Bakhar Formation
The Bakhar Formation ( Russian: Bakhar Svita ) is a geological formation in Mongolia whose strata date back to the Aalenian to Bathonian stages of the Middle Jurassic , comprising claystones deposited in a lacustrine environment . 
<triplet> Aalenian <subj> Middle Jurassic <obj> part of <triplet> Bathonian <subj> Middle Jurassic <obj> part of <triplet> Middle Jurassic <subj> Aalenian <obj> has part <subj> Bathonian <obj> has part