EAP - Oil Shale publications

PUBLISHED
SINCE 1984

Oil Shale

ISSN 1736-7492 (Electronic)
ISSN 0208-189X (Print)

Impact Factor (2022): 1.9

LECHATELIERITE-BEARING MICROSPHERULES FROM SEMICOKE HILL (KIVIÕLI, ESTONIA): CONTRIBUTION TO THE CONTAMINATION PROBLEM OF NATURAL MICROTEKTITES; pp. 415–423

PDF | doi: 10.3176/oil.2009.3.06

Authors

F. MARINI, A. RAUKAS

Abstract

During the course of the last hundred years, microscopic magnetite and glassy spherules of different genesis (extraterrestrial, volcanic, industrial, biogenic, diagenic, explosive, etc.) have often been found in various geological formations. Alongside classical geological methods, research into extraterrestrial and explosive spherules can provide valuable information and facilitates stratigraphical correlations over large areas. Several authors have recently stressed that studies on cosmic- and impact-related microspherules may seriously be hampered by outcrop- and laboratory contamination. Fly-ash particles and steel slags resembling iron-rich cosmic spheres are the most frequently invoked industrial contaminants. In contrast, little attention has been paid to glassy spherules of industrial origin that might resemble microtektites. Our finding of lechatelierite inclusions in obvious industrial provenance might cast serious doubts of the validity of the classical « Lechatelierite Criterion » as a test for impact glasses.

References

1. Montanari, A., Koeberl, C. Impact stratigraphy: the Italian record. Lecture Notes in Earth Sciences 93. – Berlin; Heidelberg; New York: Springer-Verlag, 2000. P. 364.

2. Raukas, A. Investigation of impact spherules – a new promising method for the correlation of Quaternary deposits // Quaternary International.2000. Vol. 68–71. P. 241–252.
doi:10.1016/S1040-6182(00)00047-1

3. Montanari, A. Spherules from the Cretaceous/Tertiary boundary clay at Gubbio, Italy; the problem of outcrop contamination // Geology. 1986. Vol. 14, No. 12. P. 1024–1026.

4. Wang, K., Chatterton, B. D. E. Microspherules in Devonian sediments; origins, geological significance, and contamination problems // Can. J. Earth Sci. 1993. Vol. 30, No. 8. P. 1660–1667.

5. Marini, F. Natural microtektites versus industrial glass beads: an appraisal of contamination problems // J. Non-Cryst. Solids. 2003. Vol. 323, No. 1–3. P. 104–110.
doi:10.1016/S0022-3093(03)00296-5

6. Marini, F., Raukas, A., Tiirmaa, R. Magnetic fines from the Kaali impact-site (Holocene, Estonia): Preliminary SEM investigation // Geochem. J. 2004. Vol. 38, No. 2. P. 107–120.

7. Raukas, A. Distribution and composition of impact and extraterrestrial spherules in the Kaali area (Island of Saaremaa, Estonia) // Geochem. J. 2004. Vol. 38, No. 2. P.101–106.

8. Chao, E. C. T. The petrographic and chemical characteristics of tektites // Tektites / O’Keefe, J. A. (ed.). Chicago: University of Chicago Press, 1963. P. 51–94.

9. Glass, B. P. Tektites and microtektites: key facts and inferences // Tectonophysics. 1990. Vol. 171, No. 1–4. P. 393–404.

10. Kattai, V. Oil shale – source of oil. – Tallinn: Eesti Geoloogiakeskus, 2006. P. 216 [in Estonian with English summary].

11. Orupõld, K., Habicht, J., Tenno, T. Leaching behaviour of oil shale semicoke compliance with the waste acceptance criteria for landfills // Oil Shale. 2008. Vol. 25, No. 2. P. 267–275.

12. Diamond, S. The characterisation of fly ashes // Materials Research Society Annual Meeting, 1981, Symposium N / Diamond, S. (ed.). Boston, 1981. P. 12–23.

13. Deer, W. A., Howie, R. A., Zussman, J. Rock Forming Minerals. Vol. 1. – London: Longmans, 1963. P. 236–255.

14. Raukas, A., Teedumäe, A. (eds.). Geology and Mineral Resources of Estonia. Institute of Geology. – Tallinn: Estonian Academy Publishers, 1997. P. 436.

15. Mõtlep, R., Kirsimäe, K., Talviste, P., Puura, E., Jürgenson, I. Mineral composition of Estonian oil shale semicoke sediments // Oil Shale. 2007. Vol. 24, No. 3. P. 405–422.

Back to Issue