A. M. Finlayson—Petrology of Huelva, Spain. 221 
mouth of the Guadiana, as far as the neighbourhood of Cape 
St. Vincent.’ 
Throughout Mesozoic times the area was comparatively undisturbed, 
but in the Eocene there commenced the great Tertiary disturbances of 
the Mediterranean zone, which raised the Betic Cordillera (Sierra 
Nevada and Serrania de Ronda) in the south-east and the Pyrenees in 
the north. Thus the structure of the peninsula was completed. The 
Tertiary earth-moyvements were accompanied by much igneous activity 
along the south-east coast, and also in the neighbourhood of Lisbon. 
Ore-deposition was again active during this epoch, but occurred chiefly 
along the Tertiary lines, the southern part of the meseta not being 
affected to any notable extent during these movements. Later Tertiary 
strata occupy detached areas which were basins of deposition in the 
old tableland, as well as much of the eastern and south-eastern 
districts. ‘The insunken Guadalquivir trough, which connected the 
Mediterranean with the Atlantic transgression, has also been filled 
with Tertiary and later strata. Harth-tremors are still frequently 
felt along the old Tertiary lines, notably along the south-east coast 
and in the neighbourhood of Lisbon. The recent earthquakes generally 
also affect the line of weakness along the Guadalquivir Valley, past 
Cordoba, Penaflor, Seville, and Huelva. Such was that which occurred 
on December 25, 1884.2 Our knowledge of the structure of the 
peninsula is chiefly due to the researches of Macpherson, which are 
summarized in his latest paper.® 
OvurtinE or GroLoecy. 
The copper-field, which extends for a distance of 80 miles through 
the province of Huelva into Seville Province on the east and Alemtejo 
(Pertugal) on the west, is composed of a belt of Paleozoic slates, 
fringed to the south by Tertiary and recent deposits, and succeeded 
on the north by pre-Cambrian schists and gneisses, and by less 
metamorphosed Cambrian strata. he Paleozoic rocks strike east and 
west, and have been thrown into a series of east and west folds. 
All the older formations are intruded by belts of igneous rocks which 
follow these same lines of direction, and were contemporaneous with 
the development of the structure of the district. 
METAMORPHIC AND SEDIMENTARY Rocks. 
The rocks which have been mapped as pre-Cambrian are found 
in a belt along the northern boundary of Huelva Province, outside the 
limits of the ore-bearing zone. ‘They are chiefly gneisses, with bands 
of hornblende-schist and of crystalline and metamorphic limestones, 
succeeded by less altered schists and phyllites. Cambrian schists, with 
quartzites and greywackes, lie to the north of and are conformable 
1 E. Suess, Das Antlitz der Erde, English translation, Oxford, 1906, vol. ii, p. 124. 
2 Bol. Com. Map. Geol. Esp., Madrid, 1891, vol. xvii, pp. 241 et seqq. Salvador 
Calderon, ‘‘ Movimientos pliocenicos y post-pliocenicos en el valle del Guadalquivir”’ : 
An. Soc. Esp. Hist. Nat., Madrid, 1893, vol. xxii, p. 5. J. Gonzalo y Tarin, 
‘* Descripcion fisica, geologica, y minera de la provincia de Huelva’”?: Mem. Com. 
Map. Geol. Esp., Madrid, 1886, vol. i, pp. 241-52. 
3 José Macpherson, ‘‘ Ensayo de historia evolutiva de la peninsula iberica’’:; An. 
Soc. Esp. Hist. Nat., 1902, vol. xxx, pp. 123-65. 
