Question about highly plastic clays Question about highly plastic clays killswitchengage (Geotechnical) (OP) 2 Apr 16 16:35 Hello my friends I would like to know if there are any topographical or morphological features related to highly plastic clays deposits ? RE: Question about highly plastic clays GeoPaveTraffic (Geotechnical) 4 Apr 16 18:50 No. Mike Lambert RE: Question about highly plastic clays aeoliantexan (Geotechnical) 5 Apr 16 18:26 I believe that "gilgai" features and sometimes "pimple mounds" can be associated with swelling clays. In some areas, such as central Texas, fat clays are found on flat plains, such as the soils weathered from the Eagle Ford Shale. I don't know, however, how the plains developed. Perhaps we can stir up a geologist or two. RE: Question about highly plastic clays fattdad (Geotechnical) 5 Apr 16 19:40 When there is no infiltration, there's lots of runoff. If there's lots of runoff, then you'll get streams. Streams erode. In soil science (of which I am not!), they refer to, "Hydrologic Soil Groups," which allude to the underlying infiltration rate. Landforms are often related to the infiltration rate of soils. So, when there is a lot of infiltration, there is less runoff and less erosion - i.e., the topographic highs. I refer you to the subject of, "Hydrologic Soil Groups," of which there are four, A, B, C, and D. Otherwise, I'm agreeing with Mike! f-d ípapß gordo ainÆt no madre flaca! RE: Question about highly plastic clays oldestguy (Geotechnical) 5 Apr 16 20:00 Probably the best source for info is from a soil science forum. RE: Question about highly plastic clays killswitchengage (Geotechnical) (OP) 6 Apr 16 08:37 thank you all guys , i am just trying to get some samples for my PhD i just don't want to repeat the tests all the time :D RE: Question about highly plastic clays aeoliantexan (Geotechnical) 6 Apr 16 22:29 If you are in the USA, use the USDA County Soil Survey reports RE: Question about highly plastic clays Doctormo (Geotechnical) 16 Apr 16 14:22 I don't think so, highly plastic soils can exist in flat country and hilly county so not sure how you would tell from a map. Go to Fargo ND or Mississippi and dig a hole or to Wyoming for the bentonite laden soils.