词条 | Pitch Lake |
释义 | Pitch Lake asphalt deposit, Trinidad and Tobago natural asphalt deposit at La Brea, on the southwestern coast of Trinidad, Trinidad and Tobago, southeastern West Indies. Known to European explorers since the 16th century for its large surface exposure of pure asphalt, the deposit covers some 100 acres (40 hectares) and has a maximum depth of about 250 feet (80 metres). Asphalt reserves are estimated at more than six million tons, and tens of thousands of tons are extracted annually. The English adventurer Sir Walter Raleigh (Raleigh, Sir Walter) used the deposits in 1595 to caulk his ships. They were first used for road surfacing in 1815. The asphalt is a major item of export for Trinidad and Tobago and is used, both at home and abroad, mostly for road building. |
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