Two distinct visions of human existence dominate Valente's collection of prose poems, No amanece el cantor. Readers stand before a being that is essentially a psyche, one in which the vastness of the unconscious is allowed to manifest itself and to overwhelm the limits of the body. The entire section, consisting of thirty-one short compositions, is addressed to the poet's dead companion with whom he wants to be reunited.
These are beautifully simple, poignant texts whose lack of a poematic format does not diminish in any sense their poetic essence. All three books from Tusquets', Nuevos Textos Sagrados collection deserve our attention. Not only are they successful works by very skillful writers, they retrieve and carry forward Spain's invaluable contribution to universal mysticism.
As Debicki indicates in his introduction, we find ourselves at a moment when history and literary interpretation collide, merge, and offer new syntheses. The Spanish Civil War is now no longer active in memory, for the last generation of poets presently writing was born after the war. It is also significant that in the last decade or so, criticism of Spanish literature has been subjected to a considerable demand for revision. Such a revision would necessitate new perspectives and strategies. This perceptive and well-written volume represents an innovative and substantial contribution to the study of contemporary Spanish poetry.
Two essays involve the reappraisal of Spanish women poets. As Wilcox admits, the creation of a gynocentric voice would be more expected of Aguirre, given the protestations of Figuera that she did not believe in feminism. However, Wilcox makes a strong case for the implied feminist vision in her poetry. Sharon Keefe Ugalde provides a meticulous yet very readable commentary on the feminist revision of such cultural and literary figures as Eve, Lot's wife nameless in her lack of identity and her sin , and Ophelia in Spanish women's poetry of the s.
Ugalde interprets a series of complex stages in which women poets recapture a subjectivity immersed in despair and non-being, reclaiming the power of self and Eros. This was the first work of the poet to be written in Catalan, and was translated to Spanish by the poet himself. The evolution of contemporary Spanish poetry continues to break the restraints of geometrically conceived critical strictures.
In conclusion, the volume presents an impressive contribution to the criticism of contemporary Spanish poetry. The essays included are of an unusually high calibre of scholarship, reflecting originality, depth, and clarity. Because the study is in English, it invites colleagues in other disciplines to share the experience of an exceptionally rich period of Spanish literature. It also represents an opportunity to strengthen the presence of contemporary critical strategies practiced in other Western literatures. Jerry Phillips Winfield Mercer University. While Teresa Ferrer Valls is interested in the historical development and the staging of court plays, James A.
Parr concentrates on new critical methods. And yet, Parr's book also includes a historical perspective since it is a collection of essays compiled by three editors as a tribute to Parr. They were originally published between and The book also includes a new essay. After Its Kind is divided into three sections. The first is more traditional in approach.
While Section Two of the book contributes to our understanding of genre, focusing on concepts such as Christian tragedy and broaching suggestive topics such as the misogyny implicit in Golden Age comedy , it is Section Three that contains Parr's most original insights. It would have been useful to include some of the published reactions to this essay particularly E.
Wilson's reply in an appendix. This third section also includes a article which gives an impressionistic outline of the changes that have occurred in literary criticism, and theory in this century. The juxtaposition of the two articles shows how quickly theories and fallacies change. While in Parr was decrying intentional fallacy, he notes that for many it is the referential fallacy that matters now.
The final article, written for this volume, is a personal assessment of current criticism on the comedia. Parr attempts to craft a vision of where critics should be heading. He cites recent studies attempting to assess their contributions while also cautioning about certain pitfalls. Stressing the importance of scholarship, criticism and theory, Parr argues that they cannot exist independently.
Both the article and the book as a whole delight in heterogeneity, an element that, for Parr, is at the center of the Humanities. While Parr's book moves easily from theory to scholarship, it is so wide-ranging that at times we wish for more specificity and focus. On the other hand, Ferrer Valls's study excels in its scholarly investigations of the stage, but is at times overwhelmed by data. The author begins by studying certain equestrian tournaments, showing how these court feasts became more and more elaborate, including different scenes, dialogue, action and spectacle.
The motifs utilized were often derived from classical mythology and the chivalric romances. Ferrer Valls carefully documents the close relationship between Spain and Italy during the sixteenth century, focusing on the Italian nobility in Valencia, the knowledge Charles V and Philip II had of Italian spectacles, and the presence in Spain of Italian actors. She also shows how artificial lighting was common in the peninsula.
There was, she shows, a continuing tradition of court spectacles which at times used Italian innovations. A dense chapter on court spectacles during the reign of Philip III completes the historical panorama. Here, Ferrer Valls shows how much the Conde de Lemos contributed to the development of theater and spectacle during this period. She goes on to prove that La casa confusa was actually written by Lemos. A detailed study of nine plays in terms of their contribution to court spectacle rounds out the book.
James Parr and Teresa Ferrer Valls present us with books that deal with the comedia using radically different approaches. Frederick A. Studies of the Don Juan figure have become increasingly sophisticated in recent years as critics have mastered the demanding discourse of modern theory in its several dimensions: literary, cultural, ideological, and psychological, in particular. Mandrell's contribution is, in my estimation, the most sophisticated of the lot. This is so because he is able to join together into a seamless whole so many seemingly disparate strands of theory: feminist, neo-Marxian, Lacanian, and Derridian, to mention only a few, while also offering compelling close readings.
The book represents a culmination of work done previously, by him and by others, while showing the way to an enhanced appreciation of this Protean figure and the writing within which his seductive presence is encoded. It is fair to say that Mandrell's study deals with writing and rewriting, although, stated baldly in that manner, it is impossible to convey the complexity and richness of the argument. Complementary to writing is, of course, the act of reading, and here some of the subtleties of both deconstruction and phenomenology come into play.
Suffice it to say that Mandrell has mastered not only his primary sources -to the extent that one can be said ever to master a text- and also the theories that are judiciously brought to bear in order to highlight aspects that have escaped less discerning readers. Several of the guild are queried and found wanting at opportune moments, and there is a running dialogue with Carlos Feal's utopian perspective.
There is a corresponding shift in emphasis from authorship and writing to readership and response to the seductive strategies of the narrator. A more significant problem may have to do with origins. In El burlador , seduction and there are only two instances, Tisbea and Aminta is invariably subordinated to the burla , involving a mockery of established values. The more important dimension of seductiveness lies in the fact that Don Juan has for centuries seduced both writers and readers within the realm of literature-a much larger and far more malleable universe than that of everyday reality.
March, y Estelle Irizarry. Henry Thurston-Griswold offers Valera scholars an opportunity to reconsider the credibility of the aesthetic creed of Spain's Don Juan Valera. Pursuant upon the fact that numerous critics and scholarly studies have attempted in vain to classify Valera's eclectic style, Thurston-Griswold chooses instead to reevaluate the nineteenth-century author's writings in light of the philosophical stance he held. The book is divided into four long chapters with an introduction and a conclusion, a list of works consulted, and a limited index.
Written in clear, crisp prose, this Valera study begins with a precisely stated premise, followed by well-organized, well-documented chapters on Valera's biography and aesthetic creed, critical commentary on the author's philosophy, and a discussion of the novels. Thurston-Griswold skillfully matches previous critical stances with citations from primary sources to come to grips with the often-cited divergence between Valera's aesthetic creed and his writing.
It should be noted that while Thurston-Griswold refers often to Valera's critical writing and touches all bases when discussing the novels characterization, themes, plots, use of language, and narrative technique , there is scant reference to Valera's poetry or drama.
The discussion of the theme of love fails to cite directly Carole Rupe's study, although the work is listed in the bibliography. Teresia Taylor Hardin-Simmons University. This is a most welcome volume. The anthology includes poems from Uceda's first published volume, Mariposa en cenizas , to her latest work, Del camino de humo in press. Uceda's poetry is dense, especially from the Poemas de Cherry Lane on. This is difficult and disturbing writing, reflecting a private struggle with the largest question of all, the question of Being.
And behind this question, the perplexities of naming and identity. As a passionate, uneasy meditation on the enigma of existence, such poetry challenges us to go beyond naming, beyond the certainties of categories and schema, for a kind of understanding that partakes of the vivid clarity of dream. Uceda sees her poetry along such visionary lines. Yo no suprimo el plano real cotidiano Uceda, who is an original and intensely visionary poetic voice of contemporary Spain, deserves far more recognition than she has so far received.
This volume amply demonstrates that originality. Dichos ensayos coinciden en enfocarse sobre sutilezas en la oeuvre celiana no elucidadas a pesar de estudios anteriores. No es posible citar todos los ensayos por falta de espacio, pero se recomiendan a todos los estudiosos de la obra celiana para futuras investigaciones sobre el genial gallego. Genaro J. Thus, readers might expect to find essays representative of a variety of theoretical tendencies, but they may be disappointed by the narrower criteria more accurately delineated by the second quote.
Save the brief forward by Rolando Hinojosa and Luis Leal's contribution, the rest were penned by practitioners of historically based cultural critique. Yet, while no one should judge the greater spectrum of Chicano criticism on the basis of this collection, the essays are generally informative, and a few, like Genaro Padilla's study of New Mexican women's autobiography or Elizabeth J.
Most significantly, the collection displays the talents, interests, and methodology of some of the leading figures of what can be called the second generation of Chicano critics, those who, unlike critics of the first, have had the benefit of Chicano studies courses in their training.
The second book is an example of the maturing of that second generation. Yet what defines his approach in The Dialects is the theory of cultural resistance which leads more to contrast than comparison. On the one hand is the U.
La ilustración sonriente: Feijoo y la Risa
However, despite a sophisticated display of current critical sources, the interpretations feel somehow dated by a bipolar division of ideological forces into good and evil reminiscent of the cold war years or when siding with the Cuban Revolution was the politically correct position for liberal U. In general, the image of Latin America is monolithic and uncritical, focusing only on the leftists' tradition of anti-U. Strangely enough, the critic's rhetoric empowers the very writing he wishes to attack by making the U.
He then posits a model for the U. Most telling is the underlying irony of a Chicano text, a hybrid product of on-going cultural fusion, arguing in such clear-cut binary terms. The author admits that this kind of cultural production, arising from a fluid border existence which he has attributed to Chicano writers and even to his own critical position, no longer fits within the oppositional structure he has used throughout the text.
Theorizing is, however, always problematic and much more so in our present condition of multiple and mass competition for critical positioning, that is, unless one brackets the field into unproblematic units through the imposition of some abstract formula or ideology extraneous to the material studied, principles which resolve problems a priori.
However, from the position of the last paragraph it becomes impossible to speak of our and their Americas, thus placing the entire text into an idealized space outside the reality of the historical period in which it appears. Both books are necessary reading for anyone who intends to keep abreast of developing Chicano critical thought. Este libro constituye el tercer tomo de otros dos ya publicados por los autores en la misma editorial.
El lector necesita tener a mano ambos tomos, debido a las referencias que se hacen a menudo en este nuevo volumen. Se puede recomendar como libro de consulta para cualquier curso subgraduado o graduado que trate el tema afrocubano. Luis A. Para este asunto son fundamentales los trabajos de Rolena Adorno.
Sirve muy bien para repasar de manera conjunta la realidad americana del siglo XVI. Indudablemente, hay que aplaudir el acceso de Dianne M. Latin America and the Caribbean is the result of years of collaboration among librarians and other scholars to compile a complete interdisciplinary guide to Latin American Studies.
This reference has 5, annotated entries describing the major reference sources of all of the Latin American countries including former possessions of England and Holland. Arranged by subject areas, the entries fit into fifteen chapters: general, anthropology, art and architecture, databases, economics, education, geography, history, literature, performing arts dance, film, music and theater , philosophy, politics, religion, sociology, and women's studies. Noted specialists have written introductory essays establishing the major contours of each field for the past twenty-five years; major bibliographies fist and annotate these key sources.
Author, title, and subject indexes plus a detailed table of contents multiply access to all the materials. Descriptions of the Tertiary fossil shells from South America. In Darwin, C. 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. Smith Elder and Co. ABSTRACT: Over years ago Charles Robert Darwin arrived in Argentina to find a bare and boundless plain, the brave centaur called "gaucho", Quaternary fossils everywhere, and a society strikingly strange and aggressive to the British eyes of the young traveller.
Although the voyage aboard HMS Beagle was the indispensable way towards increasing his stature as a biologist, Lyell's work awakened an inquisitive geological mind which allowed him to wonder at the splendour of the Andes. Forty-two years after having concluded his voyage on the Beagle, the National Academy of Sciences of Argentina appointed him as an Honorary Member.
This must be interpreted as an early gesture of recognition -in the context of those times- to the magnificence of his scientific work. Recibido: 25 de agosto de Aceptado: 2 de octubre de Beagle moored at Montevideo. It was a Cherokee class gun brig-sloop of the Royal Navy named after the Beagle, the famous British dog breed.
There were significant gaps in the geographical knowledge that the British Admiralty had gathered through countless reports of sailors who had visited the region for many years. Now that George Canning had signed in a commercial treaty with the newly independent federation of Argentinean states, trade was flourishing with the ex Spanish colonies and accurate geographical information was urgently needed.
Young Darwin was expected to gather information on the natural history and geology of many exotic regions that he was going to visit during a two-year long journey around the world. The trip was initially extended to threeyears and then to five-years and it would be the most extraordinary experience in the life of Charles Darwin; an experience that would change dramatically the view that humankind had of itself and of nature.
In his memoirs, he would simply state that "the voyage of the Beagle has been by far the most important event in my life and has determined my whole career". Darwin had left unfinished his medical education at Edinburgh in , and had gone to Cambridge's Christ's College where he obtained his Bachelor of Arts BA degree, without honors. He was an enthusiastic entomologist and an avid biological collector and his experience in the Earth Sciences was limited to a field trip to northern Wales with the famous Adam Sedgwick , Woodwardian Professor of Geology at Cambridge.
Notwithstanding, Darwin was supposed to become a clergyman and his father -Robert Waring Darwin- initially had strong objections when Charles was offered the opportunity of boarding the HMS Beagle for a journey to South America to "survey the S. However, after Charles's uncle, Josiah Wedgwood II, wrote an eloquent letter in which he stated that being young Charles a man of enlarged curiosity, " After an absence of five years and two days, on October 2nd, , the Beagle anchored at Falmouth, and on the 4th Darwin returned home to Shrewsbury.
As we know today, the voyage of the Beagle made him a scientific celebrity, as he produced several books and numerous articles, and profusely described and distributed many specimens that he brought home with him aboard the ship Fig. All these events rapidly led him to join the elite world of international science on an equal footing. The revolutionary ideas set into motion by this long voyage swirled through Darwin's later life until, precipitated by Alfred Russel Wallace, they suddenly broke through into Victorian society in , under the form of a book that bore the provocative title of On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life Fig.
Beagle, painted by George Richmond Figure 2: Facsimile of the front page of Origin of Species. The best place to find a detailed and personal account of Darwin's rich experiences is his first book, entitled Journal of Researches into the Geology and Natural History of the Various Countries visited by H.
The book was a success when first published, in , and Darwin's fondness for this particular work was transparent when he wrote at the end of his life that "the success of this my first literary child always tickles my vanity more than that of any of my other books". Originally published in four volumes Darwin's volume, plus FitzRoy's two and an extended appendix , Darwin describes not only the exciting travels, the exotic ports of call, and the fascinating inland expeditions in fact, he spent much more time on land than he did at sea , but also his emotions, his intense feelings on first arriving in the tropics, his dangerous overland excursions with the gauchos which he deeply admired , and the awesome sight of the stars over the Cordillera de los Andes.
Figure 3: Facsimile of the front page of Darwin's Journal of Researches, a. Voyage of the Beagle. Moreover, in his first work - later published as Voyage of the Beagle e. Along this line, it is particularly interesting to read about his impressions and views on Argentine society in times of severe turmoil, when Juan Manuel de Rosas whom he met personally was growing as a political figure in the conflictive scenario that was at the time the Argentine Confederation.
On June 10th, , the Beagle "bade farewell for ever to Tierra del Fuego". Darwin was not particularly fond of sailing rough seas and one can only imagine the feeling of relief that he experienced when they left Cape Horn for good.
Reviews of Books
Darwin would enter again Argentina's territory when he crossed the Andes and arrived in Mendoza during the 2nd half of March, The awe-inspiring sight of the Cordillera and the possibility of seeing geological processes at such large scale made a very deep impression on the young scientist. Since this article is published in a geological journal, it seems appropriate to briefly consider the geological facet of Charles Darwin.
It is accepted now that geology influenced Darwin and, conversely, he influenced the science Herbert Like FitzRoy, he had a special interest in geology and he had read most of the best-known texts in the field, particularly Charles Lyell's famous Principles of Geology Lyell , which was originally published in This shared interest in geological sciences was probably a factor that drew FitzRoy and Darwin together during their time on board. In fact, FitzRoy was approached by Lyell before the Beagle sailed off Plymouth in order to ask that specific geological features be recorded, such as erratic boulders of glacial origin.
Darwin gathered geological specimens and took detailed notes on geology during the circumnavigation of the globe. Contradicting widespread belief, upon his return to Great Britain, it was his geological findings that first promoted enthusiastic scientific and public opinion. It must be kept in mind that, as a young scientist, Charles Darwin was eager to contribute with a simple theory that would explain most, if not all, of the observed geological phenomena.
Only his scheme explaining the structure and distribution of coral reefs has survived to this day Herbert The British government sponsored publication of his research and numerous geologists, including Darwin's former teachers like Sedgwick, proved to be an interested audience. Doubtlessly the experience of the voyage of the Beagle had been transformative: the methods and hypothesis of Victorian-era geology profoundly shaped Darwin's mind and his scientific methods as he worked toward a complete comprehension of evolution and natural selection. The first to arrive in August was Prof.
Others, like the geologist Stelzner, the zoologist H. Weyenbergh, the astronomer K. As academicians and naturalists from prominent European centers of higher learning, all undoubtedly knew about the revolutionary ideas put forward in the Origin of Species and, although not all supported Darwin's views G. Burmeister, a prominent biologist, organizer of the Academy, for example, opposed evolutionary ideas , there is ground to sustain that most were enthusiastic supporters of Darwin's work.
Moreover, during his visit to Argentine territory Charles Darwin made numerous and valuable observations that increased the knowledge on the natural history and geology of the young country.
On August 7th , the President of the Academy, Dr. In return, Darwin instructed his publisher to send a copy of the Origin of Species to the Academy still in the Academy's collection of antique books , sent an autographed picture see frontispiece of this volume , and wrote a grateful letter to the Academy's President. Darwin's letter dated March 18th to the Academy's President, Dr. Hendrik Weyenbergh, read: "Dear Sir, I beg leave to acknowledge the receipt of the very handsome Diploma of your Society, and to repeat my thanks for the honour conferred on me.
According to your request I enclose my photograph, and I have directed my publisher to send a copy of my Origin of Species to the Society as I suppose that this is the best of my works. To this day, the volume presented by Darwin as a gift, as well as the photograph and the letter, are cherished in Argentina's Academy of Sciences as valuable icons of the development of world science. Darwin's approach to explain the evolution of nature and, above all, of humankind rapidly rooted in Argentina's newly born but growing science.
Perhaps nothing better than Sarmiento's own words to express the widespread feelings towards these revolutionary biological ideas. Darwin died in after a long illness; it was not realized until after his death that he had suffered from Chagas's disease, which he had contracted while visiting South America. Although he was not the only originator of the evolution hypothesis, he certainly was the first man of science that gained for such theory a wide acceptance among biological experts. By contributing his own ideas on natural selection to the evolutionism outlined by Erasmus Darwin -his grandfather-, Lamarck and other biologists, he raised the evolutionary hypothesis to a provable theory.
I wish to acknowledge the assistance of my friend and fellow academician, Dr. Alfredo Cocucci, who supplied valuable information for the preparation of this article. Gonzalo Biarnes and librarian Sandra Ledesma, both members of the Academy's staff, kindly supplied the facsimiles herein included. Most important, my wife Elizabeth kindly helped out introducing needed corrections to the original manuscript.
Sarmiento, D. Obras completas, Discursos Populares. Emails: stella gl. Charles Darwin visited the area during his South American journeys in the 19th century and discovered a geological sequence that contained a paleoflora never described before. The flora includes an important number of species, particularly what is considered a small conifer forest with many silicified trunks still in life position.
Darwin described and interpreted the sequence as sedimentary; his records show a very detailed level of observation. He also wondered about the processes that would cause the burial of the paleoflora, which he considered had happened in a marine sedimentary environment. In the modern geological framework and after a detailed study of the rocks containing the trunks, it is now interpreted that the conifer forest was buried by pyroclastic flows. A escasos 23 km de Uspallata, a lo largo de la antigua ruta nacional 7, se encuentra la localidad de Agua de la Zorra en la provincia de Mendoza al oeste de Argentina.
Charles Darwin travelled around South America between and This situation provided Dar-win with some spare time and at his expense took a six week land expedition to the east, i. During this journey, Darwin recorded everything he found. There he found a thick sequence, which he considered sedimentary, that contained some trunks never described before. Figure 1: a Path followed by Darwin from Valparaiso, towards the north in Chile, and towards the east in Argentina, where he visited the Precordillera in Mendoza. First observations of Darwin in the region of Agua de la Zorra in Uspallata are mentioned in Chapter VII Darwin , where he describes the area and refers to the paleoflora found as: "… I counted the stumps of fifty-two trees.
One of the aspects that amazed him was that the trunks were in life position and well preserved. He not only described his finding but also asked advice from specialists about the type of flora: "… Eleven of these trees were silicified and well preserved: Mr. Brown has been so kind as to examine the wood when sliced and polished; he says it is coniferous, partaking of the characters of the Araucarian tribe, with some curious points of affinity with the Yew". His records show a very detailed level of observation: " All the stumps have nearly the same diameter, varying from one foot to eighteen inches; some of them stand within a yard of each other; they are grouped in a clump within a space of about sixty yards across".
The longest stump stood seven feet out of the ground: the roots, if they are still preserved, are buried and concealed. No one layer of the mudstone appeared much darker than the others, as if it had formerly existed as soil ". Paragraphs ahead, he wondered about the processes that may have explained the origin of the deposits and the associated paleoflora: " Certainly the upright trees have been buried under several thousand feet in thickness of matter, accumulated under the sea. As the land, moreover, on which the trees grew, is formed of subaqueous deposits, of nearly if not quite equal thickness with the superincumbent strata, and as these deposits are regularly stratified and fine-grained, not like the matter thrown up on a sea-beach, a previous upward movement, aided no doubt by the great accumulation of lavas and sediment, is also indicated ".
He interpreted a possible origin for the deposits taking into account the regional geological setting known then: " At first I imagined, that the strata with the trees might have been accumulated in a lake: but this seems highly improbable; for, first, a very deep lake was necessary to receive the matter below the trees, then it must have been drained for their growth, and afterwards re-formed and made profoundly deep, so as to receive a subsequent accumulation of matter several thousand feet in thickness.
And all this must have taken place necessarily before the formation of the Uspallata range, and therefore on the margin of the wide level expanse of the Pampas! Hence I conclude that it is infinitely more probable that the strata were accumulated under the sea ". Darwin's discovery at Agua de la Zorra is located along the old National Highway 7, which links Caracoles de Villavicencio with the town of Uspallata Fig. It was only in that the deposits where Darwin's paleoflora was found were described again by Stappenbeck and later by Harrington , Figure 2 shows a schematic geological map of the area.
The sequence containing the trunks, sedimentary in origin as Darwin described, is partially covered by alkaline basalts and intruded by sills of similar composition. The abundant remains of conifers render it a classic site not only from the paleontological point of view, but also from a geological and historical perspective.
Thus, the name of Bosque de Darwin Darwin's Forest for the site was formalized in the geological reports of Map 09, Uspallata Brodtkorb et al. In a recent analysis of a section of the sequence, Poma et al. The area of Agua de la Zorra is part of the Cuyo Triassic extensional basin. According to Kokogian et al. The lowermost deposits, Early Triassic in age, were included in the synrift I stage by Kokogian et al. These coarse-grained rocks are commonly found close to positive areas and basinwards taper into fluvial sandy ephemeral braided deposits and finally pass into muddy playa-lake sequences in the central parts of the basin.
Isolated levels of rhyolitic tuffs occur at some places. The second sequence, labelled as the synrift II stage Kokogian et al. During this time prevailed different types of high-sinuosity river deposits composed of cross-bedded sandstones, conglomerates and mudstones. Lacustrine and deltaic sediments also appear in this section and indeed are dominant at the uppermost level of this section.
Lake deposits are made up of interbedded sandstones-mudstones sequences with sporadic intercalations of organic-rich shales. A noticeable feature of this interval is the occurrence of abundant pyroclastic levels covered by thick basaltic lava flows and sills included in the uppermost part of the synrift II stage. Finally, during the Late Triassic a sag phase sequence was defined by Ramos and Kay and Kokogian et al.
At this time prevailed sandstones and conglomerates sedimented by anastomosed and braided rivers that were covered by transgressive mudstones, shales and tuffs deposited in lacustrine environments. In the Agua de la Zorra region, as Darwin described, there are a series of rocks containing tree trunks typical of coniferous - including Araucarioxylon sp. According to field and microscope observations the material interbedded with the fossils comprises two main deposit types that are repeated with different thickness along the sequence. Figure 3: a General view to the SW of the Triassic pyroclastic deposits covered by Triassic alkaline basalts; b Closer view of the trunk, paleosoil, roots, and pyroclastic sequence including basal levels; c Detailed view of the trunk, approximate diameter 40 cm.
One of them is a characteristic pyroclastic flow deposit with crystal fragments, glass shards, pumice lapilli, all of them magmatically fragmented juvenile clasts product of their explosive origin. The crystals are small and irregular quartz grains and tabular or irregular fragments of oligoclase-andesine plagioclase. The matrix contains abundant angular glass shards, most of which have cuspate shape Fig.
Fine ash fills the interstices between the shards. The shards are characteristically undeformed and some of them retain original bubble wall shapes, suggesting that the deposition was at moderate temperature. The lapilli pumices are concentrated at the lower part of the deposits and are smaller than 16 mm medium lapilli. Occasionally it is possible to find silicified plant sprigs. Figure 4: Thin section pictures of Paramillo Formation tuffs. The rock is classified as a rhyolitic to dacitic medium lapilli tuff White and Houghton with thin decimetre scale variably diffuse layering, thickness varying between 50 and 20 centimetres.
They are defined by gradational grain size between pumice and lapilli. The set repeats itself several times along the sequence.
- The Coming Wave [Illustrated] The Hidden Treasure of High Rock.
- Navigation menu;
- Index of Argentina-related articles - Wikipedia.
- Winning the War Inside.
- National Identity, Collaboration and Cultural Adaptation!
- Reconstruction of Social Work Through Personalisation;
Typically the diffuse stratification is subparallel with local gradual thinning. The rock commonly grades vertically into massive beds. Associated with the tuff and separated by a clearly noticeable surface there is a thin centimetre to few decimetre scale and well sorted deposit. It is poorly lithified and is interpreted as an air fall deposit that accompanied the emplacement of pyroclastic flows. It was preserved because a later ignimbritic flow covered it and protected it from erosion. The conspicuous features in these rocks are pyroclastic cuspate glass shards and pumice fragments.
The shards and delicate spines of bubble walls were deposited undeformed, they indicate that the deposit is primary and has not been reworked from primary deposits Fig. The glassy shards are now transformed in zeolite and silica material. In the area, some massive lapilli tuff show normal vertical grading patterns defined by more or less gradual changes in grain size. Vertical grading typically occurs across a few decimetres. The record begins Fig. At the base these rocks show channel morphology probably indicative of some erosive behaviour by the flow.
In this deposit, generally at lower levels, it is possible to notice small gas escape pipes. These structures are richer in pumice lapilli, lithics and poorer in fine ash than the enclosing tuff. This is characteristic of the removal of fine ash as a result of elutriation by gas escaping through the uncompacted deposit.
The pipes were formed simultaneously with the flow accumulation, again illustrating the primary nature of the deposit. The pyroclastic rocks are intercalated with fluvial lenses of fine sandstones to conglomerate, interbedded with shales. Geomorphology and patterns of thickness variation of the pyroclastic deposits suggest a possible western provenance even though there is no conclusive evidence.
The pyroclastic and sedimentary rocks described are intercalated and covered with Triassic mafic rocks. These are sills and lava flows of basaltic composition Massabie , Ramos and Kay In the Agua de la Zorra region the olivine-bearing basalts are easily noticeable because of their dark colours, fine grain and scoriaceous or amygdaloidal textures.
The vesicles were partially filled with calcium carbonate and silica and zeolites in subordinate amounts. These materials are conspicuous in altered basalts and sometimes are found in pyroclastic and sedimentary rocks. The lower part of the basalts are resting over a poorly consolidate rhyolitic tuff that contains small spheres of basaltic palagonite lava. The size of the spheres is variable but no larger than 5 cm.
They represent the interaction between lava flows and unconsolidated water soaked material. Upwards there are peperites that result from the mingling between basalt, rhyolitic tuff and clastic sediments in variables proportions. These textures suggest that the basalts were produced shortly after or simultaneously with the pyroclastic activity and sedimentation. There were not identified volcanological structures that could relate the rhyolitic pyroclastic deposits with the basaltic lava flows, seeming the latter the result of fissure eruptions.
Just as Darwin described, the trunks are arranged vertical to the layers. They stand at approximately the same level, and although Darwin did not identify a normal paleosoil, he understood that these trees had to grow in a dry substrate. He mentioned Darwin : " As the trees obviously must once have grown on dry land, what an enormous amount of subsidence is thus indicated!
Nevertheless, had it not been for the trees, there was no appearance which would have led any one even to have conjectured that these strata had subsided ". Obviously, he was amazed at the great thickness of sediments that there are in the sequence, which hinders any simple interpretation on the origin of the set. Finally, Darwin makes up his mind and chooses the simplest interpretation, even though this is not satisfactory. On the other hand he observes and describes that the fine material plastered around the trunks as a package preserves the mould with the external texture of the plants: " The bark round the trunks must have been circularly furrowed with irregular lines, for the mudstone round them is thus plainly marked ".
Along geologic time and humankind history there are numerous examples of flora, fauna and populations buried by this type of processes. Seldom were human witnesses present while volcanic activity was taking place. In those rare cases, men and women were able to describe the catastrophic episode. Pompeii 79 BC , for example, was buried under four meters of ash and debris. Pliny the Younger, a Roman soldier, witnessed much of the eruption Francis Pompeii was covered over with a hot cloud of volcanic ash, steam and some mud material.
The pyroclastic cloud flowed down the side of the volcano at a speed of 30 meters per second Francis It took less than four minutes for the pyroclastic flow to travel from Vesuvius to Pompeii a few kilometres away. In more than , people died when Mount Tambora erupted on the Indonesian island of Sumbawa Sutawidjaja et al. It was only during the last century and after many eruptions that pyroclastic flows were thoroughly studied and documented by hundreds of volcanologists worldwide, such as the Saint Helens among others.
With detailed monitoring and modeling of active volcanism, eruption styles, type of ejecta, flows and clouds were understood and only then past volcanic expressions could be properly interpreted. In the same way it was only recently that science acknowledged the significant impact of these types of phenomena on climatic change at a planetary scale. In continental volcanic environments the interaction between hot magma and water frequently produces this kind of volcanism, in which a voluminous explosive eruption of magmatic ejects emulsionated with magmatic and external volatiles.
Figure 6 shows an interpretation of the eruption. The characteristics of the pyroclastic sequence of Agua de la Zorra allow us to make another interpretation: The eruption was not destructive at least not in that sector as the trees remain in life position; so it is inferred the eruption was not laterally directed and can be supposed to be vertical.
However, there is no concluding evidence to disregard a lateral eruption, especially if the deposits are distal or out of the lateral blast influence. Lahars recognized by Brodtkorb et al. Volcanic activity was intense enough to eliminate most of the soft tissues of the flora such as leaves, which are more abundant in the sedimentary levels. Burial must have been in a short time, as a consequence of one or more eruptions but close in time, because there are no recorded breaks between the flows that cover the trunks.
Only one paleosoil was observed below a tree Fig. Its thickness is less than 50 cm. It is dark with root marks. They are stratified and the sequence ends with an ash fall, possibly related to the co-ignimbritic cloud. There is no clear evidence of an extended ash fall deposit besides the coignimbritic cloud deposits already mentioned.
In that regard, the eruptive column is not considered to be too high.
As indicated by Sparks and Wilson , a high proportion of steam in phreatomagmatic eruptions results in shorter columns. Changing thickness and varying structures and textures seem to imply an unstable feeding system from the magma chamber to the eruptive column. Instability could have been the consequence of the variations in the magma supply and in any case is responsible for the recorded duality in the massive form or diffusely stratified deposits. This interpretation is consistent with a first deposit in the area made up of initial base surge such as the ones locally observed overlying the paleosoil.
Eruptions of these characteristics are violent and also of rapid deposition. This amount of ash had already surprised Darwin who, as we mentioned earlier, had interpreted it as material of sedimentary origin. He was successful in the interpretation that the forest was buried in life. Despite Darwin misinterpreted the origin of the deposits as sedimentary, he was accurate in describing the fine volcanic materials as an essential part of them, although he never considered the eruptive process as the one responsible for the burial.
The present interpretation as a phreatomagmatic mechanism is now plausible because of the advances in volcanological knowledge and understanding during the latter years of the Twentieth Century. The authors are particularly grateful to S. Kay, E. Sruoga for their review of the manuscript and to Miguel Griffin for his valuable suggestions to improve the English version. Brodtkorb, A. Buenos Aires. Brea, M. Ameghiniana Darwin, C. Geological observations on the volcanic islands visited during the voyage of H. Smith, Elder and co. Harrington, H. Kokogian, D.
In Chebli, G. Cuencas Sedimentarias Argentinas. In Caminos, R. Massabie, A. Morel, E. Poma, S. In Brodtkorb, M. De, Koukharsky, M. Ramos, V. Triassic rifting and associated basalts in the Cuyo Basin, central Argentina. In Harmon, R. Rolleri, E. Sparks, R. Explosive volcanic eruptions- V. Geophysical Journal Internacional Stappenbeck, R.
La Precordillera de San Juan y Mendoza. Stipanicic, P. In Leanza, A. In Turner, J. Strelkov, E. Sutawidjaja, I.
rekoworamo.ml: Juan Carlos Ramis: Kindle Store
Characterization of volcanic deposits and geoarchaeological studies from the eruption of Tambora volcano. Jurnal Geologi Indonesia 1 1 : Darwin forest at agua de la zorra: the first in situ forest discovered in South America by Darwin in Artabe 2 , 4 and Luis A. Spalletti 3 , 4. Email: aeartabe museo. Email: spalle cig. The Agua de la Zorra area near Uspallata, Mendoza, Argentina is one of the best renowned fossil localities of the country because of its spectacular in situ fossil forest.
This forest was discovered by Charles Darwin in , who described this forest as monotypic and assigned it a Tertiary age. Nowadays, this fossil locality is known as the Darwin Forest. Over a century and a half later it was reinterpreted as a mixed Middle Triassic forest and a new fossil monotypic palaeocommunity of horsetails was discovered. This palaeovegetation is included in the Paramillo Formation i. The sediments were deposited in a sinuous fluvial system, in which channel-filling sand bodies were associated with mud-dominated floodplain deposits.
The palaeoforest grew on an andisol soil that developed on volcaniclastic floodplain deposits. It had a density of trees per hectare, and was constituted by conifers and corystosperms distributed in two arboreal strata. The highest reached m tall, and was dominated by corystosperms, but it also included the tallest conifers. The second stratum, mainly composed of conifers, ranged between m tall. The forest has also emergent corystosperms, which reached 30 m tall. The understorey was composed of ferns. Growth ring anatomy suggests that conifers could have had an evergreen habit.
Structure of vegetation, growth ring analyses and sedimentation suggest that the forest developed under dry, subtropical, and strongly seasonal conditions. Los sedimentos fueron depositados por un sistema fluvial de alta sinuosidad. El sotobosque estaba compuesto de helechos. The first fossil plants in South America were recorded by European naturalists during the 18th and 19th centuries Ottone The British naturalist Charles Robert Darwin was the first who provided palaeontological and geological observations of the Agua de la Zorra area, Uspallata, near Villavicencio, Mendoza province in Argentine territory Darwin a, b, , The expeditions of Charles Darwin -on board HMS Beagle- during his historic journery around the world between and , contributed valuable information and observations on the geology, plant and animal fossils, and extant organisms of South America.
Darwin also collected a huge number of specimens and samples, many of them new to science. Then, after crossing the Cordillera de los Andes from Chile, he arrived in Mendoza province and discovered the first in situ forest in South America, at Agua de la Zorra, located about 25 km from the town of Uspallata Conwentz , Rusconi , Harrington , Brea , Ottone He recorded the presence of 52 fossil tree trunks measuring cm in diameter, buried in sandstones or volcanic sandstones and standing out as columns several meters high Darwin This discovery by Darwin is remembered by a monolith Fig.
Figure 1: a. This photo was taken in Panoramic view of Triassic sequences, the arrow shows the plaque. On 30 March he collected the first specimens of fossil wood from Agua de la Zorra. The samples were sent to London and were referred by Robert Brown to the genus Araucarites Darwin Recently, one of the authors M. Brea characterized and studied the Triassic units at Agua de la Zorra from a palaeobotanical and sedimentological viewpoint. She defined two palaeocommunities in the Paramillo Formation, together with their associated palaeoenviroments Fig. The first paleocommunity, the in situ Darwin Forest Fig.
Large fossil tree stumps in growth position in Triassic sequences; d-f-h. Petrified standing trees at fossiliferous sites C; g. Large fossil log exposed in Triassic sediments at fossiliferous site B. The Darwin Forest was first referred to the Tertiary by Darwin a, b , but new data now available suggest a late Middle Triassic age Spalletti et al. The most important feature of the Darwin Forest is that the trees are still preserved at the sites on which they grew Fig. The Darwin Forest was reinterpreted as a subtropical dry seasonal forest Brea et al.
It grew on an andisol soil that developed on volcaniclastic floodplain deposits. The volcanic detritus and the rhythmic amalgamation of upper flow-regime tractional deposits overlying the andisol indicate that the forest was buried rapidly by a subaerial, cool and wet pyroclastic base surge flow Poma et al.
The continental Triassic succession of southwestern Gondwana occurs in a series of narrow rifts produced as a result of Triassic continental extension. These rift basins are composed of a continental clastic infilling, and record complex interactions between alluvial, fluvial, deltaic and lacustrine depositional systems with intercalations of volcaniclastic sequences in most of these basins.
The rich floristic record allowed recognition of several assemblages, biozones and stages characterized by floristic events Spalletti et al. Over the last two decades, most investigations on the Argentinian Triassic have focused on the gross stratigraphy and taxonomy of fossil plants Stipanicic , Stipanicic and Marsicano , Zamuner et al. However, recently published studies Spalletti et al. The Paramillo Formation is composed of a m thick succession of clast-supported conglomerates, pebbly sandstones, tuffaceous sandstones and mudstones Figs.
These authors all agreed in interpreting the Paramillo Formation as deposited in highly sinuous fluvial systems. Figure 4 : a. Lithostratigraphic section of the Paramillo and Agua de la Zorra Formations at locality A, showing the main lithofacies and the position of the fossil forest level. FL I - V: fossiliferous levels. Previous palaeobotanical studies, comprising mostly lists of fossil plants, were published by Darwin , Conwentz , Stappenbeck , Kurtz , Du Toit , Groeber , Windhausen , Harrington and Stipanicic et al.
The Paramillo Formation is a volcaniclastic unit composed of yellowish lithic sandstones, brownish and yellowish tuffaceous sandstones, dark gray and green shales and mudstones, and pink to reddish ash fall tuffs Fig. The sedimentary record of the overlying Agua de la Zorra Formation is dominated by bituminous shales and marls with subordinate intercalations of yellowish fine-grained sandstones and mudstones Fig. At that time Mendoza was a part of the vast supercontinent called Gondwana and it was placed approximately at the same geographic latitude as it is nowadays.
Brea studied in more detail the upper part of the Paramillo Formation and the lowermost Agua de la Zorra Formation and defined several lithofacies and facies associations. The Paramillo Formation consists of cross-bedded conglomerates, cross-bedded, plane-bedded and massive pebbly sandstones, cross-bedded, massive, plane bedded and ripple-laminated sandstones and intercalations of laminated mudstones and shales. Brea interpreted that these sediments were deposited in a highly sinuous meandering fluvial system, in which channel-filling sand bodies are associated with mud-dominated floodplain deposits.
The cyclic arrangement of well preserved soil horizons and sedimentary deposits lacking evidence of soil formation indicates alternation of periods with strong sediment aggradation produced by non-channelized high-regime flows with periods characterized by very low accommodation rates that favoured the development of immature soil profiles Brea et al. The volcanic nature of detrital components suggests that the highly aggrading non-channelized flows that produced the burial of the Darwin Forest could be related to pyroclastic events Poma et al.
The forest might have died as a result of a diluted, subaerial, cool and wet base surge pyroclastic flow Poma et al. The Paramillo Formation, where the Darwin Forest emerges, has been correlated with the lower section of the Potrerillos Formation Spalletti et al. The Triassic landscape at the Agua de la Zorra area was very different in comparison with the modern-day scenery. Sphenopsids dominated the flooded areas and conifers and corystosperms were the most important components of the arboreal vegetation.
Four exposures of the Darwin Forest were found in the Paramillo Formation during fieldwork carried out in Figs. This unit was thoroughly examined at two localities: Darwin and El Sauce Figs. Imperfect carbonization processes Poma et al. The fossiliferous levels FL with stumps were found at four localities belonging to the same in situ forest. The sedimentary sequences in which this forest is preserved consist of continental volcaniclastic units, resulting from deposition on a highly sinuous fluvial system associated with river flood-plains Fig.
The palaeoecological reconstruction of the Darwin Forest was based on the quantitative data of the mapped forest mean separation of trees, basal area per ha, species distribution integrated with the taxonomic and sedimentological information Brea et al. The corystosperms are a group of extinct plants with mostly fern-like foliage with ovules borne on modified leaves or cupules. This group was the dominant seed plant in Gondwana during the Triassic Stewart All conifers are a diverse group of trees and shrubs that underwent a major radiation during the Triassic period, when the first occurrence and radiation of the eight conifer families occurred Willis and McElwain The conifers have a pyramidal arborescent growth form, with cone-bearing seed plants; the foliage is either needle-like or scale-like.
The plants are mainly small, long, and thin arranged spirally and bearing the male and female reproductive organs in separate cones on different trees, or indifferent parts of the same. The spatial autocorrelation for the species variable indicates that in some places the corystosperms and conifers are intermingled while in others the corystosperms and conifers seem to be aggregated into cohesive social groups Fig. The Darwin Forest reveals two strata: the highest, developed between m, has a preponderance of corystosperms but also the tallest conifers; the second stratum, mainly composed of conifers, ranges between m.
The forest also has emergent corystosperms which reach 30 m tall Brea et al. The corystosperms were assigned by Artabe and Brea to Cuneumxylon spallettii and constitute the dominant species in the Darwin Foest. Figure 5: Reconstruction of the Triassic Darwin Forest landscape in a high sinuosity fluvial system, in which channel-filling sand bodies are associated with mud-dominated floodplain deposits. The canopy is integrated by two arboreal strata and emergent trees with conifers and corystosperms. The understorey is formed by ferns. Cinodonts are characteristic tetrapods during the Triassic of the Cuyo Basin drawing by Jorge Gonzalez.
This fossil forest presents values of biomass and stand basal area comparable to those of the current subtropical seasonal forests Brea et al. These forests develop under a climatic regime that includes an annual cycle with one season in which water is unavailable to plants because of lack of precipitation. The dry season alternates with another in which there is abundant water. In addition to structural data of the Darwin Forest that match those of an extant monsoon forest, the polyxyly found in Cuneumxylon has been considered an important adaptive wood character to avoid water stress.
Table of contents
As suggested by the functional anatomy and distribution of living groups Fahn , the included phloem associated with great amounts of parenchyma could be a strategy of subtropical plants to fight against water stress in arid regions during drought seasons. During Permian-Triassic biosphere reorganization, aridity of the Earth increased and in the Triassic the Pangea was characterized by strongly seasonal climates in a warm-house period Parrish et al. The spreading of continental climates caused the extension of semiarid belts into middle latitudes and, partly, into high latitudes too Chumakov and Zharkov Recently, general circulation models GCMs were developed by Sellowood and Valdes to simulate Mesozoic climatic patterns.
In this scheme the Triassic Southwestern Gondwana is modelled as seasonal and winter-wet against the opinion of Robinson who stated that it was seasonal and summer-wet. Growth-ring analysis of coniferous wood - assigned by Brea to Araucarioxylon protoaraucana - was used to evaluate climatic conditions Fritts , Holmes List of South America-related topics. Dependencies and other territories. General reference Culture and the arts Geography and places Health and fitness History and events Law Mathematics and logic Natural and physical sciences People and self Philosophy and thinking Religion and belief systems Society and social sciences Technology and applied sciences.
Categories : Argentina-related lists Indexes of topics by country. Hidden categories: Articles with short description Incomplete lists from December Region topic template using suffix. Namespaces Article Talk.