Evaporites could form without evaporation (Talk.Origins)
Evaporites can precipitate from unsaturated brines; they can form without evaporation (H. M. Morris 1974). A mechanism is sketched by J. D. Morris (2002):
- Many now think the salt was extruded in superheated, supersaturated salt brines from deep in the earth along faults. Once encountering the cold ocean waters, the hot brines could no longer sustain the high concentrations of salt, which rapidly precipitated out of solution, free of impurities and marine organisms.
- Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master Books, pp. 105-106.
- Morris, John D., 2002. Does salt come from evaporated sea water? Acts & Facts 31(11) (Nov.).
It should be noted that this is not the only proposed creationist model for rapid formation of "evaporites". Dr. Gish sums up one model:
|“||It has been suggested that the mixing of different kinds of brines, say of sodium chloride and magnesium chloride, each originally saturated, might cause precipitation of one or both of the salts. Omer B. Raup has conducted some experiments that have shown that much salt is precipitated when brines are mixed. The precipitation took place without any evaporation of water or change of temperature.||”|
(Talk.Origins quotes in blue)
1. Most evaporite deposits are not associated with evidence of hydrothermal activity. The huge amount of energy needed to deposit kilometers of salt in a few weeks should have left obvious evidence, such as heat-altered rocks or evidence of magma. Typical hydrothermal deposits such as iron and manganese are not often found associated with evaporites
This only shows that the salt was deposited some distance from the hydrothermal activity. A supersaturated salt brine would have been a liquid and thus easily pushed by the current before precipitating out. In one case the salt brine may have traveled 50 miles from a hydrothermal deposit of zinc and lead that uniformitarian geologists would consider too old to be associated with the salt deposits.
Also, the model supported by Omer B. Raup's experiments does not require massive amounts of heat. See beginning of article.
Sea-floor basalts are a common site of hydrothermal activity, and other hydrothermal deposits are found there, but salt deposits are never found associated with them. 2. Hydrothermal systems operating today are not depositing any salt, much less the thick, laterally extensive layers we find in the sedimentary record. In fact, hydrothermal solutions contain less sodium and chlorine than normal sea water.
The hydrothermal activity that produced the salt deposits would be on continental crust and not oceanic crust. Also, given the size of some of these salt deposits, it is likely that the Flood drained off most of the salt available for hydrothermal solutions. Only a uniformitarian mind set would insist that current hydrothermal activity would be the same as the Flood's hydrothermal activity.
3. Evaporites are observed forming today in basins with no significant outflow; the water that flows in evaporates and leaves behind layers of dissolved salts.
Precipitation would not necessarily produce significant outflow either, so what's the point?
Ancient evaporites are also found in sedimentary context, and they are often associated with other evidence of being open to the air, such as footprints, dessication cracks and occasional raindrop impressions. None of these structures are consistent with an underwater hydrothermal environment.
Desiccation cracks would form subsurface as the deposits dried out after the flood. So called raindrop impressions are really air bubble impressions and are actually evidence of rapid deposition. The claim of footprints is unsubstantiated. There seems to be no evidence of footprints in ancient "evaporites" outside Talk.Origins' declaration that they exist. The lack of examples makes a proper analysis impossible, but there are possibilities. If the salt is currently on or near the surface, the prints could be post-Flood. Otherwise they would only indicate that the deposit was above water or near the surface at some time during the Flood.
Evaporites are also found in sabkha environments, where crystals or nodules of salt grow within fine-grained sediments as saline groundwater (usually from a nearby ocean) is drawn upwards by evaporation. As the water evaporates at the surface, salt nodules grow, often forming a chicken-wire pattern. Some sabkha evaporites grow into gypsum rosettes, huge crystals resembling flowers. These features also are known from ancient evaporites. They also are inconsistent with hydrothermal deposition.
Talk.Origins is clearly ignoring the results of water evaporation as the deposits dried out after the Flood.
Also, using data from the Mediterranean Sea, Hardie and Lowenstein showed that the chicken-wire pattern and sabkha environments can be created (and should be interpreted as) in deep water environments.
Hardie LA, Lowenstein TK. 2004.Did the Mediterranean sea dry out during the Miocene? A reassessment of the evaporite evidence from DSDP Legs 13 and 42A cores. Journal of Sedimentary Research 74:453-461.