Question

Imagine a scientist is studying a sedimentary rock formation that spans the three most recent geologic eras. Rock layers from each era are present in the rock formation. In what order, from top (closest to the surface) to bottom (deepest), should the scientist expect to find layers from each geologic era.

Answer 1

Cenozoic

Mesozoic

Paleozoic

Step-by-step explanation:

When layers of sedimentary rock are not disturbed by other geologic processes, the youngest layers are nearest to the surface, and the oldest layers are closest to the bottom.

According to the geologic time scale diagram, the current and most recent geologic era is the Cenozoic. The Mesozoic came before the Cenozoic, and the Paleozoic came before the Mesozoic.

So the scientist should find that the layers closest to the surface are from the Cenozoic. Layers farther down will be from the Mesozoic; layers ever farther down will be from the Paleozoic. This is shown below.

Answer 2

Top- Cenozoic (youngest)

Medium- Mesozoic

Bottom- Palaeozoic (oldest)

Step-by-step explanation:

The geological time scale is usually referred to as the ordered arrangement of major geological events that has taken place in the past. It is comprised of 3 distinct geological eras, namely the Palaeozoic, the Mesozoic and the Cenozoic.

Of these 3 eras, the oldest is the Palaeozoic (about 540 to 250 million years ago), followed by the Mesozoic (about 260 to 66 million years ago), and lastly is the Cenozoic (about 66 ,million years to present). All these 3 eras are characterized by the presence of fossil assemblages, that helped the geologists in constructing the geological time scale.