Extensive studies relating to the establishment of the presence of radium, uranium, and decay products of the thorium series in natural brines of the Soviet Union were carried out under the direction of V. G. Khlopin; numerous expeditions revealed a new form of accumulation in nature of radium and its isotopes in brine waters of the Na, Ca, and Cl types. The following of his students and colleagues participated in these studies: V. I. Baranov, L. V. Komlev, M. S. Merkulov, B. A. Nikitin, V. P. Savchenko, A. G. Samartseva, N. V. Tageev, and others.