Alternating forms and the Brauer group of a geometric field

We compute the theory of $H^{2}(G,\mathbb{Q}/\mathbb{Z})$ for any proabelian group $G$, using a natural isomorphism with the group $\operatorname{Alt}(G,\mathbb{Q}/\mathbb{Z})$ of continuous alternating forms. We use this to establish a sort of generic behavioral ideal, or role model, for the Brauer group Br$(F)$ of a geometric field $F$ of characteristic zero. We show this ideal is attained in several interesting cases.