Terrane and Faunal Studies in Southern Alaska

阿拉斯加东南部的亚历山大河拥有最长和最多的 完整的古生代地层的阿拉斯加，与一个 早奥陶世以来的地层和化石记录 到二叠纪 许多工人认为它的悠久历史始于 西部的“原太平洋”，只到达附近的 中生代晚期的北美洲。 一些初步的动物群 有证据表明亚历山大号 在整个古生代历史中， 北美或者西伯利亚东部。 动物群 包括志留纪牙形刺和腕足类，下， 密西西比纪中、上泥盆统牙形刺和腕足类 牙形刺，宾夕法尼亚牙形刺和腕足动物。 动物群 所描述的属于旧世界领域和显示主要是科迪勒拉 地区和加拿大北极地区。 尽管在这片土地上出现的一些动物群 其他的埃姆斯期，艾菲尔期， 吉韦阶和密西西比阶牙形刺动物群和硅化中层 泥盆纪和密西西比纪的腕足动物群 但仍然未被收集和描述。 其他有害生物 1988年发现了宾夕法尼亚沉积物，但没有收集到。 对这些动物群的持续研究将提供更多的证据 关于《西游记》的起源

The Alexander terrane, SE Alaska, has the longest and most complete Paleozoic stratigraphy of the Alaskan terranes, with a stratigraphic and fossil record extending from the early Ordovician to the Permian. Many workers believe it began its long history in the western "Protopacific" and only arrived in the vicinity of North America in late Mesozoic time. Some preliminary faunal evidence indicates that the Alexander terrane has been closely associated throughout its Paleozoic history with the continent of North America or possibly with eastern Siberia. Faunas that have been described include Silurian conodonts and brachiopods, Lower, Middle and Upper Devonian conodonts and brachiopods, Mississippian conodonts, and Pennsylvanian conodonts and brachiopods. The faunas described belong to the Old World Realm and show mainly Cordilleran Region and Canadian Arctic affinities. Although several of the faunas that occur in this fossiliferous sequence have been described, other Emsian, Eifelian, Givetian and Mississippian conodont faunas and silicified Middle Devonian and Mississippian brachiopod faunas have been discovered but remain uncollected and undescribed. Other fossiliferous Pennsylvanian deposits were discovered but not collected in 1988. Continued work on these faunas will provide additional evidence concerning the terrane's origin.