64 



ANNALi:^ NEW YORK ACADEMY OF SCIENCES 



Feet Inches 

 Massive chalky white saudstoue, cross-bedded aud cav- 

 ernous weathering 15 



Soft shaly sandstone 2 



Massive evenly laminated sandstone, ranging in color 



from red at the base to white at the top 15 



Red Beds. Red sandstone layers interstratified with red and purple 



shales . . 



J^ear Exeter post office a sandstone formation 

 appears between the Morrison and the Red Beds. 

 It lies unconformably upon the Red Beds. It ap- 

 parently underlies the Morrison conformably . It 

 is a firm, hard and rather coarse but evenly lami- 

 nated sandstone, pink to white in color. The lower 

 members are pink, while those above are lighter 

 colored. It has the appearance of being composed 

 of the coarse material eroded from the Red Beds. 

 The sandstone has a maximum thickness of 75 feet, 

 and extends from a point several miles west of 

 Exeter, where it thins out, eastward to the Okla- 

 homa-New Mexico line, where it drops beneath the 

 canyon bottom. No fossils of any kind have been 

 found in this sandstone. It occurs in a series of 

 nearly perpendicular cliflis, making a broad con- 

 tinuous band along the canyon sides (Lee, 1902, 5) . 

 The Morrison in this locality, according to Lee 

 (1902, 5), "rests in turn (1) upon the gypsum 

 conformably; (2) upon the gypsum and underly- 

 ing Red Beds unconformably; (3) upon the Exeter 

 sandstone conformably." Lee also notes that the 

 Morrison shales, as a formation, do not vary to any 

 considerable extent in character or thickness at this 

 locality. "Whatever may have been the physical 

 conditions prior to the deposition of the shales 

 [Morrison], it is evident that the shales were de- 

 posited over a well-graded surface. It follows also that there was a 

 somewhat notable time-interval between the Red Beds and the shales. A 

 part at least of this time-interval is represented by the unconformity 

 between the Red Beds and the Exeter sandstone. It is uncertain whether 

 there is a time break between the Exeter sandstone and the overlying 

 shales. However this may be, the seeming conformity which exists in 

 many places between the Red Beds and the shales is deceptive. The con- 



-i 



Fig. 22. — Section of the 

 Morrison and adjacent 

 formations in the Can- 

 yon of Bio Cimarron, 

 near Exeter post-office. 

 New Mexico. 



1. — Purgatoire ; 2. — 

 Morrison ; 3. — Exeter ; 

 4. — Red Beds. Scale, 125 

 feet to 1 inch. (Lee.) 



