STATE UNIT: PROJECT: GEOCHEMICAL MAPPING SUPERVISORY OFFICER: S. M. J. Basha, Director

Mission-IA Ground Survey (Geochemical Mapping) Item No. 027

Field Season Year FSP Number

GCM SR AP 2016 23 2016-2017 Type Code Com. Region State Unit Year of Sl. No. Code Code code/ Mission Initiation

Participating Unit(s)/ Region(s)

GCM SR AP

Division / Region State Division/ Region Division / Region / SU Division / Region / SU Project Unit Project /SU Project Project

Geographical Information

State (Code) District (s) Degree Sheet (s) Toposheet (s) Mineral/ Tectonic Belt/ Basin etc.

AP Cuddapah, 57N, 57I 57N/1, 57I/12 PGC-II, Cuddapah Basin Kurnool, Dharwar Craton

Nellore

Personnel 2G

Name of item in-charge Mrunalini V Khond

Name of other officers Namrata Mahanta

Title Geochemical mapping in toposheet no. 57N/1 and parts of 57I/12 in Cuddapah,

Kurnool and districts, Andhra Pradesh.

Key words Geochemical mapping, Baseline data, Cuddapah

Objective (s)/ Projected To create a geochemical database of 57N of Andhra Pradesh state using multi Outcome elemental analyses.

Total duration of item One Year (FS 2016-17)

Item linked with XIIth Plan

Whether GPM item is in toposheets already No covered by GCM or vice versa

Whether the item is a spinoff of any other item No

Whether the item is sponsored No

If yes, Name of the sponsor NA

Outsourced work component if any (specify) No

Nature and Quantum of work and time schedule

Total a) Expected Year of Work Work

Nature of Work workload completion already proposed for envisaged b) Circulation of final report completed FS 2016-17

(1) Mapping (sq km) a) March 2017 New Item GCM (1:50K) 800 b) September 2017 800

(2) Sampling (Nos.) (a) Stream sediment/slope 800 800

wash (Composite (207) (207)

samples) 10 10

(b) Soil C-horizon 10 10

(c) Regolith 10 10

(d) Water As Necessary As Necessary

(e) Humus As Necessary As Necessary

(f) Flood plain sediment 40 (10) 40 (10)

(g) Duplicate NIL NIL

(h) Pt-Pd Analysis

(3) Analysis# (Nos.) 247 247

# Analysis to be done at Chemical lab, SR

86

Timeline proposed for each work component Field Studies

Expected field stay Expected period of fieldwork Name of the officer

(number of days) From To

Mrunalini V Khond, Geologist 120 April 2016 March 2017

Namrata Mahanta, Assistant Geologist 120 April 2016 March 2017

Supervisory Officer: S. M. J. Basha, Director 10 April 2016 March 2017

Laboratory Studies Activity From To Pre-field laboratory component and reconnaissance for the April 2016 September 2016 assignment under consideration, finalization of report of the previous field season and planning for current programmes Geological study (fieldwork and collection, processing of samples September 2016 March 2017 and their submission) Geophysical study (consultation of interpreted geophysical data) April 2016 September 2016 th Chemical study (last date of sample submission )* 30 April 2017 Chemical study (acquisition of analytical data) October 2016 March 2017 * GCM samples to be submitted periodically and within 30 days of date of collection

Report Submission th Submission of the first draft of report 30 June 2017 Scrutiny of the report 1st July to 31st August 2017 Finalization of the report September 2017 th Circulation of the report 30 September 2017

Operational expenses Heads Amount POL NIL WAGES Rs. 2,80,000/- OC Rs. 3,90,000/- including expenditure of outsourced vehicle

Background information During the FS 2016-17, toposheet no. 57N/1 and part of toposheet no. 57I/12 will be covered. In this programme the stream sediment/slope wash samples are to be collected on 1 km X 1 km gridas per SOP of GSI on NGCM and there form the basic unit of sampling in this programme. The area of Toposheet no 57N/1 is bounded by Latitudes 14° 45' 00" and 15° 00' 00" N and Longitudes 79° 00' 00" and 79°15' 00" and falls in Cuddapah and Nellore districts, Andhra Pradesh. The area is part of Veligonda hill ranges and exhibits very rugged topography. Two almost N-S trending broad strike ridges that dot this part are separated by Sagileru, Tigaleru and Pillaperu River valleys. The maximum elevation is ∆1036 m on Siva Durgam hill while the minimum elevation is 129 m on the banks of Sagileru River in the extreme southwest. Tigaleru River in the western part and Pillaperu River in the extreme northeast drain the area towards southeast. Several third order streams drain the rest of the area. Sub- parallel, sub-rounded, sub-trellis and dendritic drainage pattern is prevalent. The temperatures in the area vary between 12°C in winter to 45°C in summer. The annual average rainfall is 400 mm. The area exposes the rocks belonging to Peninsular Gneissic Complex (PGC) II of Archaean to Palaeoproterozoic age, younger metamorphics of Nellore Schist Belt (NSB) of Dharwar Super Group, Cuddapah Super group sediments and younger granites and acid intrusives of Meso Proterozoic age. PGC-II comprises grey biotite granite gneiss. Younger suite of NSB rocks overlying grey biotite granite gneiss are exposed to east around Basinepalle and Pullayyapalle villages. It is represented by Nandavam Formation of Udaigiri Group and comprises quartz-chlorite schist. The bottle bluish green coloured quartz-chlorite schist is highly schistose and comprises mainly albite, chlorite, epidote and quartz. Under thin section, it is composed of chlorite as the dominant mineral with subordinate amounts of albite, actinolite and quartz. Cuddapah sediments unconformably overlying the gneiss are designated as Nallamalai Group of rocks. This group is divided into lower Bairenkonda / Nagari formation and Upper Cumbum Formation. The Bairenkonda Formation comprises nearly equal proportions of quartzite and shale. Quartzite is mostly grey, fine grained, compact, cherty and usually thick bedded. At places, thick bedded quartzite grades into thin to medium bedded flaggy and schistose quartzite or greenish grey to grey arenaceous shale. Thin intersections of arenaceous shales occur frequently within Quartzite. The shales and phyllites are grey to dirty grey,

87 fine grained, jointed and well foliated. They contain several quartzite intercalations and often grade laterally into quartzite. The upper Cumbum Formation is basically an argillaceous unit with thin inter layers of quartzite. This argillaceous unit occurs as thinly laminated to thick bedded, brown, grey, non-cherty shale with phyllite. These rocks are somewhat fresh earthy looking with indistinct cleavage. Younger granites intruding the above rocks are exposed to southwest around Kampasamudram over a very limited geographic area. They are mostly biotite granite type but the geographically restricted associated variants are hornblende granite. Quartz veins intruding the Cumbum sediments are exposed to western part around Ayitram Peta and Kondampalle. They run for a few km lengths with average width of 50 m. They are fine to medium grained, creamy white to dirty brown and mainly comprise quartz, with very minor amounts of opaques. The Cumbum sediments show drag folds whereas the Bairenkonda shows intricate folding. The enclaves on eastern thrust along the contact of gneisses and sediments of Cuddapah basin is a major dislocation which dips at a moderate angle of 30° to 40° towards east. The thrust is marked by close spaced shears, slicken side fault striations, pulverization along with development of tachylite and quartz veins. The quartzite, arenaceous phyllite and granite, gneiss is quarried locally for use in construction, industry and road ballast. Sand available along Sagileru, Tigaleru and Pillaperu rivers is a useful construction material. The rock types exposed in the toposheet 57I/12 belong to Nallamalai Group (Mesoproterozoic) comprising Bairenkonda Quartzite and Cumbum Formation and Neoproterozoic Kurnool Group which includes Owk Formation, Koilkuntla Formation and Nandyal Formation. Stream sediment samples from toposheet no. 57I/12 will be collected between Lat. 15° 08’ 42" & 15° 15’ and Long. 78° 42' 17" & 78° 45' from composite cell no. 124, 125, 126, 138, 139, 140, 152, 153, 154, 166, 167, 168, 180, 181, 182, 194, 195 and 196.

BIBLIOGRAPHY D. Samaddar; Geological and geochemical studies in Marripadu, Udayagiri area, , A.P.; FS 1981-82 Unpublished GSI report. K. V Ravindran; Geological and geochemical studies in Udayagiri and Marripadu area, Nellore district, A.P. FS 1982-83 Unpublished GSI report.

INDEX MAP

Degree Sheet No. 57 N Toposheet No. 57I/12

5 9 13 1

2 6 10 14

3 7 11 15

4 8 12 16

Area proposed for FS 2016-17 : TS 57N/1 Area proposed for FS 2016-17 in TS 57I/12