I O M
COH I BAE
TASIORVM
C R CVI PRAEST
ATTIVS TVTOR
PRAEF VSLLM
the text being virtually identical to RIB 830; an altar set up to Jupiter, best and greatest, by T Attius Tutor, praefect of the First Cohort of Baetasians, Roman citizens (I don't see the T for T(itus) Attius Tutor, but this photo isn't much to go on).
If you have been following reports of the excavations (or reading Current Archaeology 259) you may already be aware of the conclusion that the altars were not 'ritually buried' but merely reused in the foundations of a large timber structure.