APPLICATION OF STRUCTURAL SUCCESSION TO CHARACTERIZATION OF THE BOHEMIAN FOREST TECTONIC DOMAIN AND ELUCIDATION OF GEOLOGICAL HISTORY IN THE CENTRAL-EUROPEAN HERCYNIDES, WESTERN CZECH-REPUBLIC

The successions of observed structural. features in (i) the Domahlice crystalline complex, (ii) the adjacent (Upper Proterozoic) gneisses an d (iii) the Moldanubian assemblage of the Cesky les (Bohemian Forest) Mountains correspond and can be integrated into a regionally-expressed deformational sequence. This sequence characterizes the Bohemian Fore st tectonic domain in the Central European Hercynides of western Bohem ia and both its structural ''fingerprint'' and geological evolution di ffer from those of both the adjacent Marianske Lazne and the southern Fichtelgebirge tectonic domains. The repetition of recumbent followed by upright structures is interpreted as the result of a multi-orogenic history as is the repetition of crustal heating associated with horiz ontal tectonism. Juxtaposition of the Moldanubian and the Upper Proter ozoic gneiss assemblages with the Domahlice (Tepla - Barrandian) compl ex took place before the formation of the first recognized folds (two sets of intrafolial folds), the associated schistosities and regionall y-expressed medium-pressure Barrovian-type metamorphism, all of which are considered to represent activity during early phases of the Cadomi an episode. There were two further phases of fold formation prior to e arly Carboniferous horizontal tectonism that led to the development of a Hercynian nappe pile and another phase of medium-pressure metamorph ism. This metamorphism was expressed as a Barrovian-type zonal pattern in the cover rocks of the southern Fichtelgebirge domain in the Saxot huringian zone whereas in the previously metamorphosed rocks of the Bo hemian Forest domain it resulted in mimetic recrystallization associat ed with foliation transposition. There, in the basement, the earlier-f ormed isograds and zones remained extant but there were local reversal s in the order of zones caused by continued horizontal tectonism. A su bsequent change from recumbent to upright structures together with a l ow-pressure thermal overprint and the emplacement of granitic masses i n late Carboniferous times are linked to collision, locking, uplift an d transcurrent movements in the later stages of the Hercynian orogenic episode. The large body of new data relating to observed structures a nd the evidence for successive development of structures not only perm its the characterization of the Bohemian Forest tectonic domain and th e elucidation of its geological history, but also forms a basis for (1 ) correlation with, and discrimination from, other tectonic domains, ( 2) understanding the observed polymetamorphic mineral growths and patt ern of metamorphic isograds, (3) interpreting isotopic data that refle ct multi-episodic disturbance and (4) placing constraints on regional interpretations of Hercynian tectonism. It represents a reference comp ilation for future studies of structural stratigraphy and metamorphic mineralogy, with the integration of local structural successions into a domain-wide deformational sequence being comparable to the integrati on of local stratigraphical successions into a regionally applicable s tratigraphy that is an essential prerequisite to stratigraphical corre lation.