DEFORMASI KOMPLEKS DI PULAU SIMEULUE, SUMATRA: INTERAKSI ANTARA STRUKTUR DAN DIAPIRISME

Sonny Aribowo, Lina Handayani, Nugroho D. Hananto, Karit L. Gaol, Syuhada Syuhada, Titi Anggono

Abstract


The accretionary prism complex has unique morphological characteristic as a result of deformation and sedimentation processes that develop in the area. Simeulue Island is one example of the islands in the accretionary complex. Geological study was arranged to map geological structure and morphology of Simeulue Island by satellite images interpretation and field survey. We use Landsat TM 5, Landsat 8 and Aster-GDEM imageries for morphology and structural geology interpretation. The collision in the deformation front has generally developed reverse and thrust faults in the Simeulue Island. The north-northeast blocks tend to be higher than the south-southwest blocks. Based on imagery interpretation, the dominant thrusts are the trenchward-vergence thrusts. Measurement of structural features and folds reconstruction indicated the existence of the out-of-sequence thrusts, which might activated the arcward-vergence thrust. This arcward-vergence thrust could be interpreted as a backthrust fault of a backstop mechanism in the inner accretionary prism. The thrusts might be correlated to the mud diapirisms that were also found in some locations in the island. The finding of thrusts and mud diapirism traces concurred to the theory that the mélange complexes in subduction zones were formed through mud diapirism that facilitated by backthrust faults.


ABSTRAK

Kompleks prisma akresi memiliki karakteristik morfologi yang unik sebagai hasil dari proses deformasi dan sedimentasi yang berkembang di daerah tersebut. Pulau Simeulue merupakan salah satu contoh pulau yang terbentuk pada prisma akresi. Studi geologi dilakukan untuk menggambarkan keadaan struktur geologi yang terbentuk di Pulau Simeulue yang berhubungan dengan mekanisme pembentukan sesar-sesar anjak pada prisma akresi, pembentukan kompleks batuan bancuh dan mekanisme kubah lumpur. Morfologi dan struktur geologi Pulau Simeulue dipetakan melalui interpretasi citra dan survey lapangan. Citra yang digunakan dalam studi ini adalah citra Landsat TM5, Landsat 8 dan Aster-GDEM. Tumbukan di bagian muka deformasi mengakibatkan berkembangnya struktur berupa sesar-sesar naik dan anjak dimana di bagian utara-timurlaut cenderung lebih naik daripada bagian selatan-baratdaya. Berdasarkan hasil interpretasi citra, sesar-sesar yang berkembang tersebut umumnya merupakan sesar-sesar anjak berarah palung (trenchward-vergence thrusts). Berdasarkan hasil pengukuran fitur struktur di lapangan dan rekonstruksi lipatan di Pulau Simeulue, perkembangan struktur anjak juga terjadi secara out-of-sequence yang mengakibat-kan teraktifkannya sesar anjak berarah busur (arcward-vergence thrusts). Sesar anjak berarah palung dapat diinterpretasikan sebagai backthrust fault dari sebuah mekanisme backstop di bagian belakang prisma akresi. Sesar-sesar anjak ini dapat dikaitkan dengan keberadaan kubah lumpur (mud diapir) yang jejaknya juga ditemukan di beberapa lokasi di Pulau Simeulue. Hal-hal tersebut mendukung teori bahwa kompleks batuan mélange di Pulau Simeulue terbentuk melalui proses mud diapirism yang muncul melalui sesar-sesar anjak.


Keywords


Simeulue Island, mélange complex, accretionary prism, backthrust faults, mud diapir, subduction complex.

Full Text:

PDF

References


Akesson, M., 2008. Mud Diapir – a review. Bachelor Thesis. Lund University.

Aldiss, D.T., Whandoyo, R., Ghazali, S.A., dan Kusyono, 1993. Peta Geologi Lembar Sidikalang dan Sebagian Sinabang, Sumatra. Pusat Penelitian dan Pengembangan Geologi, Bandung.

Barber, A. J., Tjokrosapoetro, S. R., Charleton, T. R., 1986. Mud diapirs, shale diapirs, wrench faults, and mélanges in accretionary complexes, eastern Indonesia. AAPG Bull., 70. 1729-1741.

Barber, A.J. &Crow, M.J., 2005. Chapter 13: Structure and structural history. In: Barber, A.J., Crow, M.J.& Milsom, J.S. (eds), Sumatra: Geology, Resources and Tectonic Evolution. Geological Society, London, Memoirs, 31, 175-233.

Barber, A.J., 2013. The origin of mélanges : Cautionary tales from Indonesia. Journal of Asian Earth Sciences, 76, 428-438. DOI:10.1016/j.jseaes.2012.12.021.

Bellier, O., Sebrier, M., Pramumijoyo, S., 1991. La grande faille de Sumatra : Geometrie cinematique et quantite de deplacement mises en evidence par l’imagerie satellitaire. C. R. Acad. Sci. Paris II: 1219-1226.

Berglar, K., Gaedicke, C., Franke, D., Ladage, S., Klingelhoefer, F., & Djajadihardja, Y. S., 2010. Tectonophysics Structural evolution and strike-slip tectonics off north-western Sumatra. Tectonophysics, 480(1-4), 119-132. DOI:10.1016/j.tecto.2009.10.003.

Bons, P., 2009. Methods of structural geology. Httphompages.uni-tuebingen.

depaul.bonspaullecturesMethodenStrukturgeologiemethods_sg_01-2.pdf. Diunduh pada tanggal 28 September 2014.

Davis, D., Suppe, J., Dahlen, F.A., 1983. Mechanics of Fold-and-Thrust Belts and Accretionary Wedges. J. Geophys. Res. 88, 1153–1172.

Diament, M., Harjono, H., Karta, K., Deplus, C., Dahrin, D., Zen, M. T. & Malod, J., 1992. Mentawai fault zone off Sumatra: A new key to the geodynamics of western Indonesia. Geology, 20(3), 259-262.

Dimitrov, L. I., 2002. Mud diapires — the most important pathway for -egassing deeply buried sediments, 59, 49-76.

Endharto, M. dan Sukido, 1994. Peta Geologi Lembar Sinabang, Sumatra. Pusat Penelitian dan Pengembangan Geologi, Bandung.

Hulme, S. M., Wheat, C. G., Fryer, P., & Mottl, M. J., 2010. Pore waterchemistry of the Mariana serpentinite mud volcanoes : a window to the seismogenic zone, Geochem. Geophys. Geosyst., 11, Q01X09. DOI:10.1029/2009GC002674

Karig, D.E., Suparka, S., Moore, G.F., Hehanussa, P.E., 1979. Structure and Cenozoic Evolution of the Sunda Arc in the Central Sumatra region, in: Watkins, J.S., Montadert, L., Dickinson, P.W. (Eds.), Geological and Geophysical Investigations of Continental Margins, AAPG Memoir 29. American Association of Petroleum Geologist, pp. 223-227.

Kopf, A. J., 2002. Significance of mud volcanism, Rev Geophys., 40(2), 1005. DOI:10.1029/2000RG000093.

Kopp, H., Kukowski, N., 2003. Backstop geometry and accretionary mechanics of the Sunda margin. Tectonics 22, 11–1 – 11–16. DOI:10.1029/2002TC001420

Kopp, H., Weinrebe, W., Ladage, S., Barckhausen, U., Klaeschen, D., Flueh, E.R., Gaedicke, C., Djajadihardja, Y., Grevemeyer, I., Krabbenhoeft, a., Papenberg, C., Zillmer, M., 2008. Lower slope morphology of the Sumatra trench system. Basin Res., 20, 519–529. DOI:10.1111/j.1365-2117.2008.00381.x

Malod, J. A. dan B. M. Kemal, 1996. The Sumatra margin: oblique subduction and lateral displacement of the accretionary prism. Geological Society, London, Special Publications 1996, 106, 19-28. DOI:10.1144/GSL.SP.1996.106.01.03.

Marschall, H.R. & Schumacher, J.C., 2012. Arc magmas sourced from mélange diapirs in subduction zones.Nature Geoscience, 5(12), 862–867.

http://www.nature.com/doifinder/10.1038/ngeo1634 Diunduh pada 4 April 2014.

McCaffrey, R., 1992. Oblique plate convergence, slip vectors, and forearc deformation, Journ. of Geoph. Res., 97 (B6), 8905-8915.

McNeill , L. C., Henstock, T. J., 2013. Forearc structure and morphology along the Sumatra- Andaman subduction zone.

Tectonics.33.112–134. DOI:10.1002/2012TC3264.

Moore, G.F., Karig, D.E., 1980. Structural geology of Nias Island, western Indonesia, implications for subduction zone tectonics.American Journal of Science 280,193-223.

Mukti, M., Singh, S. C., Deighton, I., Hananto, N. D., Moeremans, R., & Permana, H., 2012. Structural evolution of backthrusting in the Mentawai Fault Zone, offshore Sumatran forearc. Geochemistry, Geophy-sics, Geosystems,13(12). DOI:10.1029/2012 GC004199.

Pramumijoyo , S., Natawidjaja, D. H., Kumoro, Y., Sudaryanto, 1994. Tinjauan geologi parameter bencana gempa Liwa. Makalah Ikatan Ahli Geologi Indonesia.PIT IAGI ke 23, Indonesia.

Reed, D. L., Silver. E. A., Tagudin, J. E., Shipley., T. H., Vrolijk, P. 1989. Relations between mud diapires, thrust deformation, slope sedimentation, and gas hydrate, offshore north Panama. Marine and Petroleum Geology, 7, 44-54.

Rowland, S. M., Duebendorfer, E. M., Schefelbein, I. M., 2007. Structural Analysis and Synthesis: a Laboratory Course in Structural Geology 3rd edition. Blackwell Publishing.pp. 322.

Sieh, K., Natawidjaja, D.H.,2000. Neotectonics of the Sumatran fault. Journal of Geophysical Research, 105, 28.295-28.326.

Schluter, H.U., Gaedicke, C., Roeser, H. a., Schreckenberger, B., Meyer, H., Reichert, C., Djajadihardja, Y., Prexl, a., 2002. Tectonic features of the southern Sumatra-western Java forearc of Indonesia. Tectonics 21 (5). DOI:10.1029/2001TC901048.

Shulgin, A., Kopp, H., Klaeschen, D., Papenberg, C., Tilmann, F., Flueh, E. R., & Franke, D., 2013. Subduction system variability across the segment boundary of the 2004 / 2005 Sumatra megathrust earthquakes. Earth and Planetary Science Letters, 365, 108-119. DOI:10.1016/j.epsl.2012.12.032

Singh, S. C., Carton, H., Tapponnier, P., Hananto, N. D., Chauhan, A. P. S., Hartoyo, D., Bayly, M., Moeljopranoto, S., Bunting, T., Christie, P., Lubis, H., Martin, J., 2008. Seismic evidence for broken oceanic crust in the 2004 Sumatra earthquake epicentral region. Nature Geoscience, 1, 777-781. DOI:10.1038/ngeo336.

Singh, S.C., Hananto, N., Mukti, M., Robinson, D., Das, S., Chauhan, A., Carton, H., Gratacos, B., Midnet, S., Djajadihardja, Y., Harjono, H., 2011a. Aseismic zone and earthquake segmentation associated with a deep subduted seamount. Nature Geoscience, 4, 308-311.

DOI:10.1038/ngeo1119.

Singh, S.C., Hananto, N., Mukti, M., Permana, H., Djajadiharja, Y., Harjono, H., 2011b. Seismic images of the megathrust rupture during the 25th October 2010 Pagai earthquake, SW Sumatra: Frontal rupture and large tsunami. Geophysical Research Letters, 38, L16313. DOI:10.1029/2011GL048935.

Williams, P. R., Pigram, C.J., Dow, D. B., 1984. Melange production and the importance of shale diapirism in accretionary terrains, Nature, 309, 145-146.




DOI: http://dx.doi.org/10.14203/risetgeotam2014.v24.89

Refbacks

  • There are currently no refbacks.


Copyright (c) 2014 Jurnal RISET Geologi dan Pertambangan

Copyright of Journal RISET Geologi dan  Pertambangan (e-ISSN 2354-6638 p-ISSN 0125-9849). Powered by OJS

  

Indexed by:

     

         

 

Plagiarism checker: