I understand this to be a Red Ash, (Alphitonia excelsa). This tree grows atop a creek bank, and is at least 40 years old. Photo 1 shows the canopy, upper trunk, & main branches. The leaves are thin but leathery, and are a dark green on top (photo 3), with a silver-white underside (photo 4). As with this one, I’ve seen many trees with their trunks, and branches being a mix of smooth & rough (predominantly) white, whereas patches of darker bark are mostly rough, having vertical fissures of generally narrow, but varying widths. The smoother bark is also mostly on younger growth. The trunk of this specimen has some narrower, almost bands, of light grey bark, roughly distributed along its length (photo 2). Others I’ve seen around seem to be more splotchy and random in the distribution of darker bark. The trunks and the branches are often host to a range of lichens and associated life forms.