Indian Shield
Encyclopedia
The Indian Shield is part of the Indian Craton and occupies two-thirds of the southern India
n peninsula
.
The shield has remained relatively stable since its formation, over 3500 million years ago. It is delimited on the west, south and east by the present day coastline and Phanerozoic
sediment cover. On the north, it is bounded by the Proterozoic
Province. In the northeast, it is bounded by the Godavari graben
preserving the Precambrian
pakhal rocks and Gondwana
sediments.
The important components that make up the shield are:
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
n peninsula
Peninsula
A peninsula is a piece of land that is bordered by water on three sides but connected to mainland. In many Germanic and Celtic languages and also in Baltic, Slavic and Hungarian, peninsulas are called "half-islands"....
.
The shield has remained relatively stable since its formation, over 3500 million years ago. It is delimited on the west, south and east by the present day coastline and Phanerozoic
Phanerozoic
The Phanerozoic Eon is the current eon in the geologic timescale, and the one during which abundant animal life has existed. It covers roughly 542 million years and goes back to the time when diverse hard-shelled animals first appeared...
sediment cover. On the north, it is bounded by the Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
Province. In the northeast, it is bounded by the Godavari graben
Graben
In geology, a graben is a depressed block of land bordered by parallel faults. Graben is German for ditch. Graben is used for both the singular and plural....
preserving the Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
pakhal rocks and Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
sediments.
The important components that make up the shield are:
- The Dharwar cratonDharwar cratonThe Dharwar craton in South India presents a natural cross-section of late-Archaean continental crust. There are three main structural zones: a root zone of highly heterogeneous petrology and texture , a "channel zone" where evidences of large scale magma ascent can be observed, and a zone of...
with its characteristic Archaean volcanic - plutonic belts surrounded by the vast gneissGneissGneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
ic terrain. - The southern granuliteGranuliteGranulites are medium to coarse–grained metamorphic rocks that have experienced high temperature metamorphism, composed mainly of feldspars sometimes associated with quartz and anhydrous ferromagnesian minerals, with granoblastic texture and gneissose to massive structure...
- gneiss terrain of Tamil NaduTamil NaduTamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...
- KeralaKeralaor Keralam is an Indian state located on the Malabar coast of south-west India. It was created on 1 November 1956 by the States Reorganisation Act by combining various Malayalam speaking regions....
. - The Eastern Ghat Mobile Belt (EGMB) along the east coast
- The intra cratonic "Purana" basins with thick sequences of platform facies rocks and /or riftRiftIn geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics....
related sedimentSedimentSediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s.