Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 57. (Budapest 1965)

Csalogovits, I. J.: Geological and petrological conditions of the Szanda - Bercel area

Compared to the Salgótarján basin, freshening apperas here earlier and the lyditic gravel banks are the foreshadow of general Miocene freshening. The lower clayey levels are void of microfauna. In connection with the problem of Oligocene-Miocene transition, it may be mentioned that the Chattian and Lower Miocene (Becske) brackish-water formations occur in the same place as far as the area is concerned. But continuous transition is contradicted by the deposition of the Lower Miocene gravel layers on the Chattian denudation surface, and the bedding-angle deviation of identical extent and direction — as measured in various places — of the Chattian and Lower Miocene formations, which deviation allows of conclusions as to erosion angle-discordance. 2. Lower Miocene. Burdigalian-Helvetian stage. The Miocene sediments deposited on the Chattian erosion surface are described by NOSZKY,, Sr., as being of the Helvetian age. In his opinion, the coal of Becske is a lymnetic facies that belongs to the Helvetian stage, and the base of the Lower Tortonian andésite volcanism is formed by the Helvetian schliers deposited above the gravel layers. The lithological and granulometrical character of the "' Tym.panotonos margaritaceui" lyditic gravel banks of the Upper Chattian brackish-water formations shows a transition toward the Miocene brakish-fresh-water layers depositing above them. The classification of the highly worn lyditic gravel material indicates that the frequency maximum of the second granule size occurring in the Chattian gravel material shows a gradual increase toward the upper levels or toward the Miocene gravel layers Fig. 2.: Geological profiles of the Szanda-Bereel Area. Legends: 1. Pleistocene (Loess). 2. Burdigalian gra vel sand. 3. Chattian marine formation. 4. Andésite. 5. Hydrothermal dikes