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378 NOTES contamination zones in Pimpri Chinchwad Municipal The recommendations of the seminar highlight the issues Corporation area S. Chidambaram analyzed the effects of of harmonious development, conservation and augmentahon secondary leaching, saline water intrusion and anthropogenic of groundwater, S & T inputs in groundwater management, influence on groundwater quality in Gadilam river basin rainwater harvesting, conjunctive use, village level' Reuse of treated waste waters in fish farming and ~rrigation integrated multidiscipl~narysurveys merging science with was dlscussed by V Sreekrishna and others indigenous knowledge, equlty and sustainabiltty of the In the concluding session L C Jam, former Member of resource and community participation The seminar the Planning Commission spoke at length about rural successfully brought leaders of NGOs, and water managers development planning, of whlch water is a key input He at grass root level face to face with scientists, technologtsts, was of the view that village development plans should be economists in iterative sessions on how modern science and invariably based on technical information comblned wit technology can address the needs and aspiration of the indigenous knowledge of soil, crop and water Development people for mitigation of water crisis should not tamper with natural flow of water Equipped w~th GIS scientists should assist Panchayats to prepare area Flat# M901, Tabourme development plans He spoke about relevance of village Kanakapura Road plans for economic development and social justice - 560 078

FLOW STRATIGRAPHY OF IN *

A. V JAYAPRAKASH Geolog~calSurvey of Indla, Bangalore - 560 078

EXENDED ABSTRACT

Subsequent to the cessation of sedimentatton in the elevation is seen from east to west upto Nipani hill ranges continental interior basins of varying dimensions at the end in the western part of the Belgaurn distr~ct Northeast of of Neoproterozo~cera, the Deccan Plateau segment in the town and north of Mullamari Rlver, a steep rise in Indian Peninsular , witnessed a prolonged respite in elevation gives rise to Table land, covered by a thick geological events A quiescence of such longevity was zone of laterrte complemented by a chain of events triggering one of the A cursory look at the volum~nousliterature available on most prollfic effuslon of basaltic rocks lasting over a perlod Deccan Trap shows that the lithostratigraphy of the flows is of 5 mlllion years during the late - early one of the least dlscussed domain Beane et a1 (1986) have Paleocene epoch The early flows rapidly obliterated and provided a well accepted lithostratigraphic classification concealed the pre-trappean landscape with the later ones, for the entire basaltic provlnce of Deccan assigning a by and large serially occupying the already leveled up 'Group' status with 3 subgroups and numerous formations grounds Formations were further dlvrded as Members and Southern central segment of the Deccan Trap occupies Chemical types Major and trace element geochem~stry the major part of the northern districts of Karnataka with a supported by textural and petrographic characters and Sr 28,000 sq km spread Thxs segment of basaltic country fonns isotopes ratio were the critical factors whlch determined thelr a relatively low lylng undulatory terraln, where isolated small divisions into Members In that scheme of classlficat~on, outliers of trap spread over the sedimentary sequence of flow sequence of Karnataka 1s considered to belong the Purana basins and peneplaned gneissic complex On the uppermost Wal Subgroup with three Formations western side, it forms Sahyadri ranges where as on the viz Poladpur, Ambaneli and Mahabaleshwar In the eastern side with a gentle gradlant, the are in contact ascending order with granltoids of Table land A gradual rise in In the northeastern sector of Karnataka, M~tchell

'GEs~of the lecture delivered on 28'" March 2007 at the Geological Soclety of , Bangalore

JOUR GEOL SOC INDIA, VOL 70 AUGUST 2007 NOTES

JOWR.GEOL.SOC.INDIA,VOL.70, AUGUST 2007 380 NOTES and Cox (1988) recorded Poladpur, Ambanell and nomenclature (Amos Salvador, 1994) With great emp has1 s Mahabaleshwar Formations Subba Rao and Hooper (1988) on field characters, each flow is identified by the characters in thelr reconnissance map of the southern edge of the seen at thelr contacts, such as presence of bolesr; Deccan basalts wlth selected plottlng brought out the lntertrappean beds, internal changes such as the presence of presence of all the flve Formations of Wal Subgroup in thls veslcles at the top, break in slope of topography, which 1s a sector Geological Survey of India has carrled out the rnanifestat~onof sudden changes in phys~caland chemlcal systematic reglonal geological mapping of the Deccan Trap properties Flows are clubbed to be called Members prefixed on 1 50,000 wlth a main objective of identifying indiv~dual with the local names This grouping is mainly based on their flows A total of 31 flows have been identified from the sectoral presence and pulsation's in eruptions - a gap Karnataka- border in the east upto probably marked by the presence of bole beds, lntertrappean Karnataka-MaharashtrdGoa border in the west. They have beds or zeolite zones These Members are equated or a total thickness of 630 m in the elevation ranges of 390 m asslgned to the already estabIished formatloris gtven in the on the banks of Bhlma River In Bxjapur dlstrict to 1020 m classifications proposed by Beane et a1 (1986) abov; rnsl in the Damne area of Belgaum district Certain Our work was aimed to give a map w~thflow boundaries, isolated or disconnected patches occurring as outliers on assirn~latingand adopting the widely accepted pre-existtng Archaean basements and Proterozolc cover sediments were stratigraphic nomenclature of the proposed by earller labeled as undlfferentxated flows (Table I) workers (Fig 1) Presence of lntertrappean beds for a In this scheme of classification each ~ndlvidualflow is cons~derableareal extent, boles, speclfic topographic equated to the formal unit of a 'Bed' in the llthostratigraphlc manifestations, laterit~satlonand segmental conflnernents are used as important crlterla for evolvlng this column thus Table 1 Flow strabgraphy of Deccan basalts 111 Karnataka segment make it more field oriented Parameters such as flow Flow Marker horizon Members wlth Format~on characters, petrographic and mineralogical properties are Nos between Members th~cknessin m Equivalents the other secondary characters considered Later~tecover In Karnataka sector flows in general are tabular in form and sheet llke bodles having a large areal extent (Fig I), sim~larto the ones reported from the other Continental Zeolrte zones Igneous Provinces No off-set in flow continuity (barr~ng Belvattl (25) Laterrte tops Pa~zltala

1000 -

Red bole beds, 900 - Ch~kkodt(80) Local red bole beds Mahabale -E aoo- m Belgaum segment r ltwar E (80) I Intertrappean beds In Bljapur segment, red bole in Belgaurn segment Gulbarga ( 100) Ba (ppm) Numbers represent flows Red bole & Fuller's earth in Gulbarga A~tzbanel~ segment, red bole m Bqapur segment Bldar (70) Green bole m Bidar and red bale in Gulbarga segment

Ungrouped dlscrete ~cflows in the lower levels ------*------Archaean crystalline and Proterozolc Ba (PP~) cover sediments Fig.2. Geochernlcal characters of Deccan flows

JOUR GEOL SOC INDIA, VOL 70, AUGUST 2007 NOTES

the one along Mullamari River, north of Gulbarga due to recorded in the Karnataka sector dlp slip faulting) has been noticed The Bidar plateau is the Limited geochem~calstudles have been conducted on result of post-deposit~onaltectonism that has given r~seto the samples collected during the course of mapping Plots 30 rn vert~calsh~ft of Ba in ppm vls-A-vis the flow numbers show d clear Infra-trappean beds In then type areas of central and upwardly decrease of Ba Also the deplet~onof Ba shows a has certain speclfic chronostratigraphic posrtive correlation wlth Zr/Nb ratlo gradually in younger connotation, that these are the sedlments deposited before sequences (Fig 2) The youngrng sequence of the flows as the advent of Deccan Volcanism as a whole They mark mapped In the Karnataka sector, confirms the widely the end of great sequence and ranges from accepted current model of Plume theory (Richards et aI, Santonlan to Maastric h~t~anof Late Cretaceous age 1989) Therefore caution need to be exercised before labehng The author thanks the Geological Society of Ind~afor any sed~mentarybeds of 'Deccan event' as infra-trappean givlng an opportunity to present the data In thelr lecture and to be done wlth proper age correlation Since, it IS well series, thanks are due to the Deputy Director General, establ~shedthat the flow unlts of Karnataka belong to the Southern Regxon of GSI for permlttlng to disseminate my youngestsubgroup, it is tmperative to call the Interbedded observat~onsand also the observatlons of workers of sedlments within them as ~ntertrappeanirrespective of the Operations Karnataka and , GSI associated wrth the underlying unlts As such no ~nfra-trappeanbeds are Project of Deccan Trap mapplng

References AMOSSALVADOR (1994) Tnternat~onalStrat~graphic Gulde - Co- Basalts Mem Geol Soc Ind~ano 10, pp 27-34 Pub - IUGS & The Geol Soc Amer Inc USA, pp 1-50 RICHARDS,M A , DUNCAN,R A and COURTILLOT,VE (1989) Flood BEANE,J E , TURNER,C A , HOOPER,PR , SUBBARAO,K V and Basalts and hot spot tracks, Plume Heads and Tails Sclence, WALSH,J N (1 986) Stratigraphy, compos~tlonand form of the ~24,pp 103-107 Deccan basalts, Western , Ind~aBull Volcanology, v 48, SUBBARAO,K V and HOOPER,P R (1988) Reconnaissance Map of pp 61-83 the Deccan Basalt Group In the , Ind~a In MITCHELL,C and Cox, K G (1988) A Geological Sketch Map of Deccan Flood Basalts Geol Mem Soc Ind~a,no 10, map In the Southern part of the Deccan Provlnce - rn Deccan Flood pouch

r \ Announcements

XVII NATIONAL CONFERENCE ON GEOCHEMISTRY

The XVII Nat~onalConference on Geochemistry (INAGEQ, Mex~co)IS belng organlsed by the Department of Centro de lnvest~gac~onesen Clenclas de la Tierra, Unlversrdad Autonoma del estado de Hrdalgo (UAEH), Pachuca, Hldalgo, Mex~co,dunng 1-6 October, 2007 For more detals, please contact Dr J S Armstrong-Altnn, Convener, Centro de Investlgaclones en Cienc~asde la Tierra, UAEH, Mextco Email: altnna@uaeh reduaeh mx or john-arms @yahoo corn Phone: 0052-771-7 161263

NATIONAL SEMINAR ON MAGMATISM, TECTONISM AND MINERALIZATION

The Department of Geology, Kumaun University, Nalnltal wtlI be organizing the above sern~narIn conjunction wlth Decenntal Annual Convention of South Aslan Association of Economlc Geologists (SAEEG), Indla Chapter, durlng 29- 3 1 October, 2007 For further deta~ls,please contact Prof Santosh Kumar, Convener, MTM-2007, Department of Geology, Kumaun Universlty, Nainieal - 263 001, Uttarkhand Phone: 05942-239596, 235114 (O), 239953 (R), 0941 11977 14 (M) Email: mtm-ku2007@yahoo co in or skyadavan @yahoo corn \ J

JOUR GEOL SOC INDIA, VOL 70, AUGUST 2007