Fold Belt ◽  
Volcanic Group ◽  
The North ◽  
Minimum Age ◽  
North Greenland ◽  
Age Determinations

The Kap Washington Group is a bedded suite of rhyolitic lavas and tuffs that forms the northernmost rock province of Greenland (Dawes & Soper, 1973). The volcanic group borders on the north the Palaeozoic North Greenland fold belt from which it is separated by the southerly-dipping Kap Cannon thrust (fig. 38). K/Ar whole-rock age determinations of 34.9±5.3 m.y. and 32.3±3.2. m.y. on somewhat mylonitised lava samples were earlier regarded as giving an approximate minimum age of vo1canic consolidation and a maximum age of the Kap Cannon thrusting (Dawes & Soper, 1971). This note reports on Rb/Sr isotopic work that dates the Kap Washington Group, the five samples proeessed suggesting an age of about 63 m.y. Thus the general age of extrusion and con olidation of the vo!canie pile is eonsidered to be earlie t Tertiary.

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