If the world’s oceans have been around for three billion years as evolutionists believe, they should be filled with vastly more salt than the oceans contain today.
After 3 billion years, we would expect to see 70x more salt in the ocean than we see today.
Every year rivers, glaciers, underground seepage, and atmospheric and volcanic dust dump large amounts of salts into the oceans (Figure 1). Consider the influx of the predominant salt, sodium chloride (common table salt). Some 458 million tons of sodium mixes into ocean water each year,1 but only 122 million tons (27%) is removed by other natural processes2 (Figure 1).
If seawater originally contained no sodium (salt) and the sodium accumulated at today’s rates, then today’s ocean saltiness would be reached in only 42 million years3—only about 1/70 the three billion years evolutionists propose. But those assumptions fail to take into account the likelihood that God created a saltwater ocean for all the sea creatures He made on Day Five. Also, the year-long global Flood cataclysm must have dumped an unprecedented amount of salt into the ocean through erosion, sedimentation, and volcanism. So today’s ocean saltiness makes much better sense within the biblical timescale of about six thousand years.4
Figure 1: Every year, the continents, atmosphere, and seafloor add 458 million tons of salt into the ocean, but only 122 million tons (27%) is removed. At this rate, today’s saltiness would be reached in 42 million years. But God originally created a salty ocean for sea creatures, and the Flood quickly added more salt.
Those who believe in a three-billion-year-old ocean say that past sodium inputs had to be less and outputs greater. However, even the most generous estimates can only stretch the accumulation timeframe to 62 million years.5 Long-agers also argue that huge amounts of sodium are removed during the formation of basalts at mid-ocean ridges,6 but this ignores the fact that the sodium returns to the ocean as seafloor basalts move away from the ridges.7
http://www.answersingenesis.org/articles/am/v7/n4/sea-salt