Dear Professor Hovland,

I hope to address your issue in the appropriate manner. I have been studying hydrothermal mineral deposits in different morpho-climatic regimes. In the arid zone, in many samples I found halite among other chlorides surrounding vein quartz which precipitated under subcritical conditions (< 373°C). The relation of precipitation of quartz and halite in time and space was clear. There was a significantly hiatus between the two minerals. Even in fumaroles , where halogenides are formed in some places, halite is younger and has nothing to do with the primary mineralization which also may contain silica modifications. Metamorphism of salt takes place under rather low temperatures (< 100°C) engendering the formation of minerals like langbeinite, kieserite etc. during prograding metamorphism of salt.  In deep holes like the KTB (> 9000m) there are solutions but no halite concentrations, to my  knowledge. It is mainly the "bittern" that survive higher temperatures, like polyhalite. I am rather skeptical about the proper investigation of the temporal relationship between salt and silica in the case in question. Experiments are one side of the coin, nature the other one. But I am open to convincing arguments for the presence of halite at these higher temperatures with quartz in the natural habitat: Even an old dog can learn new tricks.

Best regards

Harald G. Dill

Thanks a lot, Harald, and I am sure you are right. I have written to the Author of that abstract to send me or publish the article and the documentation of the stable isotope values etc.

Best regards

Martin

Thanks a lot, Stanislaw,

no, I do not have such halite here. The one Place you could probably acquire such halite is from the Dallol salt Volcano in the Afar (Northern end of Lake Assale), Eritrea...

one can have liquid water at -70 ° C and solid water (ice) to + 80 ° C, and it is the game of pressure that makes the difference !