Question

Why was basalt rock used for building the forts in maharashtra?

Answer 1

The layers of rock that are seen in Maharashtra, especially in the ghats resemble a pastry .

Over all they are all a rock called Basalt. There are two main types seen , one is hard and compact (thus called Compact basalt or Pashan ) and in between them is a layer of Vesicular (looks like sponge) Basalt. Vesicles are small holes and depression caused by escaping gases when the basaltic lava was cooling. Quite often , these vesicles are filled with other materials like green earth, zeolites. The rock is then called Amygdaloidal basalt

Most of the rock layer in Maharashtra is called the Deccan Traps or Deccan Volcanic province

In coastal areas due to alternate dry and wet climates ( heavy rain in monsoon , dry otherwise) causes chemical weathering of the Basalt. The residual rock or the rock that remains behind is now called a Laterite (Jhamba in vernacular) . It's usually red with circular spots and is used for construction

Answer 2

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It is a Trachyte Rock from bandongri hill of Malad. This rock is an igneous volcanic rock .

It is the volcanic equilent of syenite. The rock has been used in Mumbai Chatrapati Shivaji Maharaj Terminals VT,BMC head Office Mumbai High Court, GPO, and So many heritage buildings