Hi Thomas,
Try adding reverse_order=True or reverse_order=False to pygplates.GpmlTopologicalSection.create(). Since there’s two calls to it in the above code, there are the 4 combinations you mention.
By the way, here’s the documentation for that function (since it’s not publicly released yet; we’re releasing this very soon though, as one final beta release to support Python 3 before pyGPlates 1.0 officially comes out). Note the part circled in red…
Oh yeah, sorry I forgot to specify the valid_time parameter when creating the mid-ocean ridge topological line. I’ve corrected that in the code above (my previous post) where valid_time=(float('inf'), 0.0) is added to specify that the ridge lives from distant past float('inf') to present day 0.0. You can change to a more suitable time range if you like. When valid_time is not specified, the feature does not appear to exist at any time (and so resolving topologies returns an empty list).
Regards,
John