PALEOGENE GLAUCONITE DATES IN A SEQUENCE FRAMEWORK, SE ATLANTIC - EASTERN GULF COASTAL PLAINS

Glauconite dates in a regional sequence stratigraphic framework provide information on their accuracy.  Examination of the Rb-Sr and K-Ar dates in the Atlantic and Gulf Coastal Plains indicates that some are too young, some are too old and some agree with the suggested sequence ages.  This inconsistency of dates suggests that they have been influenced by syndepositional and post-depositional factors.  Sequences where we have multiple dates are compared below (in Ma):

 

Sequence	Mississippi	Alabama	S. Carolina	N. Carolina	Virginia
TA4.1	39.2 ± 3.2		34.1 ± 1.5 37.5 ± 1.5		34.9 ± 1.1 40.3 ± 1.6
TA3.5/3.6		32.7 ± 4.4	36.7 ± 0.6 40.4 ± 0.8 39.0 ± 1.6 40.3 ± 1.6		40.7 ± 0.6 43.7 ± 0.7 45.1 ± 0.8
TA3.4		37.8 ± 0.4 37.5 ± 0.5 40.7 ± 1.6	42.0 ± 0.5 41.6 ± 1.5 43.5 ± 1.7 46.6 ± 1.8	43.1 ± 1.2 44.5 ± 1.7 45.3 ± 0.3 46.7 ± 1.8
TA2.1			51.5 ± 0.1 49.8 ± 1.9 47.5 ± 1.8 59.8 ± 2.3	63. 6 ± 12 54.8 ± 6.7 56.7 ± 3.4