Asymmetric spreading in back-arc basins

  title={Asymmetric spreading in back-arc basins},
  author={Peter F. Barker and Ian A. Hill},
Lineated magnetic anomalies indistinguishable from those generated at mid-oceanic ridges have been found behind many subduction zones. They show that back-arc spreading, like its mid-oceanic counterpart, is to a first approximation symmetric. Nevertheless, consistently asymmetric spreading has been found in some ocean basins, and in both actively spreading and extinct back-arc basins. We argue here that the sense of asymmetry found in active back-arc basins strongly supports a mechanism for the… Expand
Early evolution of a young back-arc basin in the Havre Trough
Back-arc basins are found at convergent plate boundaries. Nevertheless, they are zones of significant crustal extension that show volcanic and hydrothermal processes somewhat similar to those ofExpand
Controls on back-arc crustal accretion: insights from the Lau, Manus and Mariana basins
Abstract Together, the Lau, Manus and Mariana basins encompass a broad range of conditions of back-arc basin development. Marine surveys have determined the tectonic setting and reconnaissance-scaleExpand
Asymmetric accretion along the slow‐spreading Mariana Ridge
[1] We report the results of several surface geophysical surveys of the central part of the Mariana Basin, western Pacific. Analysis of bathymetric and magnetic data along three distinct spreadingExpand
A back-arc basin formed within continental lithosphere: The Central Volcanic region of New zealand
Abstract The Central Volcanic Region is an area of Quaternary volcanism and tensional tectonics within the North Island of New Zealand that appears to be a direct continuation of a young oceanicExpand
Sedimentary, volcanic, and tectonic processes of the central Mariana Arc: Mariana Trough back-arc basin formation and the West Mariana Ridge
[1] We present new multichannel seismic profiles and bathymetric data from the central Marianas that image the West Mariana Ridge (WMR) remnant arc, both margins of the Mariana Trough back-arc basin,Expand
Regional distribution of volcanism within the North Atlantic Igneous Province
Abstract An overview of the distribution of volcanic facies units was compiled over the North Atlantic region. The new maps establish the pattern of volcanism associated with breakup and theExpand
Conjugate volcanic rifted margins, seafloor spreading, and microcontinent: Insights from new high‐resolution aeromagnetic surveys in the Norway Basin
We have acquired and processed new aeromagnetic data that cover the entire oceanic Norway Basin located between the More volcanic rifted margin and the Jan Mayen microcontinent (JMMC). The newExpand
Tectonic framework of the east Scotia Sea
This chapter reviews the tectonic evolution of the East Scotia Sea, testing and extending previously published conclusions in light of the additional and expanded data sets now available. The EastExpand
Age, spreading rates, and spreading asymmetry of the world's ocean crust
We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc minExpand
Seismotectonics and relative plate motions in the Scotia Sea region
Source parameter inversion of P and SH waveforms and amplitudes for 20 shallow earthquakes using a singular value decomposition technique provides important constraints on the tectonics and relativeExpand


Near-bottom magnetic anomalies, asymmetric spreading, oblique spreading, and tectonics of the Mid-Atlantic Ridge near lat 37°N
A detailed study of the magnetic anomalies of the Mid-Atlantic Ridge crest near lat 37 °N (FAMOUS) was conducted using a deeply towed instrument package. The most recent expression of the accretingExpand
Extension behind island arcs and motions relative to hot spots
The spatial distribution and episodic nature of behind-arc spreading is as yet unexplained. The present sites of rapid marginal basin opening well-developed enough to be producing unmistakableExpand
Characteristics of back arc spreading in the Mariana Trough
Although sea floor spreading of some sort has created marginal basins, it is not known whether this spreading is similar to that at midocean ridges. Back arc spreading in the Mariana Trough occursExpand
Nature and implications of asymmetric sea-floor spreading — “Different rates for different plates”
Asymmetric sea-floor spreading has occurred south of Australia within narrow longitudinal zones of the Southeast Indian Ocean. The process of asymmetric spreading can be shown to be continuous at theExpand
Ridge migration and asymmetric sea-floor spreading
Abstract We propose that asymmetric sea-floor spreading occurs as a consequence of the relative motion between ridges and slow-moving mantle material below. A fluid mechanical model of asymmetricExpand
Recent plate motions in the Galapagos area
Recent accretion on the Cocos-Nazca spreading center has been asymmetric, with more material (along most of the rise) added to the Cocos than to the Nazca plate. There is evidence in the magneticExpand
The opening of Drake Passage
Abstract Marine magnetic anomalies are used to deduce the history of the opening of Drake Passage, the deep-water channel between South America and West Antarctica. Coherent spreading started inExpand
Tectonic evolution of the Cocos-Nazca spreading center
Magnetic and bathymetric data from the eastern Pacific have been analyzed and a model for the evolution of the Galapagos region developed. The Farallon plate appears to have broken apart along aExpand
Sea-floor spreading in marginal basins of the Western Pacific☆
Abstract Observed magnetic lineations from the Shikoku, South Fiji, and West Philippine marginal basins are used to determine aspects of the tectonic evolution of these basins. In the western part ofExpand
The history of ridge-crest offset at the Falkland—Agulhas Fracture Zone from a small-circle geophysical profile
Summary. The magnetic and bathymetric profiles are described along a single ship track following a small circle of South Atlantic opening about 100 km south of the Falkland-Agulhas Fracture ZoneExpand