526 NORTHERN DETRITUS BORNE INTO BAYS OF SOUTHERN CONTINENTS. 
in great abundance at Gleinitz 1 , where they are extended from the chief boulder 
country north of Breslau, in a long trainee between the chain of Silesian crystalline 
rocks on the west and the hilly districts of Poland on the east . On inspecting the 
Map, the reader will perceive, that a considerable portion of southern Poland, par- 
ticularly all that tract of palaeozoic rocks of which Kielce is the centre, is thus 
peninsulated, like the dome of Orel in Russia, between two advanced lines of 
boulders, none of which have been distributed in the intervening higher space'. 
Now, if, as w r e believe, it is impossible to imagine, that the detritus in question 
should have been carried across the Baltic Sea, and from the level of that sea several 
hundred miles up these streams, under any conceivable terrestrial conditions, it 
follows from this consideration alone, that all theories to account for the movement 
of such bodies over the dry surface of the earth are inadmissible. The hypothesis of 
glaciers advancing up-hill for the distance of 700 or 800 miles involve in fact 
a physical absurdity. 
But if the spread of the northern detritus have no reference to terrestrial condi- 
tions, how is it, an opponent may say, that the valleys of the Don, the Vistula and 
the Oder are strewed over with it, whilst interjacent eminences are excluded? We 
reply, that a submerged condition of Russia, Poland and Prussia at the period of 
the distribution of the northern blocks being granted, there is no difficulty in sup- 
posing, that the configuration of the bottom of the waters was to a great extent 
the same as that of the present continent. In fact, we can scarcely doubt that it 
must have been so, because we have numberless proofs that the substrata were 
heaved up without any great ruptures, and must have been raised “ en masse.” 
We therefore conceive, that when submerged, the valleys of the Oder, the Vistula 
and the Don were marine bays or fiords, into which currents flowed from the north, 
and that the higher grounds, devoid of blocks, were then low promontories, ex- 
tending from the main land on the south, or isles adjacent to it. If, indeed, the 
larger blocks were for the most part transported upon floating icebergs, we can 
1 At Gleinitz, and between that town and Oppeln, the rounded boulders are not so abundant in the low- 
parts of the valley of the Oder as on hillocks of sand and gravel. The red porphyries of Sweden are 
there intermixed with northern granite, gneiss and greenstone. 
5 In a report to the Academy of Sciences of Paris (January 1842) on a memoir of M. Durocher, M. 
Elie de Beaumont has noticed certain relations between the distribution of the eiratic blocks, and the 
forms of the countries which they have invaded. We take this opportunity of specially recommending to 
the notice of our readers that report, in which M. Elie de Beaumont has thrown together, with great 
ability, a number of facts relating to the erratic phenomena of northern Europe. 
