If you open this pdf & scroll down you will see that Ac is indeed Chert,
& that would be the blue line that RH62 referred to in post #31
https://www.prospectingaustralia.com/forum/doc/member-docs/12692/1587868932_geomap_geology_legend.pdf
& that would be the blue line that RH62 referred to in post #31
https://www.prospectingaustralia.com/forum/doc/member-docs/12692/1587868932_geomap_geology_legend.pdf