Portal de Periódicos da CAPES

Unusual echinoid resting trace records change in the position of the redox boundary (Palaeogene of the Lesser Caucasus in Georgia)

2022; De Gruyter; Linguagem: Inglês

10.24425/agp.2022.140429

2300-1887

Alfred Uchman, Zurab Lebanidze, Nino Kobakhidze, Tamar Beridze, Davit Makadze, Koba Lobzhanidze, Sophio Khutsishvili, Rusudan Chagelishvili, Kakhaber Koiava, Nino Khundadze,

Geological Studies and Exploration

The first recognition of a tracemaker responding to a temporary shift in the redox boundary is recognized. This is recorded by a new trace fossil, Sursumichnus orbicularis igen. et isp. nov., which is established for mound-like structures on the upper surfaces of sandstone beds from the Borjomi Flysch (upper Paleocene–lower Eocene) in the Lesser Caucasus (Georgia). It is connected with the spatangoid echinoid burrow Scolicia de Quatrefages, 1849 and interpreted as a resting trace of the same tracemaker produced after moving up from a deeper position within the sediment. The resting is caused by an episode of unfavourable conditions related to shallowing of the redox boundary. The trace fossil is a component of the Nereites ichnofacies.