Loess in northern Pakistan: Current Understanding, Knowledge Gaps, and New Field Observations

The topic of loess (and other Late Quaternary palaeoclimate archives) in Pakistan has not been discussed much during the last decades. (Muhs, 2018) states that the extent of loess in Pakistan remains only vaguely understood, a situation that has not significantly changed. Several loess areas are reported from the Peshwar Basin, specifically the area around Nowshera west of the confluence of the Kabul and Indus Rivers, the Haro River Loess-Palaeosol deposits, and the area of Islamabad. Also Smalley et al., (2016) highlight the absence of a systematic loess study for Pakistan and emphasize that, for the Indian (sub)continent “the conditions appear to be perfect for the formation of large deposits”.

In this contribution, we summarize literature, and present observations form a recent field excursion. We consider both aeolian loess and redeposited loess-like fluviolacustrine sediments to be present in much larger areas than previously reported. We hypothesize that an aeolian sediment flux into the landscape was repeatedly intercalated by fluviolacustrine sediments of similar silt grain size. The aeolian sedimentation proceeded into mountain regions north of the basins, but preservation of fine material in sparse. At several places, loess is intercalated with (unrounded) slope deposits and fluvial deposits.