湖北宜昌地区寒武系下部小壳化石的研究集中于黄陵背斜东翼和南翼, 对西翼地区尚未有详细的报道。 作者在黄陵背斜西翼高岚河剖面灯影组天柱山段下部发现寒武纪纽芬兰世的小壳化石, 既包括扬子板块小壳化石第一生物带标准化石Anabarites trisulcatus, 同时也有Eohalobia diandongensis与Oelandiella korobkovi等第二生物带标志化石, 以及可能为第三生物带或更晚期化石分子的Paragloborilus tenuis等。该化石组合为多生物带的化石混生, 其层位可能相当于峡东地区(黄陵背斜南翼)的岩家河组顶部。在黄陵背斜南翼的滚石坳剖面岩家河组下部发现小壳化石Anabarites ternarius Missarzhevsky in Rozanov et al., 1969、Kaiyangites novilis Qian and Yin, 1984、 海绵骨针和藻类化石, 属于小壳化石第一生物带Anabarites trisulcatus–Protohertzina anabarica组合带。化石组合与沉积记录表明, 高岚河剖面与东翼如泰山庙地区具有相似的潮坪相沉积, 多发沉积间断, 导致不同生物带化石混生; 南翼滚石坳地区水体较深, 早期沉积间断不显著, 可以识别小壳化石第一组合带。上述新化石材料的发现, 为黄陵背斜周缘寒武系下部地层对比与生物古地理分析提供了新的数据。

Early Cambrian small shelly fossils (SSF) from the eastern and southern parts of the Huangling Anticline in Yichang area, Hubei Province, have been extensively studied. However, little information on the SSFs from the western part of the Anticline is known. Here we report SSFs from the Terreneuvian Tianzhushan Member of the Dengying Formation at the Gaolanhe section. These SSFs consist of Anabarites trisulcatus (an index element of Anabarites trisulcatus-Protohertzina anabarica Assemblage Zone), Eohalobia diandongensis, and Oelandiella korobkovi (index fossils of Paragloborilus subglobosus-Purella squamulosa Assemblage Zone), as well as Paragloborilus tenuis, which may belong to zone Ⅲ (Watsonella crosbyi Assemblage Zone) or later biozones. We thus suggest that this assemblage zone represents a mixture of multiple SSF biozones and it may be correlated to the top of the Yangjiahe Formation from eastern Three Gorges Area. In addition, we report new SSFs from the basal Yanjiahe Formation at the Gunshiao section in southern part of the Huangling Anticline. This assemblage, belonging to the Anabarites trisulcatus-Protohertzina anabarica Assemblage Zone, contains Anabarites ternarius Missarzhevsky in Rozanov et al., 1969, Kaiyangites novilis Qian and Yin, 1984, sponge spicules, and unnamed algae. Fossil assemblages and deposition records show that the Gaolanhe area, comparable to the Taishanmiao area in the eastern part of the Huangling Anticline, developed tidal-flat facies with significant exposure. The Gunshiao region in the southern part of the Huangling Anticline possesses an open platform facies with a minor depositional suspension; the first SSF biozone is relatively recognizable in the lower part. The discovery of these fossil materials provides new data for stratigraphic correlation and palaeobiogeographic study of the lower Cambrian in the Huangling Anticline.

中国地质调查局地质调查项目(DD20230221)；国家自然科学基金(U2244202, 41972026, 42162003)联合资助