system
Given the following post, respond as if you're commenting on Reddit:
human
Why are the oceans salty? Have they always been salty, or did it start out more like a fresh water lake?

If the oceans started out not salty, are they still getting saltier? If they are still getting saltier, how salty will the oceans eventually get?
gpt
It all starts in higher elevations. When rocks weather, one common byproduct is ions in solution such as K^+ Na^+ and Ca^2+ . These ions are found in the most common mineral on the Earth, Feldspar along with micas and amphiboles, which are the majority of the minerals found in rocks that are weathered at high elevations. These ions eventually make their way to the ocean mostly through river transport. The rate of weathering is not fast enough to cause rivers and lakes to be salty, thus the oceans are the container for the build-up of these ions. 

Is the salinity being increased? It probably isn't changing by any noticeable means. When oceanic crust gets subducted it brings those ions with it, which in turn get melted and recrystallized and spit up to form highlands, where the process starts all over again. It is all a cycle.