Evaporite sequences

As promised, I took some time on a rainy day to adapt and redraw this chart from one of my old textbooks to present the Evaporite Sequence for the readers of the Habitable Zone.

This is an idealized model assuming the complete evaporation of 1 cubic kilometer of modern terrestrial sea water. Therefore we assume no replenishment of the seawater, no adjustment for a proposed Martian sea, and no post or syn depositional erosion. Take a cubic kilometer o' sea water and let it dry, this is what you get. (of course this rarely happens - maybe on Mars- , but it's a start.)

The center panel shows a curved line representing the volume of water left during evaporation. The vertical axis represents the depth of the sea (or volume) while the horizontal axis represents the density of the water, a reflection of the salinity. It can also represent time as the water evaporates.The "tear drops" in green represent what minerals are precipitating as the water evaporates. At a particular density draw a line vertically and you will see what minerals typically precipitate at that time. There might be more than one! To the left and right are panels with the compositions of water and precipitates. The lower panel shows what environments have these salinities. In the lower right corner is a Geologic column (how the evaporite rocks would be distributed in vertical space). Note that the first minerals precipitated are going to be the bottom layer.

Well, given that we have MgSO4 and CaSO4, where does that put the Opportunity rocks, salinity-wise? If we go up or down section, what should we observe? If "bounce" is above this stratigraphically, what should it be? Endless questions.....

Enjoy.