Freehand and bipolar quartz cores classified in this analysis.

Left: types of freehand cores. F1 conical core; F2, F3, F4, F5, F6 and F7 various types of prismatic cores (with different directions of removals); F8 centripetal core; F9 multifacial core. Right: different types of bipolar cores recognised in this study, with different directions of removals. B1. Unidirectional. B2. Bidirectional. B3 is the result of rotation. B4 is typical of fracture accidents during bipolar knapping.左侧：自由打制石核的类型。F1为锥形石核；F2、F3、F4、F5、F6及F7为打制方向各异的各类棱柱形石核；F8为向心式石核；F9为多台面石核。右侧：本研究中识别出的不同类型两极石核，其打制方向各不相同。其中B1为单向打制型，B2为双向打制型，B3为旋转操作所形成的类型，B4为两极打制过程中典型的断裂失误实例。