Authorities arrested a New York man on Monday, charging him with sexually assaulting a child in Northvale. John Mark Dillon, 63, of Piermont, New York is accused of assaulting the minor and charged with two counts of first degree aggravated sexual assault, according to the Bergen County Prosecutor’s Office and Northvale Police Department. Authorities gave few details about the investigation, and did not say when the alleged assault took place. Officials said the child was under the age of 13 when the assault occurred, but did not give an exact age. Dillon was arrested in Orangeburg, New York a…