مقالة علمية
Extremely thin oceanic crust in the Proto-Indian Ocean: Evidence from the Masirah Ophiolite, Sultanate of Oman

Peters, Tjerk.


 

Extremely thin oceanic crust in the Proto-Indian Ocean: Evidence from the Masirah Ophiolite, Sultanate of Oman

Peters, Tjerk.

The Masirah Ophiolite is a good example of thin oceanic crust. Below pillow lavas and a sheeted dike complex with a relatively normal thickness of 1-1.5 km, the gabbroic lower crust barely exceeds 500 m in thickness. Inspite of this reduced thickness, the oceanic crust preserves all members of a model ophiolite in a coherent lithostratigraphic sequence. The crust was formed during the uppermost Jurassic (circa 150 Ma) when the Indian-Madagascar plate separated from the African-Arabian plate and is therefore related to the opening of the coeval Somali basin. Geological relationships indicate that this portion of oceanic crust was formed at a ridge-transform intersect. The peculiarly reduced thickness of the gabbro layer is interpreted as the result of a weak magma supply at the edge of a ridge segment, rather than the consequence of a tectonic thinning. The cooling effect due to the vicinity of two large continental lithospheric blocks (Indian-Madagascar and African-Arabian plates) during this initial stage of the oceanization might have been an additional factor contributing to the reduction of the crustal thickness.

The Masirah Ophiolite is a good example of thin oceanic crust. Below pillow lavas and a sheeted dike complex with a relatively normal thickness of 1-1.5 km, the gabbroic lower crust barely exceeds 500 m in thickness. Inspite of this reduced thickness, the oceanic crust preserves all members of a ...

مادة فرعية

المؤلف : Peters, Tjerk.

المساهم : Mercoll, Ivan

بيانات النشر : Journal of Geophysical Research : Oceans، 10 يناير 1998مـ.

التصنيف الموضوعي : العلوم البحتة|الجيولوجيا .

المواضيع : ocean .

رقم الطبعة : B1

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