Melo Trimble added 13 points to go with seven assists and five rebounds for the Terrapins (11-1), who hit a season-high 13 3-pointers to win their fifth straight game.
Rasheed Sulaimon added 14 points for Maryland, which begins its Big Ten schedule on Wednesday against Penn State.
“We had a lot of things to be happy about today," head coach Mark Turgeon said. "I thought we played well. Marshall was a tough team for us to match up with. The big guys can handle it and drive it, first half we had a hard time guarding them. I thought in the second half we were much better. We had a lot of guys play well tonight."
Stevie Browning was one of four Marshall players to score 11 points. He grabbed seven rebounds for the Thundering Herd (4-9), who made 6 of 31 3-point attempts, missing 12 straight in the second half as the Terrapins pulled away.
Carter came within two points of his career high and one off his season best with Maryland.
Stone was 8 of 10 from the field in the latest in a string of impressive performances by the highly recruited freshman.
The McDonald's All-American has scored in double figures in his last five games, including 16 points three times. He scored a total of 29 points over his first four games.
Maryland was up by 10 points at halftime and took control with a 25-10 run that stretched across much of the second half.
Trimble got it started with a jumper and a 3-pointer to make it 59-43.
Brantley's second, off a pass from Trimble, made it 77-51 with 6:32 to play.Maryland welcomes Penn State to kick off the 2015-16 Big Ten slate on Wednesday at 5 p.m. at XFINITY Center.