Pseudokarst abyss on Mužský top is unique sink hole which was discovered at the beginning of the 60th years. It is located about 100 m south-west of the tourist cottage which lies north–north–east of the Mužský top on the edge of the platform. There is 45 meters long, 20 meters wide and 6 meters deep pseudo-sink hole. While a survey there was discovered the abyss. The abyss’s opening of jaws is 12 m long and less than meter wide on average. The width of abyss sinks deeper to 40 centimeters and at times is almost unascendable. Only on the floor is the width extended again and at the south-west end there is created small cave which is less then 2 meters high. Walls of the abyss are practically perpendicular and smooth, at times slightly overhanging. It is narrow crack, 20 meters deep on average. The lowest point of the bottom is 22,5 meters bellow the mark of terrain. Meanwhile it is the deepest known abyss in Mladá Boleslav’s region. The abyss arise out of slope’s movements and washed-up disposal of sediment.
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Pseudokarst relief - sandstone phenomenon
The title pseudokarst was created for naming morphologically similar shapes relief such as surface and underground karst formations. Pseudokarst’s shapes don´t come up on rocks easily soluble mainly dissolving chemical processes but they come up on rocks which are insoluble or hardly soluble. With the assistance of the physical processes they come up by mechanical weathering processes, disintegration and denuding of rocks. During the development of these shapes on larger area of terrain and multiple and fancy forms, for example on the large sandstone’s morfostuctures, can we directly talk about psseudokarst relief. In the event of terrains which are formed by chalky rocks in the territory of the PLA Bohemian Paradise, pseudokarst relief is formed by whole scale of concave, convex macro-, meso- and microforms.
On the strenght of current knowledge of geomorphological processes involved in the formation of pseudokarst relief (mechanical, partial chemical weathering and denuding, slope movements, ruining and the accumulation of rock blocks and geest, piping, less fluvial and aeolian erosion etc.) are now pseudokarst shapes (govern for blocks of sandstone and other chalky rocks) divided into basic and intermediate morfostructures.
Basic morforstructures are divided into:
- gradual - structural denudatly platforms, table platforms and kuesty
- crest – structural ridges, anticlinal ridges, „hogback“ and earth-floe
Partial morfostructures are concave (cave in) and convex (bulging). And they are divided into:
macroforms
- a) passes, canyons, ravines, faults
- b) main platform with ridges, rock pier, rock tower
mesoforms
- a) caves and abysses (vide infra), sink holes, perforation of rocks (rock gates, rock windows, rock tunnels and rock bridges)
- b) rock formation (tors type, rock boletus, etc.)
and microforms
WARNING: Keep out close proximity of the crack!!! There is no assured!!!
You must fulfill the requirements for log this cache:
1) What are the names of the pseudokarst caves in the area of Bohemian Paradise. Name at least three of them.
2) Explain the term „PSEUDOKARST
3) On information table near the fracture you determine where they are much more frequent.
4) Pseudokarst effect are divided to basic and partial morfostructures. Of what are microforms consist?
5) Who was the first explorer of the abyss? And when? ( year )
6) What is the name of the known house which owned one of explorers? And where is it?
7) Insert your photo picture to log from leads coordinates with spoiler
- All answers send to my email krutizlab.geo@gmail.com
- The logs which will not comply with the requirements will be deleted.
Pseudokrasova propast na Muzskem byla objevena pocatkem 60. let a naleza se asi 100m JZ od turisticke chaty, ktera zase lezi SSV od vrcholu Muzskeho. Najdete ji na okraji plosiny, kde je na okraji pole remizek. V nem se nachazi 45m dlouhy, 20m siroky a 6m hluboky pseudozavrt. Pri jeho pruzkumu byla objevena propast. Vlastni vyusteni jicnu propasti je 12m dlouhe a v prumeru necely metr siroke. Hloubeji klesa sirka propasti na 40 cm a misty je temer neprulezna. Teprve na dne se sirka opet o neco zvetsuje a na JZ konci je vytvorena mensi jeskyne o vysce necelych dvou metru. Steny propasti jsou v cele vysce prakticky kolme a hladke, misty nepatrne previsle. Jedna se o prumerne 20 m hlubokou, uzkou puklinu. Nejnizsi misto dna je 22,5 m pod urovni terenu. Zatim je to nejhlubsi znama propast na Mladoboleslavsku. Propast vznikla svahovymi pohyby a sufoznim vyklizenim sedimentu.
Pseudokrasovy relief - piskovcovy fenomen
Nazev pseudokras byl vytvoren pro pojmenovani morfologicky obdobnych tvaru reliefu jako jsou povrchove a podzemni tvary krasove. Pseudokrasove tvary nevznikaji na horninách lehko rozpustnych prevazne chemickymi procesy rozpoustenim, ale na horninach nerozpustnych ci tezko rozpustnych a za prispeni predevsim fyzikalnich procesu, mechanickymi procesy zvetravani, rozpadu a odnosu hornin. Pri vyvoji techto tvaru na vetsich plochach terenu a v cetnych i pestrych formach, jako je tomu prikladne na rozsahlych morfostrukturach piskovcovych, lze primo hovorit o pseudokrasovem reliefu. V pripade terenu tvorenych kridovymi horninami na uzemi CHKO Cesky raj je pseudokrasovy relief tvoren celou stupnici konkavnich i konvexnich makro-, mezo- a mikroforem.
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Prihrazske skaly
Na podklade soucasnych poznatku geomorfologickych procesu podilejicich se na tvorbe pseudokrasoveho reliefu (mechanicke, castecne i chemicke zvetravani a odnos, svahove pohyby, ríceni a akumulace skalnich bloku a zvetralin, sufoze, mensi merou i fluviálni a eolicka eroze atd.) jsou nyni pseudokrasove tvary (s platnosti i pro kvadrove piskovce i dalsi kridove horniny) deleny na zakladni morfostruktury a dilci morfostruktury:
Zakladni morfostruktury se deli na:
- stupnoviny - strukturne denudacni plosiny, tabulove plosiny a kuesty
- hrbetoviny - strukturni hrbety, antiklinálni hrbety, "kozi hrbety" a hraste
Dilci morfostruktury jsou konkavni (vhloubene) a konvexni (vypoukle) a dale se deli na:
makroformy
- a) soutesky, kanony, strze, rozsedliny
- b) rozvodni plosiny s hrbety, skalni pilire a skalni veze
mesoformy
- a) jeskyne a propasti (viz dale), zavrty, skalni perforace (skalni brany, skalni okna, skalni tunely a skalni mosty
- b) skalni utvary (typu tors : skalni hriby apod.)
a mikroformy
POZOR: Rozsedlina neni nijak zabezpecena !!! Budte velmi opatrni!!!
Vasim cilem je zodpovedet par otazek, ktere z velke miry najdete na info tabuli ne u rozsedliny, ale na znacene turisticke ceste nedaleko :
1) Jak se jmenuji alespon tri jeskyne na uzemi Ceskeho raje pseudo-krasoveho puvodu ?
2) Vysvetlete pojem PSEUDOKRAS.
3) Na informacni ceduli pobliz trhliny zjistete, v kterych oblastech jsou tyto utvary mnohem castejsi.
4) Pseudokrasove tvary delime na zakladni a dilci morfostruktury. Jedna z dilcich morfostruktur jsou mikroformy. Jak je rozdelujeme?
5) Kdo prvni prozkoumal tuto propast? A kdy?( rok )
6) Jeden z nich byl znamy cestovatel a horolezec. Byla s nim spojena architektonicka zajimavost. Jeji jmeno a kde se nachazi?
7) Pokuste se vlozit foto s puklinou za zady viz spoiler
Za velkou pomoc s prekladem dekuji svym dceram Kacce a Lucce.
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