Limestone is a sedimentary rock formed
from precipitation(evaporation of water leaving salts) of minerals or from dead
matter such as sea shells or fish bones.The latter,which has an
organic origin is the most common.Limestone with a non-organic origin is called travertine
Limestone is
composed of calcium carbonate (calcite) which react
with acid water to give calcium bicarbonate which is
then washed away in solution.Limestone, unlike other rocks
such as granite or gabbro easily gets weatherd.This is
mainly because of the presence of joints and bedding
planes(joints running horizontally to the rock) which makes
it easy for weathering agents such as acids to penetrate at
ease.In addition to weak, Limestone rocks are permeable and
pervious also making them prone to weathering
agents.
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