Prehistoric chronology is almost entirely reliant upon the dating of material objects of which
pottery is by far the most widespread and the most resistant to decay. All locations and generations developed their own shapes, sizes and styles of pottery, including methods and styles of decoration, but there was consistency among stratified deposits and even shards can be classified by time and place. Pottery is believed to have been discovered independently in various places, beginning with China c. 18,000 BC, and was probably created accidentally by fires lit on
clay soil. The main discovery of pottery dated to the 10th millennium has been at
Bosumpra Cave (early tenth-millennium cal. BC) on the Kwahu Plateau in southeastern Ghana and
Ounjougou (c.9400 BC) in Central Mali, providing evidence of an independent invention of pottery in Sub-Saharan Africa in different climatic zones. The first chronological pottery system was the Early, Middle and Late Minoan framework devised in the early 20th century by Sir
Arthur Evans for his findings at
Knossos. This covered the
Bronze Age in twelve phases from c. 2800 BC to c. 1050 BC and the principle was later extended to mainland Greece (Helladic) and the Aegean islands (Cycladic). Dame
Kathleen Kenyon was the principal archaeologist at
Tell es-Sultan (ancient Jericho) and she discovered that there was no pottery there. The
potter's wheel had not yet been invented and, where pottery as such was made, it was still hand-built, often by means of
coiling, and
pit fired. Kenyon discovered vessels such as bowls, cups, and plates at Jericho which were made from stone. She reasonably surmised that others made from wood or vegetable fibres would have long since decayed. Using Evans' system as a benchmark, Kenyon divided the Near East Neolithic into phases called
Pre-Pottery Neolithic A (PPNA), from c. 10,000 BC to c. 8800 BC;
Pre-Pottery Neolithic B (PPNB), from c. 8800 BC to c. 6500 BC; and then
Pottery Neolithic (PN), which had varied start-points from c. 6500 BC until the beginnings of the
Bronze Age towards the end of the
4th millennium. In the 10th millennium, the Natufian culture co-existed with the PPNA which prevailed in the Levantine and upper Mesopotamian areas of the Fertile Crescent. ==Other cultural developments==