502 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



Triassic on the basis of the discovery of cycads near San Juancito. It remains, however, a mooted 

 question whether these fossils are sufficiently characteristic to estabhsh the age with certainty. 

 [See below.] The thickness is considerable (more than 800 feet) and the petrographic character 

 is very variable. Red colors predominate. According to Leggett the formation occurs not only 

 in the vicinity of Tegucigalpa and San Juancito but also near Sabana, and Dr. Fritzgartner states 

 that it has a wide occurrence in the neighborhood of Danh, where the limestones attain a 

 notable development. 



The petrographic resemblance of the Tegucigalpa formation (as it was called by Fritzgart- 

 ner) with the Metapan terrane [see Chapter XIV, Lower Cretaceous, p. 585], is so great that I was 

 unable, in the absence of fossils, to distinguish them. It may therefore well be the case that a 

 portion of the Metapan terrane, as shown in the departments of Tegucigalpa and Olancho, 

 belongs to the Tegucigalpa formation. 



Mierisch described a series of strata observed in Nicaragua which he was inclined to con- 

 sider as Triassic and which I have therefore designated in my map accordingly. These are 

 beds which in Prinzapolca occur in a horizontal or gently dipping east-west attitude and com- 

 prise red fine sandy clays and soft yellowish to white sandstones; soft red sandstones on the 

 Cuicuina River; reddish white to white clays and iron-stained sandstones on the Cuculaia 

 River; fine-grained reddish sandstones which pass over into loose gravelly marls near Ojoche; 

 red sandy clays and gravelly and pebbly strata which are strongly iinpregnated with iron and 

 contain numerous included quartz blocks near La Guardia; red sandstones below Sirena, on 

 the Rio Grande; soft red clayey sandstones on the Rio Tuma, on the lower Vaspuc; and red 

 sandy clays on the Rio Coco near Saki, Quisalaia, and Saclin. These latter occurrences I have 

 mapped as Tertiary, since the flat position of the completely unfossOiferous strata is in such 

 contrast to the steeply dipping Mesozoic formations of the middle Rio Coco as to indicate with- 

 out question a younger age. Having in this region begun to doubt the determination of the 

 age by Mierisch, I came to regard his Triassic formation with some question, the more so since 

 he rested his correlation only upon petrographic resemblance with the new red sandstone in 

 the eastern part of the United States, together with the occurrence of splendidly preserved 

 but not very surely determined sihcified cycad trunks from the vicinity of Ojoche, as well 

 as upon the intimate relationship between these rocks and the melaphyres, porphyry, and 

 the associated tufifs. * * * It is true that Mierisch calls attention to the fact that the obvi- 

 ously very young "Tertiary" sands, clays, and gravel beds of Prinzapolca rest unconformably 

 upon the Triassic. 



Inasmuch as Sapper in several successive publications implies that Newberry's 

 determination of the Rhsetic age of the cycads from Honduras shoiold be accepted 

 only with doubt, the present compiler referred the question to F. H. Knowlton, 

 who under date of December 9, 1910, answered as follows: 



At your request I have again looked over Newberry's paper on " Rhsetic plants from 

 Honduras" and, without going exhaustively into the subject, I see no reason for seriously 

 questioning the correctness of his age determination. Newberry compared this flora with 

 others from various parts of the world and found closest agreement with those of southern 

 Sweden (Bjuf) and India (Rajamahal). There is also a species very close if not actually iden- 

 tical with one in the Triassic (Rhsetic) of North Carolina. 



In this connection I may add that Dr. Arthur Holhck, of New York, happens to be here 

 now, and I have asked him about this matter. The specimens upon which Newberry based 

 his paper are in the care of Dr. Holhck, and he permits me to say that in his opinion then- 

 reference to the Rhsetic is justified. 



Mierisch °°* states briefly that Triassic rocks occur in Nicaragua. He says: 



The path from Muy-muy to Guardia leads through a swampy savannah, "Jicaral," but 

 the district is of geological interest on account of the occurrence of Triassic strata. They 



