Abstract The Late Devonian Period was a critical geological interval, affected by numerous significant global bio- and environmental events, including the Kellwasser, annulata and Hangenberg events, and a major climate transition leading to the Carboniferous ice ages. The timing and pattern of these events are unclear due to lack of the precise time scale. In this study, an analysis of calcium concentration series was carried out on the Upper Devonian cyclostratigraphic slope-facies of the Lali section, South China. Objective testing of the section indicates the presence of astronomical forcing: long orbital eccentricity, short eccentricity, obliquity, and precession index. Two independent astrochronologies were developed for the Ca series and compared with spectral analysis. The age of the Devonian–Carboniferous boundary (358.9 ± 0.4 Ma) was selected as an “anchor”, and an Astronomical Time Scale (ATS) was constructed from the late Frasnian to early Tournaisian based on 405-kyr cycles. The ATS indicates a duration of the Famennian Stage of 14.4 ± 0.28 myr, and assigns 373.3 ± 0.49 Ma to the Frasnian–Famennian boundary. The durations of the Famennian conodont zones are also indicated. The timing of Famennian bio- and environmental events also can be established by the ATS. The Upper Kellwasser horizon starts at 373.4 Ma and is constrained to a duration of 100-kyr; a sharp positive carbon isotope excursion CIE, +3‰ recognized across the Frasnian–Famennian boundary lasts 300 kyr. The Lower and Upper annulata events each last 50-kyr with positive CIEs; and the ages of two CIE peaks are 361.7 Ma and 361.3 Ma, respectively. Five transgressive events, including the Nehden, Enkeberg, Dasberg, Strunian, and Hangenberg transgressions occur at 370.6 Ma, 368 Ma, 360.4 Ma, 360.1 Ma, and 358.9 Ma, respectively. Five regressive events i.e., the linguiformis, prima, Condroz, velifer, and Derwer regressions occur at 373.4 Ma, 371 Ma, 369 Ma, 362.3 Ma, and 359.2 Ma, respectively.

中文翻译：

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华南上泥盆统拉里剖面天文时间校准

摘要 晚泥盆世是一个关键的地质时期，受到许多重大的全球生物和环境事件的影响，包括 Kellwasser、环形和 Hangenberg 事件，以及导致石炭纪冰河时代的重大气候转变。由于缺乏精确的时间尺度，这些事件的时间和模式尚不清楚。本研究对华南拉里剖面上泥盆统旋回地层斜坡相进行钙浓度序列分析。对该截面的客观测试表明存在天文强迫：长轨道偏心率、短偏心率、倾角和进动指数。为 Ca 系列开发了两个独立的天体年代学，并与光谱分析进行了比较。泥盆纪-石炭纪边界年龄（358.9±0. 4 Ma) 被选为“锚点”，并基于 405-kyr 周期构建了从弗拉斯阶晚期到图尔奈阶早期的天文时间尺度 (ATS)。ATS 表明法门阶的持续时间为 14.4 ± 0.28 myr，并将 373.3 ± 0.49 Ma 分配给 Frasnian-Famennian 边界。还指出了法门牙牙形带的持续时间。法门生物和环境事件的发生时间也可以由 ATS 确定。上 Kellwasser 地平线从 373.4 Ma 开始，持续时间为 100-kyr；一个尖锐的正碳同位素偏移 CIE，跨越弗拉斯-法门边界识别的 +3‰ 持续 300 kyr。下环和上环事件各持续 50 kyr，CIE 为正；两个 CIE 峰的年龄分别为 361.7 Ma 和 361.3 Ma。五个海侵事件，包括 Nehden、Enkeberg、Dasberg、Strunian 和 Hangenberg 海侵分别发生在 370.6 Ma、368 Ma、360.4 Ma、360.1 Ma 和 358.9 Ma。五个回归事件，即 linguiformis、prima、Condroz、velifer 和 Derwer 回归分别发生在 373.4 Ma、371 Ma、369 Ma、362.3 Ma 和 359.2 Ma。