The crossword solution for the term RICH SUPPLY is 'LODE'. A LODE is a mineral deposit that is found in a vein or layer of rock. It is usually composed of ore minerals and is often associated with quartz, calcite, and other hydrothermal minerals. Lodes are typically formed by hydrothermal activity and can be found in areas where there has been volcanic activity. They are a rich source of valuable metals and minerals, making them an important part of the mining industry.