New Zealand turbidite field trip – Day 4: Mass transport deposits
Holy cow. It just keeps getting better. I can honestly say that my mind was blown today. We saw some mass transport deposits (MTDs) that are truly seismic in scale! Maybe not as big as the Storegga slide, but pretty dang big. For a nice paper on MTDs, go here. Since there is a student actively working these rocks and trying to publish them, I won’t spoil it by showing too many photos. Just keep your eye out for a really nice paper(s) on these rocks in the next couple years. I will just show a vignette that demonstrates the kind of deformation present in this mass transport deposit (see text below):
Most MTD deformation is plastic, and the toothpaste-like arrangement of the beds in the jumbled interval clearly shows that. So, you may think that the base of the MTD is where the jumbled up stuff meets the flat lying sandstone-mudstone sucession near the middle of the photo. However, all the the rock that you see in that photo is allochthonous (i.e. is part of an MTD). Yes, wow is the word you just said.
Next we go to see an outcrop where I actually worked when doing my PhD, so more on that in tomorrow’s post!