Why is mass fraction always abbreviated wt% and not ma%? In most geology papers, major elements chemical analyses are expressed as mass fraction of oxides, i.e. SiO$_2$ 64.2 wt%, K$_2$O 4.3 wt%, etc. The mass fraction unit is always abbreviated as "wt%". Even my bible when it comes to igneous rocks classification/terminology (Le Maitre et al. 2002) uses it.

What bothers me is that "wt" refers to the weight, which is a force, not a mass. I know it is common usage to use "weight" to refer to the mass of an object, but when writing science shouldn't we be more accurate and use the proper words? Molar and volume fractions are abbreviated mol% and vol%, respectively. Isn't it time for the "ma%" or "mas%" revolution? If I write "mas%" in a paper, will the reviewers/editors accept it?
This is because of historical inertia.

Yes, you are correct that "mass" is technically more correct than "weight". However, because these are percentages, it does not matter. There are no units. A rock that has 50 weight% SiO2 also has 50 mass% SiO2, regardless of the planet (i.e. g) you are in.

Regarding using "ma%" - I have never seen it and it would be confusing, especially since "ma" will probably be interpreted as the unit "milliannum" which is weird. Using "mass%" would be better, but "wt%" is only 3 characters compared to 5 so there's the issue of laziness. I have seen papers using "mass%" and that's fine, and I wouldn't object to such usage if I were to review a paper.

That said, geologist often weigh rocks. Yes, the numbers are mass. But the action itself is "weigh". Go figure.