Wireline logs from various wells in the Vienna basin which drilled in the subsurface Triassic strata of the Northern Calcareous Alps have been analyzed. The logging tool combination of the different wells consists of either density,
neutron or sonic, gamma ray or resistivity logs. The results of the investigations are: (1) The Upper Triassic strata Hauptdolomit and Plattenkalk can be differentiated by their log reaction. In the Lower Hauptdolomit characteristic
evaporite marker horizons have been discerned which can be correlated over long distances. (2) Radioactive heavy minerals (zircon, rutile) and phosphates cause gamma ray anomalies. (3) The Hauptdolomit has a matrix density of 2.85 g/cm"3 and a matrix neutron porosity of 1.0%. (4) The Hauptdolomit contains muscowite, biotite, glauconite, kaolinite and chlorite; their neutron porosity amounts to 25-30%, their resistivity to 5m. (5) Grain-support fabric of the Hauptdolomit-Plattenkalk sequence is esteemed as good reservoir facies for hydrocarbons. (6) The Hauptdolomit has a porosity up to 10% and retains it in depths of 5000-6000 m better than limestones. (7) Triassic carbonates consist of calcite, dolomite, quartz, anhydrite, pyrite and limonite. (8) The Triassic sequence can be
attributed to standard facies zones 4 to 9 of the WILSON model. (9) Resistivity of formation water and concentration of ions drawn as isomaps show the main structural trends of the basin subsurface.
(Author, shortened by G.Q.).