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 People in some English-speaking countries are unlikely to make the distinction between this type of mine and any other type of open-pit or open-cast borrow or gravel pit mining operation. Quarries in level areas often have special engineering problems for drainage. The coquina quarry at the right is excavated to more than sixty feet (18 meters) below sea level. To reduce surface leakage a moat, lined with clay, was contructed around the entire quarry. Ground water that seeps into the pit is pumped up into the moat. Many quarries fill with water to become ponds or small lakes after abandonment for mining purposes. Others have become landfills. Water-filled quarries can be very deep with water that is often surprisingly cold. Unexpectedly cold water can cause a swimmer's muscles to suddenly weaken; it can also cause shock and hypothermia. These risks make quarry swimming dangerous, especially to kids and teenagers who might swim in a quarry not expecting any risk. Several teenagers and young men and women drown in quarries each year.  Types of rock extracted from quarries include:Cinder China Clay Coquina Blue rock Granite Gritstone Gypsum a mineral Limestone Marble Sandstone Slate |
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Danbury, CT