How does poorly sorted sediment affect porosity?

Poorly sorted sediment negatively affects porosity because it consists of a mixture of particle sizes, ranging from coarse to fine materials. When sediment is poorly sorted, larger particles create larger void spaces, but these spaces are often filled with smaller particles. Consequently, the smaller particles fill the gaps between the larger ones, resulting in a more compact arrangement that reduces the overall volume of voids available for fluid storage.

When porosity is assessed, it refers to the proportion of the sediment's total volume that is made up of void spaces. In a poorly sorted sediment, the presence of different sizes brings about an inefficiency in how space is occupied, leading to a reduction in the number of available voids for fluids like water. Hence, this arrangement ultimately decreases the porosity compared to well-sorted sediments, where similar-sized particles allow for a more efficient arrangement and greater void space.