These are K-Ar data obtained on glauconite, a potassium-bearing clay mineral that forms in some marine sediment. Woodmorappe fails to mention, however, that these data were obtained as part of a controlled experiment to test, on samples of known age, the applicability of the K-Ar method to glauconite and to illite, another clay mineral. He also neglects to mention that most of the 89 K-Ar ages reported in their study agree very well with the expected ages. Evernden and others 43 found that these clay minerals are extremely susceptible to argon loss when heated even slightly, such as occurs when sedimentary rocks are deeply buried.
As a result, glauconite is used for dating only with extreme caution. The ages from the Coast Range batholith in Alaska Table 2 are referenced by Woodmorappe to a report by Lanphere and others
Gestational age, synonymous with menstrual age, is defined in weeks beginning from the first day of the last menstrual period (LMP) prior to conception.
Official definitions Old age comprises “the later part of life; the period of life after youth and middle age. Most developed-world countries have accepted the chronological age of 50 years as a definition of ‘elderly’ or older person. At the same time, the WHO recognized that the developing world often defines old age, not by years, but by new roles, loss of previous roles, or inability to make active contributions to society.
Being 60—65 years old is usually a requirement for becoming eligible for senior social programs. In developed countries, most people in their 60s and early 70s are still fit, active, and able to care for themselves. In British English, the “third age” is “the period in life of active retirement, following middle age”. The distinguishing marks of old age normally occur in all five senses at different times and different rates for different persons.
For example, people may be considered old when they become grandparents or when they begin to do less or different work in retirement. It implies that the person being referred to is retired. Synonyms include old age pensioner or pensioner in British English, and retiree and senior in American English. Some dictionaries describe widespread use of “senior citizen” for people over the age of It is used in general usage instead of traditional terms such as old person, old-age pensioner, or elderly as a courtesy and to signify continuing relevance of and respect for this population group as ” citizens ” of society, of senior rank.
Especially in less formal contexts, it is often abbreviated as “senior s “, which is also used as an adjective. In commerce, some businesses offer customers of a certain age a ” senior discount “.
