With Captain Phil Mustard winning the toss and electing to bat, the openers put on 84 before Michael Di Venuto became youngster Danny Briggs first wicket of the day when he was caught by Ervine on 42.
Mark Stoneman reached the fifty mark having faced 81 balls, hitting nine boundaries in the process, but was dismissed the following delivery when he was bowled by Briggs.
At lunch Durham were 116-2 with Gordon Muchall 13* and Ben Stokes 7*
Stokes (10) was out in the first over after the break when he was caught by Dominic Cork in the slips off Simon Jones, bringing Dale Benkenstein to the middle.
Muchall and Benkenstein put on a hundred, securing Durham their first bonus point of 2011, before the latter, whose fifty came off 70 balls and included seven fours, fell foul to a bowling change and was caught by Adams in the deep off Cork for 62.
Benkenstein powered on, partnered by Blackwell who was dropped on 29 off a no ball, to become the third batsman to pass fifty, from just 56 deliveries, including seven boundaries.
At tea, having added 173 runs in the second session, Durham were 289-4, with Benkenstein 76* and Blackwell 32*.
Durham passed the 300 mark in the 67th over and some big hitting saw the pair’s partnership reach 100 in the 78th over.
Benkenstein went on to score his eighteenth first class century for Durham from 126 balls, including 11 fours and two sixes.
Blackwell reached 62 before he was bowled, becoming Brigg’s third victim of the day with 15 overs left of the day.
Briggs struck for a fourth time when Benkenstein was caught by Adams on 118 as Durham stood at 368-6.
Phil Mustard scored quickly in the remaining overs to ensure Durham reached the 400 mark and picked up the maximum batting points. At the close of play Durham were 413-6, Mustard 39* and Borthwick 8*.
Highlights of the day’s play will be posted online at www.durhamccc.co.uk/durhamtv on Saturday and if you want to follow the remainder of the action, as it happens, visit Live Match Chat (www.durhamccc.co.uk/live-match-chat)