Pre-breakup continental extension in East Gondwanaland and the early opening of the eastern Indian Ocean

Powell, C. McA.; Roots, S.R.; Veevers, J. J.

doi:10.1016/0040-1951(88)90269-7

Cited by 457 publications

(209 citation statements)

References 35 publications

Supporting

Mentioning

198

Contrasting

Order By: Relevance

“…fits the geological record rather well since the breakup of the Gondwanaland should not be older than 130 m.y. (Powell et al, 1988). In summing up, we conclude that the top of the Kerguelen Plateau basement is at least as old as 100 m.y.…”

Section: Resultsmentioning

confidence: 69%

“…In short, the reliable hypothesis, supported by trace element and isotope geochemistry, is that the plateau resulted from excess volcanism linked to a mantle plume in an extensional or spreading zone, as suggested by Storey et al (1989) and Weis et al (1989). The idea that the Kerguelen Plateau is a fragment of a rifted, subsided continental lithosphere (Dietz and Holden, 1970;Schlich et al, 1971;Ramsay et al, 1986) is neither supported by plate reconstructions, which provide a reasonable pre-drift fit of the continents without the need to incorporate the plateau (Powell et al, 1988;Norton and Sclater, 1979), nor by isotope geochemistry (Dosso et al, 1979). The geophysical (738, 744, 745, and 746) and 120 (747, 748, 749, 750, and 751).…”

Section: Origin Of the Kerguelen Plateaumentioning

confidence: 99%

See 1 more Smart Citation

K-Ar and 40Ar/39Ar Ages of Central Kerguelen Plateau Basalts

Whitechurch¹,

Montigny²,

Sevigny³

et al. 1992

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

Conventional K-Ar and 40 Ar/ 39 Ar analyses on whole-rock samples are reported for basaltic samples retrieved on the Central and Southern Kerguelen plateaus during Ocean Drilling Program Leg 120. Sites 747, 749, and 750 recovered basalts from the plateau basement, whereas Site 748 drilled a lava flow interbedded with sediments of probable Albian age.The freshest core basalts from the basement yielded dates falling in the 110-100 m.y. interval. Sample 120-749C-15R-3 (26-31 cm) gave conventional K-Ar, total fusion, and plateau ^Ar/^Ar ages that are closely concordant: 111.5 ± 3.2 m.y., 109.9 ± 1.2 m.y., and 109.6 ± 0.7 m.y., respectively. Sample 120-750B-15R-5 (54-60 cm), when taking into account the analytical uncertainties, yields conventional K-Ar and 40 Ar/ 39 Ar plateau ages that can be considered similar: 101.2 ± 7.5 and 118.2 ± 5 m.y., respectively. Inspection of the 39 Ar/ 40 Ar vs. 36 Ar/ 40 Ar diagram does not reveal the occurrence of an initial argon component of radiogenic composition in the two samples. Accordingly, our results suggest that the formation of the basement of the Central Kerguelen Plateau was closed at 110 m.y.. Furthermore, these results are in agreement with a K-Ar age of 114 ± 1 m.y. mentioned in the literature for a basalt dredged in the 77°E Graben.The still scant amount of data indicates that the outpourings of the Central Kerguelen Plateau correspond rather well with widespread continental magmatism in Gondwanaland that is believed to mark the incipient opening of the eastern Indian Ocean. This implies a huge head for the mantle plume at the source of these liquids. Nevertheless, on land and at sea the exact duration of magmatism remains unknown. Therefore, a catastrophic pattern similar to that currently invoked for the Deccan Traps at the end of the Cretaceous, though possible, is not yet required by present geochronologic data.

show abstract

Section: Resultsmentioning

confidence: 69%

Section: Origin Of the Kerguelen Plateaumentioning

confidence: 99%

K-Ar and 40Ar/39Ar Ages of Central Kerguelen Plateau Basalts

Whitechurch¹,

Montigny²,

Sevigny³

et al. 1992

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

show abstract

“…The formation of the Kerguelen Plateau is closely linked to sea-floor spreading between Antarctica, Australia and India that initiated 132-136 Ma ago (Powell et al, 1988;Müller et al, 2000). The South Kerguelen Plateau (SKP), the Elan Bank, the Central Kerguelen Plateau (CKP) and Broken Ridge, the 90°E Ridge and the Skiff Bank, and, eventually, the North Kerguelen Plateau (NKP), formed successively since 120 Ma (Duncan, 2002;Coffin et al, 2002).…”

mentioning

confidence: 99%

The field and remote sensing analysis of the Kerguelen Archipelago structure, Indian Ocean

Mathieu

Byrne

Guillaume

et al. 2011

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

1The Kerguelen Archipelago is part of an oceanic plateau with a complex history. Little work has been done on the tectonics of the onshore areas, even though the extensive outcrop renders the islands especially good for structural work. We present the results of three field campaigns and remote sensing analysis carried out in the main Kerguelen Island, around Val Travers valley and Mt Ross volcano (Central Plateau) and in the Rallier du Baty peninsula (SW part of the archipelago). We have mapped faults, fracture sets, and the location and geometry of intrusive bodies. We found that the plateau basalt lavas that make up most of the area are densely fractured, crossed by many veins, dykes and some small faults. This work provides a general framework for the structure of Kerguelen Archipelago that is dominated by 110°-striking faults and veins, dyke swarms and an alignment of recent central volcanoes, which have formed in N-S to NNW-SSE directed extensional stress field. The other structures are fractures, veins and dykes which strike 130°-150°, 000° and 030°-050°. They are likely related to transform faults of the Indian oceanic crust and to faults of the north Kerguelen Plateau (offshore basement of the archipelago). These buried structures were likely re-activated by a low magnitude stress field.

show abstract

“…The Eastern Continental Margin of india (ECMI) is a passive margin which has evolved as a consequence of the breakup of eastern India from East Antarctica [Powell et al, 1988] (Fig. l a).…”

mentioning

confidence: 99%

“…Recent investigations of the ECMI indicate its segmentation into a northern dried part and a southern sheared (transform) part [Subrahmanyam et al, 1999 (Fig 2). Shearing between eastern India and East Antarctica, in the early stages of continental breakup, followed by spreading along a closely spaced ridge-transform system has been suggested [Powell et al, 1988;Rangaraju et al, 1993]. The time and location marking the change from sheafing to spreading are yet to be identified.…”

mentioning

confidence: 99%

Subsidence and isostasy along a sheared margin—Cauvery Basin, Eastern Continental Margin of India

Chand

Subrahmanyam

2001

Geophysical Research Letters

View full text Add to dashboard Cite

Abstract. We have applied a process-o. riented method to a seismo-geological section across Cauvery Basin, a sedimentary basin along the southern part of the Eastern Continental Margin of India (ECMI) to examine the isostatic mechanism operating beneath the margin. The evolution of the ECMI appears to be within a shear-rift tectonic setting, mainly driven by the difference in the relative motions of India and East Antarctica and the subsequent direction of spreading and the Cauvery Basin seems to have formed in this pull-apart tectonic setting. Shearing along the southern ECMI is modeled with gravity anomalies and the resultant crustal configuration, through. various models of isostasy. Backstripping analysis suggests a very low Te of 3 km beneath the basin. The shelf edge gravity anomaly reflects a strong contrast across a wrench fault parallel to the coast inferred from gravity forward modeling, denoting coastparallel transform motion in the initial stages of continental separation prior to rotation and spreading.

show abstract

Pre-breakup continental extension in East Gondwanaland and the early opening of the eastern Indian Ocean

Cited by 457 publications

References 35 publications

K-Ar and 40Ar/39Ar Ages of Central Kerguelen Plateau Basalts

K-Ar and 40Ar/39Ar Ages of Central Kerguelen Plateau Basalts

The field and remote sensing analysis of the Kerguelen Archipelago structure, Indian Ocean

Subsidence and isostasy along a sheared margin—Cauvery Basin, Eastern Continental Margin of India

Contact Info

Product

Resources

About