The law that states that sedimentary layers extend laterally until they thin out at their edges is called the law of . (

The law that states that sedimentary layers extend laterally until they thin out at their edges is called the law of lateral continuity. This fundamental principle of geology posits that layers of sediment are initially deposited in continuous sheets in a horizontal or nearly horizontal position. When observing sedimentary rock formations, the law of lateral continuity helps geologists understand the history of geological formations and the processes that formed them.

In essence, when sediments are deposited by natural forces such as water or wind, they tend to spread out uniformly over the landscape. As these layers accumulate, they eventually may be interrupted by erosion or other geological events, but the underlying principle remains that, at the time of deposition, they were continuous until they were either eroded away or thinned out at the edges. This concept is crucial for reconstructing past environments and understanding the geological history of an area.