Dating techniques application

Uranium-series dating is by far the most widely-used dating technique applied to speleothems, and is only applicable to material that is currently in a state of disequilibrium. Given the rates of ingrowth of daughter isotopes of Pa and °Th, conditions of uranium-series disequilibrium in systems which have remained isotopically-closed are generally restricted to materials < 500 ka... 

This method was used in the examination of an Eskimo who died 1600 years ago. The body was discovered in a frozen state on St. Lawrence Island, Alaska in 1972 and remained frozen until it was brought to Fairbanks in 1973. Examination of the female individual revealed that she had a skull fracture, probably resulting from instant bunal caused by a landslide. Aspaitic acid laceiuization analysis of a tooth from the mummy yielded an age at death of 53 5 years, which correlated well with earlier estimates based upon morphological features. This method is an example of the need to preserve mummies (Alaskan. Egyptian, and Peruvian, among others) for application of new dating techniques as they develop. 

However, it must be pointed out that to date, the application of the phosphorylation and on-column methylation techniques have had only limited application. 

Testing the applicability of 14C dating techniques to the noncarbonate aquifers of the Glorious groups in the Papaland... 

Historically, our ability to apply °Th and Pa dating techniques has been limited by technical capabilities. Limitations result from the small concentrations of the key intermediate daughter nuclides. A relatively high-concentration material (a 5 X 10" yr old coral) typically has a °Th concentration of —100 fm g (60 billion atoms g ) and a Pa concentration of —3 fm g (2 billion atoms g ). At the extreme low end of the concentration range, surface seawater contains —4 X 10 " mol of °Th/g (3,000 °Th atoms g ) and -80 X 10 2 mol of Pa/g (50 Pa atoms g ). We are still limited by analytical capabilities for some applications and are actively pursuing... 

He also received the Research Corporation Award for 1951 for the radiocarbon dating technique the Chandler Medal of Columbia University for outstanding achievement in the field of chemistry (1954) the American Chemical Society Award for Nuclear Applications in Chemistry (1956) the Elliott Cresson Medal of the Franklin Institute (1957) the American Chemical Society s Willard Gibbs Medal Award (1958) the Albert Einstein Medal Award (1959) and the Day Medal of the Geological Society of America (1961). 

Important applications of ground-water dating techniques are related to the source and history of ground-water contaminations. For example, Bohlke and Denver (1995) and Johnston et al. (1998) used CFCs in combination with H or H- He dating to reconstruct the recharge history of nitrate in agricultural watersheds. 

The applications cited here focus upon the Ar-Ar dating technique, simply because most recent developments have utilized the Ar-Ar dating technique. The aim of this section is to highlight applications which illustrate the breadth of problems which have been addressed using Ar-Ar dating. 

Farley KA (2002) (U-Th)/He dating techniques, calibrations, and applications. Rev Mineral Geochem 47 819-845... 

---