Cenomanian strata of the Elbtal Group (Saxony, eastern Germany) reflect a major global sea-level rise and contain, in certain intervals, a green authigenic clay mineral in abundance. Based on the integrated study of five new core sections, the environmental background and spatio-temporal patterns of these glauconitic strata are reconstructed and some general preconditions allegedly needed for glaucony formation are critically questioned. XRD analyses of green grains extracted from selected samples confirm their glauconitic mineralogy. Based on field observations as well as on the careful evaluation of litho- and microfacies, 12 glauconitc facies types (GFTs), broadly reflecting a proximal–distal gradient, have been identified, containing granular and matrix glaucony of exclusively intrasequential origin. When observed in stratigraphic succession, GFT-1 to GFT-12 commonly occur superimposed in transgressive cycles starting with the glauconitic basal conglomerates, followed up-section by glauconitic sandstones, sandy glauconitites, fine-grained, bioturbated, argillaceous and/or marly glauconitic sandstones; glauconitic argillaceous marls, glauconitic marlstones, and glauconitic calcareous nodules continue the retrogradational fining-upward trend. The vertical facies succession with upwards decreasing glaucony content demonstrates that the center of production and deposition of glaucony in the Cenomanian of Saxony was the nearshore zone. This time-transgressive glaucony depocenter tracks the regional onlap patterns of the Elbtal Group, shifting southeastwards during the Cenomanian 2nd-order sea-level rise. The substantial development of glaucony in the thick (60 m) uppermost Cenomanian Pennrich Formation, reflecting a tidal, shallow-marine, nearshore siliciclastic depositional system and temporally corresponding to only ~ 400 kyr, shows that glaucony formation occurred under wet, warm-temperate conditions, high accumulation rates and on rather short-term time scales. Our new integrated data thus indicate that environmental factors such as great water depth, cool temperatures, long time scales, and sediment starvation had no impact on early Late Cretaceous glaucony formation in Saxony, suggesting that the determining factors of ancient glaucony may be fundamentally different from recent conditions and revealing certain limitations of the uniformitarian approach.

Elbtal Group（萨克森州，德国东部）的 Cenomanian 地层反映了全球海平面的重大上升，并且在某些区间内含有丰富的绿色自生粘土矿物。在对五个新岩心剖面的综合研究的基础上，重建了这些海冰岩地层的环境背景和时空格局，并对一些据称形成海冰岩所需的一般先决条件提出了批判性质疑。从选定样品中提取的绿色晶粒的 XRD 分析证实了它们的海绿石矿物学。根据实地观察以及对岩相和微相的仔细评估，已经确定了 12 种青光岩相类型 (GFT)，它们广泛地反映了近端-远侧梯度，包含完全序列内成因的粒状和基质青光眼。在地层序列中观察时，GFT-1 到 GFT-12 通常叠加出现在海侵旋回中，从海藻基底砾岩开始，然后是海藻砂岩、砂质海绿岩、细粒、生物扰动、泥质和/或泥质海藻砂岩；青光质泥质泥灰岩、青光质泥灰岩和青光性钙质结核继续逆积精化上升趋势。海冰含量向上递减的垂直相序列表明萨克森州森诺曼阶海冰生成和沉积的中心是近岸带。这个时间海侵的海藻沉积中心跟踪易北河群的区域上叠模式，在森诺曼阶二阶海平面上升期间向东南移动。在厚 (60 m) 最上层 Cenomanian Pennrich 组中大量发育海冰，反映潮汐、浅海、近岸硅质碎屑沉积系统，时间上仅对应约 400 kyr，表明海冰形成发生在潮湿、暖温带条件下，高积累率和相当短期的时间尺度。因此，我们新的综合数据表明，水深大、温度低、时间尺度长、沉积物饥饿等环境因素对萨克森州晚白垩世早期海冰形成没有影响，表明古海冰形成的决定因素可能与最近的条件并揭示了均变论方法的某些局限性。近岸硅质碎屑沉积系统和时间上仅对应约 400 kyr，表明蓝藻形成发生在潮湿、暖温带条件、高积累率和相当短的时间尺度下。因此，我们新的综合数据表明，水深大、温度低、时间尺度长、沉积物饥饿等环境因素对萨克森州晚白垩世早期海冰的形成没有影响，表明古海冰的决定因素可能与最近的条件并揭示了均变论方法的某些局限性。近岸硅质碎屑沉积系统和时间上仅对应约 400 kyr，表明蓝藻形成发生在潮湿、暖温带条件、高积累率和相当短的时间尺度下。因此，我们新的综合数据表明，水深大、温度低、时间尺度长、沉积物饥饿等环境因素对萨克森州晚白垩世早期海冰形成没有影响，表明古海冰形成的决定因素可能与最近的条件并揭示了均变论方法的某些局限性。