Complex sentence: It shows that the lower lithosphere in this period was newly injected and follow the NNE trend, which they concluded that subduction of the Pacific Plate caused the removal of old lithosphere and hence thinned the craton.
Split into simpler sentences: It shows that the lower lithosphere in this period was newly injected. The new material followed the NNE trend, which they concluded that subduction of the Pacific Plate caused the removal of old lithosphere and hence thinned the craton.