Far from an expert but I'd have to say no to them being CW-period. I've never encountered any Period ones which were black like those, generally they have a copper or grayish-green patina (depends a lot on the soil and their composition) and don't fan out as dramatically as those have.
Aw Bummer............ Thx dude
These are fired period caps, note the 4 way split.
These are modern CCI caps, note the six flanges on the cap, which would cause them to split 6 ways like your find.