Radish concretions exhibit a typical columnar to pear-shaped, stipe downward geometry. In Middle Jurassic mudrock in south-west Germany, radish concretions started to form around an iron-sulphide lined tube by pervasive cementation constituting an ellipsoidal parent domain in uncompacted sediment at burial depths of ≤5 to 8 m as recorded by 75 to 80% minus-cement porosity. Thereafter, the concretions grew vertically in compacting sediment as evidenced by laminae within the concretions being increasingly inclined towards the tips, and concomitantly decreasing minus-cement porosity. During early diagenesis, prior to septarian crack formation, bicarbonate generating the microbial cement originated within the sulphate reduction zone chiefly from anaerobic oxidation of methane and to a lesser degree of organoclastic material. Later, at 50 to 70 m burial depth, septarian cracks formed as evaluated by sedimentation–compaction analysis based on minus-cement porosity data and compressibility of similarly composed sediments. The outward-narrowing septarian cracks indicate that they formed when the concretions were still in a plastic state but already cemented sufficiently to be resistant against compaction. In this stage, up to one-quarter of the pore volume of the concretions was still open as suggested by shrinkage experiments. This pore volume, and the septarian cracks, were filled with cement termed late diagenetic. In the study area, the decompacted net-sedimentation rate was low, about 2 to 3 cm kyr⁻¹, for ca 2.5 Myr, allowing the concretions to reside for a long time within the sulphate reduction zone and to grow. Radish concretions formed within the transition zone from thick, rapidly deposited to long-term, slowly accumulating sediment.

中文翻译：

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压实过程中在泥浆中生长的萝卜结核

萝卜结核表现出典型的柱状到梨形，菌柄向下的几何形状。在德国西南部的中侏罗世泥岩中，萝卜结核开始在硫化铁衬里管周围形成，在埋深≤5 至 8 m 的未压实沉积物中构成椭圆形母域的普遍胶结作用，记录为 75 至 80% 减去-水泥孔隙率。此后，结核在压实沉积物中垂直生长，结核内的纹层逐渐向尖端倾斜，同时负水泥孔隙度降低。在早期成岩作用期间，在隔膜裂缝形成之前，产生微生物胶结物的碳酸氢盐主要来自于甲烷的厌氧氧化和较小程度的有机碎屑物质。之后，在 50 至 70 m 埋深处，通过基于负水泥孔隙度数据和类似组成沉积物的可压缩性的沉积压实分析评估，形成了分隔裂缝。向外变窄的隔膜裂缝表明它们是在结核仍处于塑性状态但已经胶结到足以抵抗压实时形成的。在这个阶段，多达四分之一的结核孔隙体积仍然是开放的，正如收缩实验所表明的那样。这个孔隙体积和隔膜裂缝充满了称为晚期成岩作用的胶结物。研究区解压后的净沉降速率较低，约为 2～3 cm kyr 向外变窄的隔膜裂缝表明它们是在结核仍处于塑性状态但已经胶结到足以抵抗压实时形成的。在这个阶段，多达四分之一的结核孔隙体积仍然是开放的，正如收缩实验所表明的那样。这个孔隙体积和隔膜裂缝充满了称为晚期成岩作用的胶结物。研究区解压后的净沉降速率较低，约为 2～3 cm kyr 向外变窄的隔膜裂缝表明它们是在结核仍处于塑性状态但已经胶结到足以抵抗压实时形成的。在这个阶段，多达四分之一的结核孔隙体积仍然是开放的，正如收缩实验所表明的那样。这个孔隙体积和隔膜裂缝充满了称为晚期成岩作用的胶结物。研究区解压后的净沉降速率较低，约为 2～3 cm kyr 被称为晚期成岩的水泥填充。研究区解压后的净沉降速率较低，约为 2～3 cm kyr 被称为晚期成岩的水泥填充。研究区解压后的净沉降速率较低，约为 2～3 cm kyr^-1，对于ca 2.5 Myr，允许结核在硫酸盐还原区域内停留很长时间并生长。萝卜结核在过渡带内形成，从较厚的、快速沉积到长期、缓慢堆积的沉积物。