Lineamenti geologici del Friuli
1989; eScholarship Publishing, University of California; Volume: 13; Linguagem: Italiano
10.21426/b613110240
ISSN1594-7629
Autores Tópico(s)Karst Systems and Hydrogeology
ResumoEIOGEOGRAPHIA — vol. XIII - 1987 Bfogeografia delle Alpi Sud—OrientaIi Lineamenti geologici del Friuli GIOVANNI BATTISTA CARULLI Istimto dzq Geologzkz e Pczleoiztologzkz, U/zz'versz'td dz’ Trzerte SUMMARY The lithologic differences are underlined, outlining the stratigraphic and structural features of the “Carnia—Friuliq area understood as the eastern sector of the Southern Alps. A powerful sedimentary cover, often more than 15,000 metres thick, is visible in this area, made up of an almost continuous succession of rocks ranging from the Paleozoic to the Present age, which bears witness to 450 million years of geologic history. The distribution of the rocks, mainly stretching in longitudinal strips, is such to enable the ob- servation of the following orographic-geologic zones, moving North to South and West to East: — the Paleocarnic Range, characterized by palaeozoic rocks, namely reef limestones outcropping from a wide-spreacling cover of argillites and Carboniferous siltites lying under a layer of red Permian sandstones; — the Southern Carnic Alps where, on a sole of Permian rocks in various facies, lie the predominant Middle-Triassic reef limestone and the coeval basin marls which, to the South, are followed by a variety of Carnic lithologies in a complex heteropy; - the Julian Alps, characterized by the frequent presence of late Triassic dolomites; — the Carnic Pre-Alps, with a marked development of Triassic dolomites and Giurassic and Cretacic limestones, side, to side with the Cenozoic marls and sandstones of the piedmont reliefs; — the Julian Pre-Alps, with analogous lithologies but showing a greater presence of marls and sand- stones in the vast outcrops of eocenic flysch of the Friuli eastern hills; — the rnorainic amphitheater, Wurmiaii evidence of the extended Tagliamento glacier; -— the Friuli plain, gravelly in its northern part and sandy—muddy to the South, stetching from the “springs line” to the coastal line. CONSIDERAZIONI GENERALI In Friuli, specie nella porzione rnontana, sono presenti in affiorarnento rocce rappresentative di un’enorrne successione stratigrafica che Va dall’Era Paleozoica a quella Cenozoica. Se si considerano poi i depositi quaternari intravallivi antichi e recenti nonche quelli della pianura friulana si puo affer- mare che nei Friuli sono presenti le testirnonianze pressoche continue di eventi geologici verificatisi dall’Ordoviciano superiore fino ad oggi, nell’arco cioe_ di oltre 450 milioni di anni. ‘ E questo_ fattore tempo, parametro determinante nella Geologia, che ci porta ad inquadrare gli eventi passati in un difficile spazio a quattro dimen- sioni nel quale l’uomo e protagonista e testirnone istantaneo di una lentissirna evoluzione della tetra, tuttora in atto e continua nel futuro, dalla dinamica costante nei suoi grandi tratti sia come modalita sia come intensita.
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