Hidrológiai Közlöny 1952 (32. évfolyam)

1-2. szám - Kivonatok

80 Kivonatok Geomorphological studies in the Rába-valley By Dr. Alexander Láng (Hungárián teit 1950. N° 7—8 and 11—12 p. 267 and 465). U. D. C. 551.434 + 551.436(282.243.734). The results achieved by the author during his investigations in the Rába-valley are the following : 1. The Rába-valley has three great geomorphological landscape units. a) The East-Styrian basin and the Western-Hungarian hill-country, where a strongly articulated hill area stretches between regularly developed terraced valleys. b) On the central section of the Rába river we find the little depression of Vas county between the towns of Körmend, Szombathely and Sárvár, where great accumulation has not taken place yet, but significant erosion; therefore on the right bank of the river, where there has been no sinking, the weak terrace developing activity could proceed. That part of the engulfment of the fan in Vas county, which lies between Körmend, Szombathely and Sárvár and which rest with its hypothenuse on the Rába valley, does not give the impression, on the basis of deep-borings, as if it were a greater depression of a pleistocene or holocene origin. In a deptli relatively not Iarge, beyond 10—15—20 m. there, follow everywhere loamy-sandy strata of the upper pliocen»l, thatare sometimes lignitie, which means, that the normál stratigraphic accumulation corresponding to the pliocene terraces could not develop here as yet; in this region, semeingly denudation and accumulation of the pleistocene period had been in balance and so there can be found much sediment. We suppose, that, after the denudation, which lasted till the middle pleistocene, there came invading the fans from NW the and brought with them pleistocene brown gravels. c) From the engulfment of the fan there emerge with steep slopes to the W and NW (probably smaller fault) the great extending plateaus of western Vas county, the material of which are red gravels of the upper pliocene and lower pleistocene and which are slightly tilted. This is the levél of the older ferrous (ferretto) gravel-sheets. For the presence of the middle (III.) and upper (II.) pleistocene terraces on the right bank of the Répce and Ikva rivers, namely, these rivers must have Iayn from the middle pleistocene on tlieir present place. d) The sheet of old quarzic ferretto surfaces continues in the Kemeneshát ridge. This rangé is a denuded remainder of a past plestocene fan, did not sink and has not been denuded and, though it behaves like a block, it declines successively to the N into the level of the accumulated Little Alföld (Plain). Somé parts of it separated themselves, for instance to the S. and E of the Sárviz river, and indured larger or smaller tilting or doming up ; perhaps the two kinds of tectonic movements combined to produce them (for example the parts of plateaus at Bejegyertyános, Vönöck and Ostffyasszonyfa). 2. On the part of the valley lying in hill-country, in the basin of Graz and alsó in western Hungary the Rába valley terraces developed with the same number, succession and relatíve altitude, as on the mountainecus and lully sections of the rivers of the Carpatian basin studied by Hungárián geographers. Accordingly, we find terrace I. (alluvi-i) with 1—3 m., the upper pleistocene terrace of 3—5 m., terrace III. (middle pleistocene) of 10—20 m., terrace IV. (lower pleistocene) of 25—35 m., terrace V. of the beginnig of the pleistocene with 45—60 m., terrace VI. of 80—90 m., and terrace VII. (upper pliocene) of 100—120 m. and, in the end, tjie older pliocene gravel-sheets on the Ezüsthegy-Katalinhegy of 150—180 m. (upper pliocene). 3. The smouldering together of the older terraces (V.-VII.) and their lowering is taking place on the right bank, on the section between Körmend and Sárvár, as was mentioned on the section between Körmend and Vasvár, as was mentioned already by Winkler. 4. The younger terraces II.-IV. of the right bank are more underdeveloped and disappear separately in the normál stratigrafic accumulation of the Little Alföld (Plain). To separate them downwards of Vasvár is quite difficult a problem as morphologically as petrografically. Below Sárvár they completely vanish, terrace nr. H. remaining only. 5. The old gravel-sheet, förmed of the Rába river terraces on the right bank, wears most decidedly all the marks of blockwise behaviour in direction to the Zala and Marcal river valleys. (Velence, Lak, Mountains of Baltavár and Győrvár). In between there sank somé basins (e. g. at Pácsony). We do not know well as yet the transition of the Kemeneshát ridge in direction to the Zala valley and so the problem of the Zala-Marcal river capture could not be wholly solved till the present. 6. The terrace system on the left bank of the Rába is identical to that on the right one. The lowering of the individual terraces and the approaching each otlier of the older ones — V. and VI. — can here alsó be observed. However, beyond the mouth of the Strém rivulet, terrace III. of the Rába did not develop because of the widening of the low fan engulfment. 7. The Rába terraces on the right bank below Ivánc have a remarkable, uniform decrease in height of the order of 10 m. ; here, probably, the eastern region had to endure a tectonic jolt before the accumulation of terrace III. 8. The levantian — pliocene terrace-system of the Rába river corresponds to that of the Vienna basin, describcd by Austrian geographers. Winkler, therefore, erroneously identified the terraces of the Rába river with those to be found around Vienna. . »HIDROLÓGIAI KÖZLÖNY« Felelős szerkesztő: Kovács György. Felelős kiadó: Solt Sándor. Kiadóhivatal, előfizetés : Nehézipari Könyv- és Folyóiratkiadő Vállalat. Budapest V, Alkotmány-utca 16. I. cm. Távbeszélő: 123-614, 123-369 Egyszámlaszám: 936.652 — 47. Akadémiai nyomda, Gerlóczy-utca 2. 16659/1952 — Készült 800 példányban. — Felelős vezető: ifj. Puskás Ferenc