Geochronology/Varves
Def. "a pair of sedimentary layers, a couplet, that form in an annual cycle as the result of seasonal weather changes"[1] is called a varve.
"Typically formed in glacial lakes a varve couplet consists of a coarser grained summer layer formed during open-water conditions, and a finer grained winter layer formed from deposition from suspension during a period of winter ice cover. Many varve deposits contain hundreds of couplets."[1]
"The ruin marble structure of the Cretaceous/Paleogene fine-grained marly limestone from the Outer Flysch Belt of the Western Carpathians has a non-tectonic origin, according to structural and sedimentological evidence. Distinctive offsets of coloured red-brownish ferric oxyhydroxide bands are not due to displacements along rock-cutting fractures, as they superficially appear to be. Evidences for shear movement along these pseudo-faults were not observed. Band offsets result from different velocities of pervasively diffusing fluids, precipitating ferric oxyhydroxides in corridors bounded by sets of mineralised systematic joints. During rock weathering, calcite-filled joints operated as barriers for lateral fluid diffusion, but enabled longitudinal diffusion along healed joints."[2]
See also
[edit | edit source]- Argon–argon dating
- Cathodoluminescence
- Cenozoic
- Chemostratigraphy
- Cosmogenic radionuclide dating
- Dates
- Dendrochronology
- Dye 3
- Electron spin resonance
- Fission track dating
- Geomagnetic Polarity Time Scale
- Ice cores
- Black ice
- Brittle ice
- Clear ice
- Firns
- Sea ice
- Lichenometry
- Magnetostratigraphy
- Marker horizons
- Mesozoic
- Optically stimulated luminescence
- Paleomagnetic dating
- Paleontology
- Paleozoic
- Palynology
- Potassium–argon dating
- Radiocarbon dating
- Stratigraphy
- Tephrochronology
- Thermoluminescence
- Uranium–lead dating
- Uranium-thorium dating
References
[edit | edit source]- ↑ 1.0 1.1 Eleyne Phillips (16 December 2004). Glossary of Glacier Terminology. Reston, Virginia USA: United States Geological Survey. http://pubs.usgs.gov/of/2004/1216/text.html#h. Retrieved 2014-11-09.
- ↑ František Marko, Daniel Pivko and Vratislav Hurai (2003). "Ruin marble: a record of fracture-controlled fluid flow and precipitation". Geological Quarterly 47 (3): 241-52. https://gq.pgi.gov.pl/article/download/7313/5963. Retrieved 2015-02-21.