Liquid scintillation counting and AMS 14C radiocarbon dating of associated charcoals and a carbonized seed of Annona squamosa L. to analyse its antiquity in India.

摘要

To obtain authentic dates, wood-charcoal samples associated with the carbonized seed of custard apple remains from the stratigraphic sequence of Neolithic culture at Tokwa, Mirzapur, Uttar Pradesh, India were dated by Ultra Low Level Liquid Scintillation Counting (LSC) method of 14C radiocarbon dating. The sample dated to cal. 3470+or-120 years BP; cal. BC 1740, BS-2268. Since the sample is rare, a broken seed sample of custard apple was dated, and the AMS date was 3280+or-140 years BP (cal. BP 3473; cal. BC 1530, IOPAMS-10). Wood-charcoal samples associated with the carbonized seeds of A. squamosa and other botanical remains from stratigraphic sequence of iron-using culture at Raja-Nal-ka-tila, Sonbhadra, Uttar Pradesh, were also dated in the laboratory. The sample dated to cal. 2690+or-70 years BP; cal. BC 740, BS-1988, supporting pre-Columbian existence. To identify the carbonized seeds up to a specific level, seed size of four common Annona species in the Indian region was determined on the collection. The ancient oblong seed (16 mm long) showed close resemblance with that of extant seeds of A. squamosa. The carbonized fruit coat from Sanghol during the Kushana period, with projecting and ovoid-oblong aureoles showed close affinity with that of A. squamosa. Hence, the seeds from Neolithic Tokwa have been referred to as A. squamosa. The findings of custard apple seeds from the Neolithic cultural sequence at Tokwa have placed its antiquity approx. 3500 years BP. Hence, the factual remains of custard apple in India archaeological records show Asian-American trans-oceanic contacts before the discovery of America by Columbus.