Ever wonder how sediment from land is deposited in the ocean? Submarine fan deposits occur when sediment is not only transported into the ocean, but all the way down the continental shelf to the deep abyssal plain. Submarine fan deposits occur when sediment is transported into the ocean at high velocity typically through river input into a delta. Because the sediment spreads into a fan shape when it's deposited it give the name submarine fan. Submarine fan deposits result in a predictable sequence of sediment layers due to the differences in grain sizes being transported, these sequences are called Bouma sequences and we call the current that forms them a turbidity current or turbidity flow. Because larger grains are heavier, they are deposited first, then finer grains deposit further and further out into the ocean basin. In this video, I go over submarine fan formation processes, deposition, sedimentary structures, & stratigraphy, with a focus on turbidity currents and the turbidites (or Bouma sequences) caused by these hyperpycnal flows. I go step by step through the coarse graded bedding of sand and gravel, the planar bedded medium sands, the fine rippled and laminated sands, to the fine silty muddy pelagic sediment in the fining upward Bouma section. I also discuss the sources of submarine fan deposits, in other words the canyon or valley like features in the continental shelf that allow the turbidity flows to flow down it. Such submarine canyons can be point sources for the fans or complete slope failures. Shelf to slope steepness at the edge of continental crust can effect fan morphology, the formation of submarine fluvial channels, levee deposits, point bar deposits, & depositional lobes. I also discuss how to recognize submarine environments, especially Bouma sequences, in the rock record. Hope you enjoy! ;)
References: Depositional Sedimentary Environments: amzn.to/3kutTso
Facies models 4: amzn.to/3Fp5v3B
GEO GIRL Website: www.geogirlscience.com/ (visit my website to see all my courses, shop merch, learn more about me, and donate to support the channel if you'd like!)
0:00 Where/what are submarine fans?
0:38 Submarine fans vs. alluvial fans
1:27 Fan deposition & facies distribution controlling factors
3:49 submarine fan system parts
4:16 flow diagram of submarine fan system
4:55 stratigraphy of submarine fan systems
6:39 What are turbidity currents
8:30 Where turbidites form in submarine fan systems
9:03 Turbidite stratigraphy (Bouma sequences)
15:03 Recap and other depo env videos!
Directly offset your carbon footprint with Wren: shrsl.com/3d0t2
Non-textbook books I recommend:
Oxygen by D. Canfield: amzn.to/3gffbCL
Brief history of Earth by A. Knoll: amzn.to/3w3hC1I
Life on young planet by A. Knoll: amzn.to/2RBMpny
Some assembly required by N. Shubin: amzn.to/3w1Ezm2
Your inner fish by N. Shubin: amzn.to/3cpw3Wb
Oxygen by N. Lane: amzn.to/3z4FgwZ
Alien Oceans by K. Hand: amzn.to/3clMx1l
Life's Engines: amzn.to/3w1Nhke
Tools I use as a geologist/teacher/student:
Geology field notebook: amzn.to/3lb6dJf
Geology rock hammer: amzn.to/3DZw8MA
Geological compass: amzn.to/3hfbdLu
Geological hand lens: amzn.to/3jXysM5
Camera: amzn.to/3l6fGRT
Image sources:
fastwindtoaim.blogspot.com/201...
geology.isu.edu/Alamo/rocks/li...
2.bp.blogspot.com/-fAL2QWPDUE...
www.amazon.ca/Facies-Models-R...
www.researchgate.net/figure/D...
geologycafe.com/class/chapter...
studyblue.com/notes/note/n/23-...
ajaylimaye.com/a-crisis-by-la...
media.giphy.com/media/pGqEJYE...
www.researchgate.net/figure/G...
www.geocaching.com/geocache/G...
intheplaygroundofgiants.com/wp...
gotbooks.miracosta.edu/oceans...
www.amazon.ca/Facies-Models-R...
offtheshelfedge.files.wordpre...
en.wiktionary.org/wiki/turbidite
Disclaimer: Links included in this description might be affiliate links. If you purchase a product or service with the links that I provide I may receive a small commission, but there is no additional charge to you! Thank you for supporting my channel so I can continue to provide you with free content each week! And as always, let me know your topic suggestions in the comments down below!