Mineralogical and Geochemical Characteristics of Clays at  Godean Hills, Yogyakarta – Indonesia (A Study Case at Gunung Patuk and Gunung Wungkal)

Diory Yoellanice; Anastasia Dewi Titisari; Nugroho Imam Setiawan

doi:10.22146/jag.95164

Mineralogical and Geochemical Characteristics of Clays at Godean Hills, Yogyakarta – Indonesia (A Study Case at Gunung Patuk and Gunung Wungkal)

https://doi.org/10.22146/jag.95164

Diory Yoellanice⁽¹⁾, Anastasia Dewi Titisari^(2*), Nugroho Imam Setiawan⁽³⁾

(1) Geological Engineering Department Universitas Gadjah Mada
(2) Geological Engineering Department Universitas Gadjah Mada
(3) Geological Engineering Department Universitas Gadjah Mada
(*) Corresponding Author

Abstract

Gunung Patuk and Gunung Wungkal are part of the Godean Hills in Yogyakarta, Indonesia. The Godean Hills are isolated hills consisting of a series of hills surrounded by the Young Merapi Volcanics Deposits. A previous study reported that Gunung Patuk and Gunung Wungkal are porphyry andesite – micro diorite intrusions. Both hills are igneous rock intrusion and are found almost perfect soil profiles from the source/parent rock to the A horizon. However, another previous study suggests that at Gunung Wungkal has occurred hydrothermal alteration process. There is still a debate over the genesis of clay in that area, therefore this research needs to be carried out to provide a comprehensive understanding of mineralogical and geochemical characteristics of the clays at that area. The results of petrographic identification on the source/parent rock sample indicate that the rock sample is classified as andesite rock. Meanwhile, the results of mineralogy identification using the X-Ray Diffraction (XRD) method show that almost all types of soil profiles contain illite, kaolinite, and smectite. The calculation results of CIW (Chemical Index Weathering) and CIA (Chemical Index Alteration) values based on geochemical data show that CIW and CIA values increase steadily as they approach the ground surface. Based on the presence of illite (indicates a product relating to the relatively high temperatures) in horizon A with high values of CIW and CIA, therefore it can be interpreted that clay minerals at Gunung Patuk and Gunung Wungkal were the product of superimpose of hydrothermal alteration and weathering processes.

Keywords

CIA; CIW; geochemical characteristics; hydrothermal alteration; soil profiles; weathering

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References

Akmal, M.F. (2021). Studi Geokimia Material Hasil Lapukan Batuan Beku Daerah Godean Kabupaten Sleman, D.I. Yogyakarta. Yogyakarta: Bachelor’s Thesis, Geological Engineering, Universitas Gad- jah Mada (in Indonesian), unpublished.

Ardiansah, T. (2021). Studi Petrologi Batuan Beku di Daerah Godean - Seyegan, Kabupaten Sleman, Daerah Istimewa Yogyakarta. Yogyakarta: Bach- elor’s Thesis, Geological Engineering, Universitas Gadjah Mada (in Indonesian), unpublished.

Bove, D., Eberl, D., McCarty, D., & Meeker, G. (2002). Characterization and modeling of illite crystal particles and growth mechanisms in a zoned hydrothermal deposit, Lake City, Col- orado. Am. Mineral. 87 (11-12), 1546–1556.

Bronto, S., Ratdomopurbo, A., Asmoro, P., & Adit- yarani, M. (2014). Longsoran Raksasa Gunung Api Merapi, dimuat dalam Jurnal Geologi dan Sumberdaya Mineral, Volume 15. Bandung: Pusat Survei Geologi (in Indonesian).

Corbett, G.J. & Leach, T.M. (1996). Southwest Pacific Rim Gold-Copper Systems: Structure, Alteration and Mineralization, in Manual for an Exploration Short Course, Baguio, Philippines.

Harnois, L. (1988). The CIW Index: A New Chemi- cal Index of Weathering: Sedimentary Geology, v. 55, p. 319-322, doi: 10.1016/00370738(88)90137-6.

Park, C., Chung, D., Park, C., Seo, S., Kim, J.H., Seo, S.M., & Il-Mo, K. (2022). Mineralogical and geo- chemical characteristics of the hydrothermal illite from Hoam granite, South Korea: Implications for episodic fluid injections in the hydrothermal al- teration system. Geochemistry, v.82, 14p. doi: 10.1016/j.chemer.2022.125919.

Prabawa, A. (2020). Geologi dan Karakteristik Lempung Gunung Gedang dan Sekitarnya, Keca- matan Seyegan dan Godean, Kabupaten Sleman, DIY Serta Rekomendasi Pemanfaatannya. Yo- gyakarta: Bachelor’s Thesis, Geological Engineer- ing, Universitas Gadjah Mada (in Indonesian), unpublished.

Rahardjo, W., Sukandarrumidi, & Rosidi, H.M.D. (1995). Peta Geologi Lembar Yogyakarta, Jawa. Bandung: Pusat Penelitian Dan Pengembangan Geologi.

Soeria-Atmadja, R., Maury, R.C., Bellon, H., Pring- goprawiro, H., Polve, M., & Priadi, B. (1994). Tertiary magmatic belts in Java: Journal of Southeast Asian Earth Sciences, v. 9, p. 13–27, doi:10.1016/0743-9547(94)900620.

Streckeisen, A.L. (1976). Classification and Nomen- clature of Igneous Rocks. N. Jahrb. Miner. Abh., 107, 144-240.

Velde, B. & Meunier, A. (2008). The Origin of Clay Minerals in Soils and Weathered Rocks. Springer- Verlag Berlin Heidelberg, 426 pp.

Verdiansyah, O. (2016). Perubahan Unsur Geokimia Batuan Hasil Alterasi Hidrotermal Di Gunung Wungkal, Godean, Yogyakarta. Yogyakarta: KURVATEK, v. 1, No. 1, p. 59 – 67 (in Indonesian).

Wicaksono, D.D., Setiawan, N.I., Wilopo, W., & Har- ijoko, A. (2017). Teknik Preparasi Sampel Dalam Analisis Mineralogi dengan XRD (X-Ray Diffrac- tion) di Departemen Teknik Geologi, Fakultas Teknik, Universitas Gadjah Mada. Proceeding, Seminar Nasional Kebumian Ke-10, p. 1864 – 1880 (in Indonesian).

Yoellanice, D. (2022). Karakteristik Geokimia Lem- pung di Gunung Patuk dan Gunung Wungkal, Godean, Kabupaten Sleman, Daerah Istimewa Yo- gyakarta. Yogyakarta: Bachelor’s Thesis, Geolog- ical Engineering, Universitas Gadjah Mada (in In- donesian), unpublished.

DOI: https://doi.org/10.22146/jag.95164