Why is the sea salty?

I know it's a common question, but the answers I've found by a bit of googling don't really answer it.

I fully grasp that weathering takes solutes to the sea where relative concentrating of them occurs, but I seem to have missed the part that explains why the mineral richness of sea-water is dominated by sodium and chloride specifically.

via International Skeptics Forum http://ift.tt/2n8xH5V