"Coastal sediments" refers to the sand, rocks, and other materials that are found on the beaches, shores, and seabed near the coastlines. Full definition
For example, a more refined sea - level record over millions of years is commercially interesting because it allows a better understanding of coastal sediment sequences that are relevant to the petroleum industry. (sciencedaily.com)
Such data on past sea level changes before the start of tide gauge measurements can be obtained from drill cores in coastal sediments. (realclimate.org)
The current phase of accelerated sea level rise appears to have begun in the mid / late 19th century to early 20th century, based on coastal sediments from a number of localities. (giss.nasa.gov)