Asedimentary rock containing a fern fossil was found
what does this tell about the area at the time the rock
was formed?

The area must have been on land

Explanation:

Ferns are vascular plants that produces no seeds but reproduce by their spores. They are usually land dwelling plants. Ferns are numerous flowerless and seedless vascular plants having true roots.

Sedimentary rocks usually form as a result of the accumulation of sediments within basins of their deposition. If one encounters fossils of ferns in sedimentary layer, it implies that the sediments must have been brought from land or the area where the sediments were deposited was on land.

? you expect us to answer this? ? this is your schoolwork, i don't think we can with this, i think it would considering being

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).