We revise the conceptual model of calcite varves and present, for the first time, a dual lake monitoring study in two alkaline lakes providing new insights into the seasonal sedimentation processes forming these varves. The study lakes, Tiefer See in NE Germany and Czechowskie in N Poland, have distinct morphology and bathymetry, and therefore, they are ideal to decipher local effects on seasonal deposition. The monitoring setup in both lakes is largely identical and includes instrumental observation of (i) meteorological parameters, (ii) chemical profiling of the lake water column including water sampling, and (iii) sediment trapping at both bi‐weekly and monthly intervals. We then compare our monitoring data with varve micro‐facies in the sediment record. One main finding is that calcite varves form complex laminae triplets rather than simple couplets as commonly thought. Sedimentation of varve sub‐layers in both lakes is largely dependent on the lake mixing dynamics and results from the same seasonality, commencing with diatom blooms in spring turning into a pulse of calcite precipitation in summer and terminating with a re‐suspension layer in autumn and winter, composed of calcite patches, plant fragments and benthic diatoms. Despite the common seasonal cycle, the share of each of these depositional phases in the total annual sediment yield is different between the lakes. In Lake Tiefer See calcite sedimentation has the highest yields, whereas in Lake Czechowskie, the so far underestimated re‐suspension sub‐layer dominates the sediment accumulation. Even in undisturbed varved sediments, re‐suspended material becomes integrated in the sediment fabric and makes up an important share of calcite varves. Thus, while the biogeochemical lake cycle defines the varves’ autochthonous components and micro‐facies, the physical setting plays an important role in determining the varve sub‐layers’ proportion.

中文翻译：

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方解石脉构造认识的新进展：波罗的海南部低地双重湖泊监测方法的新见解

我们修改了方解石脉管的概念模型，并首次在两个碱性湖泊中进行了双重湖泊监测研究，从而为形成这些脉管的季节性沉积过程提供了新见识。研究湖泊，德国东北部的Tiefer See和北部波兰的Czechowskie，具有独特的形态和测深法，因此，它们是解密季节性沉积的局部影响的理想之选。两个湖泊的监测设置基本相同，包括对（i）气象参数，（ii）湖泊水柱的化学分布图（包括水采样）以及（iii）每两周和每月间隔进行沉积物捕获的仪器观测。然后，我们将我们的监测数据与沉积记录中的微细微相进行比较。一个主要发现是方解石脉形成了复杂的薄片三胞胎，而不是通常认为的简单对联。两个湖泊中的瓣膜亚层的沉积很大程度上取决于湖泊的混合动力，并且是由相同的季节导致的，从春季的硅藻大花开始，到夏季变成方解石沉淀的脉动，秋季到秋季再悬浮层的终止。冬天，由方解石斑块，植物碎片和底栖硅藻组成。尽管有一个共同的季节性周期，但是在每个湖泊之间，每个沉积阶段在年沉积总量中所占的份额是不同的。在Tiefer湖中，方解石沉积物的产量最高，而在捷夫斯基湖中，到目前为止，被低估的重悬浮子层主导了沉积物的积累。即使在不受干扰的脉状沉积物中，重新悬浮的材料被整合到沉积物中，并构成方解石脉管的重要部分。因此，虽然生物地球化学湖泊周期定义了脉管的自生成分和微相，但物理环境在决定脉管亚层的比例方面起着重要作用。