Скачать или смотреть Rovinj - bauxite

Investigation of the regional unconformity between the Lowermost Kimmeridgian and the Upper Tithonian in Istria (Croatia).
The aim of the project West Istrian Anticline as an ideal natural laboratory for the study of regional unconformities in carbonate rocks - WIANLab is to study palaeosols related to the four regional unconformities in the shallow marine carbonate successions within the West Istrian Anticline as indicators of palaeoenvironment, palaeoclimate and provenance. The oldest regional unconformity between the Lowermost Kimmeridgian and the Upper Tithonian is accompanied by bauxites. During our field campaign we investigated the Rovinj 1 bauxite pit. Fieldwork at this site involved sampling the bauxite and its hanging wall, which consists of a cyclic alternation of greenish-grey palaeosols, limestones, brecciated regolith and sporadic occurrences of black pebble breccia. The main profile was selected in the thickest exposed section of the pit, where it was sampled using alpine climbing techniques. In the 2 m section above the bauxite, samples were taken every 10 cm from the hanging limestones. The bauxite was sampled at least every 0.5 m, with additional samples taken as needed. The bauxites observed were clastic (fine- to coarse-grained) and pelitomorphic in texture and white, grey and red in colour. Numerous analyses and studies are being carried out on the greenish-grey palaeosols and sediments from the hanging wall of the unconformity and the bauxites, such as SEM, ICP-MS, XRD, micromorphological studies, U-Pb zircon dating, δ34S and heavy and light mineral analysis.