Hidrológiai Közlöny 1949 (29. évfolyam)

3-4. szám - Értekezések - T. SZALAI, D. Sc.: Origin and Heat Content of the „Juvenile" Constituents of Hungarian Thermal Waters

Na, aimionig anions a lower equimleint per centages of HC0

3 than in other springs. This would indieate, in his opinion, „that the thermal water of the Váiwliget hlas extracted somle of its öonstituemts noft fronn the dolomité but froim the underlying bedroek". Whiait has been said is supported alsó by tlhe í'a.ot that only part of ouir thermal water,s eontaiins these materials. Thus B

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3 is found in the GeLlért-Hill group of springs and in well No. I. of .the Városliget, but it is misisáng in isprirugs of the József-Hül and in the artesian well of the Szent Margit Islo (18. p. 29.). B»0

3 is alsó ifound in the Pestszenterzsébet bore (9. p. 243.) and din the aritesian well No. I. of Hajduszotbosziló. The largest rádium etmaniataon has been established im springs of the GellórtHill giroujp. Where water flowúng in channeils of the deep Karöt rock is not toucih with graniite in order to (be able tio leaeh out „juven'ile" comstituerits front same, thermal siprimgis do not contaán thiese materials. Ií .the presence of these constituente eouM be siaitüisfactorlily explained by the hitherto dáivulgiaifced theories all theinmal springs whould conffeain not too much differing per centagee of ttlbese miaterials. Probleims of the source of heat, of the heat content of thertnial waiters are closely oonneoted with what has been said above. The author will niot re peat here vartious tiheories thait toied to enMighten heat prdblem® of thermal wiajters. He telieves radio-aotive heat, heat generated by latomic fission to be the oause of the lower gaothermac gradient of the Hungárián plains, which iis from 16—20 m. (Elegius Schrnidt 8 a) and the average is about 18 m. (J. Sümeghy). The influence of the radiuim content of the earth's crust on its thermal state has already been pointed out by Longwell, Knopf and Flint (5. p. 278). The introduction of this paper has endcavored to outliine the fiaulted st.ructure of the CarpaAhiam Basin. The fanning out of Mesozoic geosy ncliines, sumken blocks of thermal water stoirinig riocks haive been mentűioned with gránité and other crysitalline masses wedged between theim. Where geothermic gradients much lower than normál are found it may be supposed that water ascends to the surface from the vicinity of gránité masses. Heat energy produced by atomic fission taking piaee in granites may be the eause of the excess of heat content producing substantial differences of geothermic gradient in comparison with the normál one. This surplus heat contenit influenoes the teimpeiriature of the entire síunken basin. Neither the „juvenile" oonstituents nor the siurplus of hefat content are connected with dehydration or with „juvenile" origüin. The/rmal water, or consideraible quantities of it need nőit be supposed to be produced by dehydration. Water of the deep Karst must be of meteoric onigln. If there is somé water produced by dehydration in it, whidh cannot be proved in any way, its part muisit be imsignificamt. Fluctuiaifciotnis in the discharge of thenmal sources imJay Ibe expiaiined according to Pálfy (6 a) by different quantities of rainfall, but there aire other factors infuencánig them such ias barom otric cpndíi/tions, ohanige of the water level of the Danube iin the oase of tlhe Buda spriings e. From wihat has been said :a considerable amiount or radio-active material has to be supposed in the deep of the Graat Hungárián Plain.

4 An exeetss of heat aomtent can originale ouly in itihűe way. Tlhe already mentáoned shelf, an indepcindcnit uniiit slnce the Paleozoic Age and exposed to great teobomAc strain, has faailitated the lascension of radio-activ imlatter along fault planes produced by teoto—genetic forces. Sümeghy (10. a.) has found ifche lowest geothermic gradieinitB along the Pécs-Kuniszenitmárton fracture Eme. Thás fault limte 1'uils lalliong the etrike of the Mecsek Miountains. In thiis fault beLt lie Biharnaigybajom and Kismarja where drillinge hit gneiss rock. Along friaictiure limes are looated, accordikig to Sümeghy (10. b.) tíhe riohest gias-wells of the Alföld. Their glases oontain, besides methanie, carboeic aoid as well. From the above two examples E. Schrnidt (8. p. 75) ooncJiudes that head drop through expanision of gtases has no practioal influence upon the geothermic gradient of the wells of the Alföld. On the otlher hand, gas exptan*sion oan substantiially decrease the tempenature of hot wells oontaining large quantities of highly soluble gas (e. g. C0

2) in soluiti/on. Natural gas and low goothormiic gradient are thus niot interlinked and where they occur together, as in the Alföld, it is to be supposed that heiat produced by atoimlic fissioii ascending lowers the geothermic gradient of strata- Such heat oaninot be attributed to mignation of hot vapors ascending from the depth, as it had been supposed as yet. At the niorth and the sonth and of the shelf conitainiinig the Hungárián Plaiin (Carelia and the Belgian Oongo) uraimum ore (pitchblende) ocours. In hiis study on the Nortih-eastern Oarpathiians (14) the author has pOinted ouit that sitruetural ehlanges due to contriaotiion are generaLly foillowed by tlie rovome prooess of dilatation. Durinig the procests of contrlaetion, the various shells of diilfifeiremt deinsity of the eartih's crust sbrinlk in a differfeint degree: the shrinikage of the outer sihell exerts a presisiure on the layer bellow. Breaks, cleaivageis are produced by reaction againist this mteiohianical strtaiin, Besides meohaniöail reaction the expanlsive force of heat produced by aitoimiic fisision may alsó play a part. In the Hungárián Basin pleistocene mioivements of the earth's crust, recent learthquakes (Szombathely, Mór, Kecskemét, Eger) show that n.o stabil equilibrium has been attained as yet. Gárdonyi (2. a.) woriked up recent 1. degree levelling data of tihe Hunugiarian Land Survey and coim/pani ng them with previous survey data, found that there is ia aero-line leading through: 4 In support of this hypothesis may be mentioned that T. Szelényi and G. Csajághy (Hélium content of natural gases in Hungary. Year-'book of the Geological Institute, XXXV. 4. 1941. Budapest) tested 15 gas wells of the Carpathian Basin and fonnd in them quantities of hélium amounting to ihundredths or thonsandths of per eent. As hélium is considered to be a product of splittling of radio-active matter of the earth, from its presance the exi-stence of radio-active materials in several parts of the Hungárián hasin may be concluded. A sample taken froan 820.5 m. of the Székesfehérvár hore showed 1.54% by volume, another sample of the surface 0.0120% only. Other wells oontaining appreoiable amounts of hélium are: Szent István Source of Széchenyi Bath, Budapest: 0.0267%, Edmond Well, Balatonfüred: 0.0137%, Ágnes Source, Moha: 0.0116% by volume. AU these oocurrences lie on the same tectonic beit. 76