depression angle
2.The depression range-finder sight was probably calibrated to directly give range readings for each depression angle.
3.The extensional tectonics in upper crust in the north Mid-Hebei depression is one of the tectonics styles which created faulted-basins. It is a huge "broom-like" extensional tectonics dominated by the Daxing listric fault,which is intersected in an acute angle by the Niudong fault.
