site 10

Where is the site located?

GPS: 49° 59′ 30.04″ N, 15° 33′ 56.33″ E

The site lies in the northern part of the Iron Mountains National Geopark, in an area where the mountain range passes to a flat region of the East Bohemian Table. Near this site, spectacular rock outcrops are exposed to the surface. Forests to the north of the Lipoltice village conceal the Lipoltice Cliff .

What is the geological position of the site?

The site is located in the Bohemian Massif, in the marginal area of the Central Bohemian Region. The original sedimentary rocks were deposited by a Paleozoic sea, which flooded the place in the Cambrian and Ordovician periods.

What happened at this site in the past?

– 520 million years

In the Cambrian, the first period of the Paleozoic era, this area was lying on the Southern Hemisphere, in a shallow sea passing to dry land. It was a part of a microplate not far from the supercontinent of Gondwana. Sediments were generated by a rapid removal of material from dry land, being eroded mostly by water, and deposited in a shallow sea and possibly in lakes, too. Life in the sea expands rapidly, represented by invertebrates: trilobites, molluscs, brachiopods, sponges and jellyfish.

– 490 million years

In the Ordovician, early in the second period of the Paleozoic era, this area was still lying on the Southern Hemisphere. It was a part of a shallow sea not far from the supercontinent of Gondwana. The climate was temperate to cold, with marked fluctuations, which affected the sea level. The sea was inhabited by invertebrates – representatives of the evolving groups of trilobites, brachiopods and cephalopods. The sea bottom was colonized by sponges and corals.

What does the site display today?

This site is located in the Chrudim Paleozoic, where two rock units of different ages meet together. The younger, higher-positioned Lipoltice Formation builds the northern vicinity of Lipoltice. The older Senice Member lies in the southern vicinity of the village.

The age of the Lipoltice Formation is more or less clear, evidenced by fossils of the earliest Ordovician age. The age of the Senice Member is still disputed; the latest research dates this unit to the Cambrian. Both rock units form the so-called Přelouč Syncline – a bowl-shaped structure created by subsequent orogenic processes. These processes resulted in the folding and fracturing of the originally roughly horizontally lying sedimentary strata.

The Senice Member is dominated by shales and foliated greywackes. The Lipoltice Formation is represented by sandstones to conglomerates. It is locally affected by later material and thermal change, producing quartzites. Quartzite is a highly resistant rock, effectively opposing subsequent abrasion and earth surface lowering. As such, it forms a prominent crest on the present relief. Its topmost part is formed by a rock wall with a boulder accumulation, known as the Lipoltice Cliff.

What was affected by man?

Resistant rocks of the Lipoltice Formation were exploited in a number of small quarries opened in a morphologically prominent crest stretching between the northwestern environs of Lipoltice and Chrtníky.

Spectacular geological phenomena have been unveiled at the site of a former quarry near the road between Lipoltice and Podvrdy.

What was discovered?

The Senice Member has been studied by geologists since the late 19th century already. This unit is exposed over a relatively large area and its thickness is estimated at several hundred metres. There was no doubt about the character of the sediments: an opinion prevailed that these are cyclically-driven sediments with two main cycles of shale (fine sediments) separated from each other by prominent greywacke beds (coarser sediments). The age of the sediments was subject to a major discussion. The member was first ranked to the Ordovician. After the discovery of the trilobite fauna at Palác Hill near Heřmanův Městec, its age was corrected for the Cambrian.

The local quarry provides a good exposure of light green fine shales pertaining to the Senice Member. The rocks are favourable for further geological research, which would employ new methods of study: study of the smallest organisms (micropaleontological analysis) or study of physical and chemical properties of sediments (facies analysis).

Last but not least, it would be very interesting to discover some fossil remains at this very site.

“The Iron Mountains – a geologically significant region” project of 2014

An information panel was manufactured within the project of “The Iron Mountains – a geologically significant region”. It was placed to the edge of an abandoned quarry lying near the road between Lipoltice and Podvrdy, some 500 m from the northwestern limit of the Lipoltice village. Fieldworks entailed cleaning of cliff faces from vegetation, their stripping and washing by jet water. At the same time, the access road to the geosite itself was repaired.

Re-discovered Ordovician fauna from Lipoltice (Daniel Smutek)