what type of sediments arrive in the ocean from continents via rivers?
The type of sediments that arrive in the ocean from continents via rivers is collectively known as fluvial sediments. Fluvial sediments are a mixture of different materials that are eroded from the land surface and transported by rivers and streams into the ocean. These sediments can be classified into several main categories:
1. Clastic sediments: These are composed of fragments of weathered rocks, minerals, and organic matter. Clastic sediments are typically the most abundant type of sediment transported by rivers. They can range in size from large boulders to smaller gravel, sand, silt, and clay particles.
2. Organic sediments: These sediments are derived from partially decomposed plant and animal matter. They include materials such as peat, which is formed from accumulated vegetation in swampy areas, as well as other organic-rich deposits.
3. Chemical precipitates: These sediments form when dissolved minerals and ions in river water come out of solution and are deposited as solid particles. Examples include calcium carbonate (limestone) and salt deposits.
The composition of fluvial sediments can vary depending on factors such as the geology of the source region, climate, vegetation cover, and human activities like agriculture and mining. To determine the specific types and proportions of sediments that arrive in the ocean from a particular river, scientists use various methods of analysis, such as sediment sampling and grain-size analysis.