Mesozoic
(245 to 66 million years ago)
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Mesozoic consists of Triassic, Jurassic and Cretaceous sediments.

During Mesozoic Medvednica was mostly covered with sea. Clastic sediments; sandstones and carbonate sediments that have many sea fossils (foraminifers, algae, conodonts ) deposited. I gneous rocks gabbro and diabase were found which indicates occurrences of underwater volcanic eruptions . Diabase used to be excavated in quarry in Gornja Bistra.

Part of rock gabbro

Triassic (245-208 million years ago) is represented in many carbonate sea sediments. The youngest sediments were formed in a part of somewhat deeper sea, and older sediments in warm and shallow sea of “ carbonate platform” type (mostly dolomites and limestone).

Quarries Podsusedsko Dolje and Ivanec are connected to these layers.

Dolomites in the northeast part of the Park are located in the area of Slani stream, in the southwest part of the Park in the area Dolje-Srednjak, and in the western part in the area north of Podsused between Zakičnica and Kameni svatovi (Stone wedding).

In Triassic micas-sandy shale , siltstones, and sandstones can be found.


Kameni svatovi (Stone wedding)

Jurassic (208-144 million years ago) has left few traces of carbonate fragments that are indicators of deep sea, and remains of igneous ultrabasic rocks from ocean floor (remains of volcanic activities) that emerge from Gornje Orešje to Puntijarka and Markov Travnik. It is also presumed that Jurassic limestone is present on a small area surrounding Horvat's steps.

During Jurassic first interstice shows up as a beginning of formation of Atlantic Ocean , and future Alps emerge from the sea in the form mountain massive.


Cretaceous (144-66 million years ago) is represented with thick, porcelain limestones which were formed in the deep sea. In older rocks of Medvednica Cretaceous period is marked by sea transgression, emerging of the land, existence of short-term swamps and intensive underwater basic magmatic .

The area of lower Orešje near Zelina is a famous finding place of fossils from Mesozoic, primarily Cretaceous 100 million years ago. In warm and shallow sea barrier coral reefs were formed . The most famous remains from Cretaceous are extinct bivalves, Rudists . They were horn shaped , and attached to the surface with one shell. The most famous genus is Hippurites . Snail genus Nerinea lived here as well.


Rudist Hippurites

Between the reef and the land there was a protected lagoon area where salt water and freshwater mixed because of inflowing rivers. Bivalves Inoceramus , snail Actaeonella and foraminifer genus Orbitoides lived here.

Shell Inoceramus

Toward the open sea, on the other side of the reef very small pelagic foraminifers Globotruncane and plankton foraminifers Globigerina lived. They can be seen when magnified on facets of plate limestone (walls of Medvedgrad).

Pelagic foraminifer Globotruncana

Plankton foraminifer Globigerina