Abstract

Mikulinian (Eemian) marine deposits are widespread in the northern Arkhangelsk Region, Russia. Shoreface deposits have been found in exposures along the Pyoza and Vaskha rivers; however, deposits of undoubtedly tidal origin have not hitherto been recognized there. By contrast, here we show that shells of Macoma balthica (Linnaeus, 1758) (Tellinidae, Bivalvia) unearthed from the shoreface deposits show growth patterns indicating that the bivalves lived in an environment affected by tidal periodicity. The periodicity was a mixed tide with significantly diurnal inequality in the height of the low waters. In the Arkhangelsk Region, the Mikulinian hydrodynamical conditions of the tidally influenced regime are still poorly known. Because the spatial and temporal distribution of M. balthica is broad in the fossil record, its shells have a large potential for tidal interpretations, as contribution to hydrological reconstructions.

中文翻译：

---

米库林间冰期期间阿尔汉格尔斯克地区（俄罗斯）的贝壳生长增量作为潮汐指标

摘要

俄罗斯阿尔汉格尔斯克州北部地区广泛分布着米库利阶（埃米亚）海洋沉积物。在 Pyoza 河和 Vaskha 河沿岸的裸露区域中发现了 Shoreface 沉积物；然而，迄今为止，尚未在那里发现无疑是潮汐起源的沉积物。相比之下，我们在这里显示，从海岸沉积物中出土的Macoma balthica （Linnaeus，1758）（Tellinidae，Bivalvia）的贝壳显示出生长模式，表明双壳类动物生活在受潮汐周期性影响的环境中。周期性为混合潮，低潮高度日间不均。在阿尔汉格尔斯克地区，受潮汐影响的米库利尼亚水动力条件仍然知之甚少。由于M. balthica在化石记录中的空间和时间分布很广泛，因此它的贝壳在潮汐解释方面具有很大的潜力，可以为水文重建做出贡献。