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

tic water is (ganerally brokon up in blooks and can forin uniform watar lavel only within smaller uniits. Althiouglh faultod structure inifluiemoas the wator level of itihe deep Karst as welil the latter •may fonm a uniform wiater horizon. The peouliar phenomianon that the cheiruioal anialysis of Tnilaisiaic waters 'is fairly oonstant whiile that of the íresenvoir roclke iw variable, is attrdbuted by Szádeczky (12 p. 81.) to oo miaumoaition and the miixture of watérs of the different regions. It is evien supposialble that sediiimiants of the Mesoaoic goosync lines may be traoed up to the Alpine régióin (on basiis of researctbeis of R. Vajk (15) this is at least possible for the Bakony sytncline) iaiid in this oase the water leivel of seviaml pánt geosynclinos may coniiriunicate. Thus ain emtire subtaiTaneous river systam may be located in the depth thougih the .rate of its flow may be very slow. It ás unquestionajble that tliie uppeir Karatic water resiults from raánfall. For the of the deep Karwt wateir thfe is more diflficult to deoide. The problem is whetiher this amoun/t of water has accuimulated in the course of g'eologioal times. It is unquestkmablie that the watar of the deep Kansit is alsó >stored by the linfiiktration of pretíipitiationis. Nolbody doniles fflny long'er the major part of water ari-ives in tlhat way to the depth. In recerut litcirature, howevar, statamen,ts have appaared aceording' to whieh parit of the water, thougih not of juvenile origiin, doasi niot onigúnate from ámfiltration of raiinfall, but is due to tlie d eb yd rajt ion oif rooks sufnik into the depth (Horusitzky [4]). The authoir does nőit deny in generál the impoirtanoe of dehydration but thinlks u mimpor,tanít its part in tihe heat oontent and „juvenile" constituenits of ou.r thermal spránigs. This aliso refers to artesian wells of the Great Pláne. Szádeczky forms the «iim<: opinion with regard Karstic waters (12., p. 83). According 'to Haug and Van Hise the litosphare imay have open clefts down to 12 km. depth. Adams proved experimentiailly, Ring by tbeoretieal oalculatiions that srnall claavagiee may be open din 18 km. depth as well. Gauticr (2. p. 332.) found that hifi I trated waiter evaporates fnoim gwanite and porphyry at 150— 200° C. but oonnate water is only liberated by beating

1 im vacuum at 450—500° C. Suppoaing a nonmial geothermic giradienit, inifliltrated water wouild part at 5000 m. and connate water at 17.000 m. depth if a much greater depth were not to be assumed due to miueh gireater pressure. On hasis of these caleulations it is ito be smpposed that, wharie dehydration of rookis took place in depths íbelow ithia lower ILmiit of the systems of open eLoavagie, the water iilhenatod oould not ascend for warit of oonduits of asoansiom. 0>n basiis of these oalculations and the mentioned liypo'theisis, reductioin of coninate water oan take plaoe in depths below 17.000 m. only; tlherefore water due to dehydration oan hardly be reckoned with. It is not reasonable to lay to much itress •on dahydnation phenomona neither from the poinit of view of heat content nor of „juvenile" oon.stiitueffite, not even if suoh phenomenia oocur where eleaviag'es are sitiill possiible. Even in gireat •depths thietre are impermeable layers, faotora pröventiing- propagation of gasee and vapors. Suoh opposiing faotors gtaAn ámportaince with incréasing' depth. Only a smiaJl part of watar and heat oan creaeh upper stnata through cleavag'es if «uch exist. The ftiemperature of natural sprinigs ás lower than of walls driilled close to them, even if the wells have small depth, showing that heat losises imay be ooiusiideriable within short distanees. The Attila well of 36.8 m. depth of the Rudas Bath :iin Budapest has a temperature of 46.7—47° C. The lowest teimpenature of niatural spnings within that zlone is 35° C. Another exaauple is the well of 200 m. of the Szent Imire Bath, the temfperature of whioh is 50° C. Tlhe (natural) Máityás Spring of the same region has tem,paiiaituires from 36.3— 41.4° C. Hiigiheisit tempenatums are alsó represented by d.rilled wells: in Budapest Városliget the 870.48 :m. deep well has tömperatures of 73.4— 73.8° C., the 1257.10 m. deep well a temipariature of 77° C. These examples show that water etvenitually developed through dehydration, in íite asoeusiion, muist lo-se much of áits haat and of its quantity as well. The explianation tíliat „huge quantities of wateir feed our spiűng-s and wells, of wiater whieh áis nőit of direct metaoric origin" (12. p. 77.) is questtiomalble, all the more if lit is consi dered that the Budapest hot spriaigs have flown to the eurfaoe sinee Meditenranean times (Schréter 10.). If ithe above explanation could be aocepted, the yield of the hot. spriirugis would íhe liimited, as oil and natural gtas reserves are; but thare is no indioation whatever of tliis. If itihe above explanation is not aooepted, the question remiains open as to tlie oriigin of „juvenile" oonsitituents, of radio-aotive oompounds, of boriic, hydrofluoric aoid, and of the heat oonitant of the holt sprin®s litself, and of the way these eniter into thermal water. Under the leadership of the author the Hungárián Geologiiciail Institute was prospecting for raidio-aotive imiaterials in 1947. Althoiugh these prospeetions punsued praotioal aims they yiielded buit saientiflie nesults. Prospectons equipped with Geigcr—Müller oouniter tuibes found in the granites of tlie Velenoe-Mountainis and of the MeosekMoiuntaiins (Ráomecsike) emaniations oormsipoiiding to thrae tiimies ithe normál. Prof. Sándor Szálay of Debrecen found 6—7.3 g. t. uránium and 40—73 gr. thoirium in that roek. Fluor-spar wias found by Vendl (16) and lator by Földvári in that area. Bonic aoid is alsó often regarded as juvenile oonstituent: lacoording to Longwell, Knopf, Flint (5. p. 283.) this oompound .indicates the magmatic origin of Water. Vendl (17. p. 11.) shares this oplinion, but Goldschmidt and Peters (3. p. 403.) found tin 14 Gerimian girainlites average contents of 0-001% B

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3. The same refers to baryte and to rare constituenits. Of course, there are ao,nstituents wíhich were origiinally juvenile but now these oonstituents are leached by seepiing water froim rooks. From, all this the conclusion may be drawn that the origin of radio-active materials and other juvenile" constituents of thermal water can be explained in the simplest manner by supposing them to hawe bcen leached by waters of the deep Karst from gránité rocks, wedged between former geosynclines. Suoh waters miay even desoend into the ginanite or orystalline bedrock and perform there their dissolváng- action. Aooording- to Weszclszky (18. p. 30.) rádium emaniaition is most prolbably due to rocks underlyirifí the dolorniite. Vendl (17. p. 21.) Was surprised to find in the two deepest and hotteist wells of Budapest (Városliget) among' oationis lower equivalont per centagcs of Mg. and higiher equiivalent per ceutages of 75