Szendrei, G., T. Tóth, P. Kovács Pálffy, I. Sajó, S. Szakáll, and Á. Kovács. 2006. 
Occurrences of salt efflorescences on soil surfaces in Hungary. Topographia 
Mineralogica Hungariae. IX: 61-78.


For surveying and characterizing of the recent salt-efflorescences on soil surfaces 176 spots were 
investigated  since 1998. The aspects of selection were as follows: former published data, soil maps of  the 
scale: 1:100000; 1:25000; 1.10000 and informations of  persons well informed about the local conditions 
like from the rangers in National Parks, sephards etc.
 Salt-efflorescences were determined on 37 localities out of all selected spots. Nowdays the salt-
efflorescences are less frequent and can be found with smaller extent then in the past. Except for one spot 
(where the magnesium sulphate minerals were observed) sodium salts were dominant. Concerning the 
anion compositions sodium carbonates (nahcolite, natron, thermonatrite and trona), sulphates (thénardite, 
mirabilite) and chloride (halite) have been determined. Mixed salts (bloedite, burkeite) were very rare.
The different mineral associations of the given salt minerals have been listed as well as the salt mineral 
associations in various geographical regions have been summarized. Mainly sulphate minerals were 
dominant among the salt minerals in TransDanubia, East from Tisza river and Berettyó-Körös region. 
The most frequent salt minerals are in Hungary as follows: thénardite 76% (in % of all the occurrences), 
trona: 36%, gypsum: 34%, halite: 18%,  thermonatrite: 16%. Concerning cation compositions: 78% 
sodium, 17% calcium, 4 % other minerals, anion compositions: carbonates 29%, sulphate 62%, and 9% 
chloride minerals (Fig. 1, 2). 
The  most common salt associations are: gypsum-thénardite: 12%, thénardite-trona: 12% and gypsum-
thénardite-trona: 6%.
Concerning the chemical compositions the figures are the followings: 48% sodium, 43% sodium–calcium, 
9% other minerals or 26% sulphate, 38% carbonate–sulphate, 7% carbonate, 14% sulphate–chloride, 10% 
carbonates–sulphate–chloride, 5% carbonates–chloride minerals .
On two spots (Apaj, Hortobágy) repeated sampling were carried out to chararterize the seasonal dynamics 
of salt formations. 
For comparative basis salt-efflorescences from abroad (Argentina, Egypt, India and USA) have been 
collected. In these samples almost the same minerals were found, than  the Hungarian ones, but generally 
with higher amounts. Among them one mineral occurs which was not observed in Hungary (e.g. leonite).
Salt-efflorescences in Hungary are accumulations of relatively low concentrations comparing to data from 
abroad. There are no other data from praire ecological zones in Europe. Sodium-carbonate (thermonatrite–
trona or natron–thermonatrite or trona) association alone occurred only in Hungary and India.