Reconstruction of Indian monsoon precipitation variability between 4.0 and 1.6 ka BP using speleothem δ18O records from the Central Lesser Himalaya, India

The present study documents the monsoon precipitation variability spanned ~ 2500 years, between 4.0 and 1.6 ka BP (before 1950 AD), from the Central Lesser Himalaya, India, using δ18O measurements of Tityana cave stalagmite (hereafter referred as TC1). At present, the cave receives precipitation from both Indian Summer Monsoon (ISM) and Western Disturbances (WDs). The δ18O variation between − 8.04 and − 10.46‰ through growth axis of the TC1 and five 14C AMS dates (due to large age uncertainty by 230Th/U method) have allowed us to identify the mid to late Holocene multi-decadal to centennial scale climatic oscillations. The higher δ18O values indicate the weakening of the monsoon precipitation, while the lighter values represent the stronger monsoon precipitation strength. Based on the fluctuations in δ18O values, three distinct phases of the precipitation variability are distinguished as, declined/decreased precipitation between ~ 4.0 and 3.4 ka BP with peak aridity around ~ 3.4 ka BP, followed by slightly improved conditions from ~ 3.4 to ~ 2.7 ka BP. Subsequently, the climate was reduced from ~ 2.7 ka BP onwards until the end of stalagmite growth, around ~ 1.6 ka BP with spikes of two major drought events centred at ~ 1.9 and ~ 1.6 ka BP. In general, the droughts, centred at ~ 3.4, ~ 1.9 and ~ 1.6 ka BP, are characterized by abrupt drop (from − 8.12 to − 8.04‰) in the δ18O values and point to the weakening of the monsoon. One of the major drought events at ~ 3.4 ka BP can be correlated with the collapse of the Indus valley civilization in the NW India. A close correspondence of the TC1 data set with other WDs influenced regimes likely indicates a relative impact of mid-latitude WDs after transition of the mid-late Holocene around 3.5–3.4 ka BP.