Relatively small, triangular bifaces often considered to be projectile points have a demonstrable use history that includes the Middle Archaic, Late Archaic, Early Woodland, late Middle Woodland, Late Woodland, and Contact periods of regional archaeology. Radiocarbon dates and other data are used to document this extensive history using the Upper Delaware Valley of New Jersey, Pennsylvania, and New York as a case study. Observed trends are evaluated in a broader regional context. The degree to which triangles of different ages can be distinguished from one another is addressed and suggestions for future research are made.

中文翻译：

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三角双面的数千年使用历史

通常被认为是射弹点的相对较小的三角形双面具有明显的使用历史，包括中古风、晚古风、早林地、晚中林地、晚林地和区域考古学的接触时期。以新泽西州、宾夕法尼亚州和纽约州的上特拉华河谷作为案例研究，使用放射性碳日期和其他数据来记录这段广泛的历史。观察到的趋势是在更广泛的区域背景下评估的。讨论了不同年龄的三角形可以相互区分的程度，并对未来的研究提出了建议。