Skip to Main Content
Book Chapter

Composition and origin of the Kanar Melange, southern Pakistan

By
Ghulam Sarwar
Ghulam Sarwar
Search for other works by this author on:
Kees A. De Jong
Kees A. De Jong
Search for other works by this author on:
Published:
January 01, 1984

The Kanar Melange is an ophiolitic melange underlain by Cretaceous shelf-slope argillites and overlain by a thrust sheet of Cretaceous ophiolites. The melange consists of a chaotic mixture of millimeter to kilometer-size clasts embedded in a dominantly argillaceous matrix. The affinities of the clasts are continental (e.g., Mesozoic shelf carbonate rocks, clastic and sedimentary rocks, mafic-ultramafic and alkali-volcanic rock bearing conglomerates) and oceanic (serpentinite, gabbro, and basalt). The matrix is mildly deformed to strongly folded and foliated. The melange was emplaced during the Paleocene in a trough located on the western margin of the Indo-Pakistan subcontinent.

A two stage model for the origin of melange is proposed. It involves Paleocene oblique convergence between the western margin of the Indian Plate and the adjoining Neo-Tethys along a Cretaceous transform boundary. This resulted in the formation of a zone of tectonically mixed continental and oceanic rocks (proto-Kanar Melange) bounded by a trough (tectonic foredeep) on the continental margin. Debris from the mixed zone was shed into the trough, leading to the formation of the Kanar Melange. Tectonic mixing of contrasting rock types is considered an important step in the genesis of the Kanar Melange. However, the presence of sedimentary features in the matrix of the melange and its depositional relationship with the underlying Sembar Formation suggest that the emplacement of the melange may have been controlled by sedimentary processes. Oblique convergence culminated in the obduction of ophiolite nappes above the melange and regional-scale folding of the whole area. These events produced a tectonic overprint that obscured primary stratigraphic and structural relationships within the melange belt.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

GSA Special Papers

Melanges: Their Nature, Origin, and Significance

Loren A. Raymond
Loren A. Raymond
Search for other works by this author on:
Geological Society of America
Volume
198
ISBN print:
9780813721989
Publication date:
January 01, 1984

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

Related Articles
Related Book Content
This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now