GEOCHEMISTRY OF SEABED AND COASTAL SEDIMENTS IN LIMAU WATERS AREA
Abstract
Sediment provenance and weathering history are used to understand sedimentary processes and to explore mineral potential in coastal–marine systems in the Limau Waters. Therefore, the characteristics of seabed and coastal sediments need to be determined. This study aims to identify the source rocks, paleoweathering signatures, and sediment maturity of both seabed and coastal sediments through a geochemical approach. A geochemical approach that integrates major oxide and rare earth element (REE) analyses, the paleoweathering, and sediment maturity indices, is used to identify the source rocks of these sediments. Major oxides elements were measured using X-ray fluorescence (XRF) and REE concentrations were determined using inductively coupled plasma - optical emission spectrometry (ICP-OES) and inductively coupled plasma optical - mass spectrometry (ICP-MS). Geochemical discrimination diagrams indicate that seabed sediments are mainly derived from intermediate to felsic igneous rocks with higher compositional maturity, whereas coastal sediments are influenced by mafic volcanic rocks and are comparatively immature in composition. Both sediment types exhibit weak chemical weathering (CIA < 70), suggesting limited alteration of young volcanic sources. The CIA–ICV relationships portray contrast sediment transport and depositional processes between the coastal and marine environments. This study is expected to provide a geochemical-based framework for provenance analysis and to support the development of insights for future marine mineral exploration in the Limau Waters area.
Keywords
Full Text:
PDFReferences
Advokaat, E. L., Bonger, M. L. M., Rudyawan, A., BouDagher-Fadhel, M. K., Langereis, C. G., & van Hinsbergen, D. J. J., 2018. Early Cretaceous origin of the Woyla Arc, Sumatra. Earth and Planetary Science Letters, 498, 348–361.
Anenburg, M., & Liu, Y., 2024. A Global Marine Sediment Compilation and a Cerium Anomaly Perspective on Metasomatized Mantle Sources for REE-Mineralized Carbonatites. Journal of Geophysical Research: Solid Earth, 129(7), e2023JB028546. https://doi.org/10.1029/2023JB028546
Amin, T. C., Sidarto, Santosa, S., & Gunawan, W., 1993. Peta geologi bersistem lembar Kotaagung skala 1:250.000. Pusat Penelitian dan Pengembangan Geologi, Departemen Pertambangan dan Energi.
Barber, A. J., & Crow, M. J., 2005. Structure and structural history. In A. J. Barber, M. J. Crow, & J. S. Milsom (Eds.), Sumatra: Geology, resources, and tectonic evolution (Geological Society Memoir No. 31, pp. 295–310). Geological Society, London.
Bau, M., Möller, P., & Dulski, P., 1997. Yttrium and lanthanides in eastern Mediterranean seawater and their fractionation during redox-cycling. Marine Chemistry, 56(1-2), 123-131. https://doi.org/10.1016/S0304-4203(96)00091-6
BBSPGL., 2024. Laporan Survei Prospeksi Mineral Letakan Emas (Au Placer) Di Perairan Limau Dan Sekitarnya, Teluk Semangko, Provinsi Lampung. Balai Besar Survei dan Pemetaan Geologi Kelautan. [Internal report, unpublished].
Cox, R., Lowe, D. R., & Cullers, R. L., 1995. The influence of sediment recycling and basement composition on evolution of mudrock chemistry in the southwestern United States. Geochimica et Cosmochimica Acta, 59(14), 2919–2940. https://doi.org/10.1016/0016-7037(95)00185-9
Crow, M. J., & van Leeuwen, T. M., 2005. Metallic mineral deposits. In A. J. Barber, M. J. Crow, & J. S. Milsom (Eds.), Sumatra: Geology, resources and tectonic evolution (Geological Society Memoir No. 31, pp. 147–174). Geological Society, London.
Cruz, A., Dinis, P. A., Gomes, A., & Leite, P., 2021. Influence of sediment cycling on the rare-earth element geochemistry of fluvial deposits. Geosciences, 11(9), 384. https://doi.org/10.3390/geosciences11090384
Cullers, R. L., 1994. The controls on the major and trace element evolution of shales, siltstones, and sandstones of Ordovician to Tertiary age in the western United States. Chemical Geology, 114, 297–323.
Darlan, Y., 1997. Sedimen permukaan dasar laut sebagai perangkap endapan emas letakan di perairan Teluk Semangko, Lampung Selatan. In Proceedings of the Indonesian Geologists Association at the XXVI Annual Scientific Meeting (pp. 913–922). Jakarta.
Ekoa Bessa, A. Z., Ndjigui, P. D., Fuh, G. C., Armstrong-Altrin, J. S., & Betsi, T. B., 2021. Mineralogy and geochemistry of the Ossa Lake Complex sediments, Southern Cameroon: Implications for paleoweathering and provenance. Arabian Journal of Geosciences, 14, 322. https://doi.org/10.1007/s12517-021-06646-3
Fedo, C. M., Nesbitt, H. W., & Young, G. M., 1995. Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for paleoweathering conditions and provenance. Geology, 23, 921–924.
Garzanti, E., Resentini, A., & Andò, S., 2018. Provenance of passive‐margin sand (southern Africa). Journal of Sedimentary Research, 88(1), 47–64.
Gaspar, L., Blake, W. H., Lizaga, I., Latorre, B., & Navas, A., 2022. Particle size effect on geochemical composition of experimental soil mixtures relevant for unmixing modelling. Geomorphology, 403, 108178. https://doi.org/10.1016/j.geomorph.2022.108178
Guan, Y., Chen, Y., Sun, X., Xu, L., Xu, D., Zhu, Z., & He, W., 2023. The Clay Mineralogy and Geochemistry of Sediments in the Beibu Gulf, South China Sea: A Record of the Holocene Sedimentary Environmental Change. Journal of Marine Science and Engineering, 11(7), 1463. https://doi.org/10.3390/jmse11071463
Hayashi, K. I., Fujisawa, H., Holland, H. D., & Ohmoto, H., 1997. Geochemistry of ~1.9 Ga sedimentary rocks from northeastern Labrador, Canada. Geochimica et Cosmochimica Acta, 61, 4115–4137.
Harnois, L., 1988. The CIW index: A new chemical index of weathering. Sedimentary Geology, 55, 319–322.
Irzon, R., 2020. Komparasi geokimia batuan gunung api Kuarter dan Tersier di Tepian Selatan Lampung. Eksplorium, 41(2), 101–114. https://doi.org/10.17146/eksplorium.2020.41.2.6053
Li, X., Ge, J., Zhao, X., Qi, K., Jones, B. G., & Fang, X., 2024. Geochemistry of Quaternary sediments in the northwestern South China Sea: Sediment provenance and mid-Pleistocene transition. Marine Geology, 477, 107371. https://doi.org/10.1016/j.margeo.2024.107371
McDonough, W. F., & Sun, S. -s., 1995. The composition of the Earth. Chemical Geology, 120(3), 223–253. https://doi.org/https://doi.org/10.1016/0009-2541(94)00140-4
McLennan, S. M., 1989. Rare earth elements in sedimentary rocks: Influence of provenance and sedimentary processes. In B. R. Lipin & G. A. McKay (Eds.), Geochemistry and mineralogy of rare earth elements (Reviews in Mineralogy, Vol. 21, pp. 169–200). Mineralogical Society of America. https://doi.org/10.1515/9781501509032-010
McLennan, S. M., Hemming, S. R., McDaniel, D. K., & Hanson, G. N., 1993. Geochemical approaches to sedimentation, provenance, and tectonics. In Processes controlling the composition of clastic sediments (Geological Society of America Special Paper 284, pp. 21–40). Geological Society of America.
Metcalfe, I., 2017. Tectonic evolutions of Sundaland. Bulletin of the Geological Society of Malaysia, 63, 27–60. https://doi.org/10.7186/bgsm63201702
Morton, A. C., 2002. Provenance indicators and their value in sedimentary petrology. In: Provenance of Arenites (pp. 113–142). Springer, Dordrecht.
Muksin, I., & Heditama, D. M., 2016. Laporan eksplorasi umum endapan zeolit Kecamatan Limau, Kabupaten Tanggamus Provinsi Lampung. Pusat Sumber Daya Mineral, Batubara dan Panas Bumi. [Internal report, unpublished].
Nagarajan, R., Eswaramoorthi, S. G., Anandkumar, A., & Ramkumar, M., 2023. Geochemical fractionation, mobility of elements and environmental significance of surface sediments in a Tropical River, Borneo. Marine Pollution Bulletin, 192, 115090. https://doi.org/10.1016/j.marpolbul.2023.115090
Nesbitt, H. W., & Young, G. M., 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature, 299, 715–717. https://doi.org/10.1038/299715a0
Nesbitt, H. W., & Young, G. M., 1984. Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations. Geochimica et Cosmochimica Acta, 48, 1523–1534.
Patias, D., Zhou, R., Aitchison, J. C., Cluzel, D., Ireland, T., Lian, D., & Yang, J., 2024. Beyond zircon fingerprinting: Zircon and TiO2 polymorphs constrain genealogy and evolution of the New Caledonian ophiolite. Chemical Geology, 644, 121841. https://doi.org/10.1016/j.chemgeo.2023.121841
Ramos-Vázquez, M.A., Armstrong-Altrin, J.S. Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas State, northwestern Gulf of Mexico. J. Palaeogeogr. 10, 20, 2021. https://doi.org/10.1186/s42501-021-00101-4
Roser, B. P., & Korsch, R. J., 1988. Provenance signatures of sandstone–mudstone suites determined using discriminant function analysis of major-element data. Chemical Geology, 67, 119–139.
Ruban, A., Dudarev, O., Rudmin, M., & Semiletov, I., 2024. Rare Earth Elements in Sediments from the Laptev Sea Shelf: Insight into Sources and Distribution Factors. Quaternary, 7(1), 12. https://doi.org/10.3390/quat7010012
Sousa, T. A., Venancio, I. M., Marques, E. D., Figueiredo, T. S., Nascimento, R. A., Smoak, J. M., Albuquerque, A. L., Valeriano, C. M., & Vieira, E., 2022. REE Anomalies Changes in Bottom Sediments Applied in the Western Equatorial Atlantic Since the Last Interglacial. Frontiers in Marine Science, 9, 846976. https://doi.org/10.3389/fmars.2022.846976
Sukardjono, H., Kurnio, H., Hardjawidjaksana, K., Lugra, I. W., Silitonga, F., & Budiman., 1990. Laporan penyelidikan geologi dan geofisika di kawasan Kompleks Teluk Semangko, Lampung Selatan. Pusat Pengembangan Geologi Kelautan. [Internal report, unpublished].
Taylor, S. R., & McLennan, S. M., 1985. The Continental Crust: Its Composition and Evolution. Oxford: Blackwell.
Zhang, K., & Shields, G. A., 2022. Sedimentary Ce anomalies: Secular change and implications for paleoenvironmental evolution. Earth-Science Reviews, 229, 104015. https://doi.org/10.1016/j.earscirev.2022.104015
Zhang, Y., Zhang, Z., Stephenson, W., & Chen, Y., 2024. Geochemical Behavior of Rare Earth Elements in Tidal Flat Sediments from Qidong Cape, Yangtze River Estuary: Implications for the Study of Sedimentary Environmental Change. Land, 13(9), 1425. https://doi.org/10.3390/land13091425
DOI: http://dx.doi.org/10.32693/bomg.40.2.2025.953
Accredited by Ministry of Research, Technology, and Higher Education, Republic Indonesia













