Wow, looks like it broke where it was joined. You might consider using two thinner belts when you get er back together. The best belts I had found were GATES brand.
Years ago I had a PSRU on a subaru powered gyroplane. I stripped the belt tice, once on climb out and another time further away. Managed to get home in both cases. After the second one I ditched the belt system and went to a gear box. still runn'n strong 10 years later.