Middle Proterozoic tectonics of the Belt Basin

1989 ◽  
pp. 43-46 ◽  
Author(s):  
James W. Whipple
Keyword(s):  
Middle Proterozoic

scholarly journals The δ30Si peak value discovered in middle Proterozoic chert and its implication for environmental variations in the ancient ocean

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
T. P. Ding ◽  
J. F. Gao ◽  
S. H. Tian ◽  
C. F. Fan ◽  
Y. Zhao ◽  
...  
Keyword(s):  
Environmental Variations ◽  
Peak Value ◽  
Middle Proterozoic

scholarly journals Precambrian metamorphic complexes in the East Greenland Caledonices (72°–74°N) – their relationship to the Eleonore Bay Group, and Caledonian orogenesis

1981 ◽  
Vol 104 ◽  
pp. 5-46
Author(s):  
A.K Higgins ◽  
J.D Friderichsen ◽  
T Thyrsted
Keyword(s):  
Metamorphic Complex ◽  
East Greenland ◽  
Late Proterozoic ◽  
Isotopic Studies ◽  
Lower Palaeozoic ◽  
Caledonian Orogeny ◽  
Proterozoic Basement ◽  
Basement Gneiss ◽  
Metamorphic Complexes ◽  
Middle Proterozoic

Results are presented of regional geological reconnaissance and local detailed studies. The new fjeld work, together with isotopic studies, has made possibie a provisional reassignment of metamorphic, plutonic and deformational events recorded in the different rock units to Archaean and Proterozoic, as well as Caledonian, orogenic episodes. The infracrustal elements of the 'central metamorphic complex' are considered to be essentiaIly Archaean - early Proterozoic basement gneiss complexes, and are overlain by middle Proterozoic metasedimentary sequences. The late Proterozoic and Lower Palaeozoic sediments have arestricted outcrop at present levels of exposure. During the Caledonian orogeny the late Proterozoic cover sequences appear to have become detatched from their older metamorphic 'basernent' along a decollement surface, but the nature of this contact is usually obscured by Caledonian metamorphic effects. The main characteristics of the different rock units are described. Detailed relationships are illustrated by studies of four areas: Nunatakgletscher-Eremitdal, Knækdalen and adjacent areas, Kap Hediund, and Tærskeldal-Forsblads Fjord-Randenæs.

scholarly journals The geology of the north-eastern corner of Greenland - photogeological studies and 1993 field work

1994 ◽  
Vol 161 ◽  
pp. 21-33
Author(s):  
H.F Jepsen ◽  
J.C Escher ◽  
J.D Friderichsen ◽  
A.K Higgins
Keyword(s):  
Field Work ◽  
Tectonic Activity ◽  
Mobile Belt ◽  
North East ◽  
The North ◽  
Upper Proterozoic ◽  
North Eastern ◽  
Field Season ◽  
Upper Boundary ◽  
Middle Proterozoic

Late Archaean and Early Proterozoic crust-forming events in North-East and eastern North Greenland were succeeded by Middle Proterozoic sedimentation and volcanic activity; Late Proterozoic through Tertiary sedimentation was interrupted by several periods of tectonic activity, including the Caledonian orogeny in East Greenland and the Mesozoic deformation of the Wandel Hav mobile belt. Photogeological studies helped pinpoint areas of special interest which were investigated during the short 1993 field season. Insights gained during field work include: the nature of the crystalline basement terrain in the Caledonian fold belt, redefinition of the upper boundary of the Upper Proterozoic Rivieradal sandstones, revision of Caledonian nappe terminology, and the northern extension of the Caledonian Storstrømmen shear zone.

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