Deposits of salts from evaporated seawater are called evaporites. There are many evaporite deposits around the world that could not have formed during a worldwide flood.
This is a picture of salt deposits under Michigan
Under much of the state the salt is 400 feet thick.
http://www.geo.msu.edu/geo333/evaporite.html
Sea water is only 3.5% salt and NaCl which is 90% of the salt in seawater is soluble to about 35% in water. Thus a ten fold concentration increase is needed to even get salt to start to precipitate.
There are estimated to be 70 trillion tons of salt under Michigan alone and this is only a fraction of the salt deposits in the world.
http://www.saltinstitute.org/14.html
So to get just the salt under Michigan to deposit about 2 x 10[sup]18[/sup] Kg of water had to evaporate. Can any YEC explain how all this water evaporated during a worldwide flood?
Now I know that ICR and AiG claim that these deposits are from some sort of hydrothermal orgin. However, that doesn't really work. There are no basalts or any other evidence of geothermal activity around these deposits. Many contain pollen and other contain salt varves indicating slow evaporation. This is just another case of professional creationists coming up with an ad hoc explanation and ignoring many of the facts about evaporates.
Here is what geologist Kevin Henke has to say on the subject.
http://www.geocities.com/Athens/Thebes/7755/henke/krh-floodnonsense.html#A14
Of course the other problem with a hot water orgin of evaporites is that you need enough hot water to cook the earth to death. It is easy to calculate how much water must be boiled away. To boil 2 x 10[sup]18[/sup] of water takes about 4 10[sup]24[/sup] J of heat and this heat will be released back into the atmosphere when the water condenses from steam. From the mass of the atmosphere and the heat capacity of atmospheric gases one can calculate that this is nearly 10 times the amount of heat needed to heat the atmosphere by 100 C.
Evaporites are another falsification of the worldwide flood that YEC can't answer.
The Frumious Bandersnatch
This is a picture of salt deposits under Michigan

Under much of the state the salt is 400 feet thick.

http://www.geo.msu.edu/geo333/evaporite.html
Sea water is only 3.5% salt and NaCl which is 90% of the salt in seawater is soluble to about 35% in water. Thus a ten fold concentration increase is needed to even get salt to start to precipitate.
There are estimated to be 70 trillion tons of salt under Michigan alone and this is only a fraction of the salt deposits in the world.
http://www.saltinstitute.org/14.html
So to get just the salt under Michigan to deposit about 2 x 10[sup]18[/sup] Kg of water had to evaporate. Can any YEC explain how all this water evaporated during a worldwide flood?
Now I know that ICR and AiG claim that these deposits are from some sort of hydrothermal orgin. However, that doesn't really work. There are no basalts or any other evidence of geothermal activity around these deposits. Many contain pollen and other contain salt varves indicating slow evaporation. This is just another case of professional creationists coming up with an ad hoc explanation and ignoring many of the facts about evaporates.
Here is what geologist Kevin Henke has to say on the subject.
http://www.geocities.com/Athens/Thebes/7755/henke/krh-floodnonsense.html#A14
Another great problem for YECs is how enormous amounts of water-soluble salts (evaporites) could form in the geologic record during a "Flood." Chemistry dictates that the salts would have been dissolved and dispersed in any "Flood" waters rather than precipitated. A number of YECs have attempted to explain the origins of evaporites (for example, Nutting, 1984), but have failed miserably to account for these deposits in a short and wet YEC time frame (Henke, 1990). While Nutting (1984) and other YECs have tried to invoke a magmatic or lower crust/mantle hydrothermal origin for evaporites, Sarfati quotes John Baumgardner, who advocates precipitating them from boiling sea water. Again, Baumgardner believes that a significant amount of the world's oceans violently boiled and evaporated into the atmosphere during the "Flood." Supposedly, this event produced brines that precipitated the evaporites. However, Baumgardner admits that the steam from the boiling oceans would have quickly returned as rains during the "Flood."
The real problem for YECs is getting all of that salt distributed through the "Flood" deposits without dissolving them. This is not easy. Some salt deposits are very thick and pure. How were these thick deposits "stuffed" into a sediment column without contaminating them with silicate-rich muds or dissolving them with "Flood water"? In addition, some evaporites, such as the Castile Formation of west Texas, contain salt varves that can be laterally traced for more than 90 kilometers (Blatt et al., 1980, p. 553). As discussed in Wonderly (1987, p. 74-77), these delicate varves show no evidence of a volcanic, hydrothermal, or violent origin. They are completely incompatible with YEC and "flood geology."
A review of the origin of the salt deposits of the Michigan Basin shows that their formation is incompatible with magmatic sources or hydrothermal precipitation as advocated by Nutting (1984) or Baumgardner's deadly boiling seas. The rocks contain no evidence of nearby volcanos or other igneous or metamorphic sources (Young, 1982, p. 86).
When the Silurian paleogeography of the Michigan Basin is restored, thick semi-concentric barriers of coral reefs become very noticeable (Schreiber, 1988, p. 238-239). As evaporites formed in the Michigan Basin, massive reefs existed just to the east of Lower Michigan in Ontario, along the Ohio-Indiana border, along the Michigan-Indiana border and curving through what is now Lake Michigan and north into Upper Michigan. These reefs would have been ideal barriers to trap evaporating sea water in the Michigan Basin. Periodically, fresh seawater could have broken through or flowed over the barriers to recharge the brines.
Open marine carbonates are located at the bottom of the Silurian sequence of the Michigan Basin (Schreiber, 1988, p. 238-240) Above them are evaporites. The lower portion of the evaporites indicate deep water, but the upper portion formed in shallow water (Schreiber, 1988, p. 240). Many of the reefs in the basin have karst features and weathering zones, which indicate that the reefs were periodically above water (Schreiber, 1988, p. 238-240; Warren, 1989, p. 162). While subaerial reefs could have been effective in trapping evaporite-producing brines, such features would not be expected to form during the middle of a "Flood."
Overlying the evaporites are more carbonates that formed when fresh seawater entered the basin. Above these carbonates are more layers of evaporites that were slowly produced by evaporating brines that were again trapped in the basin by the reefs. Next, another layer of carbonates formed as seawater once more entered the basin. Finally, more than 610 meters (2,000 feet) of very shallow water evaporites filled the basin (Schreiber, 1988, p. 238-240). Again, these features are entirely compatible with slow evaporation and periodic influxes of seawater over long periods of time. However, they are incompatible with a rapidly raging YEC "Flood."
Of course the other problem with a hot water orgin of evaporites is that you need enough hot water to cook the earth to death. It is easy to calculate how much water must be boiled away. To boil 2 x 10[sup]18[/sup] of water takes about 4 10[sup]24[/sup] J of heat and this heat will be released back into the atmosphere when the water condenses from steam. From the mass of the atmosphere and the heat capacity of atmospheric gases one can calculate that this is nearly 10 times the amount of heat needed to heat the atmosphere by 100 C.
Evaporites are another falsification of the worldwide flood that YEC can't answer.
The Frumious Bandersnatch