A high-precision 40Ar/39Ar age for the Young Toba Tuff and dating of ultra-distal tephra: Forcing of Quaternary climate and implications for hominin occupation of India

A new high-precision inverse isochron 40Ar/39Ar age for the youngest Toba super-eruption is presented: 75.0 ± 0.9 ka (1 sigma, full external precision, relative to the optimisation model of Renne et al., 2010, 2011). We present the most accurate and robust radio-isotopic age constraint for the Young Toba Tuff. 40Ar/39Ar ages for biotite shards harvested from ultra-distal Toba tephra deposits (>2500 km) preserved in archaeological sites in the Middle Son Valley and Jurreru Valley, India, establish provenance with the young Toba super-eruption. The air-fall tephra at these sites can be used as an isochronous horizon facilitating stratigraphic and temporal correlation throughout India. The high-precision 40Ar/39Ar age for the young Toba tephra can serve as a tie point for linking of the multiple Greenland ice cores beyond the GICC05 timescale, and permits correlation to other absolutely dated palaeoclimate archives for the testing of synchronicity in the response of the global climate system.

► High-precision 40Ar/39Ar age for the youngest Toba super-eruption (YTT).
► Approach for the dating of small biotite shards in ultra-distal tephra deposits.
► Establish provenance of air fall tephra from archaeological sites in India.
► Demonstrate continuity of hominin occupation in India 77–38 ka.
► 75 ka tie point to link palaeoclimate archives, test response in climate system.