A. MW. Finlayson— Petrology of Huelva, Spain. 223 
chiefly Posidonomya bechert, were secured by the writer, as already 
mentioned, in slates near the lode of Cabezas del Pasto, in the west 
of the province. As regards the age of these rocks, Joaquin Gonzalo 
y Tarin, in his memoir on Huelva Province quoted above, places them 
in the Culm (Lower Carboniferous), while F. Romer’ and R. Wimmer? 
both held the same view, and this is endorsed in recent work by 
F. Klockmann’ and -by Bruno Wetzig.* On the other hand, 
J. H. Collins states that Fraas and Etheridge both concluded the 
rocks around Rio Tinto to be of Devonian age.? The only rocks, 
however, mapped as Devonian by the Spanish Survey are some local 
occurrences in the provinces of Badajoz and Cordoba, north and west 
of the present district. The bulk of the evidence, therefore, goes to 
support the conclusion that the rocks of the copper-belt of Huelva 
belong to the Culm, although the adjoining rocks in Portugal are now 
regarded by J. F. N. Delgado’ as Devonian. In any case, there is 
nothing to show that they belong to more than one epoch, as has 
previously been emphasized by Klockmann® and by J. H. L. Vogt.® 
A small patch of Triassic limestones at Ayamonte in the south-west of 
the province, and a coastal belt of Tertiary and Quaternary strata, 
complete the geological column in this district. 
Icneous Rocks. 
These form an important series, not only as constituting a defined 
petrographic province, but also in the relation that their natural 
history bears to the origin of the lodes. They are distributed in belts 
parallel to the strike and to the axes of folding of the slates, and may 
be divided, for purposes of description, into three groups—the 
granites, the porphyries, and the basic group. 
1. Granites.—Yhese occur as a series of intrusive bosses in the 
older rocks in the north of the province, and as far south as the 
Concepcion Mine, and Campo Frio, near Rio Tinto, where they are 
intrusive into the Culm slates. On the whole, however, they are not 
developed in the mineral belt itself. They are evidently con- 
temporaneous with the granitic rocks in other parts of the meseta, 
and form a part of the widespread series of plutonic intrusions 
accompanying the Hercynian earth-movements. 
1 «Uber das vorkommen von Culm-schichten mit Posidonomya becheri anf dem 
Sudabhange der Sierra Morena in der Provinz Huelva’: Zeits. deutsch. geol. 
Ges., 1872, vol. xxiv, p. 589. 
2 “ie Kieslagerstitten des sitidlichen Spaniens und Portugals’’: Berg- u.Hiittenm. 
Zeit., 1883, vol. xlii, p. 327. 
* «Ueber das auftreten und die entstehung der siidspanischen Kieslagerstitten ”’ : 
Zeits. prakt. Geol., 1902, vol. x, p. 113. 
4 «« Beitrige zur Kenntniss der Huelvaner Kieslagerstiitten ’’: ibid., 1906, 
VOlexiv, p. L738. 
° J. H. Collins, ‘‘ Geology of the Rio Tinto Mines’’?: Quart. Journ. Geol. Soc., 
1885, vol. xli, p. 246. 
® Lucas Mallada, ‘‘ Explicacion del mapa geologico de Espafia’’?: Mem. Com. 
Map. Geol. Esp., Madrid, 1898, vol. iii, p. 85. 
7 Loe. cit. sup. 
8 Loe. cit. sup. 
° “Das Huelva-Kiesfeld in stid-Spanien und dem angrenzenden Theile yon 
Portugal”: Zeits. prakt. Geol., 1899, vol. vii, p. 241. 
