Offshore extensions of the Avalon Zone of Newfoundland

1985 ◽  
Vol 22 (8) ◽  
pp. 1163-1170 ◽  
Author(s):  
H. G. Miller ◽  
A. K. Goodacre ◽  
R. V. Cooper ◽  
D. Halliday
Keyword(s):  
Strong Correlation ◽  
Sedimentary Basin ◽  
Magnetic Data ◽  
Two Dimensional ◽  
Gravity And Magnetic ◽  
Magnetic Modelling ◽  
Dimensional Gravity ◽  
Gravity And Magnetic Data ◽  
Avalon Peninsula ◽  
Block Faulting

Gravity and magnetic data from the nearshore region of the Avalon Zone of Newfoundland provide evidence of the nature of a sedimentary basin immediately east of the Avalon Peninsula. The data also suggest a strong correlation between the arcuate magnetic patterns of the offshore portion of the Avalon Zone and the Precambrian mafic volcanics mapped onshore. The offshore basin is interpreted to have been formed by Precambrian block faulting and subsequently filled by sediments derived from surrounding paleotopographic highs. Two-dimensional gravity and magnetic modelling results suggest the presence of mafic material beneath the modelled 9+ km of sediment in the basin.

Interpretation of gravity and magnetic data from southwestern Newfoundland and their correlation with Lithoprobe East seismic lines 89-11 and 89-12

1994 ◽  
Vol 31 (6) ◽  
pp. 881-890
Author(s):  
R. Wiseman ◽  
Hugh G. Miller
Keyword(s):  
Vertical Gradient ◽  
Magnetic Data ◽  
Reflection Data ◽  
Gravity And Magnetic ◽  
Magnetic Modelling ◽  
Dimensional Gravity ◽  
A Minor ◽  
Seismic Reflection Profiles ◽  
Gravity And Magnetic Data ◽  
Gravity And Magnetic Anomaly

Several Newfoundland Appalachian terranes converge in the southwest corner of the island. The recent Lithoprobe East deep seismic reflection profiles imaged the crust along a transect across this area. In this paper, we present the gravity and magnetic data for the area and process them using shaded relief, horizontal and vertical gradient, upward continuation, and layer stripping techniques to interpret the more subtle features of the fields.Traditional two and one-half dimensional gravity and magnetic modelling is undertaken using constraints from the reflection data to develop a model of the crust in this region. The results from the processing are then used to interpret the crustal structure away from the seismic line.In general, we find that the major features on the gravity and magnetic anomaly maps can be explained by sources in the upper crust. The major faults in the area bound terranes that differ in potential field character. A minor change to the location of one terrane boundary is suggested. The rest correlate well with the geophysical data.

A subdivision of the western English River subprovince

1977 ◽  
Vol 14 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
G. P. Beakhouse
Keyword(s):  
Sedimentary Basin ◽  
Magnetic Data ◽  
Lower Intensity ◽  
Metasedimentary Rocks ◽  
Gravity And Magnetic ◽  
Complete Obliteration ◽  
Winnipeg River ◽  
Gravity And Magnetic Data ◽  
North And South ◽  
Western Portion

In the western pan of the Superior province, gneisses and plutonic rocks of the English River subprovince form a 100 km wide, east trending unit bound on both north and south by metavolcanic-granitic subprovinces. Recent investigations have resulted in a major twofold subdivision of the western portion of the English River subprovince. The northern part of the subprovince, termed the Ear Falls – Manigotagan gneiss belt, is characterized by a preponderance of sedimentary gneiss that records the development of a major Early Precambrian sedimentary basin. The southern part, termed the Winnipeg River batholithic belt, is a dominantly plutonic terrain with subordinate felsic gneissic rocks and minor metavolcanic and metasedimentary rocks. This latter belt records the almost complete obliteration of a greenstone terrain of unknown age and extent by felsic plutonism. Regional seismic, gravity, and magnetic data reflect the differing physical characteristics of the two bells. The Ear Falls-Manigotagan gneiss belt has a thicker granitic crust, thinner lower crust, thinner total crust, higher Bouguer gravity values, and lower intensity and shorter wavelength magnetic anomalies than the Winnipeg River batholithic bell.

Sign in / Sign up

Export Citation Format

Share Document