Geology
Geology – in the unimaginable distant past, the largest rock masses that build Velebit were born, 310 million years ago.
Geology of the North Velebit National Park
Wild beauty of the kind you see only on Mt. Velebit, where the allure of high mountains meets the charm of the coast, mountain air meets sea air, heights meet depths, and are joined together in a unique blend.
Gizele Tarczay, PhD, Planinski vestnik, 1926
GEOLOGICAL HISTORY OF VELEBIT – geology
The story starts under the sea 310 million years ago. The largest rock masses Velebit is built of were formed unfathomably long ago, beginning with the formation of sandstones and shales in Carboniferous swamps, and continuing with the solidification of carbonate mud and the remains of sea organisms in shallow seas into limestones and dolomites.
Plate tectonics pushed Velebit on a geological journey of 6 000 km, from its birthplace at the 10th parallel south, to its present location. Tectonics started the folding and growth process of Mt. Velebit some 40 million years ago, pushing it to its current height of more than 1 700 m. Velebit continues to grow and battle the forces of nature: internal ones that are crushing it and breaking it apart, and external ones that are eroding it and carrying the pieces away.
SNAPSHOTS FROM GEOLOGICAL HISTORY
All entities move and nothing remains stil, Heraclitus
Tectonic plates are in constant motion, touching, colliding or spreading, breaking and cracking, with some parts uplifting, while some degrading, thus always forming new relief. Hills, valleys and wildlife what we see today, are just „current“ picture in an endless series of pictures which are constantly chaning from the beginning of a Planet till today.
Lands, oceans and wildlife through geological history
Rocks of the „Northern Velebit“ National Park – Geology
Area of the „Northern Velebit“ National Park is composed of sedimentary rocksa. Carbionate rocks prevails, mostly limestones, rarely and dolomites. Those rocks are formed by hardening of carbonate muds from Middle and Upper Triassic, Jurassic and Cretaceous. Clastic rocks, formed of particles and fragments of other rocks, are less common. Thios rocks are terrestrial origins, formed in Lower Triassic and Tertiary, while glacial deposits were formed in Quaternary.
Triassic – geology
Found in the Štirovača area, the oldest rocks within the Park were formed through three different sedimentary processes during the Triassic period (extending from about 235 to 201,3 million years ago). The first sedimentary process took place in the shallow sea, the second after withdrawal of the sea, and the third during a period when the sea of small depth, not deeper than 15 cm, flooded the entire area again.
Jurassic – geology
A large part of the Park lies on deposits formed during the Jurassic period (extending from 201,3 to 145 million years ago). It was a long and quiet period, some fifty million years of calm, shallow seas in which plant and animal communities of algae, gastropods, bivalves etc. flourished. During this period the largest carbonate rock masses in the Park were formed from these organisms.
In some other areas, however, this area is characterized by the presence of large dinosaurs, giant reptiles and other animals.
Cretaceous – geology
In the Park area, sediments formed during the Cretaceous period (extending from 145 to 66 million years ago) can only be found in the Rogić dolina locality. The shallow-sea environment of the Jurassic period continued, however, molluscs, especially bivalves of the rudist groups flourished during this era. Toward the end of the Cretaceous period, emersion occurred, and this is also when carbonate sedimentation in what is now the Velebit area ended.
That is when all terrestrial and sea dinosaurs became extinct.
Tertiary – geology
The broader Hajdučki kukovi and Rožanski kukovi area, as well as the coastal slopes, are made up of rocks known as Velebit breccia, which were formed in the period of intense plate movements. Velebit breccia are composed of fragments of older calcareous rocks (from the Jurassic, Cretaceous and Eocene periods), bound together by limestone material produced by the comminution and crushing of the same parent rocks. Their distinctive features include unsorted rock fragments and a somewhat chaotic structure. Made up mostly of carbonates and brecciated in structure, they are more susceptible to karstification processes, which ultimately results in remarkable relief features on the surface as well as under the ground.
Izvor: NP NORTHERN VELEBIT