Sain wedi'i Rhannu

Transgression = sandstone bottom → shale → limestone top. GEOLOGIC TIME LOOP Relative dating = compares rock layers. Radiometric dating = absolute age using decay. Parent isotope = original. Daughter isotope = decay product. Unconformity = missing rock record. Law of original horizontality = layers form flat. Time scale = Come Over Some Day Maybe Play Poker Three Jacks Call Two Queens.