Where does the salt in the oceans primarily originate from?

The primary source of salt in the oceans is the weathering of rocks, which releases various minerals, including sodium and chloride, into the waterways that eventually flow into the oceans. Over time, as rain falls and rivers and streams erode and transport minerals from the land, these dissolved materials, including salt, are carried into the oceans.

When rocks break down, they undergo a process called chemical weathering, which contributes significantly to the salinity of ocean water. The minerals from this weathering accumulate in the oceans, leading to the characteristic saltiness of seawater seen today.

While runoff and erosion do contribute to this process, the broader category of rock weathering encompasses a range of activities that release salts into waterways. Therefore, the weathering of rocks is the primary source of the salt found in oceans, rather than only focusing on runoff and erosion, which are components of the overall interaction between land and water.