Joint corresponding authors.
Sediment storage and reworking on the shelf and in the Canyon of the Indus River-Fan System since the last glacial maximum
Article first published online: 17 JAN 2014
© 2014 The Authors. Basin Research © 2014 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Special Issue: Deep Water Continental Margins
Volume 26, Issue 1, pages 183–202, February 2014
How to Cite
Clift, P. D., Giosan, L., Henstock, T. J. and Tabrez, A. R. (2014), Sediment storage and reworking on the shelf and in the Canyon of the Indus River-Fan System since the last glacial maximum. Basin Research, 26: 183–202. doi: 10.1111/bre.12041
- Issue published online: 17 JAN 2014
- Article first published online: 17 JAN 2014
- Manuscript Accepted: 5 AUG 2013
- Manuscript Revised: 1 AUG 2013
- Manuscript Received: 15 JAN 2013
The transport of sediment from the mouth of the Indus River on to the deep-water submarine fan is complicated by temporary storage within large clinoforms on the shelf on either side of the submarine canyon, where most of the sedimentation since the start of the Holocene has occurred. In contrast, shelf edge clinoform deltas represent the products of forced regression and not the progradation of highstand clinoforms as far as the shelf edge. Clinoform sediments have a mixed provenance that involves significant reworking of older sediment deposited during or before the last glacial maximum. Recent sedimentation in the canyon head has been very rapid in the last few centuries (ca. 10 cm year−1), but has been starved of sand probably because of 20th century damming. Sandy layers appear to represent annual monsoonal floods with a particularly large flood every 50–70 years. This canyon head sediment is also reworked by currents flowing along the canyon axis before being deposited deeper into the canyon. The last sandy sediment to reach the mid-canyon (ca. 1300 m depth) was transported around 7000 year BP at a time of rising sea-levels, and might reflect reworking by the transgression, or local slumping from the walls of the canyon. Dating of the uppermost in a series of terraces in the mid-canyon area suggests that the canyon may have been partly filled and emptied of sediment at least three times since ca. 50 ka. We conclude from the Holocene record that sediment flux to the deep-water fan experiences major buffering, reworking and recycling both on the shelf and within the submarine canyon prior to its deposition, so that turbidite sands in the deep Arabian Sea cannot be used to correlate with climatic or tectonic events onshore over timescales of 103–105 years.