Search Results - The Complete Work of Charles Darwin Online

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

the capital. As the Beagle intended to call at Bahia Blanca, I determined to proceed there by land; and ultimately I extended my plan to travel the whole way by the postas to Buenos Ayres. August 11th. Mr. Harris, an Englishman residing at Patagones, a guide, and five Gauchos, who were proceeding to the army on business, were my companions on the journey. The Colorado, as I have already said, is nearly eighty miles distant: and as we travelled slowly, we were two days and a half on the road

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

considerably more abundant there formerly than at present. Where the Bizcacha lives and makes its burrows, the Agouti uses them; but where, as at Bahia Blanca, the Bizcacha is not found, the Agouti burrows for itself. The same thing occurs with the little owl of the Pampas (Athene cunicularia), which has so often been described as standing like a sentinel at the mouth of the burrows; for in Banda Oriental, owing to the absence of the Bizcacha, it is obliged to hollow out its own habitation. The

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

interview passed away without a smile, and I obtained a passport and order for the government post-horses, and this he gave me in the most obliging and ready manner. In the morning we started for Bahia Blanca, which we reached in two days. Leaving the regular encampment, we passed by the toldos of the Indians. These are round like ovens, and covered with hides; by the mouth of each, a tapering chuzo was stuck in the ground. The toldos were divided into separate groups, which belonged to the different

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

at all, and was astonished that one day's deprivation should be so troublesome to me. I have several times alluded to the surface of the ground being incrusted with salt. This phenomenon is quite different from that of the salinas, and more extraordinary. In many parts of South America, wherever the climate is moderately dry, these incrustations occur; but I have nowhere seen them so ahundant as near Bahia Blanca. The salt here, and in other parts of Patagonia, consists chiefly of sulphate of

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

a hundred reasons why they could not have been Indians; but all these were forgotten at the time. We then rode on in peace and quietness to a low point called Punta Alta, whence we could see nearly the whole of the great harbour of Bahia Blanca. The wide expanse of water is choked up by numerous great mud-banks, which the inhabitants call Cangrejales, or crabberies, from the number of small crabs. The mud is so soft that it is impossible to walk over them, even for the shortest distance. Many

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

existing one; but this would have been an erroneous inference, for some of these same shells live on the luxuriant coast of Brazil; and generally, the character of the inhabitants of the sea are useless as guides to judge of those on the land. Nevertheless, from the following considerations, I do not believe that the simple fact of many gigantic quadrupeds having lived on the plains round Bahia Blanca, is [page] 8

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

Africa. I will now give an account of the habits of some of the more interesting birds which are common on the wild plains of Northern Patagonia; and first for the largest, or South American ostrich. The ordinary habits of the ostrich are familiar to every one. They live on vegetable matter, such as roots and grass; but at Bahia Blanca I have repeatedly seen three or four come down at low water to the extensive mud-banks which are then dry, for the sake, as the Gauchos say, of feeding on small

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

swimming. The inhabitants of the country readily distinguish, even at a distance, the cock bird from the hen. The former is larger and darker-coloured, and has a bigger head. The ostrich, I believe the cock, emits a singular, deep-toned, hissing note: when first I heard it, standing in the midst of some sand-hillocks, I thought it was made by some wild beast, for it is a sound that one cannot tell whence it comes, or from how far distant. When we were at Bahia Blanca in the months of September and

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

any low bank of firm sandy soil by the side of a road or stream. Here (at Bahia Blanca) the walls round the houses are built of hardened mud; and I noticed that one, which enclosed a courtyard where I lodged, was bored through by round holes in a score of places. On asking the owner the cause of this, he bitterly complained of the little casarita, several of which I afterwards observed at work. It is rather curious to find how incapable these birds must be of acquiring any notion of thickness

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

, as other toads are, and living in damp obscure recesses, it crawls during the heat of the day about the dry sand-hillocks and arid plains, where not a single drop of water can be found. It must necessarily depend on the dew for its moisture; and this probably is absorbed by the skin, for it is known, that these reptiles possess great powers of cutaneous absorption. At Maldonado, I found one in a situation nearly as dry as at Bahia Blanca, and thinking to give it a great treat, carried it to a

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

saved his life by betraying the intended plan of warfare, and the point of union in the Andes. It was believed that there were already six or seven hundred Indians together, and that in summer their numbers would be doubled. Ambassadors were to have been sent to the Indians at the small Salinas, near Bahia Blanca, whom I have mentioned that this same cacique had betrayed. The communication, therefore, between the Indians, extends from the Cordillera to the coast of the Atlantic. General Rosas's

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

the shores of Bahia Blanca, and near the settlement, there were some of quartz, which certainly must have come from this source: the distance is forty-five miles. The dew, which in the early part of the night wetted the saddle-cloths under which we slept, was in the morning frozen. The plain, though appearing horizontal, had insensibly sloped up to a height of between 800 and 900 feet above the sea. In the morning (9th of September) the guide told me to ascend the nearest ridge, which he

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

party separated, and so arranged their plans, that at a certain time of the day (in guessing which they show much skill) they should all meet from different points of the compass on a plain piece of ground, and thus drive together the wild animals. One day I went out hunting at Bahia Blanca, [page] 11

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

was removed, was like a great cauldron; I found also teeth of the Toxodon and Mastodon, and one tooth of a Horse, in the same stained and decayed state. This latter tooth greatly interested me,* and I took scrupulous care in ascertaining that it had been embedded contemporaneously with the other remains; for I was not then aware that amongst the fossils from Bahia Blanca there was a horse's tooth hidden in the matrix: nor was it then known with certainty that the remains of horses are common in

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

Megatherium, Megalonyx, and Mylodon. Within nearly this same periods (as proved by the shells at Bahia Blanca) South America possessed, as we have just seen, a mastodon, horse, hollow-horned ruminant, and the same three genera (as well as several others) of the Edentata. Hence it is evident that North and South America, in having within a late geological period these several genera in common, were much more closely related in the character of their terrestrial inhabitants than they now are. * This is

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

manners pervading every rank of life, the excellent taste displayed by the women in their dresses, and the equality amongst all ranks. At the Rio Colorado some men who kept the humblest shops used to dine with General Rosas. A son of a major at Bahia Blanca gained his livelihood by making paper cigars, and he wished to accompany me, as guide or servant, to Buenos Ayres, but his father objected on the score of the danger alone. Many officers in the army can neither read nor write, yet all meet in

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

none at all. In the middle of the day they frequently roll in the dust, in saucer-shaped hollows. The males fight together; two one day passed quite close to me, squealing and trying to bite each other; and several were shot with their hides deeply scored. Herds sometimes appear to set out on exploring parties: at Bahia Blanca, where, within thirty miles of the coast, these animals are extremely unfrequent, I one day saw the tracks of thirty or forty, which had come in a direct line to a muddy

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

boulders were brought into latitudes at which icebergs now never arrive: from conclusive but indirect reasons we may feel sure, that in the southern hemisphere the Macrauchenia, also, lived long subsequently to the ice-transporting boulder-period. Did man, after his first inroad into South America, destroy, as has been suggested, the unwieldy Megatherium and the other Edentata? We must at least look to some other cause for the destruction of the little tucutuco at Bahia Blanca, and of the many

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

analogous species in the northern hemisphere. A large Voluta is abundant in southern Tierra del Fuego and the Falkland Islands. At Bahia Blanca, in lat 39 S., the most abundant shells were three species of Oliva (one of large size), one or two Volutas, and a Terebra. Now these are amongst the best characterised tropical forms. It is doubtful whether even one small species of Oliva exists on the southern shores of Europe, and there are no species of the two other genera. If a geologist were to

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

flows from the mountains, and it soon becomes absorbed by the dry and porous soil; so that, although we travelled at the distance of only ten or fifteen miles from the outer range of the Cordillera, we did not cross a single stream. In many parts the ground was incrusted with a saline efflorescence; hence we had the same salt-loving plants, which are common near Bahia Blanca. The landscape has a uniform [page] 32

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

Macrauchenia was a living beast; but as the Patagonian coast is some way distant from the Cordillera, the rising there may have been slower than here. At Bahia Blanca, the elevation has been only a few feet since the numerous gigantic quadrupeds were there entombed; and, according to the generally received opinion, when these extinct animals were living, man did not exist. But the rising of that part of the coast of Patagonia, is perhaps noways connected with the Cordillera, but rather with a line of old

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

ashes fell. But it may now be suspected that the lake was not a temporary one. Anyhow, we may feel sure, that at some former epoch, the climate and productions of Ascension were very different from what they now are. Where on the face of the earth can we find a spot, on which close investigation will not discover signs of that endless cycle of change, to which this earth has been, is, and will be subjected? On leaving Ascension we sailed for Bahia, on the coast of Brazil, in order to complete

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

of, 117 Puna, or short respiration, 322 Punta Alta, Bahia Blanca, 81 Gorda, 129, 356 Pyrophorus luminosus, 31 Quadrupeds, fossil, 81, 127, 130, 155, 173 , large, do not require luxuriant vegetation, 85 , weight of, 87 Quartz of the Ventana, 109 of Tapalgnen, 116 of Falkland Island, 196 Quedius, 10 Quillota, valley of, 254 Quintero, 254 Quiriquina Island, 302 2 L 2 [page] 51

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

these we gathered and brought home many. During my stay at Bahia Blanca, while waiting for the Beagle, the place was in a constant state of excitement, from rumours of wars and victories, between the troops of Rosas and the wild Indians. One day an account came that a small party forming one of the postas on the line to Buenos Ayres, had been found all murdered. The next day three hundred men arrived from the Colorado, under the command of Commandant Miranda. A large portion of these men were

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F14 Book: Darwin, C. R. 1845. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2d ed. London: John Murray. Text Image PDF

; their peculiar structure Dead and submerged Reefs Areas of subsidence and elevation Distribution of Volcanos Subsidence slow, and vast in amount..452 CHAPTER XXI. Mauritius, beautiful appearance of Great crateriform ring of Mountains Hindoos St. Helena History of the changes in the vegetation Cause of the extinction of land-shells Ascension Variation in the imported rats Volcanic Bombs Beds of infusoria Bahia Brazil Splendour of tropical scenery Pernambuco Singular Reef Slavery Return to England

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CUL-DAR43.1.56a-57 Correspondence: Parish Woodbine to Darwin Charles Robert [1845?] Parish Woodbine to Darwin Charles Robert Text Image PDF

I have specimens - - Mr Sowerby was good enough to name them for me. Voluta Colocynthis of Tillwyn Voluta Angulata - Swainson ?? Buccinum – Chemnitz [Annotation by Darwin:] Globulosum Kierner cochlidium– [Annotation by Darwin:] like or from Bahia Buccinum Nov. Spec. Ditto --- Ditto Oliva patula --- Solander [Annotation by Darwin:] very like my Buenos Ayres specimen Mactra? or type novi genesis Cytheræa novi spec: - [Annotation by Darwin:] purpurascens (perhaps) } same as Bahia Blanca Venus

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CUL-DAR43.1.6-45 Note: [1845.01.00--1845.02.00?] Sowerby George Brettingham to Darwin Charles Robert Text Image PDF

Patagonia X Ostrea latissima Deshayes Coquilles Foss. des Env: de Paris t. I. pl: 52. 53. Upraised Shells, Patagonia [in margin, in pencil for items 1 and 2:] Bahia, Brazil 1 The Fossils of this locality are composed of three separate parcels, probably different epochs, viz. 1 A granular Limestone (no. 381.) containing two fossil species; one, by far the most abundant, probably a Melania, the other probably a Paludina 2. Coarse Siliceous Sand (no. 342 378) with fragments of a Cytherea, a

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

outline of the land. M. Parchappe,† however, has described groups of sand-dunes scattered over the wide extent of the Paupas southward of Buenos Ayres, which M. d'Orbigny attributes with much probability to the action of the sea, before the plains were raised above its level.‡ Southward of the Plata:—The coast as far as Bahia Blanca (in latitude 39° S.) is formed either of a horizontal range of cliffs, or of immense accumulations of sand-dunes. Within Bahia Blanca, a small piece of table-land

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

land, would form a level plain traversed by parallel lines of sand-hillocks; during a slow elevation of the land, the hillocks would rest on a gently inclined surface, like that on the northern shore of Bahia Blanca. I did not observe any shells in this neighbourhood at a greater height than twenty feet; and therefore the age of the sea-drifted pebbles of pumice, now standing at the height of 120 feet, must remain uncertain. The main plain surrounding Bahia Blanca, I estimated at from 200 to 300

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

afforded an inexhaustible supply of sand, which would naturally have accumulated on the northern shore, as on every part of the coast open to the south winds between Bahia Blanca and Buenos Ayres. At San Blas (40° 40' S.), a little south of the mouth of the Colorado, M. d'Orbigny* found fourteen species of existing shells (six of them identical with those from Bahia Blanca), embedded in their natural positions. From the zone of depth which these shells are known to inhabit, they must have been

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

bays, such as in that of Bahia Blanca, wherever the sea is accumulating extensive mud-banks, or where the winds quietly heap up sand-dunes, beds of shells might assuredly be preserved buried in the positions in which they had lived, even whilst the land retained the same level; any, the smallest, amount of elevation would directly aid in their preservation. I saw a multitude of spots in Bahia Blanca, where this might have been effected; and at Maldonado it almost certainly has been effected. In

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

some places, according to M. Parchappe,* by beds of clay two yards thick. On the banks of the Sauce, four leagues S.E. of the Ventana, there is an imperfect section about two hundred feet in height, displaying in the upper part tosca-rock and in the lower part red Pampean mud. At the settlement of Bahia Blanca, the uppermost plain is composed of very compact, stratified tosca-rock, containing rounded grains of quartz distinguishable by the naked eye: the lower plain, on which the fortress stands

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

vegetation of a country and the size of its mammiferous inhabitants. I do not doubt that large animals could now exist, as far as the amount, not kind, of vegetation is concerned, on the sterile plains of Bahia Blanca and of the R. Negro, as well as on the equally, if not more sterile plains of Southern Africa. The climate, however, may perhaps have somewhat deteriorated since the mammifers embedded at Bahia Blanca lived there; for we must not infer, from the continued existence of the same shells on

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

different composition, which are themselves frequently either foliated or fissile,—such as the alternating so-called strata of mica-slate, gneiss, glossy clay-slate, and marble. The folia of the gneiss within a few miles round Bahia generally strike irregularly, and are often curvilinear, dipping in all directions at various angles: but where best defined, they extended most frequently in a N.E. by N. (or east 50° N.) and S.W. by S. line, corresponding nearly with the coast-line northwards of the

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

, 78 Salinas, 73 Salt with upraised shells, 48, 52 lakes of, 73 purity of, in salt lakes, 75 deliquescent, necessary for the preservation of meat, 75 ancient formation of, at Iquique, 234 at S. Lorenzo, 234 strata of, origin of, 235 Salts, superficial deposits of, 69 Sand-dunes of the Uruguay, 2 of the Pampas, 3 near Bahia Blanca, 4, 17 of the Colorado, 5, 17 of S. Cruz, 10 of Arica, 47 Sarmiento, Mount, 154 Schmidtmeyer on auriferous detritus, 235 Schomburgk, Sir R. on sea-bottom, 23 on the

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

CHAPTER IV. ON THE FORMATIONS OF THE PAMPAS. Mineralogical constitution — Microscopical structure — Buenos Ayres, shells embedded in tosca-rock — B. Ayres to the Colorado — S. Ventana — Bahia Blanca; M. Hermoso, bones and infusoria of; P. Alta, shells, bones, and infusoria of; co-existence of the recent shells and extinct mammifers — B. Ayres to St. Fé — Skeletons of Mastodon — Infusoria — Inferior marine tertiary strata, their age — Horse's tooth — BANDA ORIENTAL — Superficial Pampean

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

CHAPTER VI. PLUTONIC AND METAMORPHIC ROCKS:—CLEAVAGE AND FOLIATION. Brazil, Bahia, gneiss with disjointed metamorphosed dikes — Strike of foliation — Rio de Janeiro, gneiss-granite, embedded fragment in, decomposition of — La Plata, metamorphic and old volcanic rocks of — S. Ventana — Claystone porphyry formation of Patagonia; singular metamorphic rocks; speudo-dikes — Falkland Islands, palæozoic fossils of — Tierra del Fuego, clay-slate formation, cretaceous fossils of; cleavage and foliation

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

in lava, 175 Austen, Mr. R. A., on bent cleavage-laminæ, 160 Austin, Capt. on sea-bottom, 25 Australia, foliated rocks of, 165 Azara labiata, beds of, at San Pedro, 2, 78 Bacalemu, elevated shells near, 31 Baculites vagina, 126, 131 Bahia Blanca, elevation of, 3 formations near, 80 character of living shells of, 135, 137 Bahia (Brazil), elevation near, 3 crystalline rocks of, 140 Ballade, M. on the precipitation of sulphate of soda, 74 Banda Oriental, elevation of, 1 tertiary formations of, 90

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

continent, for at Port S. Julian, in Patagonia, there is good evidence (as we shall hereafter see) that when the land stood ninety feet lower, the Macrauchenia, a mammiferous beast, was alive; and at Bahia Blanca, when it stood only a few feet lower than it now does, many gigantic quadrupeds ranged over the adjoining country. But the coast of Patagonia is some way distant from the Cordillera, and the movement at Bahia Blanca is perhaps no ways connected with this great range, but rather with

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

Earthquake-waves, power of, in throwing up shells, 34 effects of, near Lima, 51 power, in transporting boulders, 69 Edmonston, Mr. on depths at which shells live at Valparaiso, 34 Ehrenberg, Prof. on infusoria in the Patagonian formation, 110, 111, 112, 117, 118 on infusoria in the Pampean formation, 81, 85, 88 Elevation of La Plata, 1 Brazil, 3 Bahia Blanca, 3, 83 San Blas, 5 Patagonia, 5, 14, 17 Tierra del Fuego, 12 Falkland Islands, 13 Pampas, 14, 103 Chonos Archipelago, 27 Chiloe, 27 Chile

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

CONTENTS. ~~~~~~ CHAPTER I. ON THE ELEVATION OF THE EASTERN COAST OF SOUTH AMERICA. Upraised Shells of La Plata — Bahia Blanca, Sand-dunes and Pumice-pebbles — Step-formed Plains of Patagonia, with upraised Shells — Terrace-bounded Valley of Santa Cruz, formerly a Sea-strait — Upraised Shells of Tierra del Fuego — Length and breadth of the elevated area — Equability of the movements, as shown by the similar heights of the plains — Slowness of the elevatory process — Mode of formation of the

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

CHAPTER I. ON THE ELEVATION OF THE EASTERN COAST OF SOUTH AMERICA. Upraised Shells of La Plata — Bahia Blanca, Sand-dunes and Pumice-pebbles — Step-formed Plains of Patagonia, with upraised Shells — Terrace-bounded Valley of Santa Cruz, formerly a Sea-strait — Upraised Shells of Tierra del Fuego — Length and breadth of the elevated area — Equability of the movements, as shown by the similar heights of the plains — Slowness of the elevatory process — Mode of formation of the step-formed plains

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

CHAPTER IV. ON THE FORMATIONS OF THE PAMPAS. Mineralogical constitution — Microscopical structure — Buenos Ayres, shells embedded in tosca-rock — B. Ayres to the Colorado — S. Ventana — Bahia Blanca; M. Hermoso, bones and infusoria of; P. Alta, shells, bones and infusoria of; co-existence of the recent shells and extinct mammifers — B. Ayres to St. Fé — Skeletons of Mastodon — Infusoria — Inferior marine tertiary strata, their age — Horse's tooth — Banda Oriental — Superficial Pampean

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

-water origin. Of the thirteen Phytolitharia, nine are met with in the two deposits in Bahia Blanca, where there is evidence from two other species of Polygastrica that the beds were accumulated in brackish water. The traces of corals, sponges, and polythalamia, found by Dr. Carpenter in the tosca-rock, (of which I must observe the greater number of specimens were from the upper beds in the southern parts of the formation), apparently show a more purely marine origin. At St. Fé Bajada, in Entre Rios

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

rock sloped into one of the quiet bays, there were no marks of erosion at the level of the water, and the parts both beneath and above it preserved a uniform curve. At Bahia, the gneiss rocks are * Spix and Martius have collected, in an Appendix to their Travels, the largest body of facts on this subject. See, also, some remarks by M. Lund, in his communications to the Academy at Copenhagen; and others by M. Gaudichaud, in Freycinet's Voyage. † Dr. Benza describes granitic rock (Madras Journal of

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

Pampean formation was deposited by a sea-debacle rushing over the land, I may state, on the authority of a letter to me, that these translations are incorrect. The following is the passage in question:— Durch Beachtung der mikroscopischen Formen hat sich nun feststellen lassen, dass die Mastodonten-Lager am La Plata und die Knochen-Lager am Monte Hermoso, so wie die der Riesen-Gürtelthiere in den Dünenhügeln bei Bahia Blanca, beides in Patagonien, unveränderte brakische Süsswasserbildungen sind, die

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

having examined the northern and middle parts of the eastern island, said that the formation was here wholly absent. † This volcanic formation will be described in Chapter IV. It is not improbable that the height of the upraised shells at the head of the estuary of the Plata, being greater than at Bahia Blanca or at San Blas, may be owing to the upheaval of these latter places having been connected with the distant line of the Cordillera, whilst that of the provinces of La Plata was in

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

. m.) .. 250 South of New Bay (ang. m.) .. 200 to 220 North of S. Josef (estim.) .. 200 to 300 Plain of Rio Negro (ang. m.) .. 200 to 220 Bahia Blanca (estim.) .. 200 to 300 The extension, moreover, of the 560 to 580, and of the 80 to 100 feet, plains is remarkable, though somewhat less obvious than in the former cases. Bearing in mind that I have not picked these measurements out of a series, but have used all those which represented the edges of plains, I think it scarcely possible that these

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

Jesuit Falkner and other authors‡ state that they occur at intervals over the vast plains extending from the mouth of the Plata to Rioja and Catamarca. Hence it is that during droughts, most of the streams in the Pampas are saline. I nowhere met with these incrustations so abundantly as near Bahia Blanca: square miles of the mud-flats, which near that place are raised only a few feet above the sea, just enough to protect them from being overflowed, appear, after dry weather, whiter than the ground

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F273 Book: Darwin, C. R. 1846. Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. Text Image PDF

within the recent period, must lead to the suspicion that the common salt, by some unknown process, becomes in time changed into the sulphate. Friable calcareous matter is here abundant, and the case of the apparent double decomposition of the shells and salt on San Lorenzo, should not be forgotten. The saline incrustations, near Bahia Blanca, are not confined to, though most abundant on, the low muddy flats; for I noticed some on a calcareous plain between thirty and forty feet above the sea