​What is the difference between a quarry and a gravel pit?

In a gravel pit only surface gravel deposits are removed. They are usually only open for a few years. The top soil is preserved and after the gravel is removed the top soil is replaced for farming. A quarry strips away all the top soil and gravel down to bed rock then blasts into the bedrock to remove stone which is crushed and usually trucked away for a full range of construction use from roads to buildings. The Hidden Quarry proposes to blast 100 feet into the water table over a 60 acre area. It will operate for at least 20 years and maybe much longer, leaving two small lakes.  The property will no longer be available for agriculture.  It may also expand into neighbouring properties.