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Characterization and genesis of horizontal banding in Brazilian agate: an X-ray diffraction, thermogravimetric and electron microprobe study

Published online by Cambridge University Press:  05 July 2018

T. Moxon ,
C. M. Petrone  and
S. J. B. Reed
T. Moxon*
Affiliation:
55 Common Lane, Auckley, Doncaster DN9 3HX, UK
C. M. Petrone
Affiliation:
Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
S. J. B. Reed
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
*
* E-mail: moxon.t@tiscali.co.uk
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Abstract

Characterization of Brazilian agates containing a lower horizontally banded section and an upper chamber with bands parallel to the walls shows that these agates formed much later than the 135 Ma Paraná basalt host rock. Age differentiation between the two types of banding shows that the horizontal bands formed between 43 to 63 Ma ago with a final infill of wall-lining bands between 7 and 27 Ma later. The horizontal bands have a higher Al3+ concentration and a greater crystallite size than the wall-lining layers; they have a lower mogánite content and defect-site water content. The formation of these agates appears to be the result of a three-stage process. After the separate formation of horizontally banded and wall-lining agate, a silica infill seals the gap between the agate and the cavity wall. The detection of cristobalite in some specimens indicates that genesis of both the horizontally banded and wall-lining deposits in the Brazilian samples proceeds along an amorphous silica → opal-CT → opal-C → chalcedony pathway.

Keywords

agatechalcedonymogánitecristobalitehorizontal bandsgenesis
Type
Research Article
Information
Mineralogical Magazine , Volume 77 , Issue 3 , April 2013 , pp. 227 - 248
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Barreto, S.B. and Bittar, S.M.B. (2010) The gemstone deposits of Brazil: occurrences, production and economic impact. Boletín de le Sociedad Geolo´gica Mexicana, 62, 123–140.CrossRefGoogle Scholar
Bish, D.L. and Reynolds, R.C. Jr (1989) Sample preparation for X-ray diffraction. Pp. 73–99. in: Modern Powder Diffraction (D.L. Bish and J.E Post, editors). Reviews in Mineralogy, 20. Mineralogical Society of America, Washington D.C. Google Scholar
Blankenburg, H.J., Pilot, J. and Werner, C.D. (1982) Erste Ergebnisse der Sauerstoffisotopenuntersuchungen an Vulkanitachaten und ihre genetische Interpretation. Chemie der Erde, 41, 213–217. [English abstract].Google Scholar
Clark, R. (2009) South Dakota State Gemstone: Fairburn Agate. Silverwind Agates, Appleton, USA, 130 pp.Google Scholar
Collini, C. (1776) Journal d’un voyage, qui contient différents observations minéralogiques sur les agates et le basalte. After Liesegang R.E. (1915) Die Achate, Dresden, Leipzig.Google Scholar
Commin-Fischer, A., Berger, G., Polvé, M., Dubois, M., Sardini, P., Beaufort, D. and Formoso, M. (2010) Petrography and chemistry of SiO2 filling phases in the amethyst geodes from Sierra Geral Formation deposit, Rio Grande do Sul, Brazil. Journal of South American Earth Sciences, 29, 751–760.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1992) An Introduction to the Rock-Forming Minerals, Longman, Harlow, UK, 696 pp.Google Scholar
Daniels, F.J. and Dayvault, R.D. (2006) Ancient Forests. Western Colorado Publishing Co., Grand Junction, Colorado, USA, 450 pp.Google Scholar
Dumen´ska-Słowik, M., Natkaniec-Nowak, L., Kotarba, M.J., Sikorska, M., Rzymełka, J.A., Łoboda, A. and Gaweł, A. (2008) Mineralogical and geochemical characterization of the “bituminous” agates from Nowy Kos´cioł (Lower Silesia, Poland). Neues Jahrbuch für Mineralogie Abhandlungen, 184/3, 255–268.CrossRefGoogle Scholar
Fallick, A.E., Jocelyn, J., Donelly, T., Guy, M. and Behan, C. (1985) Origin of agates in the volcanic rocks of Scotland. Nature, 313, 672–674.CrossRefGoogle Scholar
Fallick, A.E., Jocelyn, J. and Hamilton, P.J. (1987) Oxygen and hydrogen stable isotope systematics in Brazilian agates. Pp. 99–117. in: Geochemistry and Mineral Formation in the Earth Surface (Rodriguez Clemente, E. and Tardy, Y., editors). CSIC, Madrid.Google Scholar
Fauvelet, E. and Ettekhar-Nezhad, J. (1992) Explanatory Text of the Gonabad Quadrangle Map: 1:250 000. Geological Survey of Iran, Tehran.Google Scholar
Feth, J.H., Rogers, S.M. and Roberson, C.E. (1961) Aqua de Ney, California, a spring of unique chemical character. Geochimica et Cosmochimica Acta, 22, 75–86.CrossRefGoogle Scholar
Flörke, O.W., Köhler-Herbertz, B., Langer, K. and Tönges, I. (1982) Water in microcrystalline quartz of volcanic origin: agates. Contributions to Mineralogy and Petrology, 80, 324–333.CrossRefGoogle Scholar
Götze, J. (2011) Agate – fascination between legend and science. Pp. 20–133. in: Agates III (Zenz, J., editor). Bode, Lauenstein, Germany.Google Scholar
Götze, J., Tichomirowa, M., Fuchs, H., Pilot, J. and Sharp, Z.D. (2001a) Geochemistry of agates: a trace element and stable isotope study. Chemical Geology, 175, 523–541.CrossRefGoogle Scholar
Götze, J., Plötze, M. and Habermann, D. (2001b) Origin, spectral characteristics and practical applications of the cathodoluminescence (CL) of quartz – a review. Mineralogy and Petrology, 71, 225–250.Google Scholar
Götze, J., Möckel, R., Kempe. U., Kapitonov, I. and Vennemann, T. (2009) Characteristics and origin of agates in sedimentary rocks from the Dryhead area, Montana, USA. Mineralogical Magazine, 73, 673–690.CrossRefGoogle Scholar
Graetsch, H., Flörke, O.W. and Miehe, G. (1985) The nature of water in chalcedony and opal-C from Brazilian agate geodes. Physics and Chemistry of Minerals, 12, 300–306.CrossRefGoogle Scholar
Grigor’ev, D.P. (1965) Ontogeny of minerals. Israel Program for Scientific Translations, 250 pp.Google Scholar
Haidinger, W. (1849) Versammlungsberichte. Berichte über die Mittheilungen von Freunden der Naturwissenschaften in Wien, 65, 61–69. and 118–120.Google Scholar
Harris, C. (1989) Oxygen-isotope zonation of agates from Karoo volcanics of the Skeleton coast, Namibia. American Mineralogist, 74, 476–481.Google Scholar
Hartmann, L.A., Duarte, L.C., Massonne, H.J., Michelin, C., Manara, L., Rosenstengel, L.M., Bergmann, M., Theye, T., Pertile, J., Arena, K.R., Duarte, S.K., Pinto, V.M., Barboza, E.G., Rosa, M.L.C.C. and Wildner, W. (2012) Sequential opening and filling of cavities forming vesicles, amygdales, and giant amethyst geodes in lavas from the southern Paraná volcanic province, Brazil and Uruguay. International Geology Review, 54, 1–14.CrossRefGoogle Scholar
Herdianita, N.R., Browne, P.R.I., Rodgers, K.A. and Campbell, K.A. (2000) Mineralogical and textural changes accompanying ageing of silica sinter. Mineralium Deposita, 35, 48–62.CrossRefGoogle Scholar
Hesse, R. (1988) Diagenesis #13. Origin of chert: diagenesis of biogenic siliceous sediments. Geoscience Canada, 15, 171–192.Google Scholar
Holzhey, G. (1999) Mikrokristalline SiO2– Mineralisation in rhyolithischen Rotliegendvulkaniten des Thüringer Waldes (Deutschland) und ihre Genese. Chemie der Erde, 59, 183–205. [English abstract].Google Scholar
Hopkinson, L., Roberts, S., Herrington, R. and Wilkinson, J. (1998) Self-organisation of submarine hydrothermal siliceous deposits: evidence from the TAG hydrothermal mound 26º N Mid-Atlantic Ridge. Geology, 26, 347–350.2.3.CO;2>CrossRefGoogle Scholar
Jones, B.F., Eugster, H.P. and Rettig, S.L. (1977) Hydrochemistry of the Lake Magadi basin, Kenya. Geochimica et Cosmochimica Acta, 41, 53–72.CrossRefGoogle Scholar
Kinnunen, K.A. and Lindquist, K. (1998) Agate as an indicator of impact structures: an example from Sääksjärvi, Finland. Meteoritics and Planetary Science, 33, 7–12.CrossRefGoogle Scholar
Knauth, L.P. (1994) Petrogenesis of chert. Pp. 233–258. in: Silica (Heaney, P.J., Prewitt, C.T. and Gibbs, G.V., editors). Reviews in Mineralogy, 29. Mineralogical Society of America, Washington D.C. Google Scholar
Krauskopf, K.B. (1956) Dissolution and precipitation of silica at low temperatures. Geochimica et Cosmochimica Acta, 10, 1–26.CrossRefGoogle Scholar
Landmesser, M. (1984) Das Problem der Achatgenese. Mitt Pollichia, 72, 5–137. [English abstract].Google Scholar
Landmesser, M. (1995) “Mobility by metastability”: silica transport and accumulation at low temperatures. Chemie der Erde, 55, 149–176.Google Scholar
Landmesser, M. (1998) “Mobility by metastability” in sedimentary and agate petrology: applications. Chemie der Erde, 58, 1–22.Google Scholar
Lange, P., Blankenburg, H.J., Schron, W. (1984) Rasterelektronmikroskopische Untersuchungen an Vulkanachaten. Zeitschrift für Geologische Wissenschaften, 12, 669–683. [English abstract].Google Scholar
Lynne, B.Y. (2012) Mapping vent to distal-apron hot spring paleo-flow pathways using siliceous sinter architecture. Geothermics, 43, 3–24.CrossRefGoogle Scholar
Lynne, B.Y., Campbell, K.A., Perry, R.S., Browne, P.R.L. and Moore, J.N. (2006) Acceleration of sinter diagenesis in an active fumarole, Taupo volcanic zone, New Zealand. Geology, 34, 749–752.CrossRefGoogle Scholar
Lynne, B.Y., Campbell, K.A., James, B.J., Browne P.R.L. and Moore, J. (2007) Tracking crystallinity in siliceous hot-spring deposits. American Journal of Science, 307, 612–641.CrossRefGoogle Scholar
Matsui, E., Salti, E. and Marini, O.J. (1974) D/H and 18O/16O ratios in waters contained in geodes from the basaltic province of Rio Grande do Sul, Brazil. Geological Society of America Bulletin, 85, 577–580.2.0.CO;2>CrossRefGoogle Scholar
Meng, S.X. and Maynard, J.B. (2001) Use of statistical analysis to formulate conceptual models of geochemical behaviour: water chemical data from Botucatu aquifer in Sa˜o Paulo state, Brazil. Journal of Hydrology, 250, 78–97.CrossRefGoogle Scholar
Miehe, G., Graetsch, H. and Flörke, O.W. (1984) Crystal structure and growth fabric of length-fast chalcedony. Physics and Chemistry of Minerals, 10, 197–199.CrossRefGoogle Scholar
Möckel, R., Götze, J., Sergeev, S.A., Kapitonov, I.N., Adamskaya, E.V., Goltsin, N.A. and Vennemann, T. (2009) Trace-element analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS): a case study for agates from Nowy Kos´ciol, Poland. Journal of Siberian Federal University, Engineering and Technologies, 2, 123–138.Google Scholar
Moxon, T.J. (1996) The co-precipitation of Fe3+ and SiO2 and its role in agate genesis. Neues Jahrbuch für Mineralogie, Monatschefte, 1996, 21–36.Google Scholar
Moxon, T. (2002) Agate: a study of ageing. European Journal of Mineralogy, 14, 1109–1118.CrossRefGoogle Scholar
Moxon, T and Carpenter, M.A. (2009) Crystallite growth kinetics in nanocrystalline quartz (agate and chalcedony). Mineralogical Magazine, 73, 551–568.CrossRefGoogle Scholar
Moxon, T. and Reed, S.J.B. (2006) Agate and chalcedony from igneous and sedimentary hosts aged 13 to 3480 Ma: a cathodoluminescence study. Mineralogical Magazine, 70, 485–498.CrossRefGoogle Scholar
Moxon, T. and Ríos, S. (2004) Mogánite and water content as a function of age in agate: an XRD and thermogravimetric study. European Journal of Mineralogy, 16, 269–278.CrossRefGoogle Scholar
Moxon, T., Nelson, D.R. and Zhang, M. (2006) Agate recrystallisation: evidence from samples found in Archaean and Proterozoic host rocks, Western Australia. Australian Journal of Earth. Sciences, 53, 235–248.Google Scholar
Nacken, R. (1948) Über die Nachbildung von Chalcedon-Mandeln. Natur und Volk, 78, 2–8.Google Scholar
Neymark, L.A., Amelin, Y., Paces, J.B. and Peterman, Z.E. (2002) U-Pb ages of secondary silica at Yucca Mountain, Nevada: implications for the paleohydrology of the unsaturated zone. Applied Geochemistry, 17, 709–734.CrossRefGoogle Scholar
Nöggerath, J. (1849) Sendschreiben an den K.K. Wirklichen Bergrath und Professor Herrn W. Haidinger in Wien, über die Achat-Mandeln in den Melaphyren. Verhandlungen des Naturhistorischen Vereines der Preussischen Rheinlande und Westphalens, 6, 243–260.Google Scholar
Peate, D.W., Hawksworth, C.J. and Mantovani, M.S.M. (1992) Chemical stratigraphy of the Paraná lavas (South America): classification of magma types and their spatial evolution. Bulletin of Volcanology, 55, 119–139.CrossRefGoogle Scholar
Petránek, J. (2004) Gravitational banded (Uruguay-type) agates in basaltic rocks – where and when? Bulletin of Geosciences, 79, 195–204.Google Scholar
Petry, K., Jerram, D.A., de Almeida, D.P.M. and Zerfass, H. (2007) Volcanic-sedimentary features in the Serra Geral Fm., Paraná Basin, southern Brazil: examples of dynamic lava-sediment interactions in an arid setting. Journal of Volcanology and Geothermal Research, 159, 313–325.CrossRefGoogle Scholar
Pinto, V.M., Hartman, L.A., Santos, J.O.S., McNaughton, N.J. and Wildner, W. (2011) Zircon U-Pb geochronology from the Paraná bimodal volcanic province support a brief eruptive cycle at ~135 Ma. Chemical Geology, 281, 93–102.CrossRefGoogle Scholar
Proust, D. and Fontaine, C. (2007) Amethyst geodes in the basaltic flow from Triz quarry at Ametista do Sul (Rio Grande do Sul, Brazil): magmatic source of silica for the amethyst crystallizations. Geology Magazine, 144, 731–739.CrossRefGoogle Scholar
Reis, O.M. (1918/19) Einzelheitenüber Bau und Entstehung von Enhydros, Kalzitachat und Achat II. Geognostische Jahreshefte, 31/32, 1–92.Google Scholar
Rodgers, K.A., Browne, P.R.L., Buddle, T.F., Cook, K.L., Greatrez, R.A., Hampton, W.A., Herdianita, N.R., Holland, G.R., Lynne, B.Y., Martin, R., Newton, Z., Pastars, D., Sannazarro, K.L. and Teece, C.I.A. (2004) Silica phases in sinters and residues from geothermal fields of New Zealand. Earth Science Reviews, 66, 1–61.CrossRefGoogle Scholar
Saunders, J.A. (1990) Oxygen-isotope zonation of agates from Karoo volcanic of the Skeleton Coast, Namibia: discussion. American Mineralogist, 75, 1205–1206.Google Scholar
Scherer, C.M.S. (2000) Eolian dunes of the Botucatu Formation (Cretaceous) in southernmost Brazil: morphology and origin. Sedimentary Geology, 137, 63–84.CrossRefGoogle Scholar
Smith, J. (1910) Semi-Precious Stones of Carrick. Cross Kilwinning, 84 pp.Google Scholar
Strieder, A.J. and Heemann, R. (2006) Structural constraints on Paraná basalt volcanism and their implications on agate geode mineralization (Salto do Jacui, RS, Brazil). Pesquisas em Geoscieˆncias, 33, 37–50.CrossRefGoogle Scholar
Stevens Kalceff, M.A. and Philips, M.R. (1995) Cathodoluminescence microcharacterization of the defect structure of quartz. Physical Review B, 52, 3122–3134.CrossRefGoogle Scholar
Stöcklin, J and Nabavi, M.H. (1971) Explanatory Text of the Boshruyeh Quadrangle Map: 1:250 000, No J7. Geological Survey of Iran, Tehran.Google Scholar
Taijing, L. and Sunagawa, I. (1994) Texture formation of agate in geode. Mineralogical Journal, 17, 53–76.CrossRefGoogle Scholar
Walger, E., Matthess, G., von Seckendorff, V. and Liebau, F. (2009) The formation of agate structures: models for silica transport, agate layer accretion, and for flow patterns and flow regimes in infiltration canals. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 186, 113–152.CrossRefGoogle Scholar
Wang, Y. and Merino, E. (1990) Self-organizational origin of agates: Banding, fiber twisting, composition and dynamic crystallization model. Geochimica et Cosmochimica Acta, 54, 1627–1638.CrossRefGoogle Scholar
Yamagishi, H., Nakashima, S. and Ito, Y. (1997) High temperature infrared spectra of hydrous microcrystalline quartz. Physics and Chemistry of Minerals, 24, 66–74.CrossRefGoogle Scholar
Zhang, M. and Moxon, T. (2012) In situ infrared spectroscopic studies of OH, H2O, and CO2 in mogánite at high temperatures. European Journal of Mineralogy, 24, 123–131.CrossRefGoogle Scholar