There is no Brock County in Ontario -- only the Brock Township in what was Ontario County (now part of the Regional Muncipality of Durham). What are you looking for in particular, as I have access to local records for the area.

Archibald died 18 June 1911, aged 80 years, 6 months, 13 days, b. 5 December 1830 Scotland, of Pt. Lot 24, Concession 1, Brock Township (Sonya); Presbyterian Minister; married, son of Edward Currie, b. Scotland, and Jane Campbell, b. Scotland; informant: Mary Currie of Sonya.