Progress in Regional Geology

Abstract

AMONG recent publications in the Verhandlungen der k.k. geologischen Reichsanstalt for 1906, it is fair to note that Prof. Hörnes and Dr. Franz Heritsch have replied to Vice-director Vacak's onslaught, the tone of which we regreted in previous article. The stratigraphy of picturesque basin of Graz thus receives further explanation (p. 305). Herr Gejza v. Bukowski (ibid., pp. 337, 309, and 397) reports his work in the far south of Dalmatia. Among other points, he notes that the Eocene Flysch changes its lithological character according to that of the rocks on which it lies. Dr. E. Römer's discussion of what he styles “fossil dunes” (ibid., 1907, p. 48) has a wide interest for students of the great European lowlands. The author urges that the post-Glacial valleys, which are cut in the deposits left on the withdrawal of the ice, have exercised a controlling action on the formation and origin of the dunes. Evidences of formerly prevailing east winds, and, later, of our present westerly winds, are clear to him, as to previous observers; but he connects the direction of the dunes with that of the river-valleys, into which the winds blew at right angles to the valley-sides. His studies in Galicia, round the head-waters of the Vistula and the Bug, assure him that the typical barchan, the dune with concave front and outstretched wings, is a phenomenon of deserts, and is constantly in a state of change. The European dune, now often surrounded with peat and itself grown over, is a stable product connected with a climate of steppes, not deserts. Dr. Römer (p. 53) observes how Neolithic settlements were established in the shelter of the dunes, indicating a wetter climate, following on that of the east winds and the steppes. Then a return of the steppe-climate led to the Tormation of sandbanks over the hearths and dwelling-places; and, finally, our present moister climate has restored the boglands and promoted the growth of trees. Anyone who has seen the winds in Poland laying bare the roots on the outskirts of a clump of pines will realise how easily the present balance may be disturbed, and how a slight meteorological change may allow the dunes again to grow.