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The Sisak Cermik thermal field about 20 km west of Sivas in Central Anatolia displays subrecent and recent
thermal activitiy, the latter being used extensively as spa for health seeking visitors. The nearby subrecent
parts of the thermal field however, which are exposed by travertine quarrying, give a rare opportunity to research the lower parts of a thermal system, which are normally obscured by water and carbonate and/or silica sediments.
The whole vein like structure, which is clearly visibile in satellite imagery, runs roughly in North - South direction and can be traced easily for more than 5 km and possibly much further. Extensive ferrugineous carbonate deposition has taken place in the subrecent thermal basins, whereas the sediments
show remarkable coarse crystallinity, often resembling yellow sponges. In fact the texture of this "sponges" consists almost entirely of individual ferrugineous calcite crystals, which may reach dimensions of more than tweo meter.
The travertine quarry exhibits an almost ideal geological profile through the fossil thermal bassin. In the center we find a large, predominantly white coloured, 8 m wide and several hundred meter long travertine feeder channel, which is on both sides accompanied by at least 10 m thick, yellow ferrugineous carbonate sediments of the above mentioned "spongy" crystal type.
For another turkish locality with giant probertite crystals please click here and for an interactive & panoramic voyage to some turkish world heritage sites please click here.
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Sisak Cermik in a nutshell :
Mineralogy : |
Ferrugineous calcite |
Crystal Size : |
2 m dendritic crystals confirmed |
Geology & Origin : |
Epithermal formation from Ca - Fe hot mineral water |
Status : |
Inactive travertine and fertilizer quarry, now used as wild waste dump. Protection urgently needed |
Remarks : |
A rare opportunity to investigate the usually hidden and unacessible root zone of an active hydrothermal spring system
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Other notable & famous giant calcite occurences :
Note : Calcite is one of the most common minerals world wide, therefore large and even giant calcite crystals are considered not to be very rare. Hence there are certainly other remarkable giant calcite occurences not listed here.
- More information about giant Iceland spar occurences can be found here (New Mexiko, USA), here (Helgustadir, Iceland) and here (Garibaldi mine, Australia)
- Another remarkable Iceland spar deposit with crystals up to 0,7 x 0,5 cm occur in basalt from Nizhnyaya, Krasnoyarsk kray Siberia, GUS.
- Sharp yellow scalenohedral crystals up to 1 m occur with galena and sphalerite in the famous Tri State District, Oklahoma / Missouri / Kansas, USA.
- For more information about calcite pseudomorphs after giant ikaite crystals and crystal aggregates please look here and here.
- Large to giant crystals of calcite up to 1 x 1 m size from metamorphic marbles have been reported from Sterlingbush, New York, USA.
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Overview of ths Sisak Cermik quarry. Note excavated travertine vein in center
Photo : Giant Crystal Project
2 m cone shaped ferruginous calcite crystals on top of the quarry. Note girl for scale
Photo : Giant Crystal Project
Detail of the ferrugineous calcite travertine precipitations
at Sisak Cermik
Photo : Giant Crystal Project
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Resources and relevant weblinks :
There is only little information provided on this locality outside Turkey, but here is an interesting
publication about this locality by TEKIN, ERDOGAN & AYYILDIZ, TURAN (2001), published in the Geological Bulletin of Turkey, which you can access here.
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