Normal paraffins in the C(16) to C(32) range and the saturated isoprenoid hydrocarbons, pristane and phytane, have been found in chert from the Gunflint iron formation (1.9 x 10(9) years old) of the north shore of Lake Superior. The distribution of n-alkanes shows two maxima, one at about C(18) to C(19) and the other at about C(22) with a minimum occurring at C(20) to C(21). No predominance of odd- to even-carbon-number alkanes is observed within the C(16) to C(32) range. The results agree with micropaleontological observations made on the Gunflint chert and provide a chemical characterization of Precambrian life existing about two eons ago.
Normal n class="Chemical">paraffins in the C(16) to C(32) range and the saturated isoprenoid hydrocarbons, pristane and phytane, have been found in chert from the Gunflint iron formation (1.9 x 10(9) years old) of the north shore of Lake Superior. The distribution of n-alkanes shows two maxima, one at about C(18) to C(19) and the other at about C(22) with a minimum occurring at C(20) to C(21). No predominance of odd- to even-carbon-number alkanes is observed within the C(16) to C(32) range. The results agree with micropaleontological observations made on the Gunflint chert and provide a chemical characterization of Precambrian life existing about two eons ago.