Zoltán Unger

Zoltán Unger: “Concretion formation puzzles many researchers, including me, but that is not why I became a geologist. The Moon landing sparked my curiosity about lunar rocks. Now I ask whether the Moon has concretions—Mars does! Today I focus on how these varied stone balls form. They may be spherical, slightly flattened, elongated or joined together. Those formed in loess are called ‘loess dolls’ in Hungarian. We mostly know sandy material cemented by lime. Some researchers think a dissolving lime nucleus cements surrounding sand. I believe, supported by research, that the process is more complex and reverse osmosis has a crucial role alongside other factors. Either explanation requires water, so concretions indicate its presence, demonstrated on Mars at several levels. Erosion later removes the softer, uncemented grains around them, leaving the hard concretions exposed. My research aims to produce concretions artificially and needs young scientists. Besides lime concretions, iron and manganese concretions are also important resources that have been mined historically and sometimes still are.”