?????? ??? ????? (????? 1?31 ISO)
???	??	????
a	annum / year	${\displaystyle 10^{0}}$
Ha	Hecto-annum	${\displaystyle 10^{2}}$
Ka	Kilo-annum	${\displaystyle 10^{3}}$
Ma	Mega-annum	${\displaystyle 10^{6}}$
Ga	Giga-annum	${\displaystyle 10^{9}}$

??"? ( ???? ????? : ???? ?????? ???, ??? ???"? : ?????? ??? ???? ?????; Ma ??? ISO , ??????? ????? ??: Mya ? Million years ago) ??? ????? ??? ??????? ? ?????????? , ???????? ? ???????????? ??? ?????? ??????? ??? ??????. ??????? ????? ?? ??????? ?????? ????????? . ????? ??????, ????? ? ??? ?????? ?? ??? ????? ISO ????? ??? ? ????? ??????? ?????????? . ?????? ?? ????? ???? ??? ? ????? ???? ?? ???????? ???? ^[1] .

???? [ ????? ??? ???? | ????? ]

??????????? ?????? ???"? ???? ?????? ? ??? ????????? ????? ?????? ?????? ??? 365.25 ????. ?????? ?? ??????? ?? ??? ???? ?? ????? ????? ??? ??? ^[2] .

?????????, ?????? ?????????? ? ?????????? (ICS) ???? ???? ???? ??? ??? ???? ???? ???????? ???? ????? ???????? ?????? ????????? ?????? ?????? ? ?????? ??????? ?????. ??, ????? ? ?????? ???? ???? 11,700 ???? ????? 0.0117 ??"? (???? ?? ???? ????) ????? ????? ? ?????? ???? 66 ??"? ???????? ?-56 ??"? (???? ?? ??????? ????) ^[3] .

??? ???? [ ????? ??? ???? | ????? ]

??? ? ?????????? ?? ?????? ?????????? ???????????, ???? ???? ?????? ?????? ????? ?-Ma ??? ??? 1950 ????? ?? ??????? ? ?????? ??? ????-14 ^[4] . ?? ???, ?????? " ???? ????? " ????? ?????? ?-Mya, ????? ?????? ?? ??? ???? ? ????? ??????? . ???? ???????? ???????? ???? ??? ????? ??????, ?? ?????? ???????? ?? ???? ????, ????? ?? ???, ?? ???? ?????.

?????? ???? ????? ?????? [ ????? ??? ???? | ????? ]

????? ????? ISO 31-1 ?-811 NIST ???? ???? ????? ???"? ??? ?????. ????, ????? ?????? ?????, ??? ????? ???? ?-Myr ?? myr ????? '??????? ????' (Millions of years). ????? ?? ?????? ?????? Mya ?? mya ????? ' ???? ?????? ????' (millions of years ago ) ??????? ??? ????? ?????? ?????? ?????.

ISO ???? ????? ??? ???? ???????? ?? ????? ??????? (?????? ???? ????, ??? ???????, ???? ???????? ???') ^[5] . ?????? ????? ??????? ?? ???????, ???? ??? ?????? ???? ????? ???????, ?????? ?? ???: annum. ????, ?????? ??? ?????? Mega-annum) Ma), ??????? ??? Giga-annum) Ga) ???? ??? Kilo-annum) Ka). ??????? ???? ????? ???? ?? ?????? ??? ("???? 50 Ma") ??? ????? ????? ("???? 50 ?????? ???"). ??? ?????? Ma ?????? ?? Myr ??? Mya ????.

????? ?? ???? ?????? ?? ???. ?????? ?????-???????? ??????????? ?????? ??? ?????? ????? ?????, ???? ??? ?????? ????? ?-Mya, ???? ?????? ????? ???, ???? ??? ????? ?-Ma . ????, ????? ???? ??? 30 Mya ?-80 Mya ????? 50 Ma ^[6] . ????? ??????????? ?????? ???? ?? ????? Ma ??? ?????? ^[3] .

??????? [ ????? ??? ???? | ????? ]

• 3 ??"? ???? ?:"???? 3,000,000 ???" ?? "???? 3 ?????? ???".
• ??????????? ??? ?? ?????? ? ??????? 68?66 ??"?. ?? ???, ?????? ??????? ???? ?????? "??????????? ??? ?? ?????? ???????? 68?66 ???"? (?????? ???? ???? ?????)".

??? ?? [ ????? ??? ???? | ????? ]

• ????? ??? ????????
• ????? ????? ?? ???
• ??? ?????
• ??? ??????
• ????"?

??????? ???????? [ ????? ??? ???? | ????? ]

• ???? GSA ????? ????? ??????? ??????? ???? , ???? ????? ????????? ????????? GSA
• ???? ?? ????? ??????? ??????? ???? MYA ?-Ma , ???? ????? ????????? ????????? GSA

????? ?????? [ ????? ??? ???? | ????? ]