PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



413 



May 30, 1860. 



1. " On certain E-ocks of Miocene and Eocene age in Tuscany, including 

 Serpentine, accompanied by Copper-ore, Lignite, and Alabaster." By W. P. 

 Jervis, Esq., E.G.S. 



Three distinct eruptions of serpentinous igneous rocks have been recognized 

 by the Italian geologists ; two are considered to have occurred in Tertiary 

 times, and one previously in the Mesozoic period : dykes of diorite (also of 

 Tertiary age) are more rare in the same geographical area. Erom the abundant 

 occurrence of these eruptive rocks, and the extensive development of Miocene 

 strata, unknown in England, arise many pecularities of Tuscan geology and 

 mineralogy. 1st. The diallagic serpentine has pierced the Upper Cretaceous 

 beds, but does not enclose any fragments of Tertiary rocks. It is non-metalli- 

 ferous, and is employed in architecture. 2ndly. The euphotide or "granitone," 

 is unfit for building purposes. The contact of this with the diallagic serpentine 

 has metamorphosed the latter into the curiously marked " Ranocchiaja," 3rdly. 

 Diorite, penetrating the euphotide, and, like it, belonging to the Eocene age. 

 This and the serpentine acting on the " Macigno' has produced the " Gabbro 

 rosso." 4thly. " Gabbro verde," or serpentine, without diallage, of Miocene 

 age. This is much softer than the diallagic serpentine. It forms dykes ; but 

 more generally it is the axial nucleus of hills and mountains, the strata of which 

 are much disturbed. In most cases the serpentine rocks, piercing the sedim^ii- 

 tary strata, have upheaved them from all sides . to this remarkable speciezS of 

 axis the author proposes the term periclinal, indicating that the strata fall off 

 in every direction. The limestones are often altered by the serpentine into 

 dolomite (Miemmite), and are otherwise variously affected Near Mataraua a 

 mouse coloured limestone is changed (by the alteration of the carbonate of iron 

 to a peroxide) into a brick-red marble, often brecciated and veined with serpen- 

 tine and calc-spar (Ofiocalce") 



June 13, 1860. 



1. " On the Ossiferous Caves of the Peninsular of Gower, in Glamorganshire, 

 South Wales." By H. Ealconer, M.D., E.R.S., E.G.S. With an Appendix by 

 J. Prestwich, Esq., E.B.S., Treas. G.S., "On a liaised Beach in Mewslad'e 

 Bay, and the occurrence of the Boulder-clay on Cefn-y-bryn, in Gower. 



This communication was a summary of researches made during the last three 

 years by the author and Lieut. -Col. Wood, E.G.S. The known bone-caves of 

 Gower, (of which Paviland, Spritsail Tor, and Bacon Hole have already supplied 

 Dr. Buckland and others to some extent with materials for the history of the 

 Cave-period) are in the Carboniferous Limestone ; and, with the exception of 

 that of Spritsail Tor, which is on the west coast of the peninsula, they all occur 

 between the Mumbles and the Worm's Head. The most important are " Bacon 

 Hole," "MinchinHole," "Bosco's Den," "Bowen's Parlour," "CrowHole,"^ 

 " Raven's Cliff Cavern," and lastly the well-known " Paviland Caves." Bone- 

 caves at the Mumbles, in Caswell Bay and in Oxwich Bay formeily existed ; 

 but the sea has destroyed them. One cavern named "Ram Tor" between 

 Caswell Bay and the Mumbles, presumed to be ossiferous, remains unexplored. 



Before describing the bone-caves, the author briefly noticed that which Mr. 

 Prestwich had lately traced, a raised,^ach and talus of breccia, for a mile along 

 Mewslade Bay, westward of Paviland; and he pointed out their important 

 relationship to the marine sands and overlying limestone-breccia found in several 

 of the Gower Caves. Some patches of Boulder-clay had also been found by 

 Mr. Prestwich, on the highlands of Gower, and in Rhos Sili Bay. 



" Bacon Hole" was first treated of. On the limestone floor of the cave are, — 

 (1) a few inches of marine sand, abounding with Litomia rudis, L. lUoniUs, and. 



