Which preposition to use with kalpas

of Occurrences 3%

I had no longer that feeling of unutterable loneliness; but felt, rather, that I was less alone, than I had been for kalpas of years.

after Occurrences 1%

(1) The Kalpabhavas again are subdivided into twelve genera who live in the Kalpas after which they are named; viz, 1.

Which preposition to use with  kalpas