Székessy V. szerk.: A Magyar Természettudományi Múzeum évkönyve 41. (Budapest 1948)

Szurovy, G.: Geological structure of the Southern part of the Great Hungarian Plain

9 small oil field of Bükkszék. In Transdanubia the Hungarian American Oil Industry Co. worked on the oil fields of Lispe, Lovászi and Hahót in the years 1937 to 1945 attaining a daily output of about 11.300 barrels of oil. It was evident that the search for hydrocarbons should be reassumed in the Great Plain too, in spite of the fact that the Hungarian Fisc had drilled their deep wells without any particular results. The work was started in 1940. The results obtained till the end of 1944 will be reviewed in brief in the following lines. The writer expresses his hopes that this work will not cease entirely after world war II but has only been post­poned, and that the further exploration of the Great Plain will be reassumed very soon. II. Former Assumptions as to the Geological Structure of the Great Plain. ,J. Böckh, the explorer of the oil field Egbell on the basis of salt dome examinations in Transylvania assumed that the salt for­mation must also exist in the Great Plain. He further assumed that this formation in the Great Plain is much folded and disturbed in its general development, and therefore offers a favourable founda­tion for the accumulation of hydrocarbons (1). Professor E. C h o 1 n o k y conceived the Great Plain to be a continuous basin the rims of which have sunk and form a large and steep block fault system. The well Budapest­Városliget 1. served as a foundation to his theory. About 3 kms East of the Danube, at a depth of about 3.200 ft, this well has struck the Trias dolomite strata which crop up on the right bank of the Danube. He further assumes that the Danube and the Tisza have taken their courses along great fault lines (2). Professor L. de Loczy j un. however, formulated the best theory. It is as follows: The Great Plain is a continous large basin. While in the Me­sosoic period, in Transdanubia and at the rim of the Great Plain, the Hungarian Central Mountains were formed (Bakony, Vértes, Pilis, Bükk, Mecsek and Villányi Mountains), the Great Plain was a continuous inland sea. The elevation of the Alföld began only after the Upper Cretaceous period This elevation must be considered as the result of epirogenic movements in the course of which the pretertiary fold- and thrust structures were succeeded by fault structures. At the beginning of the Eocene period the whole Plain was a continuous