hrvatski

Sedimenti u podmorju Kvarnera

U radu je prikazana karta sedimenata morskog dna u podrucju Kvarnera (kanalsko podrucje sjeverernog Jadrana). Izvorna karta napravljena je mjerilu 1:250.000. Sedimenti su klasificirani prema standardno prihvacenoj klasifikaciji u marinskoj geološkoj kartografiji. U najvecem dijelu podmorja Kvarnera prevladavaju pjeskoviti muljevi (sM), u kojima se povremeno nalaze zone šljunkovitih muljeva (gM). Mulj (M) se nalazi u Rijeckom zaljevu, sjevernom dijelu Kvarnera, Kvarnericu i Vinodolskom i Velebitskom kanalu. Pretežno pjeskoviti sedimenti odnosno muljeviti pijesci (mS) nalaze se zapadno od Cresa i Lošinja, jugozapadno od Raba, te u Paškom i Velebitskom kanalu. Sitnozrnati mulj je recentnog postanka. Izvori sitnoznatih cestica su stalni i povremeni vodotoci, izravno spiranje naslaga a vjerojatno i vrulje uz obalu. Šira podrucja kamenog dna, kao i onog pokrivenog šljunkom i grubim pjeskom nalaze se na morskom dnu u dosegu erozijskog djelovanja valova. Krupnozrnati sedimenti mogu biti litogenog i/ili biogenog podrijetla. Zbog vrlo nagle gornjovirmsko-holocenska transgresije, kada je morska razina podignuta više od 100 m, rezidualne pjeskovite sedimente nalazimo i ispod današnje valne baze. Zato je raspored sedimenata u podrucju Kvarnera samo djelomicno u skladu s današnjim hidrodinamickim prilikama. ABSTRACT: The map of seabottom sediments in the Kvarner area (channel part of the Northern Adriatic Sea), is presented in this paper. Original map was made in scale 1:250.000. The sediments were classified according to standard classification in marine geologic cartography. On the larger part of the Kvarner area at the bottom sandy muds prevail (sM) with subordinate presence of gravelly mud (gM). Mud (M) is found at the bottom in the Rijeka Bay, northern part of the Kvarner Bay, in Kvarneric, and in Vinodol and Velebit Channels. Prevalently sandy sediments, i.e. muddy sands (mS) are found west of the Cres - Lošinj archipelago towards the open part of the Adriatic Sea, southwest of the Rab Island, in Pag Channel and Velebit Channel. The fine grained particles have recent origin. Sources of these particles are local permanent and temporary streams and direct input from the weathering processes, along with the input by submarine springs (vrulje) near the coast. The large areas of the rocky bottom not covered with sediments, or covered with gravelly and sandy sediments are found above the wave base. Coarse grained particles are of terrigenous and/or biogenic origin. Due to the very rapid Latewürmian-Holocene transgression, during which the sealevel has been raised for more than hundred metres, residual sandy sediments are found also below the recent wave base. Therefore the sediment pattern found in the Kvarner area is only partly in accordance with modern hydrodynamic conditions.

pleistocen; holocen; morska razina; morsko dno; Kvarner; Jadransko more

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