Glacial Depositional Environments & Stratigraphy - Pt. 2: Glaciomarine | GEO GIRL

Glaciolacustrine and glaciomarine processes (glacial deposition in lake and marine basins) is different than glacioterrestrial deposition, which I discussed in the part 1 video over glacial depositional systems: • Glacial Depositional E... . But if glaciers form on land, how do they deposit sediment in oceans or lakes? In this video, I discuss how glaciolacustrine and glaciomarine deposition works, the sedimentary structures and stratigraphy of ice-proximal versus ice-distal glaciomarine systems (varves, ice-berg scour marks, dropstones, rain-out diamict, till, submarine fans and turbidites), and the major glacio-epochs (ice ages) of Earth's history and how the evidence of these ice age events, such as snowball earth can be interpreted. Glaciers move over land and sometimes deposit sediment on land in moraines or other landforms, however, most glacial deposits in the rock record are deposited in marine environments. This is because glaciers move downslope and typically all end up leading to an ocean or lake basin at the end of the downslop, thus, these glaciers transport sediment into ocean or lake basins. Glaciers break up into ice bergs once they hit the water body and as they melt, they drop sediment into the basin floor, these are called dropstones. Ice bergs can also scour the basin floor as the move along the surface if their bottom half is large enough. Submarine fans from meltwater flows coming from the base of the glacier also form. Glacial till deposits directly from the glacier form more proximal to the basin margin or fjord that the glacier carved. We can also track sea level changes with glaciomarine deposits because the glacial deposits that form during high sea level are distinct from those at low sea level. Glaciomarine sediments in the rock record represent the major lines of evidence for glaciations or ice ages throughout Earth's History. I close out the video by discussing the liklihood of snowball earth based on the glacial deposits in the rock record.
References:
Depositional Sedimentary Environments: amzn.to/3kutTso
Facies models 4: amzn.to/3Fp5v3B
Carolyn H. Eyles and Nick Eyles, 2010. Glacial Deposits. Facies models 4. Toronto: Geological Association of Canada, pp. 73-104. www.scribd.com/document/96543...
Dowdeswell, J. A., Canals, M., Jakobsson, M., Todd, B. J., Dowdeswell, E. K. & Hogan, K. A. (eds) 2016. Atlas of Submarine Glacial Landforms: Modern, Quaternary and Ancient. Geological Society, London, Memoirs, 46, 437- 444. doi.org/10.1144/M46.171
Domack, E.W., Powell, R., 2018. Modern Glaciomarine Environments and Sediments: An Antarctic Perspective. In: Menzies, J., van Der Meer, J. (Eds.), Past Glacial Environments, 2. Elsevier, pp. 181-272. doi.org/10.1016/B978-0-08-100...
Lee, J., 2018. Glacial Lithologies and Stratigraphy. In: Menzies, J., van Der Meer, J. (Eds.), Past Glacial Environments, 2. Elsevier, pp. 377-429. doi.org/10.1016/B978-0-08-100...
Young, G.M., 2018. Precambrian Glacial deposits: their origin, Tectonic setting, and key role in Earth evolution. In: Menzies, J., van Der Meer, J. (Eds.), Past Glacial Environments,2. Elsevier, pp. 17-45. doi.org/10.1016/B978-0-08-100...
McClenaghan, M.B., Paulen, R.C., 2018. Application of Till Mineralogy and Geochemistry to Mineral Exploration. In: Menzies, J., van Der Meer, J. (Eds.), Past Glacial Environments,2. Elsevier, pp. 689-751. doi.org/10.1016/B978-0-08-100...
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 Glacioterrestrial vs. glaciomarine deposition
2:01 Glaciolacustrine deposition
5:32 Outcrop examples of glaciolacustrine deposits
7:31 Ice-proximal glaciomarine deposition
11:38 Ice-proximal glaciomarine stratigraphy
17:17 Ice-distal glaciomarine deposition
17:50 Outcrop examples glaciomarine deposits
19:40 Glaciation periods in Earth's history
23:16 Was there a Snowball Earth?
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
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[@frankmoore7292]

Great adjunct to any earth science course. Thank you 👍

[@tongkronganparapensiunan]

It is good... This explanation help me to teach about Glacier. There is no glacier in Indonesia

[@prosperitygama9730]

Not you giving me my entire course summary and saving my butt

[@wolfgangvon4261]

unbelievable, geology time also experienced glacial

[@VolcanoGoldDiggerAdirondacks]

I just read the Grate Lakes you are in my neck of the woods. I look on New York state DEC topo map shows you elevation, their is no elevation from there to Hudson Bay that will do anything to the grate lakes or in the Candian shield. the Candian shield is mostly bed rock and no sand that wore away

[@JasonKale]

If I had a suggestion on a video after watching part 1 and 2 of this series it would be something along the lines of out of place rocks or erratics from ice ages as thats what I think I see where I live and have seen hiking in Pennsylvania. People may or may not be aware they seem to be a lot of places in the north part of the US. They seem the most noticeable of objects that people may see in every day life. To me the ones I think are erradics really stand out in the forests of Pennsylvania and have always caught my attention of how boulders seem to be so randomly placed at such strange places with no obvious reason to a lay person of how they got there...

[@GEOGIRL]

What a great idea, thanks! This would be perfect for a future playlist I am planning which will be about geology of specific regions so that people that live in these regions know what the rocks around them mean! :D

[@JasonKale]

@@GEOGIRL As Im a laymen as said before but for years Ive always wanted Answers to the different rock formations and soil composition of the baby mountains where I live and hike or mountain bike in Lancaster, PA. Some of the mountain bike trails on top of mountains are like a Pink sandy soil and have tiny pebbles that are rounded...And so many conglomerate rocks with the same composition. I always assume the one small mountain range is actually a former glacial moraine. But now everything is covered in forest but its so strange to see on top of Mountain ridge something that looks like a stream bed...

[@JasonKale]

@@GEOGIRL I actually sent some images of local Rock oddities to your instagram...

[@botryoidalbishhh3150]

Excellent explanation 👌thank you

[@GEOGIRL]

Thanks so much! I am glad you found it helpful :D

[@VolcanoGoldDiggerAdirondacks]

Geo Girl When you see a rock that got their by glacier, try to find out where it came from the rock is where you found it So the mountain has to be still standing. 80 year old and still learning.

[@bobmurray6792]

If I had a grand daughter...you'd be her.

[@VolcanoGoldDiggerAdirondacks]

Geo girl do you know what hot lava sand is it comes from Rhyolite Rock that is to acidy. Geologist now a rhyolite rock is acidy. That is how you get all them colored sand

[@yuyutsuk6171]

i drive

[@gabeesp9654]

Geology can get lonely