Honestly, I'm way behind on the literature, but I know that we've all pictured sediment "slugs" and such from our field observations, at least since the late 1980's. Maybe it's been described, but I doubt visualized before now.
So here's a placeholder.
I've seen these pattern in our models for years. We've recently developed a finer color-coded media that shows them more strongly. Here's a short, rough, demonstration.
We're able to build the models, but have no funding now for research using them; I hope you'll do this!
Sediment waves/slugs visualized in an Emriver model from Little River Research on Vimeo.