Quaternary Geology and Hydrogeology of the Madiun Basin, Indonesia
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Journal of Geosciences, Osaka City University Vol. 37, A,l. 8, p. 213-242 March, 1994 Quaternary Geology and Hydrogeology of the Madiun Basin, Indonesia Shigeru KUMAZAWA* (With 19 Figures and 1 Table) Abstract The Madiun basin is located in the eastern part of Java Island, Indonesia. In the basin, a total thickness of more than 250 I'll of Quaternary sediments has been deposited after the Pucangan statge (Lower Pleistocene). After thick argillaceous sediments of the Pucangan Formation, the Kabuh Formation, the Notopuro Formation and the Setri Formation, consisting of thick Auviatile sediments, were deposited. The Kabuh, Notopuro and Setri Formations form good aquifers, so that various types of tubewells have be-;'n constructed since 1972 under the groundwater development projects in the basin. Tubewells constructed vary in depth, e.g., deep wells are between 80 I'll and 250 I'll, intermediate wells are-between 40 I'll and 80 I'll, and shallow wells are less than 40 I'll in depth respectively. The deep wells are generally pumping water from the aquifers of the Kabuh Formation and the lower half of the Notopuro Formation; the intermediate wells from the aquifers of the upper half of the Notopuro Formation and partly from the Setri Formation; and the shallow wells mostly from the aquifers of the Setri Formation. Transmissivity is larger in the Kabuh Formation and relatively smaller in the Setri Formation. The Madium basin is separated into the Madium sub-basin and the Ponorogo sub-basin topographically by projected Tertiary rocks and by a subsurface dyke of Tertiary rocks geologically as well as hydrogeologically. The aquifer system of the Madium basin is significantly related to the Quaternary geology of the basin. The aquifer of the Ponorogo sub-basin receives water from the eastern and western mountains, and water moves towards the center mainly through the Kabuh Formation and the otopuro Formation. Upward leakage takes place and water discharges into the Madium river near the main dyke between the sub-basins, and is then recharged again through the Setri Formation, entering the Madium sub-basin. In the Madium sub-basin, water entering and recharging the aquifer also moves mainly throught the Kabuh Formation and then the Notopuro Formation toward the center of the Madiun sub-basin. Near the Madiun river at the center of the Madiun sub-basin, water moves upward by vertical leakage, and is then discharged into the Madiun river. Lowering of the piezometric head has taken place in the Kabuh Formation in the area north of Caruban; this has probably been caused by abstraction of groundwater from the Kabuh Formation. Key Words: Madiun Basin, Kabuh Formation, Notopuro Formation, Setro Formation, Groundwater Aow system in the Quaternary strata 1. Introduction 1.1. Background The Madiun basin IS \cated in the eastern part of Java Island between longitude 111 °10'£ and 111°50'£ and latitude 7°20'S and 8°1O'S, as shown in Fig. 1. In "The * Geotechnical and Hydrogeological Department, ippon Koei Co., Ltd. Research student of Department of Geoscience, Faculty of Science, Osaka City University during the priod from April 1992 to March 1993. Address; 2-6-2, Isogo, Kawasaki-ku, Kawasaki City, Kanagawa 210, Japan 214 Shigeru I{UMAZAWA To Su boya 200 ( 500 \ i ""·'AMI. Liman ,7 (2563) f-~~~if?!:l~-+-tln-~r~-t---\ ; ) ../ / -----'- Main Rood / -H+++++++++ Rai Iway 10 20km, B·'~F,·L'O~'E------,,-C'·-"-20""'E------"'-:!-·30-''''''E-----'-'-;;''·40C-::O::'E,--------,....":<C'·50'E Fig. 1. General Location Map. Geology of Indonesia"(VAN BEl\1l\1ELEN, 1949), the geology of the northern part of the Madiun basin is described In some detail. This was because the area from Sangiran to Mojokerto, through the northern rim of the Madiun basin, i.e., along the southern foot of the Kendeng Hills, had been given special attention by many geologists and anthropologists since 1893, when E. Dubois announced the first discovery of a Homo erectus (Pithecanthropus erectus) skull on the left bank of the Solo river at Trinil, 11 km west of the conjunction with the Madiun river. A geological survey of hominid fossil-bearing formations in Central and East Java was commenced in 1976 as an Indonesia-Japan joint research project, and completed in 1979 (WATANABE & KADAR et al., 1985). The joint geological study covered the sites of Sangiran, Sambungmacan, TriniJ, Sonde, Ngandong, Kedungbrubus and Mojokerto. This joint geological study was followed by the next study project on the "Geology of Quaternary Environment", which started in 1988 and was completed in 1992, with expanded scope covering the area from Surakarta to Caruban, including the whole Quatemary Geology and Hydrogeology of the Madiun Basin, Indonesia 215 Bemmelen (1949) Joint Study Team (1992) Text Age Southern Kendeng Madiun Ponorogo Discussion Mts. Area Area Area Young Alluvium Alluvium Alluvium/ Holocene volca f-------r----~Sambirejo F. / noes S.~!-,ireio F_~,on F. Maron F. of I----TI 1II IIIII -I 111I,'TITIhll''rl--"I:=..:....::"'----=-'------j Upper the High Pleistocene Solo terra Setri Setri Setri Formation -~~ .E...e~~lftrril?mT For-!!!ation Middle _ I;!~t.ol'.I;F9_.!l._ Upper Notopuro Pleistocene Notonuro F. Formation -------! Uplift __~K~a~bu~h~Be~d~Sjml1Jn-.l-ll<:.rU-rr-l-Cwrit-h~~~I~:;;---1 I-- Totokan F. Kabuh Pucangan Kabuh Formation Lower Beds Formation Tumpuk Bed Pleistocene Pucangan F. Pucangan F. Upper Young Kalibeng B. Ban- Dangean Tertiary Rocks Pliocene f------~ Kali- cak Formation (Kalibeng F. / beng Form. Bancak F. / Old Lower Form. Sanpumg Lst. / Pliocene Kalibeng Miocene Vol. ) Beds Upper lilllLSamp- ung F Mio- f-----+--.,-;-::-:::-::-;-,----;~;-::----- cene Kepek Beds Miocene Middle 1----- [la_l).:@k Bed~ Volcanics 1I11111111111 Hiatus 1, -'1 Not exposed Fig. 2. Stratigraphic correlation of the Madiun-Ponoogo Area. Madiun basin. The results of the latest Indonesia-Japan joint study were presented at the workshop on Quaternary geology held in February 1992 (Joint Study Team, 1992) at Bandung, Indonesia. On the other hand, a groundwater development project of the Indonesian government had been going on in East Java since 1972 and more than 280 tubewells have been drilled in the Madiun basin till early 1991. Drilling data of these tubewells, consisting of cutting samples and logs, enables an In depth study of the subsurface geology and hydrogeology of the basin to be made. The author joined the Indonesia-Japan joint study team in 1991/92 and reviewed the drilling data. In this paper, the subsurface geology and hydrogeology of the basin, as revealed by the drilling data, are discussed. 1.2. The Madiun Basin The Madiun basin is enclosed by Mt. Lawu (3,265 m) on the west, Mt. Wills (2,563 m)* on the east, the Sourthern Mountains on the south and the Kendeng Hills on the north. The Madiun river begins in Mt. Lawu and gathers tributaries from Mt. Wilis and the Southern Mountains near Ponorogo city. The river then flows north through Madiun city. After being joined by the Jeroan fiver and the Muneng rIver * Mt. Wilis is a volcanic complex, of which the highest peak is Mt. Liman (2,563 m). 216 Shigeru KUMAZAWA from the east, at about 10 km north of Madiun city, the river turns to the northeast. Finally, the Madiun river joins the Solo rIver (Bengawan Solo) at the northeast corner of the basin, and the Solo river then traverses the Kendeng Hills farther to the north. The basin has an elongated north-south shape and narrows at the middle by the projections of mountain slopes from both the west (Mt. Lawu) and the east (Mt. Wills). The southern (or upstream) half of the basin is centered on Ponorogo city and the northern (or downstream) half is centered on Madiun city; these are hereinafter called the Ponorogo sub-basin and the Madiun sub-basin, respectively. The altitude of Ponorogo city is 95 m above s.l. (sea level) and that ofMadlun city is 68 m above s.l. 1.3. General stratigraphy of the area VAN BEMMELEN (1949) divided the Quaternary geology of the area into four stratigraphic units, i.e., Pucangan Beds, Kabun Beds, Notopuro Beds and Yound volcanics of the Solo Zone/High terraces from the lower to the upper strata, as summarized in Fig. 2. The type locality of the Pucangan Beds is Mt. Pucangan, 20 km north of Jombang; that of the Kabuh Beds is in the Sumberingin river, 3.5 km east of the Kabuh village; and that of the Notopuro Beds is at the village of Notopuro, 35 km east-northeast of Madiun (P. MARKS, 1957). The series of strata is, however, well exposed and has been studied in the Sangiran dome, north of Surakarta, or 65 km east of Ngawi, by VAN Es (1931), VON KOENIGSWALD (1940) and VAN BEMMELEN (1937; 1947), and by the Indonesia-Japan Joint Research Project (WATANABE and KADAR et al., 1985) more recently. The Indonesia-Japan Joint Study Team (1992) divided the Upper Pleistocene and Holocene deposits in more detail and identified the Setri Formation of Upper Pleistocene age and the Sambirejo Formation and Maron Formation of Holocene age. The finding and identification of the Setri Formation which is widespread in the area, not only on the slopes of the mountains but also beneath the basin, are significant in the study of the Quaternary geology and hydrogeology of the area. The type locality of the Setri Formation is in the middle reaches of the Sawur river, which has dissected the gentle slope of the northern foot of Mt. Lawu. The type localities of the Sambirejo Formation and the Maron Formation are in the downstream parts of the Madiun and Ponorogo sub-basins of the Madiun river, respectively.