Pipestones of the midcontinental U.S. have a long history of use by native peoples to craft high status and religious objects, especially pipes, that were often widely exchanged. In this research we describe native use of west central Wisconsin Baraboo Range pipestone as well as identify chemical and mineralogical variation within that formation. The pipestone variants are Baraboo A (dominated by kaolinite, muscovite, and pyrophyllite) and Baraboo B (dominated by pyrophyllite with minor quartz). The recognition of Baraboo pipestone variation allows us to identify previously unsourced pipestone objects. This sourcing project modifies assumptions of Cahokia-centric patterns of earspool manufacture and exchange during the Mississippian period (CE 1000-1400). It demonstrates that Baraboo pipestone Mississippian earspools were quarried, produced, and circulated among a small group of contemporaneous Mississippian societies located in the northern Upper Mississippi River valley — quite outside the Cahokia exchange network. This work establishes that employing rigorous, scientifically sound, and reproducible methodologies to identify the geological source of objects is essential to the interpretation of native interactions.

美国大陆中部的烟斗有着悠久的历史，土著人民使用它来制作高地位和宗教物品，尤其是经常广泛交换的烟斗。在这项研究中，我们描述了威斯康星州中西部 Baraboo Range 管道石的原生用途，并确定了该地层内的化学和矿物学变化。尖晶石变体是 Baraboo A（以高岭石、白云母和叶蜡石为主）和 Baraboo B（以叶蜡石和少量石英为主）。Baraboo 管道石变异的识别使我们能够识别以前无来源的管道石对象。这个采购项目修改了密西西比时期 (CE 1000-1400) 以 Cahokia 为中心的耳轴制造和交换模式的假设。它表明 Baraboo pipestone 密西西比州的耳轴是采石、生产、并在位于密西西比河上游河谷北部的一小群同时代的密西西比社会中传播——完全在 Cahokia 交换网络之外。这项工作表明，采用严格、科学合理且可重复的方法来识别物体的地质来源对于解释原生相互作用至关重要。