Trough Cross Stratification/Lamination (sed strat)
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- čas přidán 20. 01. 2009
- In this video, I describe variations in geometry in dune and ripple cross stratification/lamination due to non-linear bedform crests.
David Rubin at the United States Geological Survey has posted numerous excellent animations of how bedform geometry influences cross stratification. They can be found at: walrus.wr.usgs.gov/seds/bedforms/ I particularly like these two animations for showing the effects of linear vs sinuous ripples: walrus.wr.usgs.gov/seds/bedfor... and walrus.wr.usgs.gov/seds/bedfor...
You can see my lecture notes for cross stratification at dawnssedstrat.blogspot.com/201...
Thank you so much! My teacher got himself into a hopeless muddle though he is totally wise! My savior!!! ❤️
I had troubling interpreting these sedimentary structures. Your videos are great. They are very helpful for me to understand sedimentary structures. Thanks so much! Please continue making these videos:-)
Superb video! I have a Stratigraphy and Sedimentology exam in 4 days, I think you've finally helped me crack understand Trough-Cross Lams.
Finally I understand that type of Cross lamination, Thanks
finally I understand cross lamination. very clear. thanks!
very good and really helpful to understand the cross-stratification features and processes behind. I did learn some value able stuff. Thanks
Thank you! Please continue making these videos, extremely helpful even at a masters level. Cheers!
thank you very much, it's help me a lot, your explanations are very clear !!!
Really informative video, thanks!
very helpful diagrams thank you!
cool thanks i can visualize the third dimention now. they seemed to skip over this rather fast in my lecture today. cheers
Very cool vid💓
. What controls the thickness of a set of tabular cross bedding
Thanks because before I struggled to understand this! (:
This was really helpful.
It would been cool if you would of show us this in class
Good job
thanks a lot
On what factors the shape of the ripple (or dune) crestline depends?
I.e., when it's straight and when it's sinuous?
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Based on my understanding, hummocky cross-stratification is a type of trough cross-bedding. But when I look into the textbooks, they explain hummocky and trough cross-bedding in two separate paragraphs, as if to imply that they are different types of cross-bedding. So, I'm a little confused here, is hummocky a type of trough cross-bed, or are they two different things altogether?
Hummocky cross stratification is a different type of cross stratification than trough cross stratification and forms from different flow types. Trough cross stratification forms from a fast flow in a single direction. This creates dunes that migrate down stream and cause laminae to dip in that general direction. Hummocky cross stratification forms from a mix of waves and currents where the water flow directions change several times per minute. Thus, the locations of erosion and deposition shift around, reflecting those changes in flow direction. This results in mounds of sediment with laminae that dip in multiple directions. It looks quite different from trough cross stratification when viewed in 3d. However, a small segment of hummocky cross stratification can look similar to trough cross stratification in you look at only a single surface.
Thank you! Still have trouble differentiating it from the look. But I got the idea now
Isn't the sine in a horizontal plane, instead a vertical plane?
Exactly what I'm thinking.... She simply draws it in the vertical plane though it was supposed to be in the horizontal
Thanks, you wanted to add the animation in the comment section?!
so that hummocky cross beddddddding?