23-12-2017, 09:46 AM
Silica
*Rich deposits of silica are found in the Alappuzha-Cherthala region
*The coastal tract between Alappuzha and Aroor in Alappuzha District contain extensive deposits of silica sand.
*The best deposits of silica are found on either side of Vembanad lake
*In Kerala, the deposits of clay are found maximum at - Kundara
*Graphite occurs in the parts of Thiruvananthapuram, Kollam, Kottayam, Idukki and Ernakulam.
*Gem stones like cat’s eye and Alexandrite are found in the eastern part of Thiruvananthapuram and Kollam.
*Lignite is the only mineral fuel found in Kerala.
*Mica Deposits are found in the district Thiruvananthapuram
Mineral Based Industries
*Mineral based industries of Kerala are Indian Rare Earths Ltd., Kollam, Kundara Ceramics, Kollam; English Indian Clays Ltd. (EICL), Thiruvananthapuram; Excel Glasses Limited Alappuzha; Kerala Clays and Ceramic Products Ltd., Pappinissery, Kannur
SOILS
*On the basis of the morphological features I and physio-chemical properties, the soils.of the Kerala have been classified into red loam, laterite soil coastal alluvium, riverine alluvium, Onattukara alluvium, brown hydromorphic, saline hydromorphic, Kuttanad alluvium, black soil and forest loam.
Red loam
*Red loams of Kerala are found mostly in the southern parts of Thiruvananthapuram district. These soils occur in chain sequence along with laterites.
*The soils have red colour due to the presence of iron oxides.
*They are low in organic matter content.
Laterite
*The major soil type found in Kerala - Laterite Soil
Heavy rainfall and high temperature is suitable to the process of laterisation. They have poor water-holding capacity with low organic matter content.
*The major crops that grown in the laterite soil of Kerala
Ans:Rubber, Cashewnut, Pepper and Coffee
Coastal alluvium
*These soils are seen in the coastal tracts along the west.
*They have been developed from recent marine deposits.
*These soils are acidic and of low fertility level.
Riverine Alluvium
*These soils occur mostly along the banks of rivers and their tributaries.
*They are very deep soils. They are moderately supplied with organic matter, nitrogen and potassium.
*They are acidic and poor in phosphorus and lime.
Onattukara Alluvium
*These soils confined to the Onattukara region comprising the Karunagapally, Karthikapally and Mavelikara taluks of Kollam and Alappuzha districts.
*They occur as marine deposits.
*These soils have very rapid permeability.
Brown hydromorphic
*Hydromorphic soils are mostly confined to valley bottoms of undulating topography in the midland and to low lying areas of coastal strip.
*They have been formed as a result of transportation and sedimentation of material from adjacent hill slopes and also throughdeposition by rivers.
*They are moderately supplied with organic matter.
*Acidity is a problem in some areas.
Saline hydromorphic
*These soils are mainly found in the coastal tracts of the districts of Ernakulam, Alappuzha, Trissur and Kannur.
*The origin, genesis and development of these soils have been under peculiar physiographic conditions.
*They are not comparable with the saline soils occurring in the other parts of the country.
*The Pokkali (Ernakulam district) and Kaipad (Kannur District) soils come under this category.
Kuttanad alluvium
*A good portion of Kuttanad lies 1 -2 m below MSL and is submerged for major parts of the year. The soils of Kuttanad area are faced with the serious problems of hydrology floods, acidity and salinity. The construction of the Thanneermukkam bund, salinity hazards have been considerably reduced. The soils of Kuttanad can be grouped into three categories, the Kayal soils, the Karappadam soils and the Kari soils which are dealt with in the zone of Problem Areas.
*Acid sulphate soils occur in Kerala in Kuttanad region.
*The puncha season of Kuttanad - October-November to February-March
Black soils
*Black soils are restricted in their occurrence to Chittoor taluk of Palakkad district. These soils are dark, low in organic matter and high in clay content
*The region where black soils are found in Kerala
Ans : Chittur Taluk (Palakkad Dist)
*The major crops that grow in the black soil of Kerala
Ans : Cotton and Groundnut
Forest loam
*They are restricted in occurrence to the eastern parts of the State. They are rich in nitrogen; but poor in the bases because of heavy leaching.
*The major rock type found in Kerala
Ans : Metamorphic rocks
