The Mora 001 and Solberga 1 drill cores provide the best available overview on the early Silurian (Llandovery, Rhuddanian to Telychian) graptolite succession available for the Siljan Ring impact structure of central Sweden. The Solberga 1 succession includes a nearly complete graptolite succession from the Pernerograptus revolutus Biozone (late Rhuddanian) to the Oktavites spiralis Biozone (late Telychian). Older graptolite faunas are unknown from the Siljan region. The Mora 001 drill core includes a graptolitic succession from the Monoclimacis crenulata Biozone to the O. spiralis Biozone, found in two lithostratigraphically separated lithological units here identified as the Kallholn Formation. A slice of the Orsa Sandstone Formation of possible later Silurian age is tectonically introduced into the Kallholn Formation in the Mora 001 drill core. The strong tectonic deformation of the Kallholn Formation in both drill cores can easily be understood through the Devonian impact history of the region.

中文翻译：

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瑞典中部 Siljan 区 Mora 001 和 Solberga 1 钻芯的志留纪地层学和笔石群

Mora 001 和 Solberga 1 钻芯提供了可用于瑞典中部 Siljan 环冲击结构的早期志留纪（Llandovery、Rhuddanian 到 Telychian）笔石演替的最佳可用概览。Solberga 1 演替包括从Pernerograptus revolutus生物带（Rhuddanian 晚期）到Oktavites spiralis Biozone（Telychian 晚期）的几乎完整的笔石演替。Siljan 地区不知道更古老的笔石动物群。Mora 001 钻芯包括从Monoclimacis crenulata Biozone 到O.spiralis的笔石序列生物带，发现于两个岩石地层分离的岩性单元中，在这里被确定为 Kallholn 组。在 Mora 001 钻芯的 Kallholn 组中，可能是志留纪晚期的 Orsa 砂岩组的一部分被构造引入。通过该地区的泥盆纪撞击历史，可以很容易地了解两个钻芯中 Kallholn 组的强烈构造变形。