WHPierce Exploration
| Horizon | Overburden | Burial | Structural | |||
| Base | Neogene | 1v | 1u | 1s | ||
| Base | Oligocene | 2v | 2u | 2s | ||
| Base | Eocene and Paleocene | 3v | 3u | 3s | ||
| Base | Upper Cretaceous | 5v | 5u | 5s | ||
| Base | Middle Cretaceous | 6v | 6u | 6s | ||
| Base | Lower Cretaceous | 7v | 7u | 7s | ||
| Base | Upper/Middle Jurassic | 8v | 8u | 8s | ||
| Base | Lower Jurassic and Triassic | 9v | 9u | 9s | ||
| Base | Permian | 11v | 11u | 11s | ||
| Base | Carboniferous | 12v | 12u | 12s | ||
| Base | Devonian | 13v | 13u | 13s | ||
| Base | Silurian | 14v | 14u | 14s | ||
| Base | Ordovician | 15v | 15u | 15s | ||
| Base | Cambrian and Infracambrian | 16v | 16u | 16s | ||