The Castile Formation is situated in the Delaware Basin in New Mexico and Texas on top of thousands of meters of oil-containing sedimentary rock (the Delaware Mountain Group). The up to 550-meter-thick formation is composed of laminae of mostly anhydrite and calcite (Kirkland, 2003) and contains oil itself as well. The overlying Salado Salt Formation covers a wider area, including the Central Basin Platform and the Midland Basin in Texas, with a thickness up to 600 meters.
Evolutionists claim an origin of the 10,000 km3 Castile Formation by evaporation of salty ocean water in a continental basin over 209,000 years. Every year a layer of calcite was overlain by a layer of gypsum. However, they need to impose a yearly reflux of salt brine back into the ocean to get rid of the undeposited NaCl. Despite the significant water volumes in and out, the surrounding - assumed extinct - reef (Capitan Formation) oddly didn’t erode. The dehydration of gypsum to form anhydrite after burial is another difficulty in the contrived evolutionary explanation.
An igneous origin of salt formations during Noah’s Flood is a more acceptable explanation (Heerema, Van Heugten, 2018). From the Flood waters, the Wolfcamp, Cherry and Bell Canyon formations were deposited, after which the salt eruption occurred. The feeder dike for the salt magma probably was the fault at the west side of the Central Basin Platform (see figure). There are similarities between salt welds and igneous dikes as molten material invades and then is removed (Willis, 2018). The heat of the igneous salt may have contributed to the rapid development of the fossil fuels in the sediment layers below. Anhydrite and calcite crystals are not chemically bound to each other. That offered the oil the opportunity to penetrate the Castile rhythmites in a secondary migration phase.
Silicate magmas can produce layered igneous intrusions (e.g., Bushveld chromitite and flow-banded rhyolite). Likewise, the crystallization and cooling of a salt magma after deposition will probably cause segregation of the different salts into homogenous layers. Where we refer to salt, we do not solely indicate NaCl, but all salts naturally occurring in salt-rich formations. Several salts like NaCl (halite), CaSO4 (anhydrite), CaCO3 (calcite), CaMg(CO3)2 (dolomite), KCl (sylvite), MgCl2(Chloromagnesite), et cetera, are involved. In a melt, these salts form an ionic liquid. The more different salts (or other chemicals) are dissolved, the lower the melting temperature becomes (Smith, 2014). A modern analogy of such low temperature ~500 degrees C magmas can be found at the Ol Doinyo Lengai volcano, within the Great Rift Valley (Mitchell, Belton, 2008). An ionic liquid is a powerful solvent and can become contaminated with dissolved rock on its way from the mantle. A small volume that is slowly delivered, as is the case with Ol Doinyo Lengai, will be more susceptible to contamination than a large volume that is delivered fast like the magma under investigation.
Crystallization processes from ionic liquids are complex. They strongly rely on temperature, cooling rate, pressure, composition, density differences, turbulence, miscibility and other parameters. Interaction with water, sediments and additional eruptions are complicating solidification even further. The Castile and the Salado Formations are perfect examples to unravel some of the mysteries of this precipitation process. The layers suggest that the Castile Formation is a cumulate rock wherein the denser anhydrite and calcite crystallized from the parental salt magma. The overlying Salado Formation probably crystallized from the less dense residual magma that overflowed the Central Basin Platform.