A possible Lower Permian age for the onset of ocean floor spreading in the northern North Atlantic

1976 ◽  
Vol 12 (4) ◽  
pp. 315-323 ◽  
Author(s):  
M. J. Russell
Keyword(s):  
North Atlantic ◽  
Ocean Floor ◽  
Lower Permian ◽  
Ocean Floor Spreading

The Mid-Atlantic Ridge Near 45° N. XVII. Magnetic Anomalies and Ocean Floor Spreading

1971 ◽  
Vol 8 (8) ◽  
pp. 883-898 ◽  
Author(s):  
B. D. Loncarevic ◽  
R. L. Parker
Keyword(s):  
North Atlantic ◽  
Magnetic Anomalies ◽  
Ocean Floor ◽  
The North ◽  
Ocean Floor Spreading ◽  
Magnetic Model ◽  
Mid Atlantic Ridge ◽  
The North Atlantic

In the North Atlantic it is difficult to correlate single magnetic profiles with the spreading ocean floor magnetic models. Within the area of intensive surveys at 45° N, it is possible to average the observations in the direction of the trend of the magnetic anomalies. The profile of averaged anomalies for all data between 45° N and 45.5° N correlates well with a magnetic model spreading (with respect to the ridge axes) westwards at 1.28 cm/y and eastwards at 1.10 cm/y, if the trend of the anomalies is assumed to be 015° East of North.

Ocean Floor Spreading: Olduvai and Gilsa Events in the Matuyama Epoch

Science ◽  
1969 ◽  
Vol 166 (3910) ◽  
pp. 1267-1269 ◽  
Author(s):  
D. A. Emilia ◽  
D. F. Heinrichs
Keyword(s):  
Ocean Floor ◽  
Ocean Floor Spreading

Andean Orogeny and Ocean Floor Spreading

Nature ◽  
1971 ◽  
Vol 233 (5317) ◽  
pp. 252-255 ◽  
Author(s):  
R. W. R. RUTLAND
Keyword(s):  
Ocean Floor ◽  
Ocean Floor Spreading

Heterotrophic flagellates and other protists associated with oceanic detritus throughout the water column in the mid North Atlantic

1993 ◽  
Vol 73 (1) ◽  
pp. 67-95 ◽  
Author(s):  
David J. Patterson ◽  
Kari Nygaard ◽  
Gero Steinberg ◽  
Carol M. Turley
Keyword(s):  
Species Diversity ◽  
Water Column ◽  
North Atlantic ◽  
Food Supply ◽  
Pressure Effects ◽  
Ocean Floor ◽  
Heterotrophic Flagellates ◽  
Incertae Sedis ◽  
First Time

Heterotrophic protists, mostly flagellates, encountered in association with marine detritus from various collections in the mid North Atlantic are described. About 40 species have been identified and are reported. Taxa reported here for the first time are: Caecitellus gen. nov. (Protista incertae sedis) and Ministeria marisola gen. nov., sp. nov. (Protista incertae sedis). The flagellates form a subset of the community of heterotrophic marine flagellates encountered in more productive marine sites. Most species are bacterivorous and small. The community extends to the ocean floor but the diversity is reduced in samples taken from greater depths. The decline in species diversity is linked also to a decline in numbers of individuals. We discuss these changes in relation to food supply and pressure effects.

The Mid-Atlantic Ridge near 45& deg;N. III. Bald Mountain

1969 ◽  
Vol 6 (1) ◽  
pp. 11-23 ◽  
Author(s):  
F. Aumento ◽  
B. D. Loncarevic
Keyword(s):  
Magnetic Anomaly ◽  
Rift Valley ◽  
Ocean Floor ◽  
Ocean Floor Spreading ◽  
Mid Atlantic Ridge ◽  
Spreading Rates ◽  
Steep Slopes ◽  
Block Faulting ◽  
Age Determinations

Metamorphosed and metasomatized basalts, and unmetamorphosed equivalents, were recovered from the steep slopes of Bald Mountain, a north–south elongated seamount lying 60 km west of the Median Rift Valley at 45° N. Block faulting and uplift of the seamount, together with the removal by submarine erosion of extrusive rocks capping the seamount, have resulted in the exposure of the more deep-seated metamorphosed horizons along the fault scarps.The block-faulted nature of Bald Mountain, indicative of brittle fracturing of the upper crustal layers of the Mid-Atlantic Ridge, may be a result of the low ocean floor spreading rates implied from age determinations and magnetic anomaly patterns at 45 °N.

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