Another landform seen out the window of that very productive photo-flight last March:
That’s a breached plunging anticline – doubtless a Laramide structure. This was over Wyoming; I think here.
Looking north-ish, along the axis of the fold:
Note that the lengths of section line A and B are not equal: this anticline is asymmetric. The facing direction of the hogbacks on the left (west) indicate it’s not overturned, but those strata are definitely dipping more steeply than their counterparts on the eastern limb of the fold.
Happy Friday!
The limb on the left certainly looks to be more steeply dipping than the limb on the right. But in order to identify a fold as asymmetric don’t we need more information? I.e. the orientation of the axial plane relative to the dip of the limbs or the enveloping surface, or the length of the limbs of the fold.
Sure, that would be great info to have. I’m working from an airplane window here, though – so consider this an inference, a testable hypothesis…
Wyoming sheepherder anticlines. I think (if I remember my Wyoming geology, it’s been 25+ years) that one is the Emigrant Gap anticline, the north end. It is oversteepened to the west with dips of 40-75 degrees and dips generally of 10-30 degrees on the east limb.
You are right! I just got back from there on a field trip. That is Emigrant Gap.