Preliminary Results from the Deer Creek Section

 Tapeats Sandstone

 

Equal Area Projection for TSDC 22.1, up to 500 TT Ortho projection for TSDC 22.1, up to 500 TT
In the original sampling done by Elston and Bressler (1978), it appeared that there was a mixed polarity zone near the base of the Tapeats.  However, our preliminary results indicate that the reversed polarities that Elston and Bressler observed may have been a weak reversed overprint that comes off rather nicely at higher temperature steps.  Above are projections from a representative sample that was originally thought to be reversed polarity.  A similar pattern of demag is seen in all of the samples that originally displayed reversed polarities.
Here is an excellent example of present field being progressively removed from a Cambrian normal polarity.  The graphs are of TSDC 46, up to 575 TT.