Which method is the best and cheapest way to estimate the thickness of the unit Ps?

• A. Structural analysis
• B. Remote sensing
• C. Core sampling
• D. Geophysical logging

Answer: (A)

Estimating thickness hinges on the geometry of the beds and their contacts. Structural analysis uses the orientation of bedding and the surfaces that bound the unit to reconstruct how the unit sits in 3D. By measuring dip and strike of the beds, and mapping where the top and bottom contacts occur, you can build cross-sections and back-calculate the true thickness between those contacts. This approach works well for large areas with outcrops or measured sections and doesn’t require drilling or special instruments, making it cheaper than pursuing cores or geophysical logs.

Remote sensing can show surface features, but it doesn’t reveal how thick a subsurface unit is. Core sampling gives direct thickness but is expensive and limited to drilled locations. Geophysical logging provides thickness information where you drill, but again, it’s costly and invasive. Structural analysis, when you have good surface geology, offers a practical and economical way to estimate thickness by leveraging the geometry of the exposed unit and its bounding surfaces.