Avodah Zarah 46: Attached to the Ground

More on the hills and mountains and rocks - where they are being worshipped by a non-Jew, that is, the boulders that separate from a rocky mountain. Is that boulder like the mountain which isn't prohibited from benefit, or is it like the object of idolatrous worship? Usually, human engagement is necessary to make the object of idolatry prohibited. With a comparison to an animal -- including one that is blemished, as a parallel to the boulder. Also, the factor of being attached the ground - to what extent does that establish the worshipped object as something problematic or not?