Geology of Jalpaiguri BY ndtpdz684868 2. 1 . Geology Jalpaiguri Districts almost entirely covered with alluvium expect that a narrow belt of hard rock is exposed along the northern border of the districts. The geological formations found in the districts are given below in the order of increasing antiquity. ??? Recent and Sub-Recent: Alluvium and other soils boulder and people beds. Miocene: – Siwaliks: – Sandstone with clay and lignite. Permian (Lower Gondwana):- Sandstone shape with Genes of Graphite coal. ?Pre-cambnan (Buxa series): – Gneiss, Schist, Slate and Quartzite banded ferruginous rocks. ??? Achaeans (Daling and Darjeeling): – Gneiss, Schist, Slate and Quartzite. The north eastern part of the districts forms the foothills both of the Himalayan as where the elevation gradually increases from the alluvium plain to about 200 metres and above towards the gentle slope which becomes appreciable steep as the interior mountain ranges is approached where the terrain becomes extremely rough with ragged scarps. 2. 2. Phsiography
The district is almost not a flat country rather there are mountainous area in the North. The blocks like Nagrakata, Malbazar, Kalchini and Metili are consisting of moderate relief pattern. The general slope of the districts is from north-west to south. Tea plantation is mostly found in hilly terrain along the part of Siwalik. In the plains Rice, Jute and Wheat are the main crops. 2. 3. Climate The climate of terrain and duars is characterized by heavy humidity and heavy ppt, which is the A. M type of koppens classification.
After the hottest day of summer, the onsoon winds from the Bay of Bengal continue to sweep along the teesta valley, bringing heavy rain in their woke. The cold season from mid-November to the end of February. This followed by the hot season from March to May. The period from June to about the beginning of October is the South West monsoon season. October to Mid- November constitutes the post monsoon season. The average annual rainfall in the districts is 3925. 1 m. m. The rainfall generally increases from the southwest to the northeast. About 79% of the rainfall is received during the south west monsoon eason.
In the latter half of the summer season and in October, the districts get some rainfall mostly as thunder showers. July is generally the rainiest month 2. 4. Soil Jalpaiguri district is entirely covered with both alluvium with hard rocks exposed along the northern border. In general the soil is mainly sandy loam and has low water holding capacity, characterized by low fertility with low nitrogen and potassium, medium phosphate content. The leaching of salts under heavy rainfall conditions increases acidity in the upper portion of the surface soil.