Otok v prostoru in času/ An Island in Space & Time EarthCache

(SI) Šmarna gora je popularen vrh, ki vabi z izjemnimi razgledi, raznoliko naravo ipd. Manj obljudena pot vas vodi preko razglednih delov strmega južnega pobočja do skalnih robov sten.

PRED ZAČETKOM:
Opis tega Geološkega zaklada je dolg. Prosimo, preberite ga in si zapišite naloge za vpis se pred obiskom zaklada!

NALOGE ZA VPIS OBISKA
1. Na poti po zgornji polovici grebena Grmade (med Geološkim zakladom - EarthCache točko - in vrhom Grmade) izpod prsti vse naokrog poti štrlijo skale. Katera spodnja trditev najbolje opise usmerjenost kamninskih plasti teh skal?
a) So skoraj vodoravne, zelo primerne so za skakanje s skale na skalo;
b) Ravnina plasti ima manjši padec od vzhoda proti zahodu,
c) Ravnina plasti je skoraj vertikalna, zgornji rob je rahlo nagnjen proti jugu,
d) Plasti kamnin so povsem neurejene, usmerjene v vse možne smeri;
Poizkusite odgovoriti zakaj (ta del odgovora ni obvezen) - če ste pozorno prebrali opis Geološkega zaklada, najbrž že veste.
2. Zelo bomo veseli, če kakšno zanimivo fotografijo z mesta zaklada priložite svojemu vpisu (logu) obiska.

POMEMBNO!
- Preden vpišete obisk zaklada, pošljite odgovor preko GC profila ali neposredno na e-naslov vane.si.geo@gmail.com. Takoj potem lahko vpišete obisk zaklada na spletu – ne potrebujete dodatnega dovoljenja. Ce ste fotografirali, prosimo, priložite kakšno fotografijo.
- Vpisi brez ustrezne spremljajoče e-poste, ki vsebuje pravilne odgovore, bodo najprej trajno kodirani, kasneje izbrisani!
- Vpisi, ki vsebujejo odgovor bodo izbrisani!

(ENG) Šmarna gora is a popular hill which invites with its astounding views of Ljubljana basin plain and wider surroundings, heterogeneous nature etc. Less visited trails lead you along the scenic parts of the steep southern slopes to the edge of the cliff with a great viewpoint.

BEFORE THE BEGINNING:
This EarthCache has a long description! Please, read it and write down logging tasks before visiting the EarthCache site!

LOGGING TASKS
1. There are many rocks jutting out through soil along the upper part of ridge, on the trail from the Earthcache viewpoint to Grmada peak (waypoint No. 3). Which description fits the direction of rock layers best?
a) The rock layers are nearly horizontal; it is easy to use them as jumping stones;
b) The rock layers are slightly slanted form East to West;
c) The rock layers are nearly vertical, rock tips are slightly leaning towards South;
d) The rock layers are completely disordered, oriented in all possible directions;
Try to answer why (this part of the answer is not obligatory) - if you have read text carefully, you might already know.
2. We would be glad if you added interesting photos from the EarthCache location to your log.

IMPORTANT!
- Send answer through GC profile or directly to e-mail vane.si.geo@gmail.com
before logging. After that you can log - you don't need an additional permission to log. Please, upload photos if you have taken them.
- Logs without an accompanying e-mail containing correct answers will be encrypted and later deleted!
- Logs containing the answer will be deleted!

(ENG) TRAIL DIRECTION AND VIEWPOINTS
Earthcache coordinates invite you to enjoy a view from the cliff at the turn ob trail named »Mazijeva steza«.
We suggest trail which will take you along the most scenic path across southern slope of Grmada and follow its ridge to the peak:
- Start at parking area in Tacen (waypoint No. 1)
- follow trail »Čez Spodnjo Kuhinjo in Zatrep« to crossroads at waypoint No. 2
- take trail »Mazijeva steza« uphill to Earthcache (viewpoint)
- take ridge trail to the Grmada peak (waypoint No. 3)
- descend to saddle between Grmada and Šmarna gora (waypoint No. 4)
- descend back to Tacen using trail »Čez Spodnjo Kuhinjo«.

ŠMARNA GORA...
...is a twin-peak hill, one of peaks is named Šmarna gora (669m) and the other Grmada (676m). Taller peak has been named after big bonfires that used to be lit as a signal of danger - approaching Ottoman Empire armies in the Middle ages. Šmarna gora is the most popular hill for short hikes in the surroundings of Ljubljana, visited by about 250.000 people every year. Hill invites with its astounding views of Ljubljana basin plain and wider surroundings, heterogeneous nature, small old church with defence wall and an inn with friendly innkeeper, tasty tea, barley porridge and nut rolls. Sport fans attend mountain-run or start their paragliding there. Climbers practice and improve their skills at bottom section of southern Grmada stone slopes named Turnc (small tower), which they also call »Climbers kindergarten«.
If crowded trails were not your favourite, proposed trail to reach Earthcache was the best for you. Of course, you can always combine and also visit the other Šmarna gora peak with an inn.

1. AN ISLAND IN SPACE
Earthcache viewpoint gives you a view of flat Ljubljana basin plain, above which Šmarna gora is rising as a proper ISLAND IN SPACE. Nowadays Ljubljana basin is the largest plain in the central Slovenia. The plain and Šmarna gora »Island« have been created as a result of three main processes. Collision of two tectonic plates caused folding and breaking of the surface and also pushed Šmarna gora upwards. This process has partly still been active when the second process started - sinking of Ljubljana basin. A part west and north of Šmarna gora started to sink about 30 million years ago, and the part southeast about 2 million years ago. The bottom of Ljubljana marshes - the southern most part of the plain - is still sinking today. Third process, which levelled the surface of Ljubljana basin has been caused by ice-ages. At the time Sava river filled in the bottom with gravel deposits.
You can get even better view of the »Island in the middle of the plain« from Grmada peak (Waypoint No. 3), since the view is wider.

2. AN ISLAND IN TIME
Major part of Šmarna gora consists of rock formations 85 to 270 million years old, lower part of southern slope is even older – about 300 million years! You can see the formation composition at clipping of Slovenian geological map. Plain formations surrounding Šmarna gora are of completely different age.
There were many ice-ages with warmer intermediate periods in the last few hundred thousand years. The last ice-age ended only 10.000 years ago. Each ice-age was a time of intense mechanical rock-weathering because of frost, and water erosion of arid areas close to glaciers. Glacier-waters added enormous loads of mechanical sediments in the summer time, filling in the bottom of the Ljubljana basin.
Ice-age gravel-deposits have been mainly transported by Sava river, only a small part by its tributaries. The process has been so extensive the old »Šmarna gora Island« ended completely surrounded by deep and very, very much younger gravel deposits. The latest are no more than 10.000 years old. So, Šmarna gora, which youngest rock formations are many hundred to many thousand times older than gravel deposits is an proper ISLAND IN TIME. Deposit thickness depends on the depth of the old basin bottom and distance from river Sava. Some parts of basin are covered with more than 100 meters of deposits! During each warmer intermediate period Sava has cut new riverbed into previous ice-age deposits and filled it in during next ice-age again. This way terraces have been made on the surface of Ljubljana basin. A couple of terraces are clearly visible from Earthcache viewpoint, remains of older terraces have also been found on the slopes of Šmarna gora.

ŠMARNA GORA ROCK FORMATIONS (shown on Image 3):
- 99: Upper Carboniferous / Lower Permian (ca. 300 million years): Alternation of shale, quartz sandstone and quartz conglomerate;
- 94: Middle Permian (ca. 270 million years): Red and gray sandstone, shale and conglomerate - Val Gardena Formation
- 92: Lower Triassic (ca. 250 million years): Dolomite, micaceous siltstone, sandstone, claystone, oolitic limestone and dolomite, marlstone, marly limestone;
- 91: Middle Triassic - Anisian (ca. 240 million years): Thick-bedded and massive dolomite, subordinately limestone;
- 84: Upper Triassic - Cordevol (ca. 220 million years): Massive coarse-crystalline dolomite and limestone;
- 53: Upper Cretaceous - Coniacian - Campanian (ca. 85 million years): Platy Volče limestone with chert, red marly limestone and marlstone;

ŠMARNA GORA SURROUNDINGS ROCK FORMATIONS:
- 6: Quaternary (ca. 10.000 - 230.000 years): Deluvium (mostly clay with various rock fragments)
- 10,12,13: Quaternary (ca. 10.000 - 230.000 years): Gravel and sand and other fluvial deposits in terraces

3. AFRICA IN EUROPE?
Yes, there is Africa in Europe! A considerable part, as a matter of fact. Unusual? A part of what is European continent today is situated on Adriatic micro tectonic plate, which has split from African plate some time ago in geological history. Only northeastern part of Slovenia is situated on Eurasian tectonic plate while southern part in the form of Adriatic plate crashed into Eurasian plate about 50 million years ago. At that time African plate itself continued its journey towards Eurasian plate which caused folding of the surface of lands between them. Further continuation of this compression process caused surface folds to break, broken parts to slide one over the other in a slanted stack, and the stack also being lifted. Šmarna gora represents the edge of one of those uplifted surface scales, its southern slopes are an old broken edge. At this place one of the sedimentary rock folds has broken, after being compressed and uplifted by African and Eurasian plate.

4. BOTANICAL ISLAND
Šmarna gora is known for its rich variety of plants, which is primarily consequence of variety of bedrock, presence of different types of soil, variable incline and alternation of sun exposed and unexposed areas. Even looking from a far it is easy to see that ridge of Grmada is also a clear boundary between forest communities on the southern and northern slope. There are Common Beech (Fagus sylvatica) forests on the northern slope, the Hop Hornbeam (Ostrya carpinifilia) with the Downy Oak (Quercus pubescens) community on the southern slope. There are many interesting plants growing on Šmarna gora, some draw attention of every passerby with their beautiful flowers. Among those are daffodil (Narcissus poeticus), Dictamnus albus, »kranjska lilija« (Lilium carniolicum) and Chamaecytisus purpureus, which has been discovered on Šmarna gora and described and named by botanist Scopoli in 18th century. Great variety of plant communities, many infrequent and protected species and even some which survived from the age before ice-ages is enough to claim Šmarna gora also as a BOTANICAL ISLAND.
Taking a hike along educational circular forest trail (»Učna pot po Šmarnogorski Grmadi«) you can find more about plants on Šmarna gora. Trail starts and ends in village Vikrče.

(SI) POT IN OPAZOVALIŠČA
Koordinate Geološkega zaklada vas vabijo na razgledišče nad robom pečin, na ovinku Mazijeve steze.
Predlagamo pot, ki vas povede preko najbolj razglednih steza po južnem pobočju Grmade, po njenem grebenu in čez vrh:
- Izhodišče v Tacnu s parkirnega prostora (točka 1),
- po poti »Cez Spodnjo Kuhinjo in Zatrep« do križišča poti pri začetku »Mazijeve steze« (točka 2),
- naprej po Mazijevi stezi do razgledišča (koordinate Geološkega zaklada),
- po grebenu do vrha Grmade (točka 3),
- spust na sedlo med Grmado in Šmarno goro (točka 4),
- spust v dolino po poti »Čez Spodnjo Kuhinjo«.
Waypoint točke lahko tudi snamete (glejte spodaj).
Šmarna gora je prepredena z označenimi in neoznačenimi potmi, zato si lahko izberete tudi svojo različico.

ŠMARNA GORA
je hrib z dvema vrhovoma: Šmarno goro (669m) in Grmado (676m). Višji vrh je dobil svoje ime v srednjem veku, ko so na njem z velikim kresom - grmado - opozarjali na bližajočo nevarnost vdora turske vojske.
Je najpopularnejši vrh v bližini Ljubljane, saj ga letno obišče kar okrog 250.000 ljudi. Na goro vabijo izjemni razgledi, raznolika narava, stara cerkvica z obzidjem in tudi gostišče s prijaznim osebjem in dobrim čajem, ričetom in potico. Športni navdušenci se udeležijo gorskega teka ali z vrha poletijo z jadralnim padalom. Plezalci svoje znanje utrjujejo na spodnjem delu sten Grmade - v Turncu, ki ga imenujejo kar »plezalni vrtec«. Ce ne marate gneče, bo predlagana pot do Earthcache točke prava za vas. Lahko pa jo združite s katerokoli bolj obljudeno potjo.

1. OTOK V PROSTORU
Z razgledne točke, na katero vas pripeljejo koordinate Geološkega zaklada, se pogled odpre na ravnino Ljubljanske kotline, nad katero se kot pravi OTOK V PROSTORU dviguje kamniti osamelec Šmarna gora. Ljubljanska kotlina je dandanes največja ravnica osrednje Slovenije. Ravnina in »šmarnogorski otok« sta nastala kot posledica treh glavnih procesov. »Trčenje« dveh tektonskih plošč je povzročilo gubanje in razlamljanje površine ter hkrati potisnilo Šmarno goro navzgor. To se je dogajalo deloma tudi se v času, ko se je pričel drugi proces, pogrezanje Ljubljanske kotline. Del zahodno in severno od Šmarne gore se je začel pogrezati pred 30 milijoni let. Pred dvema milijonoma let se je pričel pogrezati se del kotline vzhodno od Šmarne gore, to sta Ljubljansko polje in Ljubljansko barje. Dno Ljubljanskega barja na jugu kotline se še vedno pogreza. Tretji proces, ki je uravnal površino Ljubljanske kotline, so povzročile ledene dobe. V tem času je reka Sava zasipavala dno kotline s prodnimi nanosi.
Na drugem predlaganem opazovališču - na vrhu Grmade (Waypoint No. 3) - je predstava o otoku sredi ravnine se bolj izrazita, saj se lahko razgledamo po večjem delu obzorja.

2. OTOK V ČASU
Večji del Šmarne gore sestavljajo kamnine stare od 85 do 270 milijonov let, spodnji del južnih pobočij pa celo okoli 300 milijonov let! Sestava je vidna iz izseka geološke karte Slovenije. Povsem iz drugega časa so ravninski predeli okoli Šmarne gore.
V zadnjih nekaj sto tisoč letih se je izmenjalo več ledenih dob z vmesnimi toplejšimi obdobji. Zadnja ledena doba se je končala pred 10.000 leti. V obdobju vsake poledenitve se je močno povečalo mehansko preperevanje kamnin zaradi zmrzali ter vodna erozija na neporaščenih območjih blizu ledenikov. Poleti so tudi ledeniške vode v kotlino prinašale ogromne količine mehanskih sedimentov in v debelih slojih nasule dno kotline.
V obdobju ledenih dob je prodne nanose po celotni kotlini v glavnem nanosila reka Sava, nekaj malega pa njeni pritoki. Ta proces je bil tako obsežen, da je stari »šmarnogorski otok« dobesedno obsut z mnogo, mnogo mlajšimi prodnimi nanosi. Najmlajši so stari »le« 10.000 let. Prodni nanosi so torej več stokrat do več tisočkrat mlajši od najmlajših kamnin šmarnogorskega OTOKA V ČASU! Debelina prodnih nanosov je odvisna od globine starega dna kotline in oddaljenosti od reke Save. Na nekaterih delih ljubljanskega polja to pomeni skupaj tudi več kot 100m!
V toplih obdobjih med zaporednimi ledenimi dobami, je reka v nanose vrezovala novo strugo, ki jo je v naslednji poledenitvi znova zasipala. Tako je poleg nasutih ravnin ustvarjala tudi terase. Nekaj jih jasno vidimo z razgledišča, ostanki starejših pa so razporejeni tudi po pobočjih Šmarne gore.

KAMNINSKA SESTAVA ŠMARNE GORE (prikazana na sliki 3 / Image 3):
- 99: Zgornji karbon / spodnji perm (ca. 300 milijonov let): Menjavanje skrilavega glinavca in kremenovega peščenjaka, kremenov konglomerat
- 94: Srednji perm (ca. 270 milijonov let): Rdeč in siv peščenjak, glinavec in konglomerat - Groedenska formacija
- 92: Spodnji trias (ca. 250 milijonov let): Dolomit, sljudnati meljevec, peščenjak, glinavec, oolitni apnenec in dolomit, laporovec, laporasti apnenec
- 91: Srednji trias - anizij (ca. 240 milijonov let): Debeloplastnat in masiven dolomit, podrejeno apnenec
- 84: Zgornji trias - cordevol (ca. 220 milijonov let): Masiven debelozrnat dolomit in apnenec
- 53: Zgornja kreda - coniacij - campanij (ca. 85 milijonov let): Ploščast volčanski apnenec z rožencem; rdeč laporasti apnenec in laporeovec

KAMNINSKA SESTAVA OKOLICE ŠMARNE GORE:
- 6: Kvartar (ca. 10.000 - 230.000 let): Deluvij (pretežno glina z delci različnih kamnin)
- 10,12,13: Kvartar (ca. 10.000 - 230.000 let): prod in pesek ter drugi rečni sedimenti v terasah

3. AFRIKA V EVROPI?
V Evropi imamo Afriko! In to kar precejšen kos. Sliši se nenavadno, a del današnje Evropske celine lezi na Jadranski mikro tektonski plošči, ki se je v geološki zgodovini odlomil od afriške. Le severovzhodni del Slovenije lezi na Evrazijski plošči, južni del pa je v obliki Jadranske mikro plošče prvič trčil v Evrazijsko ploščo pred okoli 50 milijoni let. Nadaljevalo se je zbliževanje robov Evrazijske in Afriške plošče, kar je povzročilo neizbežno gubanje površine vmes ležečih predelov. Z nadaljevanjem stiskanj so se gube pretrgale, pretrgani deli so se zaceli narivati drug čez drugega in se dvigovati.
Šmarna gora lezi na robu ene taksnih narinjenih lusk, njena južna pobočja so rob starega preloma. Tu se je prelomila ena od gub sedimentnih kamnin, ki jih je k višku potisnilo stiskanje Afriške in Evrazijske plošče.

4. BOTANIČNI OTOK
Šmarna gora je znana tudi po izredno bogatem rastlinstvu. To je predvsem posledica raznolike kamninske podlage, prisotnosti več tipov prsti, različnega nagiba ter menjavanja osojnih in prisojnih leg. Po grebenu Grmade lahko že od daleč opazimo izrazito mejo med dvema različnima gozdnima združbama na južnem in severnem pobočju. Severno pobočje poraščajo bukovi gozdovi, južno pa predvsem toploljubni gozd črnega gabra in puhastega hrasta. Na Grmadi in Šmarni gori uspevajo številne zanimive rastline, ki zaradi lepih cvetov pritegnejo tudi pozornost nebotanikov. Med njimi narcise (Narcissus poeticus), jesenček (Dictamnus albus), kranjska lilija (Lilium carniolicum) in rdeča relika (Chamaecytisus purpureus), ki jo je botanik Scopoli v 18. stoletju našel ravno na Šmarni gori, jo opisal in jo poimenoval. Zaradi pestrosti rastlinskih združb, mnogih redkih in zavarovanih vrst ter celo posameznih vrst, ki so se ohranile iz obdobja pred ledenimi dobami, je Šmarna gora tudi BOTANIČNI OTOK.
Nekaj več lahko o rastlinstvu na Šmarni gori izveste, če prehodite krožno učno pot »po šmarnogorski Grmadi«, ki ima svoj začetek in zaključek v vasi Vikrče.