Those are very old shingles. If no water penatration, remove/replace in 8 months. Unless you are in Texas, get a Pro-Roofer out there next week to get you an estimate.

 

Slower. You would have to remove one to see. Even if they are something I've never seen before, pretty sure that roof is due for replacing.

 

I lifted one.
And I agree 100% that roof is end of life. It's also mid-November, not the ideal time to start a roofing project. The evaluation is can the roof last until spring.

The left and right eaves of the roof are also basically unsupported. The rafters run front to back, and there's nothing supporting the eaves other than hope and plywood, as far as I can tell

Someone stuffed rigid foam insulation up under the decking, between the rafters, at some point, without much care for vapor sealing or much of anything.

 

Those are asphalt shingles. Just very old to the point the asphalt part has weathered away leaving the fibreglass mat and some of the granules.

 

Time for replacement. Within a 100 miles of the coast minimum 110 MPH RATED shingles (not 3 tabs that are 55 MPH).