What type of map shows the thickness of a specific stratigraphic interval using isopachs contour lines?

• A. Lithofacies map
• B. Hypsometric map
• C. Isopach maps
• D. Tectonic maps

Answer: (C)

Isopach mapping shows the thickness of a defined stratigraphic interval by drawing contour lines that connect points of equal thickness. Each isopach line marks a constant thickness, so thicker areas indicate more rock was deposited and thinner areas show less deposition or erosion. This approach focuses on how the interval's thickness varies across the landscape, unlike lithofacies maps that depict rock types, hypsometric maps that portray surface elevation, or tectonic maps that highlight faults and structural features. Isopach maps are especially useful for basin analysis and resource exploration because they reveal how thickness changes spatially across an area.