The Polish Carpathian oil fields are located in the formations of the Flysch facies, ranging in age from Lower Cretaceous to lower Miocene.

Oil is concentrated in two distinct tectonic zones. (1) In the Marginal zone--particularly in the deepest element of that zone--directly overthrust onto the foreland, are the large fields of Boryslaw-Tustanowice-Mraznica, Rypne, and Bitkow. On that deep element is overthrown a folded and faulted mass which contains oil, as at Schodnica. The width of the overthrust exceeds 7 miles. (2) In the Central depression--more particularly in the vicinity of Krosno--many fields, generally of minor importance, are related to anticlines; for example, Wankowa, Krosno, Rowne-Rogi, Harklowa, and Lipinki. The main oil horizons are Eocene and Oligocene in age.

Because of the overthrusts, the problem of the origin and of the migration of oil in the Carpathians is particularly difficult to solve. The main fields of the Marginal zone correspond with the uplifts of the substratum, but they do not coincide everywhere with the uplifts of the overthrusts; hence, there is some discrepancy between the surface structure and the location of the oil fields.