#cosmogenic

If you like what you hear, feel free to join! We hope that wherever you are that your skies are clear. Note: The link will expire in 30 days so join while you can until we learn how to set up something on Disboard!

Along those lines, are we also the only ones who don't communicate with each other back at the Hub, or with whoever is here, via "thinking", mental talk or otherwise telepathy? We have to actually, verbally, speak to be heard. Out loud. It's no different than talking to someone on this planet. I'm low-key jealous of others who can just... Be on the same page as others because they can mentally sync up.

DATING TECHNIQUES: COSMOGENIC EXPOSURE DATING Cosmogenic exposure dating, also known as surface exposure dating, is used to estimate the amount of time a rock has been exposed at the surface. It is useful for dating many different geological events such as, fault scarps (which is a displacement of the surface of the land because of fault movement), rock slides, meteorite collisions, lava flows, erosion areas, and glacial advances and retreats. Cosmogenic exposure is most useful for dating rocks that have been exposed to the surface for 10 thousand years to 30 million years but can be used for dating younger time periods as well. The primary dating technique used in Cosmogenic exposure dating is Cosmogenic radionulide dating, but Lichenometry (dating rocks using lichens) can also be used in surface exposure dating as well. Earth is assaulted with high energy particles every day, (ex: protons and alpha particles). These are known as primary cosmic rays. When the primary cosmic rays interact with atoms in gasses from the atmosphere, there are secondary particles that are produced and provide energy for many different reactions in the atmosphere. These rays reach the earth’s surface are mostly composed of neutrons When the particle rays strike an atom on the earth’s surface, they can dislodge protons from an atom or add/dislodge neutrons in a process called spallation. Spallation is a process in which a heavy nucleus emits a large number of nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight This will produce a different isotope of the atom or producing a completely different element all together. These new isotopes are called cosmogenic nuclides With rocks, usually only the first meter of the material is affected. Using this technique, scientists can find out information about geologic events such as how long a surface was exposed, how long a piece has been buried, even how quickly a certain area is eroding. The Radionuclides are produced at a known rate and the decay rate is also known. Variables: The results can be affected by fluxuation in cosmic rays. These are variables such as: elevation, latitude, intensity of the magnetic field, solar winds, and air pressure variations. Aluminum-26 and Beryllium-10 are the two most common and measureable isotopes produced by Cosmogenic exposure. They are produced from silicon-28 and oxygen-16 respectively. The two parent isotopes are commonly seen in materials at the earth’s crust and surface and therefore are present in most measureable Cosmogenic exposure situations. Cosmogenic exposure dating can be used in conjunction with other dating methods to get more precise information about ages and exposures. In this picture here you can see that 4 different types of dating methods are used. Cosmogenic exposure dating, radiocarbon dating, optically stimulated luminescence dating, and uranium –series dating. -CS More info: http://www.landforms.eu/cairngorms/cosmo.htm http://quaternary-science.publiss.net/issues/57/articles/782