U-Pb zircon dating evidence for a Pleistocene Sarasvati River and capture of the Yamuna River

Abstract

The Harappan Culture, one of the oldest known urban civilizations, thrived on the northwest edge of the Thar Desert (India and Pakistan) between 3200 and 1900 BCE. Its demise has been linked to rapid weakening of the summer monsoon at this time, yet reorganization of rivers may also have played a role. We sampled subsurface channel sand bodies predating ca. 4.0 ka and used U-Pb dating of zircon sand grains to constrain their provenance through comparison with the established character of modern river sands. Samples from close to archaeological sites to the north of the desert show little affinity with the Ghaggar-Hakra, the presumed source of the channels. Instead, we see at least two groups of sediments, showing similarities both to the Beas River in the west and to the Yamuna and Sutlej Rivers in the east. The channels were active until after 4.5 ka and were covered by dunes before 1.4 ka, although loss of the Yamuna from the Indus likely occurred as early as 49 ka and no later than 10 ka. Capture of the Yamuna to the east and the Sutlej to the north rerouted water away from the area of the Harappan centers, but this change significantly predated their final collapse.Peer reviewe

Fluvial landscapes of the Harappan civilization

“…2B; SI Text). Zircon dating of sand in this confluence region indicates inputs from both Beas and Sutlej drainage basins (32). Continuing to the southwest on the Ghaggar-Hakra interfluve, we document well-watered lands in the region of Pat, where channels ran parallel with the Indus and joined the Nara valley; their fluvial deposits at Fakirabad, among the dunes of the expanding desert, are even younger at approximately 3;350 y old.…”

“…Existing chronologies (27,28) and our own age on the bank of Sutlej (SI Text) identified deposits of Late Pleistocene age, indicating that the interfluve formed instead during the last glacial period. Provenance detection (32) suggests that the Yamuna may have contributed sediment to this region during the last glacial period, but switched to the Ganges basin before Harappan times. The present Ghaggar-Hakra valley and its tributary rivers are currently dry or have seasonal flows.…”

Fluvial–Eolian Interactions In Sediment Routing and Sedimentary Signal Buffering: An Example From the Indus Basin and Thar Desert

“…It delivers sediment to the Arabian Sea, building the world's second-largest submarine fan. The Indus has a long history of drainage evolution, including, in Holocene time, abandonment of the Yamuna River course in the northeastern Punjabi floodplain owing to headwater capture (Valdiya 2002;Saini et al 2009;Clift et al 2012) and the drying up of the Ghaggar-Hakra River tributary after , 4 ka . Fluvial sediment recycling in the Indus system is apparent from incision of rivers into the northern portion of the floodplains, adjacent to the Himalaya (whereas the southern portion of the Indus floodplain adjacent to the delta continues to aggrade); Clift and Giosan (2014) estimated that incision and reworking of sediment from the northern floodplains accounts for 21-23% of the flux into the coastal zone since the last glacial maximum (LGM), totaling.…”

Large-Scale, Multi-Temporal Remote Sensing of Palaeo-River Networks: A Case Study from Northwest India and its Implications for the Indus Civilisation

“…The traces of palaeo-rivers that have been identified cover the entirety of the landscape in the northern sector forming an almost continuous parallel pattern, which points to the changing nature of these channels and the likelihood that floods and river avulsions have been a relative common occurrence. The waters feeding the various palaeo-rivers originated from glacier-fed sources, such as water supplying the various palaeo-rivers related to the Sutlej, which appear to include the main Ghaggar-Hakra channel, as well as monsoonal rain which is likely to have contributed to both perennial and ephemeral rivers (see [10,27,65]). The geographic source of watercourses ranges from the Himalayas to the Aravalli mountains, and seasonal rain patterns and discharge across this zone are very different.…”