kolar gold ppt

2. 1. INTRODUCTION
2. ORIGIN
3. FORMATION OF KOLAR GOLD
4. GOLD DEPOSITES SITUATED
5. KOLAR GOLD DEPOSITS
6. MODE OF OCCURANCE OF GOLD
7. CONCLUSTION

3. • All primary Gold deposits are formed usually during the late
stages of the chilling of the magma ,which along fissures to the
upper layers of the earth`s crust from great depths. The Gold is
transported together with the magma from the depths of the
earth in hot aqueous solution and vapors. These solutions get
solidified with the falling of temperature, giving rise to ore
bodies mostly in the form of veins in rocks.
• These veins generally consist of Quartz with a small admixture
of other minerals. The particles of gold in the form of fine
grains, platelets and flaks and some times crystals wires,
filaments etc.
• In the course of time these rocks and veins under the action of
geological agents, undergo mechanical disintegration and
chemical decomposition. The weathered products while being
carried down to the depositional site undergo the process give
rise to placer Gold deposits

4. ECONOMICS
GOLD
MINERALS
NATIVE GOLD
GOLD AMALGUM
TELLURIDE

5. Gold occurs many geological settings. The following are the important
principal modes of occurrences observed in India.
 LODE GOLD
 GOLD IN CONGLOMERATE
 STRATIFORM
 PLACER AND ALLUVIAL GOLD
 GOLD IN GRANULITE
 GOLD IN LATHERITE SOILS
 DISSIMINATED

6.  In Kolar Gold field the Gold deposits are associated with
schistose rocks where aluminiumferous quartzite lodes
occur along closely placed mineralized zones.
 KGF is about 30 kilometers from Kolar and 100 kilometers
from Bangalore.

8.  The Kolar Greenstone or Schist Belt covers a 3 - 6km wide area
extending up to 80km in length. The rocks within the belt are
comprised of complexly folded and faulted mafic and felsic volcanic
sequence generally of low metamorphic grade.
 The northern 40 km long portion of the belt has laterite cover restricts
exploration work.
 Gold is preferentially concentrated in vein quartz, often
associated with sulphides. Most of these gold prospects represent
typical Archean hydrothermal lode gold mineralization.
 The three groups of the Kolar Gold Fields.
1. South Kolar
2. East Kolar
3. North Kolar

10.  North Kolar covers the northerly extension of the Kolar
Greenstone Belt and includes major synformal fold.
 Lode gold mineralisation is hosted by shear zones, sheared
granite and quartz viens.
 Quartz bodies of different types, both barren and
mineralised and several generations occur in the
ferruginous and carbonaceous Phyllites and within linear
bodies of metagabbro.

11.  mineralisation occurs near to the contact of the mafic
amphibolitic metabasalt with felsic volcanic and
metasediments of the Champion Gneiss.
 Gold is concentrated in vein quartz and also associated with
sulphides.
 The zone having highly sulphidic rocks and at one of the
prospects and quartz viens on the other end.

12.  This horizon is a heterogeneous assemblage of volcano-
sedimentary rocks.
 The volcanics are represented by rhyolite and acidic tuffs of
dacitic composition. All these are deformed and
metamorphosed to lower amphibolite facies.
 Gold mineralisation in the Surapalle area occurs in highly
tectonised shear zones which transect the foliation at a very
low angle.

14.  The Oriental lode of KFG is a stratiform sulphide type lode
lying about 400 to 500 mts to the west of champion reef
lode in north Kolar.
 It is strongly a pyritic lode. Width of this lode is ranges
from 1.5mts-4.5mts
 This lode is localized between volcanic flows and it is made
up of alternating bands of sulphide and amphibole-
quartzite encountered in archian schist belts.
 Dominating sulphide minerals are pyrhotite with
arsenopyrite and minor pyrite chalcopyrite and sphalerite.

17. Kolar gold field have four productive mines
1. Nandydurg mine
2. Champian reef
3. Mysore mine
4. Ooregum
 The champian reef mine is one of the deepest mine in the
word.
 The average content of champian reef was 15e grams/tonn
 There were about 15 parallel lodes in thkolar gold field, in
them 6 were gold-quartz lodes,9 were gold-quartz-sulphide
lodes About 84 tones of gold have been produced since the
mines were nationalized

18.  The gold -quartz lode is localized along a shear zone
traversing the mafic rocks of komatitic and tholeitic
character.
 This lode have been mined over a strike lenth of more than
8 km and to depth of 3400 mts.
 Lode are mainly made up of quartz and calcite .Other
minerals include sheelite, biotite, muscovite, and
tourmaline. Sulphides are pyrite, arsenopyrite, pyrhotite,
chalcopyrite and galena. High values of Cr and Ni are also
noticed

19.  Gold has been prised high and considered as king of the
metals.
 Kolar gold fields are important gold producing centers in
karnataka
 Champion reef is the richest gold bearing quartz-lode in so
far encountered in india.
 The champian reef mine is one of the deepest mine in the
word.
 Gold deposits generally occurs with quartzite and sulphide
lodes within these two gold fields Main reef is the
important gold producing reef among the Hutti gold field