Page 34 - GEMINA | Percorsi nel Carso Rurale | Poti podeželskega | Karst Countryside Ways | Touren im ländlichen Karst

kristali kalcita –CaCO 3 – v velikosti od tisočinke
milimetra domilimetra; dolomitne kamnine pa
sestavljajo kristali dolomita –CaMg(CO 3)2 – v
velikosti od desetinkemilimetra domilimetra.
Zaradi razlike v velikosti kristalov imajo dolomitne
in apnenaste kamnine povsemrazlične lastnosti in
drugače reagirajo na atmosferske dejavnike, kot sta
deževnica inhudourniška voda. Za apnenčasta tla so
značilni kraški pojavi, saj se kalcit topi in je erozija
manj očitna. Dolomitne kamnine pa so sicer na videz
bolj kompaktne in kristalaste, a jih voda lažje razjeda
in so zato na njih kraški pojavimanj vidni.
To vpliva na izgled same pokrajine, ki je še vedno
“kraška”, a nekoliko drugačna. Nad prelomnico
lahko opazimo relief zmehkimi linijami in
kopastimgričevjem, ki se vzpenja do nekaj sto
metrov nadmorske višine in je posut z kamnitimi
brazdami. Debelina rodovitnih tal omogoča rast
površinske vegetacije. Tla so primerna so tudi
za vinogradništvo, vrtnarstvo innajrazličnejše
obdelovalne dejavnosti. Pod prelomnico pa ponovno
opazimo tipično kraško pokrajino, kjer se goščava
izmenjuje s kraškimi dolinami, grobljami, brazdami
in škrapljami [31]. Kraške jame so zelo pogost pojav
innekatere se ponašajo s širokimi rovi in številnimi
jaški. Vešče oko lahko prepozna doline, ki so nastale
z vdori stropov večjih podzemnih jam, indoline,
ki so nastale z raztapljanjem– požiralnike, kamor
se steka deževnica. Poznavalci se lahko zabavajo z
ugotavljanjemrazličnih tipologij škrapelj: škrapljišča
[32], škavnice, korozijske zajede, kamenice in
griže. Tistim, ki se želijo spustiti v podzemne rove
med stalaktite in stalagmite,
priporočamo ustrezno
jamarsko opremo.
TheKarst is a geological
structurewith outcrops of
limestone and dolomite, mostly
dating back to theCretaceous,
the result of the diagenesis of
marine sediments deposited
between 90 and 60million
years ago. Thesewere either
sediments in an open sea, a
lagoon or a rocky coast, all
environments similar to those present today, and
containing a varying number of fossils of all shapes
and sizes. The sediments, having become rock, were
folded and raised as a result of theAlpine orogeny
and today the layers are slightly inclined towards
the sea. This structural geological situationmeans
that right along the Sgonico –Malchina axiswe
encounter the demarcation line (that geologists
call a “limit”) betweenmainly dolomitic rocks and
strictly limestone rocks. The difference is subtle but
significantwith the limestones beingmade up of
crystals of calcite –CaCO3 – of a size ranging froma
thousandth of amillimetre through to amillimetre
while the dolomite crystals aremade up of dolomite
–CaMg(CO3 )2 – ranging in size froma tenth of a
millimeter to amillimetre.
This difference causes the dolomite and limestone
to behave differentlywhen exposed to the elements,
that is to say rainwater and runoff. The limestones
aremore easily subject to karstification, the
calcite dissolvingwhile erosion is less evident.
Thedolomitesontheotherhand,eventhoughthey
appearscompactandcrystalline,aremoreeasily
erodedandthekarstificationprocessesarenegligible.
Thisisthedifferenceinthelandscape,alwayskarstic
but varying indetail. Uphill of the aforementioned
linewe have smallmountains, rounded hills rising
a fewhundredmetres above incised valleys. The
soil is of a thickness that promotes the growth of
vegetation and is ideal for growing grapeswith
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