Sludge Metal

Sludge metal (sometimes referred to simply as "sludge") is a subgenre of heavy metal that melds elements of doom metal and hardcore punk and sometimes incorporates influences from grunge and noise rock. Sludge metal is typically harsh and abrasive; often featuring shouted or screamed vocals, heavily distorted instruments and sharply contrasting tempos. While the style was anticipated by the Melvins from Washington, many of its earliest pioneers were from New Orleans.

-- Wikipedia