Geographica Helvetica 1975 - Nr. 1 V.J.Gupta

On the stratigraphic Position of the Valley Sediments,

Dieser Artikel bildet eine Ergänzung zum Bei¬ ments are intercalated with thick bands of trag von Boesch, H.: "Untersuchungen zur lignite and these are best exposed near Lokun¬ Morphogenese im Katmandu Valley", Heft 1/74. dol, , Phurlong, Gangotikhola and Lagentole. The hard clay bands overlying the Abstract: The stratigraphic position of the lignite beds near Lokundol (adjoining Chapa- Sediments is discussed and gaon at the head portion of Nakhukhola) have these have been correlated with the Karewa yielded remains of vertebrate fossils which Formation of Kashmir. include Hexaprotodon sivalensis, Arkidiskodon Zusammenfassung: Die stratigraphische Stel¬ planifrons, Stegodon ganesa, Crocodylus sp. The fauna is identical to the one described lung der Sedimente des Kathmandu Tals wird from the Karewa Formation of Kashmir diskutiert und mit der Karewa Formation von Upper and Formation of Siwaliks. The fossils Kashmir verglichen und korreliert. Pinjaur are indicative of a Lower Pleistocene age, The Kathmandu valley constitutes one of the but the possibility that they represent in parts most important areas of the Kingdom of Nepal a pliocene succession can not be ruled out. The and occupies an area of 30 x 25 km. The major thickness of the lignite seams varies from 1,0 part of the valley is covered by plio-pleistocene to 1,5 meters; the seams dip towards the cent¬ and recent Sediments; its average elevation is re of the basin. 1340 meters. To the north of the valley lies the The upper parts of the Kathmandu valley Sedi¬ Sheopuri Lekh (2689m. consisting of precamb- ments are essentially Sandy and silty with rian granites, whereas the Southern parts are intercalations of carbonaceous and diatomaceous bordered by the Phulchauki Range (3132m. clays. The Sediments in the northern part of comprising Sediments ranging in age from the valley were derived from the Sheopuri Precambrian to Devonian. In the eastern and Granite. The Sediments of the southern part western parts of the valley there are passes of of the valley comprise pebbly clay conglome- low lying ridges (180Qm.) near and rates and diatomaceous earth. The conglome- Sanga Bhanjyang. The Kathmandu valley is rates are quartzitic in nature and the diatoma¬ drained by the and its tributaries ceous white clay contains monocotyledonous like Bishnumati, Manohra, Dhobikhola, Hanuy and dicotyledonous plant fragments. The Se¬ mante and Nakhukhola. After passing through diments near Harisidhi consist of several eye- the centre of the valley, the Bagmati River cuts les of gravel, powdery Sandy soil and clay. through a narrow gorge of Limestone The upper part of the succession which has a in the south. The Kathmandu valley is a tec- very wide distribution throughout the valley tonic valley of the synclinorium type controlled is also intercalated with bands of peat as weH by trough faults in the central part. The geo¬ as clay diatomaceous earth, butthe thickness morphology of the Kathmandu valley has been of these is much less if compared with the discussed in detaü by YONECH1 (1973) and lower part of the succession. The carbonaceous BOESCH (1974) and for detailed maps of the black clays are associated with the diatomaceous area the reader is referred to these publica- white clay and are being used as fertilizer all tions. over the valley. This clay is locally known as and is so abundant in the Kathmandu Valley Sediments "Kalimati" it area Bishnumati in Kathmandu on the Kath- The Kathmandu valley Sediments are of fluvio- across mandu-Thankot road that this area is lacustrine nature and consist of clays, sand geographi- named "Kalimati". The and clays, silts, micaceous sandstones, carbonace- cally peat lignite bands in the part of the succession con- ous clays, peat and lignite. These are well upper tain tissues and these in thickness exposed near the Tribhawn Air Port, Pashupat- plant vary from 30 cms. to one meter. These are being nath temple, opposite the Guneshwaridevi temp- mined for brick At several le, Lovenkhel, Lokundol, Hariäidhi, Khumbol- locally burning. in the central of the (at khola, Kokdukhola, Guekhola, etc. The thick- places part Valley ness of these Sediments vary from place to place; near Harisidhi the maximum with about 500 meters has been ascertained. Dr. V. J. Gupta, Centre of Advanced, Study in Geology, The lower parts of the Kathmandu valley Sedi¬ Panjab University, Chandigarh 14, India

27 Tanchal, Lahantole, Singh Darbar, Bir Hospi¬ Literature tal, Patan Industrial District, ete) Inflamable Boesch, H. Untersuchungen zur Morphogene¬ gas is found which is generally associated with se im Katmandu Valley. GH 1, the "Kalimati". S. 15 - 26, 1974. and the Kath¬ Lithologically palaeontologically Yonechi, F. : A preliminary report on the mandu valley Sediments can be correlated with Geomorphology of Kathmandu the Karewa Formation of Kashmir and both of valley. Science Report of Yamaga- them to seem have been deposited under similar ta University, 7th Series (Geo¬ environments. graphy), 23(2), S. 153-161,1973.

1 2

*2* «3* -<> TS - m ¦¦¦

«. ¦-¦'. .> » .-* '+ ,fe

fst m '. «*v M j Abb. 1: Archidiscodon planifrons XI.

Abb. 2: Hexaprotodon sivalensis XI.

Abb. 3: Crocodylus sp. XI.

28