https://www.usgs.gov/publications/boulder-creek-batholith-colorado-part-i-allanite-and-its-bearing-upon-age-patterns
Boulder Creek batholith, Colorado part I: Allanite and its bearing upon age patterns | U.S....
Allanite is abundant and commonly attains unusually large size as a late-replacement mineral in: (1) the comagnatic rocks of the Precambrian Boulder Creek...