Palynostratigraphy of the Lower Cretaceous Section at DSDP Site 391, Blake-Bahama Basin, and its Correlation in the North Atlantic

1978 ◽  
Author(s):  
D. Habib
Keyword(s):  
North Atlantic ◽  
Lower Cretaceous ◽  
The North ◽  
The North Atlantic ◽  
Dsdp Site

scholarly journals Deep drilling results of Leg 47b (Galicia Bank area) in the framework of the early evolution of the North Atlantic Ocean

1980 ◽  
Vol 294 (1409) ◽  
pp. 51-61 ◽  
Keyword(s):  
Atlantic Ocean ◽  
Continental Margin ◽  
North Atlantic ◽  
Lower Cretaceous ◽  
North Atlantic Ocean ◽  
Regional Scale ◽  
Upper Jurassic ◽  
Borehole Data ◽  
The North ◽  
The North Atlantic

Lithologic and stratigraphic evidence from D.S.D.P. Site 398 (3910 m water depth, 1740m total penetration) and regional seismic reflexion data are placed in the context of the early tectonic evolution of the North Atlantic ocean. The morphology of the western Iberian continental margin is the result of two main tensional episodes dated Permo— Lias and Upper Jurassic - Lower Cretaceous, during which the initial basins between Grand Banks and Iberia were created by subsidence and tilting of continental blocks. A limited oceanic opening had probably occurred in Jurassic time between these two tensional episodes. There was no relative motion during Lower Cretaceous between North America and Iberia. One of the main results is that the 398 drillhole penetrated into the basement structure of a tilted block of the continental margin. Borehole data indicate an Uppermost Aptian age for the end of the Upper Jurassic - Lower Cretaceous tensional episode at the level of the site. The subsequent beginning of sea floor spreading in the Uppermost Aptian is associated with a change of sedimentary facies from graded sequences interbedded with slump beds or debris flows to dark, detritic shales. The continental margin had subsided on a regional scale since this time.

Lower Cretaceous Sourcelands and the North Atlantic

Nature ◽  
1969 ◽  
Vol 222 (5194) ◽  
pp. 657-658 ◽  
Author(s):  
P. ALLEN
Keyword(s):  
North Atlantic ◽  
Lower Cretaceous ◽  
The North ◽  
The North Atlantic

Plio-Pleistocene radiolarian biostratigraphy and palaeoceanography of the mid-latitude North Atlantic (DSDP Site 609)

1994 ◽  
Vol 131 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Simon K. Haslett
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Sea Surface ◽  
Abundance Distribution ◽  
The North ◽  
Radiolarian Biostratigraphy ◽  
The North Atlantic ◽  
First Time ◽  
Drilling Project ◽  
Dsdp Site

AbstractRadiolaria were examined throughout the Plio-Pleistocene of Deep Sea Drilling Project (DSDP) Site 609. Eight radiolarian datum-levels (first and last appearances) were identified, some for the first time in the North Atlantic. The recognition of these datums allows correlation between the Atlantic, Pacific and Indian oceans, through a previously published zonal scheme (Johnson et al. 1989). Zones NR1 to NR11 were recognized, although some zones had to be combined (NR1–2 and NR8–10) due to the absence of some stratigraphically important taxa. The relative abundance distribution of the radiolarian palaeoceanographical proxy Didymocyrtis tetrathalamus indicated three cool phases (0/0.56–0.75 Ma, 1.2–1.33/1.69–1.86 Ma, and 2.14–2.32/3.73– > 4.1 Ma) interrupted by two relatively warm episodes (0.56–0.75/1.2–1.33 Ma and 1.69–1.86/2.14–2.35 Ma). These fluctuations in sea-surface temperature (SST) correspond with palaeoclimatic events indicated by other proxies (e.g. Foraminifera), such as the onset of Northern Hemisphere glaciation. This study illustrates the usefulness of radiolaria in North Atlantic stratigraphical and palaeoceanographical analysis.

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