Deen Castronovo Arrested -- Journey Drummer Busted for Girlfriend Assault

Deen Castronovo -- the current touring drummer for Journey -- was popped this weekend in Oregon for allegedly assaulting his girlfriend, TMZ has learned.

Sources close to the drummer tell us, Deen was arrested Saturday ... after a heated argument with his lady turned physical.

According to law enforcement, Deen was booked into Polk County Jail on a laundry list of charges -- including coercion, assault in the 4th degree, criminal mischief in the 2nd degree, interfering with making a report, and harassment.

Sources tell us the additional charges stem from an altercation that occurred after the alleged physical blowout -- when his girlfriend ran out of the house to call her father, and Deen grabbed the phone out of her hand and refused to let her contact her dad.

Deen's bail was set at $52,500.00 -- which he posted before being released.

A rep for Deen tells us, the rocker believes "it was a misunderstanding that should not have been escalated to such a level in the first place."