noun
- a line on a map connecting points of equal thickness of a rock layer or sedimentary deposit
Usage: technical; geology
Examples
- Geologists used isopach maps to determine the thickness variations of the sandstone formation across the basin.
- The isopach lines revealed that sediment accumulated more rapidly in the central depression.
- By plotting isopachs, researchers could reconstruct the depositional history of the ancient seaway.
- The isopach pattern suggested that the limestone layer thinned toward the basin margins.