GEOLOGI DAN PROSPEK GEOWISATA PERBUKITAN JIWO, BAYAT, JAWA TENGAH
DOI:
https://doi.org/10.34151/technoscientia.v1i1.386Keywords:
Goelogy, Geotourism, Jiwo HillsAbstract
Jiwo Hills, Bayat is one of the three place in Jawa that pre-tertiary and paleogene rocks are exposed, the other two are at Karangsambung, Central Java and Ciletuh, West Ja-va. These rocks consist of metamorphics, igneous and sedimentary rocks where some of them able to proposed as geotourism sites.The spesific rocks outcrope and olso its spe-cific relation exposed at Bendungan, Sekarbolo, Watuprahu, Bukit Temas and Bukit Jo-kotuwo. The oldest rocks at the Jiwo Hills is pre-Tertiary Phillyte Lithodem, its consist phyllites, mica schist, chlorite schist and marble that unconformably covered by Eocene Gamping-Wungkal Formation. Phyllite Litodem and Gamping-Wungkal Formation are cutted by some Late Eocene to Early Oligocene (39.8, 33.2 dan 31,3 Ma) basaltic oroge-nic dyke. These thee litologic units (formation) are unconformably covered by Oyo For-mation that concist of calcarenite and marl stratification. The Geotourism sites in the Jiwo Hills are the ideal places for the object study and researh for students and geologists. At last, we propose to preserve all the object geotourism at the Jiwo Hills as natural labora-tory for earth sciences.
References
Briqueu, L, Bougault, H, and Joron, J L, 1984, Qualification of Nb,Ta,Ti and V anomalies in magmas associated with subduction Zone: Petrogenetic Implication, Earth and Planetery Science Letters, vol. 68: 297-308.
Bothe, A C D, 1929, The Geology of the Hills near Jiwo and the Southern Range; Excursion Guide, Fouth Pacific Science Congress, Bandung, Indonesia, GB C I, no.3, 14p.
Hamilton, W, 1979, Tectonic of the Indo-nesian Region., Geol Survey Prof. Paper 1078, U.S.Gov Printing Office, Washington, 345 p.
Maury, R C, 1984, Les Conséquences Volcaniques de la Subduction Bull. Soc. geol. France, t.XXVI,n°3: 489-500.
McCulloch, M T, and Gamble, J A, 1991, Geochemical and geodynamical constraints on subduction zone magmatisme Earth and Planetary Science Letters, vol. 102: 358 374.
Sun, S S, and McDonough, W F, 1989, Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes in "Magmatism in the Ocean Basin", Saunders, A.D., et Norry, M.J. (eds.), Geological Society Special Publication, No. 42: 313 - 345.
Sutanto, 1993, Evolutions géochimiques et géochronologiques dumagmatisme tertiaite de Java (Indonésie), Rapport de Stage de DEA, Université de Bretagne Occidentale, 76p.
Sutanto, Soeria Atmadja, R, Maury,R C, and Bellon, H, (1994), Geochronology of Tertiary Volcanism in Java, Proceeding Geologi dan Geotektonik Pulau Jawa, ISBN: 979 8611 - 00 - 4: 53 - 56, Yogyakarta.
Wilson, M, 1989, Igneous Petrogenesis, A Global Tectonic Approach. London, Unwin Hynman.446p.
Woodhead, J, Eggins, S, and Gamble,J, 1993, High field strength and transition element systematics in island arc and back-arc basin basalts: evidence for multi-phase melt extraction and a depleted mantle wedge, Earth Planetery Science Letters, vol.114: 491-504.