Karakteristik Geokimia Basalt Busur Gunungapi Tholeitik Formasi Manamas di Sungai Metan, Baun, Timor
DOI:
https://doi.org/10.33332/jgsm.geologi.v21i3.449Abstract
Lava basalt berstruktur bantal tersingkap di Sungai Metan, Baun, Timor, yang termasuk dalam anggota batuan gunung api Formasi Manamas. Penelitian geokimia batuan dilakukan menggunakan metode analisis XRF dan ICP-MS menunjukkan basalt memiliki karakteristik basalt subalkalin, bersifat tholeitik yang terbentuk pada busur gunungapi tholeitik akibat penunjaman Lempeng Samudera Hindia di bawah Busur Banda yang berumur Miosen-Pliosen. Basalt subalkali di Sungai Metan menunjukkan pengayaan unsur logam dan unsur large ion lithophile (LILE) yang dipengaruhi fluida, ditunjukkan oleh adanya hubungan positif antar unsur logam jejak mudah bergerak. Pengayaan yang dipengaruhi oleh fluida ditafsirkan sebagai produk akibat meleburnya lempeng samudera yang menunjam di bawah busur gunung api.
Katakunci: Basalt, busur tholeitik, Sungai Metan, Formasi Manamas, Timor.
Downloads
References
Arndt, N.T., Lesher, C.M., and Barnes, S.J., 2008. Komatiite. Cambridge University Press, Cambridge.
Audley-Charles, M.G., 1968. The Geology of Portuguese Timor. Memoir Geological Society of London, 4:76-96.
Audley-Charles, M.G., 2004. Ocean Trench Blocked and Obliterated by Banda Forearc Collision with Australian Proximal Continental Slope. Tectonophysics, 389: 65-79.
Audley-Charles, M.G., 2011. Tectonic Post-Collision Processes in Timor,. Dalam: Hall, R., Cottam, M.A., dan Wilson, M.E.J., (Eds.), The SE Asian Gateway: History and Tectonics of the Australia–Asia Collision. The Geological Society 355. London: 241-266.
Charlton, T.R., Barber, A.J., and Barkham, S.T., 1991. The Structural Evolution of the Timor Collision Complex, Eastern Indonesia. Journal of Structural Geology, 13: 489-500.
Dostal, J., Dupuy, C., Mruscott, M., Dautria, J.M., and Dautria, M., 1984. Uranium in Peridotite Inclusions in Basalts from Hoggar (Southern Algeria). Bulletin of Volcanology, DOI: 10.1007/BF01961231,
Harris, R.A., 1991. Temporal Distribution of Strain in the Active Banda Orogen: A Reconciliation of Rival Hypotheses. Journal SE Asian Earth Science, 6: 373-386.
Harris, R.A., Sawyer, R.K., and Audley-Charles, M.G., 1998. Collisional Mélange Development: Geologic Associations of Active Mélange-Forming Processes with Exhumed Mélange Facies in the Western Banda Orogen, Indonesia. Tectonics, 17: 458-480.
Harris, R.A., 2006. Rise and Fall of the Eastern Great Indonesian Arc Recorded by the Assembly, Dispersion and Accretion of the Banda Terrane, Timor. Gondwana Res., 10: 207-231.
Hastie, A.R., Kerr, A.C., Pearce, J.A., and Mitchell, S.F., 2007. Classification of Altered Volcanic Island Arc Rocks using Immobile Trace Elements: Development of the Th–Co Discrimination Diagram. Journal of Petrology, 48: 2341-2357.
Hollocher, K., Robinson, P., Walsh, E., and Roberts, D., 2012. Geochemistry of Amphibolite-Facies Volcanics and Gabbros of the Støren Nappe in Extensions West and Southwest of Trondheim, Western Gneiss Region, Norway: A Key to Correlations and Paleotectonic Settings. Am. Jour. Sci., 312(4): 357-416.
Ishikawa, A., Kaneko, K., Kadarusman, A., and Ota, T., 2007. Multiple Generations of Forearc Mafic–Ultramafic Rocks in the Timor–Tanimbar Ophiolite, Eastern Indonesia. Gondwana Research, 11: 200-217
Kaneko, Y., Maruyama, S., Kadarusman, A., Ota, T., Ishikawa, M., Tsujimori, T., Ishikawa, A., and Okamoto, K., 2006. On-Going Orogeny in the Outer-Arc of Timor–Tanimbar Region, Eastern Indonesia. Gondwana Research, 11: 216–231.
Keep, M. and Haig, D.W., 2010. Deformation and Exhumation in Timor: Distinct Stages of a Young Orogeny. Tectonophysics, 483: 93–111.
Rosidi, H.M.D., Tjokrosapoetro, S., dan Gafoer, S. 1996. Peta Geologi Lembar Kupang-Atambua Skala 1:250.000. Pusat Penenlitian dan Pengembangan Geologi, Bandung, Indonesia.
Shervais, J.W., 1982. Ti-V Plots and the Petrogenesis of Modern and Ophiolitic Lavas. Earth Planet. Sci. Lett., 59: 101-118.
Spakman, W. and Hall, R. 2010. Surface Deformation and Slab-Mantle Interaction During Banda Arc Subduction Rollback. Nature Geoscience, 3: 562–566.
Standley, C.E. and Harris, R.A. 2009. Tectonic Evolution of Forearc Nappes of the Active Banda Arc-Continent Collision: Origin, Age, Metamorphic History and Structure of the Lolotoi Complex, East Timor. Tectonophysics, 479: 66–94.
Sun, S.S. and McDonough, W.F., 1989. Chemical and Isotopic Systematics of Oceanic Basalt: Implications for Mantle Composition and Process. Dalam: Saunders, A.D. and Norry, M.J. (Eds.), Magmatism in the Ocean Basins. Geological Society, London, Special Publications 42. GSL, London: 313–345.
Wahyudiono, J., Safri, I., Sudrajat, A., dan Panggabean, H., 2016. Geokimia Batuan Gunungapi di Pulau Timor Bagian Barat dan Implikasi Tektoniknya. Jurnal Geologi dan Sumberdaya Mineral, 17(4): 241-252.
Winchester, J.A. and Floyd, P.A., 1976. Geochemical Magma Type Discrimination: Application to Altered and Metamorphosed Basic Igneous Rocks. Earth and Planetary Science Letters, 28 (3): 459-469.
Zhao, J.J. and Zhou, M.F., 2006. Neoproterozoic Mafic Intrusions in the Panzhihua District, SW China: Implications for Iinteraction Between Subducted Slab and Mantle Wedge. Geochim. Cosmochim. Acta, 70: A740–A1740.
Downloads
Published
Issue
Section
License
Authors who publish articles in Jurnal Geologi dan Sumberdaya Mineral (JGSM.Geologi) agree to the following terms:
- Authors retain copyright of the article and grant the journal right of first publication with the work simultaneously licensed under a CC-BY-NC or The Creative Commons Attribution–ShareAlike License.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access)
