Geology and Geochemistry

The nunataks Plogen and Basen consist of basalt flows of the Kirwan Volcanics cut by basalt dikes that strike northeast. The flows are interbedded with minor layers of pluvial sediment and the total stratigraphic thickness of the flow and sediment layers is greater than 900 m on Plogen and greater than 300 m on Basen (Luttinen and Siivola 1997). 

The K-Ar dates of the flows and dikes on these nunataks reported by Peters et al. (1991) range widely from 90 to 352 Ma based on analyses of plagioclase, groundmass, and whole-rock samples. Eight dates that range only from 160 to 190 Ma are included in Fig. 14.17. The three dates that occupy the interval from 175 to 180 Ma have a mean of 178 2 Ma (la) which corresponds to the early Middle Jurassic on the lUGS (2002) geologic time scale. 

The Plogen nunatak consists of about 30 basalt flows most of which are porphyritic with phenocrysts of plagioclase, ohvine, and pyroxene in a groundmass of plagioclase laths, clinopyroxene, Fe-Ti oxides, and mesostasis. The plagioclase phenocrysts of many flows are altered to sericite and, in some cases, have been converted to pseudomorphs of saussurite (mixture of alteration products containing chlorite, calcite, albite, and epidote). Olivine was also altered, but clinopyroxene is pristine, hi contrast to the pervasive alteration of the flows, the basalt dikes are unaltered. The flow tops are typically amygdaloidal and the former vesicles are filled with chlorite, quartz, prehnite, and calcite. 

The TVY ratios in Fig. 14.18 identify the flows and dikes of Plogen and Basen as low-H basalt 

In a subsequent work, Luttinen et al. (1998) measured isotopic compositions of strontium and neodymium and added a fourth magma type (CT-4) based on the chemical compositions of two dikes on Basen which are subalkaline tholeiites but have higher Ti/Zr and Ti/ Mg than the CT-3 samples. They also have higher concentrations of MgO and iron than most of the flows and dikes on Plogen and Basen probably because they contain excess olivine. 

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R. Giovanoli, Natural and synthetic manganese nodules , in Geology and Geochemistry of Manganese , Vol. 1 (Eds. I. M. Varentsov, G. Grassely), Akademiai Kiado, Budapest, 1980. 

Lu, K.I. (1983) Geology and geochemistry of the Uchinotai-East ore deposit, Kosaka mine, Akita Prefecture, Japan. Mining Geology, 33, 367-384. 

Reed, M.H. and Spycher, N.F. (1985) Boiling, cooling and oxidation to epithermal systems. A numerical modeling approach. In Berger, B.R. and Bethke, P.M. (eds.). Geology and Geochemistry of Epithermal System. Reviews in Economic Geology, 2, 249-272. 

Introductory Remarks on Coal Paleobotany, Geology and Geochemistry... 

The purpose of the collection of papers in this volume is to review what can be said about the susceptibility to liquefaction of coals from different parts of the world. We and later authors will present data relative to coals of the areas with which we are familiar. However, with the Editor s approval, we are going to devote the first part of this paper to making some general remarks about coal geology and geochemistry, in the hope that this will provide a useful background to what comes later. 

Thus our rather small set of samples from a few selected areas of the U.S.A. shows a dispersion of some aspects of liquefaction behavior that is evidently associated with differences in the geology and geochemistry of the sample. Still more would we expect many sets of complex interrelationships between coal characteristics to emerge had we had a sufficiently large world-wide sample base to work with. 

The variety of life forms to be found near hydrothermal vents does not, of course, mean that life itself originated there these geological systems are much too unstable for that. The dynamics of tectonic plates cause the vents to disappear after some decades, or at most after a few hundred years. According to Nils Holm from the Department of Geology and Geochemistry at the University of Stockholm, the discovery of the hydrothermal vents led to intense, and in some cases controversial, discussions of the question as to whether hydrothermal systems were the birthplaces of life around four billion years ago. Many geologists believe that hydrothermal activity on the primeval Earth was probably stronger than it is today, as the thick... 

Hughes, R.E. and Smith, R.L. (1993). Archaeology, geology and geochemistry in obsidian provenance studies. In Effects of Scale on Archaeological and Geoscientific Perspectives, ed. Stein, J.K. and Linse, A.R., Special Papers 283, Geological Society of America, Boulder, pp. 79-91. 

Institute of Geology and Geochemistry of Combustible Minerals National Academy of Sciences of Ukraine 3N. Emmanuel Institute of Biochemical Physics ... 

Lydon, J.W., Paakki, J.J., Anderson, H.E., Reardon, N.C. 2000. An overview of the geology and geochemistry of the Sullivan deposit. In Lydon, J.W., Hoy, T., Slack, J.F. Knapp, K. (eds.), The Geological Environment of the Sullivan Deposit, British Columbia, Geological Association of Canada, Mineral Deposits Divison, Special... 

Sinclair, B.J. 1994. Geology and geochemistry of the Que River Shale, western Tasmania. BSc (Hons.) Thesis, University of Tasmania, Hobart. 

Luo, L. 1999. Geology and Geochemistry of the Jinwozi Gold Mine in Gansu, (in Chinese). Geological Exploration for Non-ferrous Metals, 8, 522-525 (in Chinese with English abstract). 

Dr. Jonathan Icenhower, Applied Geology and Geochemistry, Pacific Northwest National Laboratory, Richland, WA 99352, USA. 

Guillemette, N. (1991) Geology and geochemistry of the Ixtahuacan Sb-W Deposits, Northwestern Guatemala. Master s Thesis, McGill University, Montreal, QC, p. 110. 

Cinque A, Civetta L, Orsi G, Peccerillo A (1988) Geology and geochemistry of the island of Ustica (Southern Tyrrhenian Sea). Rend Soc It Mineral Petrol 43 987-1002... 

Bermuda investigating the geology and geochemistry of its waters and sediments. In the following discussion, we will expand on the Bermuda case history by integration of observational data from other areas, and theoretical and experimental arguments. 

Ashley, R. P., Cunningham, C. G., Bostick, N. H., Dean, W. E., and Chou, I.-M. (1991). Geology and geochemistry of three sedimentary-rock-hosted disseminated gold deposits in Guizhou Province, People s Republic of China. Ore Geol. Rev. 6, 133—151. 

Li, Z., and Peters, S. G. (1996). Geology and geochemistry of Chinese sediment-hosted (Carlin-type) gold deposits. Geological Society of America, Abstract with Program, 1996 Annual meeting, p. A153. 

Defant M. J., Clark L. E., Stewart R. H., Drummond M. S., de Boer J. Z., Maury R. C., Bellon H., Jackson T. E., and Restrepo J. F. (1991a) Andesite and dacite genesis via contrasting processes the geology and geochemistry of El VaUe Volcano, Panama. Contrib. Mineral. Petrol. 106, 309 -324. 

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