SIGNIFICANCE OF MOENCOPIE SHALES 



385 



writer came to the conclusion 

 that "the Moencopie series 

 was probably laid down in a 

 shallow sea where estuarine 

 conditions may possibly have 

 prevailed, as is indicated by 

 the intercalated layers of 

 gypsum and the almost total 

 lack of fossils in strata ad- 

 mirably adapted to their 

 preservation had they ex- 

 isted." The estuarine origin 

 is extremely doubtful, how- 

 ever. It is probably incon- 

 sistent with the red color and 

 with the numerous changes 

 in the character of the strata. 

 The beds as a whole present 

 a large number of the feat- 

 ures which have been de- 

 scribed above as characteristic 

 of subaerial deposits laid 

 down under arid conditions. 

 They are capped by the Shin- 

 arump conglomerate, the fos- 

 sil trees of which prove it to 

 be of subaerial origin. The 

 middle part of the Moencopie 

 shales consists of a large 

 number of alternating red 

 and white layers. The red 

 portions appear to be of sub- 

 aerial origin, to judge from 

 their color and from the fre- 

 quent changes of texture to 

 which they are subject. The 

 white appear to have been 

 deposited in standing water. 

 If the red and white layers 

 respectively originated sub- 

 aerially and in somewhat 



-rr-T 



~r-^ 



Sorr purple and red shalea. 

 -Nodular gray stialefl. 



60-60 feet — Hard Shinarump conglomerate and sandstone. 

 — — Sllgbt UQConformlly. 



150-200 feet — Chocolate shale and sandstone. 



JO feet — Hard brownish red sandstone. 

 16 feet — Soft brown shale. 



240 feet — Alternating soft red shale and harder white or 

 gray-green shale, while predominating. 



1.^0 feet^Alternatlng soft red shale and harder while or 

 gray green shaie, red predominating. 



1 foot — Hard green calcareous shale. 

 20 feet — Brownish red shale. 



20 feet — Green shale. 

 5 feet — Sandy, greenish hrowo, calcareoua shale. 

 10 feet — Soft reil shale. 



20 feet — Soft green shale. 



12 feet — Hard calcareous green shale. 



^=— -^ 170 feet — Soft, red, sandy shale, with some white liand« 

 snd a few fossils at the base. 



30 feet — Soft, blue gray Super-Aubre!/ shale. 



10 feet — Cherty ^-onglomerate. Suprr-Aiibrei/. 



20 feet^Chetty -nodular MmestoQe. Super-Aiihrey. 



— — Fosslllferoos Aubrey limestone iCorhonf/erousl. 



Figure 15. — Section of the Moencopie Shales at 

 Dry Creek, near Toquerville, Southern Utah. 



The scale of this figure and the next is one- 

 fourth that of figures 3-10 and 12-13. Scale : 1 

 inch = 160 feet. 



