This type of map shows contour points of equal formation thickness. It may also show depth of the zone.

This type of map shows contour points of equal formation thickness. It may also show depth of the zone.

• A. Isopach Map
• B. Contour Map
• C. Topographic Map
• D. Seismic Map

Answer: (A)

Contours connecting points of equal formation thickness are used to map how thick a rock unit is across an area. This is exactly what an isopach map does: it shows where the formation thickens or thins by drawing lines of equal thickness. It’s especially helpful for spotting thicker intervals that might indicate better reservoir quality or sand continuity, and you can also note the depth to the zone along with thickness data when that information is available. In contrast, a general contour map simply maps any chosen value, a topographic map shows surface elevation, and a seismic map displays subsurface seismic properties, not the thickness of a formation.

Contours connecting points of equal formation thickness are used to map how thick a rock unit is across an area. This is exactly what an isopach map does: it shows where the formation thickens or thins by drawing lines of equal thickness. It’s especially helpful for spotting thicker intervals that might indicate better reservoir quality or sand continuity, and you can also note the depth to the zone along with thickness data when that information is available. In contrast, a general contour map simply maps any chosen value, a topographic map shows surface elevation, and a seismic map displays subsurface seismic properties, not the thickness of a formation.