The Budaörs-1 well revisited: contributions to the Triassic stratigraphy, sedimentology, and magmatism of the southwestern part of the Buda Hills

Abstract

The 1,200-m-deep Budaors-1 borehole provided important data for our understanding of the stratigraphy and tectonic setting of the southern part of the Buda Hills. Although previous reports contained valid observations and interpretations, a number of open questions remained. The importance of this borehole and the unsolved problems motivated us to revisit the archived core. The new studies confirmed the existing stratigraphic assignment for the upper dolomite unit (Budaors Dolomite Formation) as the dasycladalean alga flora proved its late Anisian to Ladinian age assignment. An andesite dike was intersected within the Budaors Dolomite. U–Pb age determination performed on zircon crystals revealed a Carnian age (~233 Ma), and settled the long-lasting dispute on the age of this dike, proving the existence of a Carnian volcanic activity in this area after the deposition of the Budaors Dolomite. Palynostratigraphic studies provided evidence for a late Carnian to early Norian age of the upper part of the lower ...