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JUNIUS HENDERSON 



the same phenomenon (which in local field parlance has been 

 designated a "slump") at various points north and south for 

 some distance. It frequently results in the production of a 

 bench similar to the one on Flagstaff, locally known as Huggin's 

 Park, but does not usually result in covering intervening forma- 

 tions on so extensive a scale. Whether like conditions exist at 



JURA-TRIAS DAKOTA BENTON NIOBRARA PIERRE 



Fig. 2. — Cross-section of east slope of Flagstaff Mountain. 



all places in the Denver Basin where overturns occur, the writer 

 is unable to say, not being familiar with the foothill region south 

 of the Boulder county line ; but the matter is worthy of further 

 investigation before assuming that such overturns have any bear- 

 ing upon the theories of mountain structure. The same process 

 that caused the overturns in these cases, has presumably caused 

 the greater dip of the later formations in cases where they have 

 not been overturned. 



Junius Henderson. 



Museum, University of Colorado, 

 Boulder, Colo. 



