Petrological characteristics of gondwana system

Petrological characteristics of gondwana 

system 

Following are the petrological characteristics of gondwana system

• A glacial boulder yet to start with followed by sandstone, shale and coal in an ascending order in the lower part

• These rocks are largely fluvio-lacustrine deposits and glacio-marine rocks in some case

• They have the presence of plant fossils and are of fluvatile in nature

• It proves that they have enclosed terrestrial plants, crustaceans, insects, fishes, amphibians, reptiles etc; and by the total absence of marine mollusks, corals and crinioids

• Gondwana rocks are dominantly clastic and are characterized by glacial and glaciogenic sediments at the base, coal measures in the middle and red beds at the top

• Besides minor marine ingressions at the basal part rest of the Gondwana sequence is fluvial in nature

• These rocks also have animals fossils and have scattered occurrences of vertebrate and invertebrate fossils found in different formations of the Gondwana supergroup

• These rocks have the composition of glacial tillites, glacial striations, carbonate rocks, and evaporite deposits

• This system has varied depositional characteristics under varied palaeoclimatic conditions

• This means that the sediments deposited in the gondwana has been deposited in different climatic conditions such as glacial, warm, fluvial and humid phase and have resulted in rock formation of different types.