Góra Zamkowa – reserve
The quarry is located in the western part of Góra Zamkowa, which overlooks Chęciny. Mining works that took place in the 1940-ties have exposed almost vertical rock layers. These are narrow-banked limestones that formed in the middle and late Devonian period (375-390 Ma). The sediment from which the limestone was formed had accumulated on the bottom of the shelf of a warm, shallow sea. Rich organic life had developed there. It was, however, a somewhat deeper area than the ones exposed at Kadzielnia or Wietrznia. Remains of old organisms can be seen on the isolated limestone surface in the northern part of the quarry. Some of the rock banks are full of Brachiopoda, remains of Anthozoa and sponges. Fragments of Gastropoda, fossil Coelenterata – Stromatoporoidea and Amphipora and Crinoidea that come in various sizes can also be observed. In the middle section of the exposure, among limestones, one can see layers with hard quartzitic rock. The whole Góra Zamkowa was once a site of lead ore mining and prospecting – many traces of old mining works can be found here. The galena (lead sulphide) that was mined here contained traces of silver.
The rock layers on the ridges of Góra Zamkowa and Góra Zelejowa are steeply sloping. In the past they had laid horizontally, as had the sediment in the Devonian sea. During the Variscan orogeny in the late Carboniferous and the Permian periods (251-325 Ma) the Świętokrzyskie region was folded. A fold was formed between the two aforementioned heights where the rock layers were strongly uplifted. The long-lasting erosion had first levelled the terrain by cutting through the Devonian rock which served as a hard shell. It then formed the vast, flat Chęciny Valley. On the edges of an old hill, the ridges made of steeply sloping Devonian rock remained and resemble fragments of a hard shell.