Motorhead & Venom influenced Cro Mags which would influence Metalcore pioneer bands later on like Rorschach, Integrity and Earth Crisis. EC would say they were influenced by bands like Slayer, Iron Maiden and Metallica
Jacob Bannon of Converge was influenced by Slayer and Rorschach for example and he went on to influence most of the pre-mall modern metalcore
You can also hear the thrash influence in a lot of the Straight Edge hardcore bands. Some like XREPENTANCEX have some early metalcore aspects
I'd say that Trivium has some definite trad metal vibes sprinkled through their music.