I'm having a surprising amount of trouble finding precise ages for geologic formations. Is there a public database available with the ages of a significant number of stratigraphic units?
No.It's actually not surprising at all, because many formations simply cannot be dated radiometrically, and others that could be haven't been because it requires effort and money.
Worse, I'm having trouble finding exact numbers for many units. I understand the gist of say, "late Maastrichtian" but I need exact numbers to enter into the timeline template and to enter guesstimates as to what exact numbers the authors meant by this would violate Wikipedia's policy forbidding original research.
In most cases, the authors simply don't mean exact numbers, because they can't do absolute dating.