Stratification and Lamination
by Metwally Hamza, Full Geologist, Egypt
- Stratification and Lamination, in "El-Galalla Plateau Formations", along the new road of "Marine El-Galalla Plateau", above the red sea by "750m" almost, Suez, Eastern North of Egypt, Egypt, Northern Africa, Africa.
- That's notable to be mentioned, there are some factors of stratification, meaningly or some barometers to say -exactly not almostly- that formation or rock unit is stratification or lamination "lamination is a small stratification, or lamina is very smaller than stratum, meaningly the scale of lamina is millimetres, but that of stratum is centimetres, but also that of bed is meters or may be kilometres", the most six ones of this factors are sequencely:
1) Color: must have different colors one by one "stratum by stratum".
2) Chemical Composition: each one "stratum" has chemical composition differ from the following one "stratum".
3) Mineralogical Composition: may have the same mineralogical content, otherwise may not.
4) Fossil Content: any stratum is deposited in limited and determined time and age by its fossil content, as fossils refer to fixed and well known age, so when two following strata have different fossil content, we can say that contact surface between this two strata is unconformity surface, that may be one only type of four different types, "angular", "differental", "disconformity", or "paraconformity", and may be also special type, that's called "diastem", but the last special type can be applied when only the age difference between this two strata is very smally short, so we can say that almostly there is no stratification or lamination without difference in fossil content, if stratification or lamination is consisted from many strata "as shown in this exposure".
5) Size: that's very rarest to find two following strata, have both the same size or thickness similarly or identically, but there is a difference in size or thickness, even if it's slight or very small.
6) sequence of strata: the geometry of strata or of lamina and the shape of them may verify.
- If we note, this conditions and differences factors are applied all in this exposure, and we must refer to that scale of this picture of this exposure is in ordinary or normal scale, not zoomed-up or not zoomed-down.
Taken and Itemized by Metwally Hamza.
Submitted on 26 Mar 2020
Credit: Metwally Hamza (distributed via imaggeo.egu.eu)
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