Atlanta prog-metal band Mastodon were set to join Dinosaur Jr. and hand-selected openers Netherlands for a tour kickoff in Edmonton, Alberta on September 1st, but "a critical situation of a member of the Mastodon family" has those plans on indefinite hold according to an official statement from the band.
Mastodon's statement continues, stating that they "would like to extend their sincerest thanks to their loyal fans as well as the fans of Dinosaur Jr. for their support and understanding at this time. The band hopes to make up these shows at a future time, but as of now, no plans for rescheduling have been set."
Refunds will be offered at ticket-holders' point of purchase. Check Mastodon's official site for updates regarding any future rescheduled dates.