Before I went on the tangent to make this pretty extensive tileset; I had several mods in mind, not to completely change the setting of Dwarf fortress, but rather add to the gameplay core of dwarf fortress, but expanding upon the low fantasy aspects of DF with some more authentic European (or North Atlantic) folklore. I am not sure if I was going to go ahead basing it on a modest/reduced mod, but the initial approach was to reduce the ammount of different plants, trees, animals, clothes included in DF to lay groundwork for more unique content. There is really no need to have 10 different spider monkeys or 20 different amaranths if the regular person do not care for the difference. Furthermore, the preference system in DF doesn't really allow for much variation (sad but true). So first my first deeds where removing most if not all historically non-eurasian animals, plants and so on. All this to make room for new systems, industries etc.
I worked on a geology overhaul aswell, since I'm actually one of them Geologists. Geology in DF is extensive, but very weird. deformed layers above nondeformed etc. Gems and Ore in weird localities, Ruby in bauxite etc. Plagioclase/microcline in high pressure environments and a lot more. Most problems are only fixable with a geology rewrite or a dfhack script like 3dveins. Also, tetrahedrite isn't really a major thing. Ultimately, where are the mafic dikes, hydrothermal, contact deposits, sills, eclogites, migmatites and so forth?
It is weird how olivine comes in large clusters when it is mostly part of the upper mantle as dunite and intrusions like that is very rarely pure olivine, since pure olivine require a huge degree of partial melting. Pure Olivine would imply crystal fractionation of other minerals during crystallization in any case.
I'll continue the rant in next post, stay tuned.