1871.] DE OKtTEBA GEOLOGY OF MALAGA. 109 



rising or have recently risen. The reason of this is, that an up- 

 ward bend in a stratum is resisted only by the weight of the stratum 

 itself, while a dowuAvard bend is resisted by the pressure on the 

 strata below ; so that an upward bend is more likely than a down- 

 ward one to become great enough to produce fracture. 



3. On Some Poikts in the Geology of the Neighbotjehood of Malaga. 

 By Don M. be Ortjeba. 



(Communicated by Sir. E. I. Murchison, Bart. F.E.S., F.G.S.)! 



[Plate V.] 



Much remains to be done in the investigation of the geological 

 structure of Spain. The Spanish geologists have principally de- 

 scribed in a general manner the mineral character of the soil 

 in various districts, but they have not paid sufficient attention to 

 the order of superposition and the character of the fossils, and 

 few foreign men of science have made this country the subject of 

 their investigations. For this reason, what we know at present 

 about the formations of the province of Malaga is principally 

 owing to the able memoir and excellent map of M. Verneuil. 

 However, as I believe this gentleman did not travel in the northern 

 part of this district, he has not given any j)articular description of 

 manj^ geological formations which, by their order of superposition, 

 mineral composition, and the character of their fossils, might be of 

 great help in ascertaining the place in the geological scale of the 

 analogous strata which exist in other localities of the province, 

 but which do not present so many interesting data and facilities for 

 study. Although I am only acquainted by reference with the 

 opinions of this gentleman (possessing only the map he published 

 in conjunction with M. E. Collomb), I believe that he dwelt prin- 

 cipally on the Tertiary formations in this vicinity, and, above all, 

 on those on which the city of Malaga is built. I think that he 

 was the first person that ever described them, publishing also a list 

 of several shells, which he collected at the " Tejares" (clay -pits in 

 the suburbs of this city). Professor Ansted also .wrote a very valu- 

 able article on the Geology of Malaga, which appeared in the 

 ' Quarterly Journal of the Geological Society ' for 1859*. He also 

 paid a deserved attention to the " Tejares " clays, which are no 

 doubt of the greatest interest, and described several formations in 

 this neighbourhood, particularly those lying on the eastern side of 

 the town ; but I feel rather surprised to see that, while treating on 

 the metam Orphic rocks, he does not mention the plutonic, which 

 are also found about here, mentioning only the serpentine of the 

 Sierra de Meijas, and not saying one word about the greenstone 

 (diorite), which is very abundant in several parts of the province, 

 especially in this locality, and which may have been the cause of 



* Vol. XV. p. 58.5. 



