bed

1. The smallest division of a stratified rock series, marked by a well-defined divisional plane from its neighbors above and below. 2. An ore deposit, parallel to the stratification, constituting a regular member of the series of formations; not an intrusion. 3. The bottom of a channel for the passage of water. 4. In geology, the term bed describes a layer or seam, or a horizontal stratum of one formation between layers of others, for example a bed of coal, iron, etc.

Related terms:

• coal bed
• key bed
• topset bed
• foreset bed
• plane bed
• permeable bed
• passage bed
• Underclay
• index bed
• confining bed