D’Orbigny named the Callovian stage after Kellaways in Wiltshire, UK, in the 1850 s. However, agreement on its boundaries and, more recently, on the position and location of the Global Boundary Stratotype Section and Point (GSSP) for the base of the Callovian has proven difficult for the last 170 years. This is mainly due to the lack of agreement on the appropriate index fossil and its regional and global correlations, as well as the location of the stratotype section. Stable carbon isotope chemostratigraphy and event stratigraphy are now essential tools for aiding in the definition of GSSPs. In this study, stable carbon isotopic analysis of 91 samples from east Greenland’s Middle Jurassic shallow marine sandstones of the Pelion Formation (Store Koldewey and Hold with Hope) and correlative and well-dated offshore siltstones and mudstones of the Fossilbjerget Formation (Jameson Land) is used to discriminate several isotopic events previously observed in other European basins and propose the early Callovian (δ13CTOC) positive carbon isotopic excursion as a secondary marker for defining the Callovian GSSP. The early Callovian (δ13CTOC) positive carbon isotopic excursion is a fundamental tool for superregional correlation between candidate GSSPs and Standard Auxiliary Boundary Stratotypes. It can also help establish a chronological order (synchronous vs diachronous) of species occurrences between different locations.

中文翻译：

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格陵兰岛 Callovian 基底的稳定碳同位素化学地层学


D'Orbigny 在 1850 年代以英国威尔特郡的 Kellaways 命名了 Callovian 舞台。然而，在过去的 170 年里，事实证明，就其边界以及最近就卡洛维亚山脉底部的全球边界层型剖面和点 （GSSP） 的位置和位置达成一致是困难的。这主要是由于对适当的索引化石及其区域和全球相关性以及层型剖面的位置缺乏共识。稳定碳同位素化学地层学和事件地层学现在是帮助定义 GSSP 的重要工具。在这项研究中，对来自格陵兰岛东部中侏罗世浅海砂岩的 91 个样品进行稳定的碳同位素分析，这些样品来自格陵兰岛东部中侏罗世浅海砂岩，属于 Pelion 组（Store Koldewey 和 Hold with Hope）以及 Fossilbjerget 组（Jameson Land）的相关且年代明确的海上粉砂岩和泥岩，用于区分先前在其他欧洲盆地观察到的几种同位素事件，并提出早期 Callovian （δ13CTOC） 正碳同位素偏移作为定义Callovian GSSP.早期 Callovian （δ13CTOC） 正碳同位素偏移是候选 GSSP 和标准辅助边界层型之间超区域相关性的基本工具。它还可以帮助建立不同地点之间物种出现的时间顺序（同步与历时）。