Wilson Cycle Phase 3: Ocean Closing

“I enjoy, and have always enjoyed, disturbing scientists.”

~ John Tuzo Wilson

“From great oceans, giant mountains will form. This is the prediction of the third phase of the Wilson Cycle where we see the closure of the vast oceans like the Iapetus Ocean, and the formation of continent to continent collision mountains.”

~ Professor Dougal Jerrom, intro to Wilson Cycle Phase 3: Ocean Closing video linked below

In the 24 minute video below (a great watch), we continue our travels with Professor Dougal Jerrom of Oslo University, to look at evidence of the closing of the former Iapetus Sea in the Caledonian of Norway. The video starts with a nice recap of the other videos.

Whenever there is an ocean closure, geoscientists always look for ophiolite. Ophiolites in the geologic record provide evidence of subduction zone tectonics. We have already seen the pillow basalts, sheeted dikes (gabbros) and peridotites that form ocean crust in earlier videos in this series. An ophiolite is then a bit of oceanic crust that got swept up in the continental collisions and provides the first proof of an ocean closure.

Next we learn about melange - the sediments that were scraped up during subduction, also known as an accretionary wedge. There are also remnants of the island arc formed during subdution all accreted between the bits of continental crustal blocks that eventually collided.

Enjoy the video below where you see glimpses of the geology of the beautiful Norwegian Caledonian.

Wilson Cycle Phase 3: Ocean Closing: https://youtu.be/jYlQCbDmEVw

More on the closing of the Iapetus Sea here: https://en.m.wikipedia.org/wiki/Iapetus_Ocean

Includes Step 5 of the Wilson Cycle: https://c.im/@vickyveritas/10962360456...

Refer to this great labeled diagram of the Wilson Cycle for the components of the ocean closure and continent to continent collision and mountain building: https://c.im/@vickyveritas/109628513962823739

Note: We will see the last steps of the Wilson Cycle, the continent to continent collision and the formation of giant mountain belts, and the great grand finale of this series. Stay tuned.

#JohnTuzoWilson #TheWilsonCycle #Caledonides #IapetusOcean #Norway #PlateTectonics #Ophiolite #AccretionaryWedge #granites #SutureZones #Laurentia #Baltica #geology #ScienceMastodon #NorwegianGeologyRocks @geology