1 Definition of formal units 2 Stratotypes 3

: ﺍﻻﺗﻴﺔ ﻣﻨﻪ ﻭﻳﺘﻢ ﺩﺭﺍﺳﺔ ﺍﻟﻤﻮﺿﻮﻋﺎﺕ 1 - Definition of formal units 2 - Stratotypes 3 - Correlation p. 851 - 853. p. 854. : ﻭﻧﻨﺘﻘﻞ ﺍﻟﻰ ﺍﻟﻮﺣﺪﺍﺕ ﺍﻻﺳﺎﺳﻴﺔ ﻟﻼﺳﺘﺮﺍﺗﺠﺮﺍﻓﻰ ﺑﻌﻨﻮﺍﻥ Formal units distinguished by contents, properties, or physical limits p. 855

Lithostratigraphic Units : ﺣﻴﺚ ﻳﺘﻢ ﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ ﺍﻻﺗﻰ ﻟﻬﺬﻩ ﺍﻟﻮﺣﺪﺍﺕ 1 - Nature of Lithostratigraphic Units. P. 855 1 -1 Formation p. 858 1 -2 Member 1 -3 Bed(S) 1 -4 Group 1 -5 Supergroup 2 - Lithostratigraphic Nomenclature p. 859