Leonid Neymark is a Scientist Emeritus with the Geology, Geophysics, and Geochemistry Science Center.
I am currently a Scientist Emeritus in the Geology, Geophysics, and Geochemistry Science Center after being transferred from the Geochemistry Team, Yucca Mountain Project Branch where I conducted U-series studies of soils, fracture minerals and water-rock interaction processes.
I conduct a wide spectrum of isotope-geochemical studies involving radiogenic isotopes of U, Pb, Sr, and Nd and using ICP-MS and TIMS techniques. Before 2010 I was a principal investigator and a member of the Geochemistry Team in the Yucca Mountain Project Branch, WRD. The team's task was to evaluate geochemical aspects of the hydrogeologic suitability of Yucca Mountain to permanently store high-level radioactive waste. My focus was on the history of secondary mineral deposition (largely calcite and silica) in soil and unsaturated- and saturated-zone settings and on isotope-geochemical indicators of water-rock interaction as evidence of past water flow. These studies used U-Pb and U-series and other isotope-geochemical methods to characterize the timing of low-temperature surface processes of mineral deposition and to evaluate past water-rock interaction. In 2004 I was closely involved in the installation and detailed testing of a new ThermoFinnigan thermal-ionization mass-spectrometer Triton. I developed reproducible mass-spectrometric methods of U-series isotope measurements for whole rock samples with large Th/U and 232Th/230Th ratios. Previous YMPB work included systematic characterization of subsurface and soil hydrogenic minerals to provide a basis for understanding past hydrologic and climate variability in the Yucca Mountain region.
- Sources of Pb contamination in domestic well water in SW Missouri
- Matrix Pore Waters - Ultracentrifugation Method for Low-Permeability Sedimentary and Crystalline Rocks
- The U-Th-Pb whole-rock isotope system in the Chalk River core and past redox conditions
- Impact of Exhalative Hydrothermal Systems on Marine Chemistry: Applications for Mineral Assessment
- Conditions and Processes Affecting Radionuclide Transport (writing a chapter for the GSA Memoir devoted to Yucca Mountain, volume 2
Research Chemist, Geology, Geophysics, and Geochemistry Science Center, USGS
Principal investigator and member of the Geochemistry Team in the Yucca Mountain Project Branch, USGS
2001-2004. S.M. Stoller Corporation, Senior Geochemist
1996-2001. Pacific Western Technologies, Ltd. Senior Scientist
1993-1996. US Geological Survey Visiting Research Scientist
1985-1993. Institute of Precambrian Geology and Geochronology (IPGG), St. Petersburg, Russian Academy of Sciences
1971-1985. All Union Geological Research Institute, Leningrad (USSR Ministry of Geology). Engineer (1971-1981) and Junior Research Scientist (1981-1985)
Education and Certifications
Ph.D. in Geochemistry, St. Petersburg, Russia
MS degree in Radiochemistry, St. Petersburg, Russia
Affiliations and Memberships
American Geophysical Union
Geological Society of America
International Geochemistry Association
Science and Products
Science and Products
Pre-USGS PublicationsYu.V. Amelin and L.A. Neymark. 1998, Lead isotope geochemistry of Paleoproterozoic layered intrusions in the eastern Baltic Shield: Inferences about magma sources and U-Th-Pb fractionation in the crust-mantle system. Geochim. Cosmochim. Acta., vol. 62, no. 3, 493-505, https://doi.org/10.1016/S0016-7037(98)00056-8.E.Yu. Rytsk, L.A. Neimark, Yu.V. Amelin, 1998, Paleozoic granitoids in the Northern Part of the Baikal Orogenic Area: Age and Past Geodynamic Settings. Geotectonics, vol. 32, no. 5, 379-393.L.A. Neymark, E.Yu. Ritsk, B.M. Gorokhovskiy. 1996. Pb isotope characteristics of some late Riphean Pb-Zn deposits in the folded environs of the Siberian platform. Transactions of the Russian Academy of Sciences. vol.342, no.4, p. 183-187.L.A. Neimark, A.M. Larin, G.V. Ovchinnikova et al., 1996, U-Pb geochronologic and Pb-isotopic evidence for the Mesozoic mineralization stage of the Archean Stanovoi Megablock, Aldan-Stanovoi Shield. Petrology, vol. 4, no.4, 421-435.V.A. Vernikovsky, L.A. Neymark, V.A. Ponomarchuk, and S.Z. Yakovleva, 1996, New U-Pb, Sm-Nd, Rb-Sr, and K-Ar ages for the North Taymyr collisional granites and metamorphites: Transactions of the Russian Academy of Sciences. vol. 345a, no.9, 329-334.R.A. Kumpulainen, J. Mansfeld, K. Sundblad, L. Neymark, and T. Bergman, 1996, Stratigraphy, Age, and Sm-Nd Isotope Systematics of the country rocks to Zn-Pb Sulfide Deposits, Ammeberg District, Sweden: Economic Geology, vol. 91, 1009-1021, https://doi.org/10.2113/gsecongeo.91.6.1009.L.A. Neimark, E.Yu. Ritsk, G.V. Ovchinnikova et al. 1995. Lead isotopes in gold deposits of the Eastern Sayan (Russia). Geology of Ore Deposits. vol. 37, no. 3, 201-212.E.V. Khain, L.A. Neymark, Y.V. Amelin, 1995, Isotope-geochronological study of the granites and granite-gneisses of the Gargan Block, Eastern Sayan Range, Siberia, by Pb-Pb and U-Pb method on zircons and Sm-Nd method, Doklady of the Russian Academy of Sciences, vol. 342, no. 5, 776-779 (in Russian).L.A. Neimark, E.Y. Ritsk, B.M. Gorokhovsky, V.F. Guseva, S.Z. Yakovleva, 1995, Age of Muya granites, Baikal-Vitim ophiolite belt (U-Pb and Sm-Nd isotopic evidence), Doklady of the Russian Academy of Sciences, vol. 343, no. 5, 673-676 (in Russian).V.A.Vernikovskii, L.A. Neimark, V.A. Ponomarchuk et al. 1995. Geochemistry and age of collision granitoides and metamorphites of the Kara microcontinent (Northern Taimyr). Russian Geology and Geophysics. vol. 36, no.4, 46-60.V.A. Vernikovsky, A.E. Vernikovskaya, S.M. Lyapunov, L.A. Neimark, V.F. Proskurin, A.I. Chernykh, I.Yu. Safonova, 1994, Petrology, geochemistry, and tectonic setting of plagiogranites of the Chelyuskin ophiolite belt: International Geology Review, vol. 36, no. 10, 961-974.L.A. Neymark, Yu.V. Amelin, A.M. Larin. 1994. Pb-Sr-Nd isotopic and geochemical constraints on the origin of the 1.54-1.56 Ga Salmi rapakivi-granite -- anorthosite batholith (Karelia, Russia). Mineral. Petrol., vol. 50, no.1-3, 173-193, https://doi.org/10.1007/BF01160146.S.A. Alekseenko, S.L. Ivlev, and L.A. Neimark, 1994, Standard reference sample of lead isotopic composition: Journal of Analytical Chemistry, vol. 49, no. 12, 1154-1158.L.A. Neymark, A.A. Nemchin, V.R. Vetrin, E.B. Sal'nikova. 1993. Sm-Nd and Pb-Pb isotope systematics in the lower crust xenoliths from the diatremas in the Southern Kola Peninsula. Transactions of the Russian Academy of Sciences. vol.329, no. 6, 781-784.I.M. Gorokhov, M.S. Dufour, L.A. Neymark et al. 1993, Early Paleozoic Gondwana fragments in the nappes of the Central Pamirs and Lesser Himalayas: geochemical and isotopic characteristics. Stratigraphy and Geologic Correlation. vol.1, no.3, 250-263.G.V. Ovchinnikova, L.A. Neymark, O.A. Levchenkov et al. 1993. On the use of the apatite as an U-Pb geochronometer. Stratigraphy and Geological Correlation. vol.1, no.1, 9-19.L.A. Neymark, E.Yu. Ritsk, N.G. Rizvanova. 1993. Hercynian age and Precambrian crustal protolith of the Barguzin granitoides of the Angar-Vitim batholith : U-Pb and Sm-Nd isotope evidence. Transactions of the Russian Academy of Sciences, vol.332, no.7, 201-206.L.A. Neymark, V.P. Kovach, A.A. Nemchin et al. 1993. Late Archean intrusive complexes in the Olekma granite-greenstone terrain (Eastern Siberia): geochemical and isotopic study. Prec. Res. vol.62, no.2, 453-472, https://doi.org/10.1016/0301-9268(93)90016-U.L.A. Neymark, E.Yu. Ritsk, N.G. Rizvanova, B.M. Gorokhovsky. 1993. U-Pb zircon age evidence for a polichronous Angaro-Vitim batholith. Transactions of the Russian Academy of Sciences. vol.333, no.5, 634-637.V.A. Vernikovsky, L.A. Neymark, V.F. Proskurin, S.Z. Yakovleva. 1993. Late-Riphean age of the Kunar massif plagiogranites (U-Pb zircon dating). Transactions of the Russian Academy of Sciences. vol. 331, no. 6, 706-708.L.A. Neymark, E.Yu. Ritsk, B.M. Gorokhovsky, Yu.V. Amelin, G.V. Ovchinnikova. 1993. Geochronological and isotope-geochemical study of the gold ore deposits in the Baikal fold area. In: Isotope Dating of Ore Deposits. Moscow, Nauka, p. 124-146 (in Russian).L.A. Neymark, A.M. Larin, E.Yu. Ritsk, G.V. Ovchinnikova, B.M. Gorokhovsky. 1993. U-Pb geochronological and Pb-isotope evidence of the Hercynian ore-forming event within the Proterozoic frame of the South Siberian Platform. Transactions of the Russian Academy of Sciences. vol.333, no.6, 765-768.L.A. Neymark, A.M. Larin, G.V. Ovchinnikova, and S.Z. Yakovleva. 1992. U-Pb age of the Dzhugdzhur anorthosites. Transactions of the Russian Academy of Sciences. vol.323A, no.3, 57-62.L.A. Neymark, A.M. Larin, S.Z.Yakovleva, B.M. Gorokhovsky. 1992. U-Pb age of igneous rocks of the Ulkan graben in the Southeastern part of the Aldan Shield. Transactions of the Russian Academy of Sciences. v.324, no.4, 92-96.L.A. Neymark, A.A. Nemchin, O.M. Rozen, V.P. Serenko, V.P. Spetsius, I.K. Shuleshko. 1992. Sm-Nd isotope systematics in the lower crust xenoliths from kimberlites of Yakutia. Transactions of the Russian Academy of Sciences. vol.327, no.3, 88-93.L.A. Neymark, A.M.Larin, S.Z. Yakovleva, N.A. Sryvtsev, and V.V. Buldygerov. 1991. New U-Pb zircon age data on the Akitkan suite, Baikal-Patom fold area. Transactions of the USSR Academy of Sciences. vol. 321, n.8, 197-201.A.M. Larin, Yu.V.Amelin, and L.A.Neymark. 1991, Age and genesis of the complex scarn ores of the Pitkaranta ore district associated with the Salmi rapakivi massif (Southern Karelia). Geologia Rudnykh Mestorozhdenij (Geology of Ore Deposits), vol. 6, 15-33 (in Russian).L.A. Neymark, E.Yu. Ritzk, B.M. Gorokhovsky et al., 1991, Lead isotopic composition and genesis of the Pb-Zn mineralization of the Olokit zone of the Northern Baikal region. Geologia Rudnykh Mestorozhdenij (Geology of Ore Deposits), vol. 6, 34-49 (in Russian).L.K. Levsky and L.A. Neymark. 1991, Isotopic constraints on a prototerrestrial matter. In: The Early Crust : its composition and age. Moscow, Nauka, p. 48-63 (in Russian).Yu. Amelin, A. Beljaev, A. Larin, L. Neymark, I. Stepanov, 1991. Rapakivi granites and related rocks symposium, July 29-31, 1991, Helsinki, Finland; Salmi batholith and Pitkaranta ore field in Soviet Karelia excursion, August 1-4, 1991 Haapala, Ilmari; Ramo, O Tapani; Salonsaari, Pekka T; GCP, International Geological Correlation Programme Opas - Geologian Tutkimuskeskus, vol.33, 57 pp.S.A. Sergeyev, Ye.V. Bibikova, O.A. Levchenkov, S.B. Lobach-Zhuchenko, S.Z. Yakovleva, G.V. Ovchinnikova, L. A. Neymark, A.N. Komarov, B.M. Gorokhovskiy, 1990. Isotope geochronology of the Vodlozerskiy gneiss complex, Geokhimiya, vol.1990, no.1, 73-83. (in Russian).G.V. Ovchinnikova, S.B. Lobach-Zhuchenko, S.A. Sergeyev, S.Z. Yakovleva, O.A. Levchenkov, L.A. Neymark, A.N. Komarov, B.M. Gorokhovskiy, A.M. Fedoseyenko, I.N. Krylov, 1990. Geochronology and petrology of the late kinematic granites of southeastern Karelia based on geochemical and isotopic data. Geokhimiya, vol.1990, no.11, 1561-1573 (in Russian).V.L. Dook, L.A. Neymark, and V.A. Rudnik (Eds.). 1989. The Oldest Rocks of the Aldan-Stanovik Shield, Eastern Siberia, USSR. IGCP Project 280 “The Oldest Rocks on Earth”, Excursion guide, Leningrad-Mainz, 121 p.Yu.V. Amelin, L.A. Neymark, D.I. Matukov et al. 1988. Analytical parameters and operation experience of MI1320-PRM2 mass-spectrometers . In: Isotopic methods in geology, geochemistry and metallogeny. Leningrad, Nauka, p.102-116. (in Russian).L.A. Neymark, G.V. Ovchinnikova, B.M. Gorokhovsky et al. 1988. Pb isotopes in sulfides from rocks of the Sumozero--Kenozero greenstone belt. In: Isotopic methods in geology, geochemistry and metallogeny. Leningrad, Nauka. p. 42-48. (in Russian).L.A. Neymark, A.B. Kotov, D.P. Vinogradov et al. 1988. Age and occurrence of early folded and post-folded granitoids of northwestern Lake Ladoga region according to data of Pb, O isotopes. In: Isotopic methods in geology, geochemistry and metallogeny. Leningrad, Nauka p. 21-41. (in Russian).L.A. Neymark, S.L. Mirkina, A.G. Rublev et al. 1987. Isotope age of the granites in the Irelsky Complex, Baikal Region. Izvestiya Akademii Nauk SSSR. vol. 5, 18-25 (in Russian).A.G. Rublev, G.A. Murina, A.P. Chukhonin, L.A. Neimark, et al. 1987. Geochronology of early-Proterozoic granitoid magmatism in the Kodar-Udokan Zone. Soviet Geology and Geophysics, vol. 28, no.6, 26-33, 1987 (in Russian).L.A. Neymark. 1987. Potential and restrictions of the lead-isochron method in dating Precambrian polymetamorphic rocks. In: Isotopic dating of metamorphic and metasomatic process. Shukoljukov Yu.A. (Ed.). Moscow, Nauka, p. 29-44 (in Russian).L.A Neymark. 1987. The application of U-Pb to the geochronological studies of Precambrian metallic ore deposits. In: Gorokhov I.M., Levchenkov O.A. (Editors) Isotopic methods on Geochronology. Leningrad, Nauka, p.29-44 (in Russian).L.A. Neymark. 1986 U-Pb isotopic constraints on the age and primordial materials of the Earth. In: Isotope methods in geochemistry and cosmochemistry. L.K.Levsky (Ed.) Leningrad, Nauka, p. 3-21 (in Russian).L.A. Neymark, A.D. Iskanderova, E.P. Miron'uk et al. 1984. U-Pb age of the Charskoje ore deposit of BIF, Eastern Siberia. Doklady Akademii Nauk SSSR. vol. 234. 1246-1249. (in Russian).L.A. Neymark. 1983. Quantitative models for the evolution of the crust-mantle system utilizing Pb isotope data. In: Geochemistry of radiogenic isotopes in the early stages of the Earth's evolution. Shukol’ukov J.A. (Ed.), Moscow, Nauka, p.151-167 (in Russian).G.V. Ovchinnikova, L.A. Neymark. 1981. The excess lead in meteorites. Geochemistry International. vol.18, no.4, 102-115.L.A. Neymark, A.D. Iskanderova, A.P. Chukhonin, et al. 1981. U-Pb data on the Archean age of metamorphic rocks of the Stanovoy Range: Geochemistry International, vol.18, no.5, 55-64.L.A. Neymark, O.A. Levchenkov. 1979. A method of age calculation for open U-Pb isotope systems. Geochemistry International. vol.16, no.3, 34-39.S.L. Mirkina, L.A.Neymark, B.B. Golubev, I.G. Smyslova. 1976. Radiologic dating of Neogene-Quaternary uranium minerals by Pb-isotope method. Geokhimia, no. 9, 43-48 (in Russian).