for both dtb & REB

"If you soaked a hunk of basalt in salty, evaporating water, would you get a "hard, dark" coating of evaporites?"

I believe so. It's included in some of the reading list I offer above in "Arm-waving about chlorine", and a popular model with some geologists.

While I did not discuss the chlorine coming from seawater in my arm-waving, it is a likely model. (In my mind, I kinda group it generically under "weathering", but I should be more specific, perhaps alteration is a better term of rock-sea water interactions.)

What I've been also trying to ascertain is where the chlorine came from originally, even if in sea water, it has to have a parent source. On earth, it is the weathering of rocks, but which rocks? Do mafic rocks contain more chlorine than felsic ones, or is it the other way round? I've thousands of chem analysis on rocks, I'll look at them and see if they had chlorine as part of the analysis package, see if I spot any trends. Or I'll keep on reading.