Field course on Fluid-rock Interaction in Shallow Hydrothermal Systems was held in Hungary between 27-31 May, 2019. The field course was organized by the ENeRAG H2020 project and co-organized by the József and Erzsébet Tóth Hydrogeology Chair Foundation. The host of the event was ELTE and it was led by GTK.
The maximum number of participants were 39, with a total of 8 institutions (ELTE, GTK, UMIL, ELTE-MTA /ELTE-Hungarian Science of Academy/, Mawson, University of Oulu, LEM Resources, Eldorado Gold) from 4 countries (Hungary, Finland, Italy, Romania). BSc, MSc, PhD students and early career scientists were among the participants.
The 5-day long course started in Budapest at ELTE, with 8 introductory lectures held by instructors from GTK and ELTE, where participants could get the basic knowledge for the following field days.
Based on the experience of the first day, we can state that the warming up event achieved its aims: the participants started to get closer and detailed discussions in the topics of the course started in the breaks.
The next 4 days continued outside of the university walls. On the first field day the group travelled to the Velence Mts. The first stop was the quarry of Nadap, where the participants observed the hydrothermal alteration of a Variscan granite intrusion and Paleogene andesite necks. At the second stop (Pázmánd- Zsidó Hill) they could examine the advanced argillic alteration with pyrophyllite in Paleogene andesite, while interesting minerals with interesting occurrence were discussed (e.g. rainbow-like goethite). From Velence Mts. the group headed back to Budapest, where springs, wells and caves were visited of the Gellért Hill area. Great hydrogeological and mineral precipitating problems were discussed in the tunnel with 33°C under the Gellért Hill.
On the next day the first field stop was Recsk – Lahóca Hill, where advanced argillic alteration in crystal tuff was seen and the participants also used the opportunity to collect some nice enargite-luzonite samples from the waste dump of the abandoned mine. At the next 3 stops (Parádfürdő, Ilona Valley, Darnó Hill) respectively, the following topics related outcrops were presented: advanced argillic alteration and silicification in the Recsk intrusive-volcanic complex, hydrothermal breccia and submarine hydrothermal alteration of Mesozoic pillow basalt. In spite of the heavy rain, the participants were very interested in the traceable fluid-rock interaction on the pillow basalts and hyaloclastite breccia.
On the third day fresh, poorly welded ignimbrite with gas-emanation channels were shown at the first stop in Vizsoly. Later the group had the chance to examine a zonal hydrothermal alteration with alunite in a steam heated hydrothermal zone hosted by ignimbrite in Mád, Király Hill. The last geological location of this day was Mád, Kerektölgyes, where hot-spring fed lake environment with silica pods and argillites was seen. The participants barely wanted to leave the quarry but after the professional program the group had the opportunity to visit one wine cellar of the famous Tokaj region in Tállya, where the discussions about the hydrothermal alterations, fluid-rock interactions continued completed with great wines.
The last day of the field course started in the perlite quarry of Perlit-92 Ltd. in Pálháza, where the group could observe perlite and peperitic perlite (hot rhyolite lava interaction with water-saturated sediments) as well as unique columnar rhyolite. They were very active there and new thoughts, problem-solving ideas came up concerning the quality of the perlite. At the next field stop (Rudabányácska – Bányi Hill) medieval gold mining pits and K-feldspar alteration in acidic tuff were visited. Before travelling back to Budapest one more last field stop left at Sárospatak-Botkő, where silicification with cinnabar mineralisation was presented.
This 5-day long field course was a really good networking opportunity between young geoscientist, who are experts in different fields of geology and have a wide range of interest about geofluids. The field days have passed in a cheerful mood, all participants were enthusiastic and interested in all topics, many questions were raised at the field stops.
All in all, it can be said that the field course on Fluid-rock interaction in shallow hydrothermal systems has reached its goals, when the hydrogeologists got familiar with the processes of hydrothermal systems, geologists with different experiences started to exchange knowledge and the planning of the next joint project has begun.
Group photo in Mád, Kerekestölgyes