(FIGURE 137. Voluta Lamberti, Sowerby. Variety characteristic of Faluns of
Touraine. Miocene.)
Among the conspicuous fossils common to the faluns of the Loire and the Suffolk
Crag is a variety of the Voluta Lamberti, a shell already alluded to (Figure
123). The specimens of this shell which I have myself collected in Touraine, or
have seen in museums, are thicker and heavier than British individuals of the
same species, and shorter in proportion to their width, and have the folds on
the columella less oblique, as represented in Figure 137.
UPPER MIOCENE OF BORDEAUX AND THE SOUTH OF FRANCE.
A great extent of country between the Pyrenees and the Gironde is overspread by
tertiary deposits of various ages, and chiefly of Miocene date. Some of these,
near Bordeaux, coincide in age with the faluns of Touraine, already mentioned,
but many of the species of shells are peculiar to the south. The succession of
beds in the basin of the Gironde implies several oscillations of level by which
the same wide area was alternately converted into sea and land and into
brackish-water lagoons, and finally into fresh-water ponds and lakes.
Pages:
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410