These photos taken at Sandstone layer . Please can somebody help me in the identification of these concentric and parralel laminations ? And which is the origin of this process ? NB : outcrops located on the coast influenced by marrine erosion.
these look to me like liesegang rings. see: https://en.wikipedia.org/wiki/Liesegang_rings_(geology)
Dear Dr. Idries
These fine-grained sandstones show a rock parting on a different scale and intensity which allows the infiltration of (meteoric) fluids to a different extent and leave behind a residue of Fe-oxide hydrates (“limonite”). The latter “mineral” gives rise to the concentric structures resembling the contour lines of topographic maps which reflect the different altitudes. It is a near-surface (supergene) process.
With kind regards
H.G.Dill
@ Prof Harald G. Dill thank you very much for your helpful answer. Best regards.
saber
this is water action ( slowly current and different concentration of iron minerals through well to poorly sorted sandstone
Liesegang rings for sure, and the Fe++ oxidises and precipitates different minerals according to pH.
Goethite FeO.OH pH>5
Limonite FeO.OH pH>5 and usually after carbonate
Hematite Fe2O3 indicates acid conditions pH
It's the work of aliens, just like the pyramids (according to The History Channel).
Harald G. Dill Dr., does the rock parting shows the gap between sedimentation or the concentric pattern are just the growth of weathering. so this is a single litho unit. Though, I see the the bedding and lamination characters on photo two and three respectively, and the residues are more than the concentric layers.
It is a marl structure that is precipitated by a hot spring and its roles are called nodules.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts