About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
More than 40,000 km of bathymetric, magnetic, and gravity data and 2,000 km of seismic-reflection data were obtained in 1971 and 1972 aboard the NOAA ships Researcher and Discoverer over the Barbados Ridge complex and the adjacent southwestern North Atlantic. Most of the tracklines were oriented east-west and spaced closely (20 km) to attempt correlation between adjacent lines. About a dozen long, north-south-trending tracklines provided control on the structural variations in that direction.
From bathymetric and magnetic data it was established that from the Late Cretaceous to Holocene the development of the Mid-Atlantic Ridge in this area is essentially the same as in the rest of the North Atlantic.
Indications for relatively recent tectonic activity were found on some seismic records along several east-west faults, some of which were in alignment with offset zones of the magnetic-anomaly lineations. The implicit suggestion is that intraplate tectonic activity is common, and that the western extension or "dead traces" of transform faults may provide avenues where the accumulated tectonic energy within the oceanic plate is released.
The influence of many of the major east-west faults extends westward from the Atlantic basin across the Barbados Ridge complex to the platform of the Lesser Antilles volcanic arc. Major topographic changes, as well as changes in the character of the geophysical anomalies and in the chemistry of the volcanic rocks across the fault lines suggest that the faults have played a significant role in the evolution of this area. As these faults apparently have affected the structure west of the shallow earthquake belt and the axis of the gravity minima, this area appears ideal to study possible anomalies in the subduction process or, perhaps, the applicability of the concept itself.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
|Protected Document: $10|
|Internal PDF Document: $14|
|Open PDF Document: $24|
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].