88 H. B. Miser — Llanoria, the Paleozoic Land 



was disconnected from Appalachia to the east, from 

 Mexia (a new name for the positive area in Mexico) to 

 the southwest, and from Colorado Land to the northwest. 

 Schuchert'^ considered that it extended from Columbia 

 (old name for positive element in Mexico) northeastward 

 across eastern Texas into Louisiana and into southern 

 Arkansas. The Llano (Central Mineral) region he 

 placed on its northwest border. Ulrich^^ agrees with 

 Schuchert's location of the Paleozoic land area in Louisi- 

 ana and eastern Texas except that he says it was discon- 

 nected from Columbia by an embayment running 

 northeastward from Mexico across Texas, passing just 

 east of the Central Mineral region, and then connecting 

 with the west end of the embayment in the Ouachita 

 geosyncline. 



Conclusions. 



Conclusions regarding the Paleozoic land area under 

 discussion can not be very definite, as the rocks that 

 formed it have been entirely concealed by Cretaceous and 

 later rocks, but the conclusions presented below appear to 

 be justified by the evidence at hand. 



A land area, which has been called Llano by Willis, 

 Schuchert, and Ulrich and Llanoria by Dumble and 

 Powers, existed in Louisiana and eastern Texas during 

 much if not most of the Paleozoic era and during the 

 Triassic and Jurassic periods of the Mesozoic era. It 

 varied in outline from time to time. It may have occu- 

 pied a part of the area of the present Gulf of Mexico ; at 

 times it was doubtless connected with large land areas 

 that occupied at least much of central and northern Texas, 

 southern Oklahoma, and southern Arkansas, and for short 

 periods it may have extended eastward across the lower 

 Mississippi Valley and joined the southwest end of the 

 Appalachian area. It furnished most of the sediments 

 that formed the clastic rocks of Pennsylvanian age in 

 north-central Texas and those of Ordovician, Silurian, 

 Mississippian, and Pennsylvanian age in the Ouachita 

 Mountains and Arkansas Valley of Arkansas and Okla- 

 homa. At times, as during the Devonian period, it had 



" Schuchert, Chas., op. cit., p. 470, and plate 49. 



''^ Ulrich, E. O., Eevision of the Paleozoic systems : Geol. Soc. America, 

 Bull, vol. 22, fig, 7 on page 368, 1911. 



