Nov. 27, 1873] 



NATURE 



59 



It is difficult to conceive how all traces of the vast 

 igneous action which occurred within the distance of 30 

 miles from the Scottish Silurian area should be absent 

 from the rocks of the Southern Uplands. The uncon- 

 formability of the Caradoc deposits on the Upper 

 Llandeilo strata in the Southern Uplands may per- 

 haps afford some clue to this difficulty. The Skiddaw 

 slates were probably ancient land in the area now occu- 

 pied by the Lake district during the period of the deposi- 

 tion of the Upper Llandeilo rocks of the south of Scotland. 

 This ancient land seems to have been subject to violent 

 sub-aerial volcanic action, being the earlier epoch of the 

 Caradoc series. During the later portion of the same 

 epoch this violent volcanic action ceased, the area covered 

 with igneous products again subsided beneath the sea, and 

 allowed of the accumulation of the materials of the 

 Coniston limestone and the succeeding groups. 



In the Southern Uplands of Scotland the well-marked 

 break recognised by the officers of the Survey points to 

 a lapse of time between the deposition of the highest 

 of the Upper Llandeilo groups and the conglomerates at 

 the base of the Caradoc rocks. It is probably during this 

 lapse of time that volcanic action was so rife on the other 

 side of what is now the Solway Firth. This lapse of time 

 is stiU further indicated by the comparative small deve- 

 lopment of the Caradoc rocks of the South of Scotland, 

 as contrasted with those of the typical Caradoc areas of 

 Shropshire and Wales, and also by their fossil contents, 

 which indicate that only a portion of the group is repre- 

 sented in this area, and that this portion appertains to the 

 upper part of the series. 



From what has been said it will be apparent that the 

 labours of the officers of the Geological Survey of Scot- 

 land have put us in possession of most important infor- 

 mation concerning the very difficult series of rocks making 

 up the strata of the bulk of the Southern Uplands. There 

 are other matters amply detailed in the " Explanatory 

 Memoirs " such as the metamorphism which the Silurian 

 rocks have in some places undergone, and the intrusive 

 rocks which are associated with them. The Old Red 

 Sandstones as laid down in Sheet 15 are fully described. 

 The important carboniferous areas of New Cumnock and 

 Guelt, of Lugar and I\Iuirkirk, and of Glespin or Douglas 

 Water, with their thin limestone and low coal, are largely 

 detailed. In relation to Dumfriesshire, the Sanquhar 

 coal-field, made up of strata belonging to the true coal 

 measures, and the carboniferous rocks which underhe it 

 are also fully described. The Permian rocks of a portion 

 of the Nith basin, having porphyries in different beds at 

 their base, and brick-red sandstones with trapean detritus 

 forming their upper portion, and also rocks of the same 

 age occurring on the shore near Corsewall House, 

 Wightonshire. are subjects treated of in the Memoirs. 

 Igneous rocks of an age posterior to the Permian are 

 also referred to. Superficial deposits in the condition 

 of drift sands, and gravels, brick clays, and erratic 

 blocks, also still more recent products in the foi-m of 

 raised sea beaches, blown sands, peat and alluvium are 

 fully alluded to. Finally the explanations afford infor- 

 mation concerning the economic minerals of the several 

 districts, the whole containing a record of an amount of 

 careful observations and inferences such as could only 

 have been arrived at by the labour and experience of such 



a staff of officers as that which constitutes the Geological 

 Survey. 



Robert Harkness 



LEYBOLD'S EXCURSION' TO THE ARGEN- 

 TINE PAMPAS 



Escursion a las Pampas Arjentinds : hojas de mi diario : 

 Frbrcro ae 1871.- Segiddo de tablas de obscrvaciones 

 baromltricas, un boceto dc la ruta toniaaa. For Fede- 

 rico Leybold. 8vo, pp. 108. (Santiago, 1873.) 



THE publication of a book relating to Natural History 

 in Chili is a rare event, and therefore well worthy of 

 record. Except PhiHppi and Landbeck's " Catalago de 

 las Aves Chilenas," and some few papers by the same 

 authors in the " Anales " of the University of Santiago, 

 the present is almost the first that has come before our 

 notice. And these, it must be recollected, are not the 

 productions of native Chilians, but of members of the all- 

 pervading Teutonic race, who have brought their science 

 with them from their distant fatherland. 



Herr Leybold, or Don Federico Leybold, as we suppose 

 we must call him, for he writes in Spanish, has been long 

 resident in Santiago, and active in investigating every 

 branch of Natural History in his adopted country. During 

 the last few years, as he tells us in the introductory 

 chapter of the present work, he has sent six expeditions 

 over the Andes to explore the natural riches of the 

 "Argentine Tempe," and finally in the month of February 

 of 1871 was able to make arrangements to proceed him- 

 self upon a collecting tour into the same district. The 

 route taken from Santiago was up the valley of the 

 Maipo, to the junction with it of the "Valle del Yeso," 

 and thence up this northern branch to the foot of the 

 " Portillo de los Piuquenes," where the watershed was 

 crossed. But a second and more elevated pass — the 

 " Portillo Mendocino '' — succeeds on this route over the 

 main chain, which is, we believe, that usually taken to 

 Mendoza. From the summit the descent was made over 

 the elevated eastern slopes of the Mendozan Andes to an 

 estancia called Vistaflores, situated at the foot of the 

 range, which was made the headquarters of the party 

 while they explored the surrounding country. Rainy 

 weather and drunken servants much hindered operations 

 during the stay at this place, which appears only to have 

 lasted about a week, when it was determined to return 

 to Santiago by the more southern " Paso del Diamante." 

 This pass leads under the volcano of Maipo into the 

 main valley of the Maipo, and thus enabled the travellers 

 to join their former route after about a week's difficult 

 and occasionally dangerous travel amid the snows and 

 storms of the higher Andes. 



Herr Leybold's diary of this interesting month's ex- 

 cursion is replete with notes and observations in every 

 branch of Natural History — Zoology, Botany, and Geology. 

 Birds, beetles, and plants appear to have engaged his 

 chief attention — but other objects are not passed un- 

 noticed. Not only are frequent references given to known 

 species observed in the Andes and on the adjacent dis- 

 tricts of the Argentine Republic, but descriptions are 

 introduced of species believed to be new to science, and 

 discovered on this occasion. Thus we have characterised 



