1 Pol ish Geo log i cal In sti tute -Na tional Re search In sti tute, Rakowiecka 4, 00-975 Warszawa, Po land 2 Na tional Acad emy of Sci ences of Ukraine, In sti tute of Ge ol ogy and Geo chem is try of Com bus ti ble Ma te ri als, Naukova 3a, Lviv 79060, Ukraine Ac cord ing to com mon in ter pre ta tions, two nar row crustal blocks are sup posed to oc cur on the south west ern edge or in the fore land of the East Eu ro pean Craton. The first one, bounded to the NE by the Nowe Miasto-Radom-Rava Ruska fault system, and to the SW by the Holy Cross Fault (£ysogóry-Rava Ruska Block), stretches NW-SE from the £ysogóry-Radom region in Po land to the Rava Ruska Unit in Ukraine. The sec ond one, bounded to the NE by the Holy Cross Fault, and to the SW by the Chmielnik-Ryszkowa Wola-Krakovets fault zone (Kielce-Kokhanivka Block), is thought to tie to gether the Kielce area of the Holy Cross re gion with the Kokhanivka Unit in Ukraine. Both these blocks may have formed in con nec tion with the de vel op ment of re gional listric faults dur ing Pre cam brian asym met ric stretch ing of the Baltica con ti nent, and were part of the mar ginal zone of the East Eu ro pean Craton. The sed i men tary de vel op ment of the blocks may be com pa ra ble to that of the Blake Pla teau off the Florida coast. Both the Pa leo zoic sec tions and tec tonic de for ma tion styles in the Pol ish and Ukrai nian seg ments of these blocks are dif fer ent. Pa leo zoic tec tonic struc tures of the Holy Cross re gion, and in par tic u lar its part compris ing the £ysogóry Re gion, have a south ern vergence, while the Pa leo zoic rocks of the Rava Ruska and Kokhanivka units in west ern Ukraine are thrust along flat thrust sur faces to wards the NE. This dem on strates the dif fer ent tec tonic evo lu tion of the Pa leo zoic suc ces sion be tween the Holy Cross re gion and west ern Ukraine, and makes ques tion able the ge netic re la tionships be tween these two re gions. In this sit u a tion, the tec tonic blocks of the fore land should be con sid ered het er o ge neous. On the other hand, these dif fer ences can in di cate a dif fer ent mech a nism of tec tonic de for ma tion dur ing Variscan move ments in both these ar eas, in duced by the same sub-me rid i o nal com pres sion of the north ward-thrust ing Variscan orogen of Europe. Struc tural-fa cies ev i dence sug gests that the SW bound ary of the East Eu ro pean Craton should be moved at least to the Chmielnik-Ryszkowa Wola-Krakovets fault zone.