This study focuses on the description and interpretation of the origin of dolocretes and their siliciclastic host rocks in the upper part of the Amata Formation (Fm) in four exposures in Latvia. The dolocretes occur in at least four intervals. The composition and structure, as well as stable oxygen and carbon isotope data of the two upper dolocrete intervals, suggest that they developed in soils. The dolocretes correspond to an episode of climate change from warm, moist to drier and hotter conditions, which started in the Late Givetian and continued to the EarlyâMiddle Frasnian. They formed during a short-lived sea-level fall, which took place after a longer sea-level rise trend. The diversity of vertebrate fossils decreases from the lower to the upper part of the Amata Fm, which is consistent with the sea-level fall and gradual climate change marked by the studied dolocretes in the upper part of the Amata Fm.
Stinkulis et al. (Mon,) studied this question.