Sedimentary bodies, forms and occurrences in the Tudorevo and Mirovo glacial deposits of northern Velebit (Croatia)

Abstract

A small glacier of cirque-valley type existed during the Late Pleistocene Würm Glacial in the Tudorevo and Mirovo karst valleys of Northern Velebit. Its source was in Tudorevo, and it moved through Dundović Mirovo and Bilensko Mirovo to Baričević Dolac, shaping U-valleys around 4 km in length. After melting, glacial deposits remained, composed of chaotic and unsorted till, composed of carbonate sand, debris and sub-rounded clasts, cobbles and blocks of predominantly Middle Jurassic and subordinately Lower Jurassic carbonate rocks. In Dundović Mirovo and Bilensko Mirovo, where the largest masses of glacial deposits occur, terminal and recessional moraines can be found over the ground moraine, as well as some other features, mostly drumlins (drumlin field), eskers, erratic blocks, kettle holes and striations. Some erratics have been transported for more than 4 km from their primary outcrops, e.g. clasts of Lower Jurassic Toarcian Spotty limestone. A terminal moraine was deposited between Bilensko Mirovo and Baričević Dolac, perpendicular to the glaciated U-valley and it forms the Bilo hill, the northern and southern foothills of which are composed partly of glaciofluvial deposits. Between Tudorevo and Mirovo, a recessional moraine occurs above the ground moraine. The glacier was subject to polyphase melting and freezing, and the youngest freezing events may be related to cirques in Tudorevo. During melting events, glacier lakes are supposed to have existed, initially in the Baričević Dolac, later in Mirovo area and finally in Tudorevo. These discharged into the karst underground by percolation through till and by erosion to the karstified underlying Middle Jurassic carbonates.

Keywords

• Tudorevo–Mirovo glacier, till, moraines, drumlins, esker, kettle holes, erratics, glaciolacustrine deposits, glaciofluvial deposits, Late Pleistocene, Northern Velebit, Croatia