Applied mineral exploration methods, hydrothermal fluids, baro-acoustic decrepitation, CO2 rich fluids
Newest Topics:

New model 216 decreptiometer

Exploration of the Mt. Boppy Au deposit, NSW

Forensic tests on soil samples


Do IOCG deposits form from CO2 fluids?

How CO2 inclusions form from aqueous fluids (UPDATED)

Understanding heterogeneous fluids : why gold is not transported in CO2-only fluids

Gold-quartz deposits form from aqueous - CO2 fluids: NOT from CO2-only fluids

Discussions why H2 analysis by mass spectrometry is wrong


Gold at Okote, Ethiopia

Kalgoorlie Au data

Sangan skarn Fe deposits, Iran

Studies of 6 Pegmatite deposits

A study of the Gejiu tin mine, China

Exploration using palaeo-hydrothermal fluids

Using opaque minerals to understand ore fluids

Understanding baro-acoustic decrepitation.

An introduction to fluid inclusions and mineral exploration applications.

 Interesting Conferences:


ECROFI Iceland
     July 2-6

AOGS Singapore
    30 Jul - 4 Aug 2023

SGA Zurich Aug 2023

Comprehensive Geology Conference Calendar

Samples from the Banksa Stiavnica area, Slovakia

This area is one of the earliest mining districts and gold was mined from numerous epithermal quartz veins intersecting the Stiavnica stratovolvcano of miocene age. A geological description of this area has been published in the ACTA Mineralogica-Petrographica, IMA2010 Field guide series, trip SK3, Vol 29, 2010 by Peter Kodera & Jaroslav Lexa.

The area is located in western Slovakia, about 130 Km NE of Bratislava. The field trip details (august 2010)  are here.

Rozalia mine

The Rozalia vein, which is a few km west of the village of Banksa Stiavnica, is one of many veins in this area. A small gold mining operation provided access to quartz ore in the bins at the crushing plant. The geological context of the 6 samples collected is uncertain.

3 of these samples have very low decrepitation intensities, which is normal for epithermal fluid inclusions. But 3 samples show substantial decrepitation intensities which is characteristic of mesothermal veins. None of the samples show low temperature decrepitation caused by CO2 rich inclusions and it seems these fluid systems were dominantly aqueous.

Rozalia vein mine samples

Kremnicia area

The geological context of quartz samples from the Kremnica pit is unclear because this pit was caused by collapse of the underground workings during an earthquake.
Most of the samples show only weak decrepitation and no low temperature CO2 peak. 2 samples have moderate decrepitation intensity and sample h2581 has a very prominent peak at 310 C caused by CO2 rich fluid inclusions. There is a mixture of quartz types here including epithermal and mesothermal.

kremnica collapse pit

An attempt was made to collect quartz from some of the old underground workings area, although no actual workings were safely accessible. These samples showed very low decrepitation intensity with no CO2 and are probably of epithermal origin. One sample, h2585, has no decrepitation at all and may well be a chert sample rather than hydrothermal quartz.

kremnica underground samples

CO2 occurs only rarely in the samples collected in this mining district, in contrast to the archaean type quartz vein gold deposits. Most samples have low decrepitation intensity consistent with a high level epithermal origin for the quartz. But there are occasional exceptions and it is likely that there are some mesothermal systems amongst the mostly epithermal systems in this district.

Sample descriptions

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