Yes it's a early buckle,it would date 1690-1720 era.Could date a little earlier say 1660-1720.Yours is missing the little rivet on the tab end.Here's a couple like your in date range I've found pics. below..............
Also to show the age you can look through this section of the U.K. site two piece buckles. http://www.ukdfd.co.uk/ukdfddata/showrecords.php?product=10832&cat=177
Just wanted to add a few things I forgot on these type buckles.Some of these small buckles were used on spurs as seen in the pics. & sites below.................. buckles