Graptolite belongs to the ----------- phylum.
In an unconformity, the rocks on opposite sides are not parallel, then its is
Joints perpendicular to the axes of folds are common in orogenic belts, such joints are called
Oscillation ripple marks can readily be used to identify whether a bed is right-side-up or
In a fold, the downward-facing beds are
The strike direction is commonly recorded like -------- using quadrant bearing from the north point.