Discovery of the palaeo-Indus delta-fan complex

The Indus River carries sediments from the western Himalaya and deposits some of these as channel and floodplain sediments or molasse, The rest of its load forms the Indus delta at the margin of the Indian Ocean. The Indus delta passes some of its sediments to be deposited as Indus submarine fan turbidites. Thus, as elsewhere, Himalayan molasse, delta, and fan deposition are related in time and space, However, when we examine fluvial and marine age-range data of the older Indus deposits, in terms of this sedimentary assemblage, a major portion of its marine record is missing. The oldest known molasse along the Indus suture zone, and in the foredeep are middle Eocene and late Palaeocene in age, respectively. A recent synthesis of sedimentation in the northern Indian Ocean, however, shows that turbidite sedimentation started around early Miocene in the modern Indus fan, and even later in the Bengal fan. Where are the Palaeogene Indus delta and fan sediments? We suggest herein that these are preserved as the Palaeogene siliciclastic Khojak Formation in the Katawaz Basin and eastern Makran.