Niels Stensen

Rocky Road.

The principle of original lateral continuity proposes strata originally extended in all directions until they thinned to zero or terminated against the edges of their original basin of deposition.  This was the third of the principles of Niels Stensen (alias Nicolaus or Nicolas Steno) (Dott and Batten, 1976).

He established three principles still accepted today. The first was the principle of superposition, the crucial discovery that old rock layers underlie new rock layers. The second was the principle of original horizontality, that sediments are deposited as liquids, and like water, they are deposited horizontally, filling in irregularities at the bottom, but making a smooth surface at the top. The third was the principle of lateral continuity, that layers of sediment are continuous, unless a barrier prevents the sediments from spreading during deposition, or subsequent changes in the landscape break those sediment layers apart.

References
Dott, Robert H. and Batten, Roger L., 1976, Evolution of the earth, McGraw-Hill, New York, ISBN 0070176191,  2nd edition, 504 p.