/'lOCKNK IIIS'I'ORV OF MliXKAN CHIJ' COAS/'AL JA'A.I .p)^ 



()I,I(;()CI';ni': 



Nowhere williiii the Texas area, has any (race ol' Vieksl)iir;i; 

 slrala, been loniid, hut llilfj;a,r(l and L()ii}:;hri(|[!;e holh (onleiided 

 thai the (iniiul (iuK sandstones were found alonji; I he Sahine, and 

 Lough ridge traced them nearly across the state. 



There is a. beh. of sandstone; crossing the sta,te just as <h'S( libed 

 by I Ins observei" and it has some of the Hlhologic ( haraclerislies 

 of the (irand (iuH". Our invesligalions seem to indicate, however, 

 that while it may I)e traced in apparent (ontimiity across tin; iinvA 

 it is in reality not honuigenous, but is in fact, a, coin|)osile seri(!S. 

 That it represents in |)art renuiants of a deposit of the (irand (iulf 

 sands, even if not fully susceptible; of proof, is strongly |)robable. 

 We also know that it comprises beds of later deposition which have; 

 surrounded and overlapped these (irand (iiilf renmanls. 'i'hese 

 later dc;j)osits are th(; Oakville sands of western Texas and are of 

 Miocene age. Among tiie outcrops now remaining which we 

 think are (irand (iulf are those at (Olmesneil, the; (|ua,rry north of 

 Corrigan, near Riverside, (;tc. 



The lack of fossils in the (irand (iulf sands a,n<l the close resem- 

 blance to them (ev(;n including the; (juart/itic phases) of those of 

 Oakville age will probably prevent any complete dilTeicnt iai ion 

 of the two, although this may be done in pa,rt through a, study of 

 the scanty flora occurring in them here and there. 



If any other OligoceiK; d(;posits besides the remnants of the 

 (irand (iulf were laid down in the Texas area, they ha.ve been 

 ero(|(;d or are also covcri^d by the ov(;rla,p of the Oakville. 



in Mexico, on the contrary, we lind a, broa,d development of the 

 Marine facies of t he ( )ligo( cue de|)osits such as are fouiul in Morida, 

 and the Antilles as distinguished from the near shore bra,(kish- 

 water phase of most of the (iulf area. 



North of the Tamaulipas l<a,nge we Imd, overlying the I'loicne, 

 a series of yellow sands, cla,ys, and ca,lca,r(;ous beds whi( h (arry an 

 abundant OligoccMu; fauna,, 'i'hey were first studied in the vi( im'ly 

 of San I'ernando, on the; Conchos Kiver, where; there are line 

 exposures, and we have (ailed this local development of the beds 

 the San (''ernando. 



