quinta-feira, 15 de novembro de 2007
Mud Logging OverviewSolidsLiquidsGassesPermian Basin Mudlogging Services
Mud Logging
Back to Exploration IndexBack to Logging Index
OverviewSolidsLiquidsGassesPermian Basin Mudlogging Services
Overview :
Mud logging is the process of collecting, analyzing and recording the meaningful solids, fluids, and gasses brought to the surface by the drilling fluid (mud). The mud logger keys all of his data to the Geolograph on the rig floor.
Back to top
Solids:
The mud logger collects samples of the cuttings from the downhole strata on a regular basis, usually every ten feet. Collections are usually made at the shaker table for the mud system. The logger then washes and dries the cuttings, keeping them properly labeled as to depth that they represent. In order to know what depth the samples actually come from the logger must constantly calculate a "lag" time, i.e. the time it takes the samples to reach the surface from the time they were cut. The greater the depth, the greater the time for the samples to reach the surface after they were cut. In order to help with the lag calculations, the logger tracks hole size, pump strokes, and occasionally sends distinctive samples down the pipe to measure the actual lag.
The logger examines the dried samples under a binocular microscope and records the predominant rock types on a depth strip chart that has drill times and chromatograph readings also recorded on it. Rock types are often correlated with the drill times for a particular rock type, e.g. fast drill time for a porous sandstone. Obviously properly recording what rock type is being drilled at what depth is not an exact science. Some factors that affect the accuracy are logger experience in an area, improper lag times, interbedded thin layers of multiple rock types, finely-ground rock fragments, sloughing of uphole rock material, and diligence of the logger.
Back to top
Liquids:
The logger analyzes for liquids primarily in two ways: chloride content and fluorescence. Chloride content of the mud is constantly monitored. An increase in chlorides from a certain depth can indicate a strong salt water flow from a permeable formation. Samples are also viewed under ultraviolet light to check for fluorescence because most oils fluoresce. In the event that fluorescence is detected. The sample is subjected to cleaning fluid to determine whether it is hydrocarbon or mineral fluorescence.
Back to top
Gasses:
A key component of a mudlogging unit is a gas chromatograph. This unit continuously samples the gases coming out of the mud and analyzes them for methane and the heavier hydrocarbons. The presence of a 'show' of hydrocarbons on the chromatograph alerts the logger to be more alert for other evidences of hydrocarbons. Sometimes a separate "lag" must be determined for gasses as they may rise faster to the surface than the samples. A bag of carbide dropped down the drill pipe is usually used for this purpose.
sábado, 10 de novembro de 2007
III Congresso Brasileiro de Rochas Ornamentais Associação Brasileira da Indústria de Rochas Ornamentais
30/10/2007 III Congresso Brasileiro de Rochas Ornamentais O Núcleo Nordeste da Sociedade Brasileira de Geologia promove e organiza, na cidade de Natal, no período de 15 a 18 de novembro de 2007, o III Congresso Brasileiro de Rochas Ornamentais e o VI Simpósio de Rochas Ornamentais do Nordeste.
Os eventos contam com o apoio técnico do CETEM, Governo do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Universidade Federal do Ceará, Universidade Federal de Pernambuco, Departamento Nacional da Produção Mineral, Serviço Geológico do Brasil, Instituto de Pesquisas Tecnológicas do Estado de São Paulo e CODECIR-PE.
O geólogo Cid Chiodi Filho representará a ABIROCHAS apresentando, no dia 17, a palestra "Situação Atual e Perspectivas do Setor de Rochas Ornamentais do Brasil".
Saiba mais sobre a programação do evento acessando o link:
------------------------------------------------------------------------------------------------
27/08/2007 Feira COVERINGS 2008
Estão abertas as inscrições para a participação de empresas no Pavilhão Brasileiro da Feira COVERINGS 2008, que será realizada em Orlando, EUA, entre os dias 29 de Abril e 02 de Maio. O prazo final para as inscrições é 20 de setembro de 2007.
Estão abertas as inscrições para a participação de empresas no Pavilhão Brasileiro da Feira COVERINGS 2008, que será realizada em Orlando, EUA, entre os dias 29 de Abril e 02 de Maio. O prazo final para as inscrições é 20 de setembro de 2007.
Estamos à disposição para maiores informações.ABIROCHAS - Tel: +55 11 3253-9250 / Fax: +55 11 3253-9458
Clique aqui para maiores informações e ficha de inscriçã
------------------------------------------------------------------------------------------------
CONHEÇA AS ROCHAS ORNAMENTAIS
CONCEITOS E DEFINIÇÕES
As rochas ornamentais e de revestimento, também designadas pedras naturais, rochas lapídeas, rochas dimensionais e materiais de cantaria, abrangem os tipos litológicos que podem ser extraídos em blocos ou placas, cortados em formas variadas e beneficiados através de esquadrejamento, polimento, lustro, etc. Seus principais campos de aplicação incluem tanto peças isoladas, como esculturas, tampos e pés de mesa, balcões, lápides e arte funerária em geral, quanto edificações, destacando-se, nesse caso, os revestimentos internos e externos de paredes, pisos, pilares, colunas, soleiras, etc.
CONHEÇA AS ROCHAS ORNAMENTAIS
CONCEITOS E DEFINIÇÕES
As rochas ornamentais e de revestimento, também designadas pedras naturais, rochas lapídeas, rochas dimensionais e materiais de cantaria, abrangem os tipos litológicos que podem ser extraídos em blocos ou placas, cortados em formas variadas e beneficiados através de esquadrejamento, polimento, lustro, etc. Seus principais campos de aplicação incluem tanto peças isoladas, como esculturas, tampos e pés de mesa, balcões, lápides e arte funerária em geral, quanto edificações, destacando-se, nesse caso, os revestimentos internos e externos de paredes, pisos, pilares, colunas, soleiras, etc.
Estima-se movimentação de US$ 18 bilhões/ano nos mercados internos dos países produtores, de US$ 12 bilhões/ano com a comercialização de materiais brutos e beneficiados, no mercado internacional, bem como de US$ 10 bilhões/ano para negócios com máquinas, equipamentos, insumos, materiais de consumo e prestação de serviços. A alavancagem de atividades pode ser examinada ao referir-se que a produção mundial de rochas ornamentais e de revestimento evoluiu de 1,5 milhões de t/ano, na década de 20, para um patamar atual de 65 milhões de t/ano.
Tal incremento foi determinado tanto por novos tipos de utilização das rochas ornamentais nas paisagens urbanas, principalmente no que se refere a obras de revestimento, quanto por novas tecnologias de extração, manuseio, transporte e beneficiamento de blocos.
Os avanços tecnológicos permitiram o aproveitamento e difusão de diversas rochas anteriormente não comercializadas, enquanto as novas utilizações viabilizaram soluções estéticas e funcionais muito interessantes e confiáveis na construção civil.
Cerca de 80% da produção mundial é atualmente transformada em chapas e ladrilhos para revestimentos, 15% desdobrada em peças para arte funerária e 5% para outros campos de aplicação. Aproximadamente 60% dos revestimentos referem-se a pisos, 16% a fachadas externas, 14% a interiores e 10% a trabalhos especiais de acabamento.
Os mármores representam, na atualidade, cerca de 45% da produção mundial, com 40% atribuídos aos granitos, 5% aos quartzitos e similares, e 5% às ardósias. A participação dos granitos elevou-se de um patamar de 15% no princípio da década de 50, para 22%, na de 70, 38% em meados da década de 80, até os atuais 40%, incrementando a demanda global sem restringir a utilização dos mármores.
Os blocos extraídos nas pedreiras têm volume variável entre 5 m3 e 8 m3, podendo atingir, excepcionalmente, 12 m3. Materiais especiais, com alto valor comercial, permitem, no entanto, o aproveitamento de blocos a partir de 1m3. As dimensões-padrão especificadas variam de 2,4 x 1,2 x 0,6 m (1,73 m3) a 3,3 x 1,8 x 1,5m (8,91 m3). Rochas com planos preferenciais de partição paralelos, como quartzitos e ardósias, são lavradas pela extração direta de placas no maciço.
Os mármores mais categorizados são os de massa fina, tanto brancos quanto desenhados coloridos, muito apreciados para arte estatuária e outras peças isoladas de acabamento e mobiliário. Entre os granitos, verifica-se, atualmente, melhor aceitação para os amarelos movimentados (tipo Juparaná), brancos (tipo Bianco Cardinalle, Cotton, Cashmere) e movimentados multicores (tipo Sul de Minas e Bahia), além, é claro, dos azuis (Azul Bahia e Azul Macaúbas).
Outros Links
- Principal-
- Principal-
Associação Brasileira da Indústria de Rochas Ornamentais
Avenida Paulista 1313 - 8º Andar - Sala 802 - São Paulo/SP - BrasilCEP 01311-200 - Fone 55 11 3253-9250 - Fax 3253-94582004 -
Todos os Direitos Reservados
sexta-feira, 9 de novembro de 2007
Associação Brasileira de Metalurgia e Materiais
UFOP realiza Simpósio Mineiro de Ciência dos MateriaisAssociação Brasileira de Metalurgia e Materiais
08/11/2007
O Departamento de Física (Defis) da UFOP promoverá nos próximos dias 12, 13 e 14 o II Simpósio Mineiro de Ciência dos Materiais, que ocorrerá no Instituto de Ciências Exatas e Biológicas, campus Morro do Cruzeiro.
O evento terá a presença de professores, pesquisadores, estudantes e profissionais que atuam em Ciência e Engenharia dos Materiais e áreas afins. O objetivo é estimular a interação entre pesquisadores de diferentes instituições de ensino e pesquisa do Estado, integrar os setores acadêmicos e estabelecer o estado de arte da Ciência dos Materiais no Estado de Minas Gerais. O simpósio abordará a fabricação, caracterização, propriedades e aplicações de materiais cerâmicos, metálicos, poliméricos e compósitos. Os trabalhos aprovados serão publicados em número especial da revista Materials Research.
Os resumos deverão ser preparados conforme instruções disponíveis na página: www.fisica.ufop.br.
As normas para preparação do artigo estão no site: www.nit.ufscar.br/matres.
A entrega do texto completo em inglês deverá ser feita até o dia 12 de novembro.
Épocas Metalogenéticas no Cráton Amazônico
Antiquities and Native Soil
Posted Oct 8, 2007
Hiram Bingham photographed this excavation of a human skeleton in a cave at Machu Picchu during the Yale University and National Geographic Society-funded expedtion of 1912.
In the last few days two major contentious situations involving estranged antiquities were more or less resolved. I’m talking about the agreement between the Italian Cultural Ministry and the J. Paul Getty Museum of Los Angeles which arranged the return to Italy of 40 artifacts and the agreement between Yale University and the Government of Peru to return what Hiram Bingham III collected at Machu Picchu almost one hundred years ago.
National Geographic gave its first archaeological grant to Bingham in 1912 to fund his return to Machu Picchu and continued to fund him for several years. What the Society got out of it was a highly popular April 1913 National Geographic Magazine article and a longstanding fruitful relationship with Peru and scientists working there. What Yale got was over 380 museum quality specimens and thousands of other artifacts that it displayed at the Peabody Museum or used for research.
It wasn’t until recently that National Geographic became aware that the Machu Picchu collection at the Yale Peabody Museum was a loan and should have been returned to Peru. Terry Garcia, an executive vice president of the Society, investigated the terms of the agreement with Peru and Yale and one could say he was responsible for triggering a lengthy cascade of events that finally led to the recent agreement.
It took seven years for Yale to come around. Why? Admittedly there are complexities in all cases involving antiquities. In the Getty case, for example, the 40 objects came from different sources and the Getty wasn’t about to hand over objects worth millions without checking to make sure of the facts. But still, it appears that Italy had to threaten to break relations with the Getty Museum before there was action. And Peru had to threaten to sue Yale.
There are numerous other examples of countries that have been less successful in retrieving their heritage, despite threats. The “Elgin” Parthenon Marbles are still in London, aren’t they? And Zahi Hawass, Secretary General of Egypt’s Supreme Council of Antiquities and National Geographic Explorer-in-Residence, still has not managed the return of the Nefertiti bust from Berlin. These prominent cases may be resolved some day through agreements like the ones reported above.
Another controversial case involves the Persepolis Fortification Archive (see map), a collection of thousands of cuneiform tablets from Iran that are in the U.S. for research. Victims of a 1997 Hamas terror bombing in Jerusalem argue that since Hamas was funded by Iran, the tablets should be seized and sold to raise the $400 million in damages awarded by a court (with Iran not present to contest). National Geographic is funding the scanning of the tablets to facilitate their return to Iran as soon as possible, but at this moment Iran is fearful that its cultural heritage, loaned in good faith to the Oriental Institute of the University of Chicago in 1936, will never come home.
All of these situations have a common denominator: the artifacts left their country of origin. In some cases, this occurred illegally and in others there were clear agreements in place. The UNESCO convention (Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property) establishes guidelines which should, in principal, protect the cultural heritage of countries from illegal antiquities trade going forward. There are still problems implementing this, as the Getty situation illustrates, but what about cultural property that left countries illegally or under murky circumstances before 1972, when the convention was ratified? If 114 ratifying countries now agree that “…the transfer of ownership of cultural property is one of the main causes of the impoverishment of the cultural heritage of the countries of origin of such property,” then perhaps more countries and institutions holding such “transferred” artifacts should be more helpful in facilitating the return of cultural material when it is requested.
If you know of any cultural material that should really get back home, let’s hear about it. If you have pix, send them to stonesbonesnthings@gmail.com.
Posted by Chris Sloan Comments (2) Filed Under: archaeologyEmail this post
Feathers for Velociraptor
Posted Sep 30, 2007
Greg Paul's prescient illustration of a Velociraptor with quilled arm feathers (on the left) was prepared almost twenty years ago. © Gregory S. Paul
Isn’t it interesting that a high-power trio of scientists, Alan Turner of Columbia University , Pete Makovicky of the Field Museum (an NGS grantee) and Mark Norell of the American Musuem of Natural History have now identified quill knobs on a Velociraptor ulna (see Science )?
It was not so long ago that such a claim would have generated an outcry from a vocal minority of scientists who opposed the hypothesis of a bird-dinosaur link like Storrs Olson of the Smithsonian Institution National Museum of Natural History and Alan Feduccia of the University of North Carolina at Chapel Hill, but I haven’t heard a peep, have you? I remember that Feduccia threatened to cancel his subscription to National Geographic he was so incensed with an article we published in 1998 on the dinosaurian origin of birds. I don’t know if he ever followed through on that, but when National Geographic published an article including “Archaeoraptor,” a fossil dino-bird that turned out to be a faked composite of two skeletons, he and his other colleagues of like mind screamed bloody murder (partly because they were suspicious of all “dinobirds,” but also because the creature had not yet been properly described in a scientific journal).
I have the dubious distinction of having written that article article back in November 1999 and remember distinctly the sharp tone of Storrs Olsen’s open letter which he sent to numerous scientists and which was reported heavily in creationist web sites as evidence against evolution. It was addressed to Dr. Peter Raven, chairman of the National Geographic Society’s Committee for Research and Exploration. I present here a couple choice bits from that letter:
“With the publication of "Feathers for T. rex?" by Christopher P. Sloan in its November issue, National Geographic has reached an all-time low for engaging in sensationalistic, unsubstantiated, tabloid journalism.”
and
“The idea of feathered dinosaurs and the theropod origin of birds is being actively promulgated by a cadre of zealous scientists acting in concert with certain editors at Nature and National Geographic who themselves have become outspoken and highly biased proselytizers of the faith. Truth and careful scientific weighing of evidence have been among the first casualties in their program, which is now fast becoming one of the grander scientific hoaxes of our age—the paleontological equivalent of cold fusion. If Sloan's article is not the crescendo of this fantasia, it is difficult to imagine to what heights it can next be taken.”
I don’t know what happened to vocal opposition of this sort. Olson, Feduccia and their colleagues were dutifully quoted by journalists in almost every news article on feathered dinosaurs back then. But as evidence to support the hypothesis has been pouring in, those opposing views quoted so often before in news media have trickled to nothing. So discoveries like the quill knobs on a Velociraptor are reported without mention of controversy.
Yet, this particular discovery should be controversial and generate discussion. Not because a dinosaur had feathers, but because it raises the nagging question of why a non-flying dinosaur had quilled feathers? Quilled feathers, as opposed to downlike “protofeathers” are necessary for flight in birds. There are the standard explanations for why they might appear in flightless dinosaurs: display, thermoregulation, and lift when running up inclines, for example, but another explanation is that quilled feathers are on Velociraptor because it was secondarily flightless, like penguins are today.
I’m sure that many paleontologists will remember that Greg Paul, who published Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds in 2002, has long argued that just because birds descended from dinosaurs doesn’t mean that the relationship can’t be reversed to produce flightless dinosaurs that descended from birds.
This new debate won’t be resolved anytime soon, but it will be interesting to hear the differing viewpoints. In the meantime, I’m interested in finding the earliest published illustration of Velociraptor that shows it with quilled arm feathers. What’s printed above is the earliest one I could find. It is by paleontologist Greg Paul and appeared in his book Predatory Dinosaurs of the World published in 1988. It is reprinted here with Greg's kind permission. Send anything you think might be earlier to stonesbonesnthings@gmail.com.
Posted by Chris Sloan Comments (11) Filed Under: palentologyEmail this post
Dmanisi Early Human Reconstructed
Posted Sep 21, 2007
In the current issue of Nature you’ll find a much-awaited report on the bodies (as opposed to the heads) of the folks that lived at Dmanisi in Georgia (the former Soviet Republic) about two million years ago. The report was much-awaited because only the heads of four of the individuals discovered there have been thoroughly reported. That left many of us wondering what their bodies were like.
We knew their brains were small and early estimates of their height and weight showed they were small in body as well, but we didn’t have a good sense of their body proportions or skeletal details from the neck down. And the reason why we cared about their bodies so much was that a paradigm was about to be broken.
Continue reading this entry »
Posted Oct 8, 2007
Hiram Bingham photographed this excavation of a human skeleton in a cave at Machu Picchu during the Yale University and National Geographic Society-funded expedtion of 1912.
In the last few days two major contentious situations involving estranged antiquities were more or less resolved. I’m talking about the agreement between the Italian Cultural Ministry and the J. Paul Getty Museum of Los Angeles which arranged the return to Italy of 40 artifacts and the agreement between Yale University and the Government of Peru to return what Hiram Bingham III collected at Machu Picchu almost one hundred years ago.
National Geographic gave its first archaeological grant to Bingham in 1912 to fund his return to Machu Picchu and continued to fund him for several years. What the Society got out of it was a highly popular April 1913 National Geographic Magazine article and a longstanding fruitful relationship with Peru and scientists working there. What Yale got was over 380 museum quality specimens and thousands of other artifacts that it displayed at the Peabody Museum or used for research.
It wasn’t until recently that National Geographic became aware that the Machu Picchu collection at the Yale Peabody Museum was a loan and should have been returned to Peru. Terry Garcia, an executive vice president of the Society, investigated the terms of the agreement with Peru and Yale and one could say he was responsible for triggering a lengthy cascade of events that finally led to the recent agreement.
It took seven years for Yale to come around. Why? Admittedly there are complexities in all cases involving antiquities. In the Getty case, for example, the 40 objects came from different sources and the Getty wasn’t about to hand over objects worth millions without checking to make sure of the facts. But still, it appears that Italy had to threaten to break relations with the Getty Museum before there was action. And Peru had to threaten to sue Yale.
There are numerous other examples of countries that have been less successful in retrieving their heritage, despite threats. The “Elgin” Parthenon Marbles are still in London, aren’t they? And Zahi Hawass, Secretary General of Egypt’s Supreme Council of Antiquities and National Geographic Explorer-in-Residence, still has not managed the return of the Nefertiti bust from Berlin. These prominent cases may be resolved some day through agreements like the ones reported above.
Another controversial case involves the Persepolis Fortification Archive (see map), a collection of thousands of cuneiform tablets from Iran that are in the U.S. for research. Victims of a 1997 Hamas terror bombing in Jerusalem argue that since Hamas was funded by Iran, the tablets should be seized and sold to raise the $400 million in damages awarded by a court (with Iran not present to contest). National Geographic is funding the scanning of the tablets to facilitate their return to Iran as soon as possible, but at this moment Iran is fearful that its cultural heritage, loaned in good faith to the Oriental Institute of the University of Chicago in 1936, will never come home.
All of these situations have a common denominator: the artifacts left their country of origin. In some cases, this occurred illegally and in others there were clear agreements in place. The UNESCO convention (Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property) establishes guidelines which should, in principal, protect the cultural heritage of countries from illegal antiquities trade going forward. There are still problems implementing this, as the Getty situation illustrates, but what about cultural property that left countries illegally or under murky circumstances before 1972, when the convention was ratified? If 114 ratifying countries now agree that “…the transfer of ownership of cultural property is one of the main causes of the impoverishment of the cultural heritage of the countries of origin of such property,” then perhaps more countries and institutions holding such “transferred” artifacts should be more helpful in facilitating the return of cultural material when it is requested.
If you know of any cultural material that should really get back home, let’s hear about it. If you have pix, send them to stonesbonesnthings@gmail.com.
Posted by Chris Sloan Comments (2) Filed Under: archaeologyEmail this post
Feathers for Velociraptor
Posted Sep 30, 2007
Greg Paul's prescient illustration of a Velociraptor with quilled arm feathers (on the left) was prepared almost twenty years ago. © Gregory S. Paul
Isn’t it interesting that a high-power trio of scientists, Alan Turner of Columbia University , Pete Makovicky of the Field Museum (an NGS grantee) and Mark Norell of the American Musuem of Natural History have now identified quill knobs on a Velociraptor ulna (see Science )?
It was not so long ago that such a claim would have generated an outcry from a vocal minority of scientists who opposed the hypothesis of a bird-dinosaur link like Storrs Olson of the Smithsonian Institution National Museum of Natural History and Alan Feduccia of the University of North Carolina at Chapel Hill, but I haven’t heard a peep, have you? I remember that Feduccia threatened to cancel his subscription to National Geographic he was so incensed with an article we published in 1998 on the dinosaurian origin of birds. I don’t know if he ever followed through on that, but when National Geographic published an article including “Archaeoraptor,” a fossil dino-bird that turned out to be a faked composite of two skeletons, he and his other colleagues of like mind screamed bloody murder (partly because they were suspicious of all “dinobirds,” but also because the creature had not yet been properly described in a scientific journal).
I have the dubious distinction of having written that article article back in November 1999 and remember distinctly the sharp tone of Storrs Olsen’s open letter which he sent to numerous scientists and which was reported heavily in creationist web sites as evidence against evolution. It was addressed to Dr. Peter Raven, chairman of the National Geographic Society’s Committee for Research and Exploration. I present here a couple choice bits from that letter:
“With the publication of "Feathers for T. rex?" by Christopher P. Sloan in its November issue, National Geographic has reached an all-time low for engaging in sensationalistic, unsubstantiated, tabloid journalism.”
and
“The idea of feathered dinosaurs and the theropod origin of birds is being actively promulgated by a cadre of zealous scientists acting in concert with certain editors at Nature and National Geographic who themselves have become outspoken and highly biased proselytizers of the faith. Truth and careful scientific weighing of evidence have been among the first casualties in their program, which is now fast becoming one of the grander scientific hoaxes of our age—the paleontological equivalent of cold fusion. If Sloan's article is not the crescendo of this fantasia, it is difficult to imagine to what heights it can next be taken.”
I don’t know what happened to vocal opposition of this sort. Olson, Feduccia and their colleagues were dutifully quoted by journalists in almost every news article on feathered dinosaurs back then. But as evidence to support the hypothesis has been pouring in, those opposing views quoted so often before in news media have trickled to nothing. So discoveries like the quill knobs on a Velociraptor are reported without mention of controversy.
Yet, this particular discovery should be controversial and generate discussion. Not because a dinosaur had feathers, but because it raises the nagging question of why a non-flying dinosaur had quilled feathers? Quilled feathers, as opposed to downlike “protofeathers” are necessary for flight in birds. There are the standard explanations for why they might appear in flightless dinosaurs: display, thermoregulation, and lift when running up inclines, for example, but another explanation is that quilled feathers are on Velociraptor because it was secondarily flightless, like penguins are today.
I’m sure that many paleontologists will remember that Greg Paul, who published Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds in 2002, has long argued that just because birds descended from dinosaurs doesn’t mean that the relationship can’t be reversed to produce flightless dinosaurs that descended from birds.
This new debate won’t be resolved anytime soon, but it will be interesting to hear the differing viewpoints. In the meantime, I’m interested in finding the earliest published illustration of Velociraptor that shows it with quilled arm feathers. What’s printed above is the earliest one I could find. It is by paleontologist Greg Paul and appeared in his book Predatory Dinosaurs of the World published in 1988. It is reprinted here with Greg's kind permission. Send anything you think might be earlier to stonesbonesnthings@gmail.com.
Posted by Chris Sloan Comments (11) Filed Under: palentologyEmail this post
Dmanisi Early Human Reconstructed
Posted Sep 21, 2007
In the current issue of Nature you’ll find a much-awaited report on the bodies (as opposed to the heads) of the folks that lived at Dmanisi in Georgia (the former Soviet Republic) about two million years ago. The report was much-awaited because only the heads of four of the individuals discovered there have been thoroughly reported. That left many of us wondering what their bodies were like.
We knew their brains were small and early estimates of their height and weight showed they were small in body as well, but we didn’t have a good sense of their body proportions or skeletal details from the neck down. And the reason why we cared about their bodies so much was that a paradigm was about to be broken.
Continue reading this entry »
quarta-feira, 31 de outubro de 2007
Mud logging is the process of collecting, analyzing and recording the meaningful solids, fluids, and gasses
Well logging, also known as borehole logging is the practice of making a detailed record (log) of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface (geological logs) or on physical measurements made by instruments lowered into the hole (geophysical logs). Well logging is done when drilling boreholes for oil and gas, groundwater, minerals, and for environmental and geotechnical studies.Geophysical well logs
The oil and gas industry records rock and fluid properties to find hydrocarbon zones in the geological formations within the Earth's crust. A logging procedure consists of lowering a 'logging tool' on the end of a wireline into an oil well (or hole) to measure the rock and fluid properties of the formation. An interpretation of these measurements is then made to locate and quantify potential depth zones containing oil and gas (hydrocarbons). Logging tools developed over the years measure the electrical, acoustic, radioactive, electromagnetic, and other properties of the rocks and their contained fluids. Logging is usually performed as the logging tools are pulled out of the hole. This data is recorded to a printed record called a 'Well Log' and is normally transmitted digitally to office locations. Well logging is performed at various intervals during the drilling of the well and when the total depth is drilled, which could range in depths from 300 m to 8000 m (1000 ft to 25,000 ft) or more.
History
The first geophysical well log was a self-potential log recorded in 1927 in a well in oil field of Pechebronn, Alsace France
The first geophysical well log was a self-potential log recorded in 1927 in a well in oil field of Pechebronn, Alsace France
Wireline and "While Drilling" well logging
Well logging usually refers to downhole measurements made via instrumentation that is lowered into the well at the end of a wireline cable. The wireline consists of an outer wire rope and an inner group of wires. The outer rope provides strength for lowering and lifting the heavy instruments and the inner wiring provides for transmission of power to the downhole equipment and for data telemetry uphole to the recording equipment on the surface.
In recent years, a new technique, Logging While Drilling (LWD), has been introduced which provides similar information about the well. Instead of sensors being lowered into the well at the end of wireline cable, the sensors are integrated into the drill string and the measurements are made while the well is being drilled. While wireline well logging occurs after the drill string is removed from the well, LWD measures geological parameters while the well is being drilled. However, because there is no high bandwidth telemetry path available — no wires to the surface — data is either recorded downhole and retrieved when the drill string is removed from the hole, or the measurement data is transmitted to the surface via pressure pulses in the well's mud fluid column. This mud telemetry method provides a bandwidth of much less than 100 bits per second. Fortunately, drilling through rock is a fairly slow process and data compression techniques mean that this is an ample bandwidth for real-time delivery of critical information.
Logging measurement types
Logging measurements are quite sophisticated. The prime target is the measurement of various geophysical properties of the subsurface rock formations. Of particular interest are porosity, permeability, and fluid content. Porosity is the proportion of fluid-filled space found within the rock. It is this space that contains the oil and gas. Permeability is the ability of fluids to flow through the rock. The higher the porosity, the higher the possible oil and gas content of a rock reservoir. The higher the permeability, the easier for the oil and gas to flow toward the wellbore. Logging tools provide measurements that allow for the mathematical interpretation of these quantities.
Well logging usually refers to downhole measurements made via instrumentation that is lowered into the well at the end of a wireline cable. The wireline consists of an outer wire rope and an inner group of wires. The outer rope provides strength for lowering and lifting the heavy instruments and the inner wiring provides for transmission of power to the downhole equipment and for data telemetry uphole to the recording equipment on the surface.
In recent years, a new technique, Logging While Drilling (LWD), has been introduced which provides similar information about the well. Instead of sensors being lowered into the well at the end of wireline cable, the sensors are integrated into the drill string and the measurements are made while the well is being drilled. While wireline well logging occurs after the drill string is removed from the well, LWD measures geological parameters while the well is being drilled. However, because there is no high bandwidth telemetry path available — no wires to the surface — data is either recorded downhole and retrieved when the drill string is removed from the hole, or the measurement data is transmitted to the surface via pressure pulses in the well's mud fluid column. This mud telemetry method provides a bandwidth of much less than 100 bits per second. Fortunately, drilling through rock is a fairly slow process and data compression techniques mean that this is an ample bandwidth for real-time delivery of critical information.
Logging measurement types
Logging measurements are quite sophisticated. The prime target is the measurement of various geophysical properties of the subsurface rock formations. Of particular interest are porosity, permeability, and fluid content. Porosity is the proportion of fluid-filled space found within the rock. It is this space that contains the oil and gas. Permeability is the ability of fluids to flow through the rock. The higher the porosity, the higher the possible oil and gas content of a rock reservoir. The higher the permeability, the easier for the oil and gas to flow toward the wellbore. Logging tools provide measurements that allow for the mathematical interpretation of these quantities.
Beyond just the porosity and permeability, various logging measurements allow the interpretation of what kinds of fluids are in the pores — oil, gas, brine. In addition, the logging measurements are used to determine mechanical properties of the formations. These mechanical properties determine what kind of enhanced recovery methods may be used (tertiary recovery) and what damage to the formation (such as erosion) is to be expected during oil and gas production.
The types of instruments used in well logging are quite broad. The first logging measurements consisted of basic electrical logs (resistivity) and spontaneous potential (SP) logs, introduced by the Schlumberger brothers in the 1920's. Tools later became available to estimate porosity via sonic velocity and nuclear measurements. Tools are now more specialized and better able to resolve fine details in the formation. Radiofrequency transmission and coupling techniques are used to determine fluid conductivity (brine is more conductive than oil or gas). Sonic transmission characteristics (pressure waves) determine mechanical integrity. Nuclear magnetic resonance (NMR) can determine the properties of the hydrogen atoms in the pores (surface tension, etc.). Nuclear scattering (radiation scattering), spectrometry and absorption measurements can determine density and elemental analysis or composition. High resolution electrical or acoustical imaging logs are used to visualize the formation, compute formation dip, and analyze thinly-bedded and fractured reservoirs.
In addition to sensor-based measurements above, robotic equipment can sample formation fluids which may then be brought to the surface for laboratory examination. Also, controlled flow measurements can be used to determine in situ viscosity, water and gas cut (percentage), and other fluid and production parameters.
Geological logs
In the petroleum industry, geological logs are commonly called mud logs, because they are made by examining cuttings, which are bits of rock circulated to the surface by the drilling mud in rotary drilling. The wellsite geologist, or mudlogger, describe cuttings, monitors traces of natural gas in the mud, as well as rig operations during both drilling and non-drilling phases. The geologist analyzes the cuttings which have travelled up the wellbore suspended in the drilling fluid or mud which was pumped into the wellbore via the drill string/pipe and returns to the surface via the 'flow line'. Cuttings are then separated from the drilling fluid as they move across the shale shakers and are sampled at drilled depth intervals (determined by the operator, but 10', 20', 30' and 50' intervals are commonly used at different sections of the wellbore), analyzed and described by the logging geologist on duty. The mud log is prepared by a company contracted by the operating company. A typical mud log displays formation gas (gas units or ppm), rate of penetration (ROP, in units of inverse velocity, or T/L); lithological sample descriptions; interpretive geology based upon ROP, formation gas/oil cut-stain-fluorescence, and gas curves including a total gas (gas units = ppm/1000) curve and methane through pentane (ppm). A mud log usually also displays drillbit information, drilling parameters, mud weights, directional information about the wellbore (deviation surveys), casing shoe depths, and formation tops.
The well and mud logs are usually transferred in 'real time' to the operating company, which uses these logs to make operational decisions about the well and to make interpretations about the quantity and quality of hydrocarbons present. Specialists involved in well log interpretation are called log analysts.
Geosteering
Drilling mud
Drilling rig
List of oilfield service companies
Formation evaluation
MWD/LWD
Wireline
The types of instruments used in well logging are quite broad. The first logging measurements consisted of basic electrical logs (resistivity) and spontaneous potential (SP) logs, introduced by the Schlumberger brothers in the 1920's. Tools later became available to estimate porosity via sonic velocity and nuclear measurements. Tools are now more specialized and better able to resolve fine details in the formation. Radiofrequency transmission and coupling techniques are used to determine fluid conductivity (brine is more conductive than oil or gas). Sonic transmission characteristics (pressure waves) determine mechanical integrity. Nuclear magnetic resonance (NMR) can determine the properties of the hydrogen atoms in the pores (surface tension, etc.). Nuclear scattering (radiation scattering), spectrometry and absorption measurements can determine density and elemental analysis or composition. High resolution electrical or acoustical imaging logs are used to visualize the formation, compute formation dip, and analyze thinly-bedded and fractured reservoirs.
In addition to sensor-based measurements above, robotic equipment can sample formation fluids which may then be brought to the surface for laboratory examination. Also, controlled flow measurements can be used to determine in situ viscosity, water and gas cut (percentage), and other fluid and production parameters.
Geological logs
In the petroleum industry, geological logs are commonly called mud logs, because they are made by examining cuttings, which are bits of rock circulated to the surface by the drilling mud in rotary drilling. The wellsite geologist, or mudlogger, describe cuttings, monitors traces of natural gas in the mud, as well as rig operations during both drilling and non-drilling phases. The geologist analyzes the cuttings which have travelled up the wellbore suspended in the drilling fluid or mud which was pumped into the wellbore via the drill string/pipe and returns to the surface via the 'flow line'. Cuttings are then separated from the drilling fluid as they move across the shale shakers and are sampled at drilled depth intervals (determined by the operator, but 10', 20', 30' and 50' intervals are commonly used at different sections of the wellbore), analyzed and described by the logging geologist on duty. The mud log is prepared by a company contracted by the operating company. A typical mud log displays formation gas (gas units or ppm), rate of penetration (ROP, in units of inverse velocity, or T/L); lithological sample descriptions; interpretive geology based upon ROP, formation gas/oil cut-stain-fluorescence, and gas curves including a total gas (gas units = ppm/1000) curve and methane through pentane (ppm). A mud log usually also displays drillbit information, drilling parameters, mud weights, directional information about the wellbore (deviation surveys), casing shoe depths, and formation tops.
The well and mud logs are usually transferred in 'real time' to the operating company, which uses these logs to make operational decisions about the well and to make interpretations about the quantity and quality of hydrocarbons present. Specialists involved in well log interpretation are called log analysts.
Geosteering
Drilling mud
Drilling rig
List of oilfield service companies
Formation evaluation
MWD/LWD
Wireline
Overview :
Mud logging is the process of collecting, analyzing and recording the meaningful solids, fluids, and gasses brought to the surface by the drilling fluid (mud). The mud logger keys all of his data to the Geolograph on the rig floor.
Solids:
The mud logger collects samples of the cuttings from the downhole strata on a regular basis, usually every ten feet. Collections are usually made at the shaker table for the mud system. The logger then washes and dries the cuttings, keeping them properly labeled as to depth that they represent. In order to know what depth the samples actually come from the logger must constantly calculate a "lag" time, i.e. the time it takes the samples to reach the surface from the time they were cut. The greater the depth, the greater the time for the samples to reach the surface after they were cut. In order to help with the lag calculations, the logger tracks hole size, pump strokes, and occasionally sends distinctive samples down the pipe to measure the actual lag.
The logger examines the dried samples under a binocular microscope and records the predominant rock types on a depth strip chart that has drill times and chromatograph readings also recorded on it. Rock types are often correlated with the drill times for a particular rock type, e.g. fast drill time for a porous sandstone. Obviously properly recording what rock type is being drilled at what depth is not an exact science. Some factors that affect the accuracy are logger experience in an area, improper lag times, interbedded thin layers of multiple rock types, finely-ground rock fragments, sloughing of uphole rock material, and diligence of the logger.
Back to top
Liquids:
The logger analyzes for liquids primarily in two ways: chloride content and fluorescence. Chloride content of the mud is constantly monitored. An increase in chlorides from a certain depth can indicate a strong salt water flow from a permeable formation. Samples are also viewed under ultraviolet light to check for fluorescence because most oils fluoresce. In the event that fluorescence is detected. The sample is subjected to cleaning fluid to determine whether it is hydrocarbon or mineral fluorescence.
Gasses:
A key component of a mudlogging unit is a gas chromatograph. This unit continuously samples the gases coming out of the mud and analyzes them for methane and the heavier hydrocarbons. The presence of a 'show' of hydrocarbons on the chromatograph alerts the logger to be more alert for other evidences of hydrocarbons. Sometimes a separate "lag" must be determined for gasses as they may rise faster to the surface than the samples. A bag of carbide dropped down the drill pipe is usually used for this purpose.
Texaco and GRI conducted extensive research on ways to improve the sampling of gases from the mud stream.
Mud logging is the process of collecting, analyzing and recording the meaningful solids, fluids, and gasses brought to the surface by the drilling fluid (mud). The mud logger keys all of his data to the Geolograph on the rig floor.
Solids:
The mud logger collects samples of the cuttings from the downhole strata on a regular basis, usually every ten feet. Collections are usually made at the shaker table for the mud system. The logger then washes and dries the cuttings, keeping them properly labeled as to depth that they represent. In order to know what depth the samples actually come from the logger must constantly calculate a "lag" time, i.e. the time it takes the samples to reach the surface from the time they were cut. The greater the depth, the greater the time for the samples to reach the surface after they were cut. In order to help with the lag calculations, the logger tracks hole size, pump strokes, and occasionally sends distinctive samples down the pipe to measure the actual lag.
The logger examines the dried samples under a binocular microscope and records the predominant rock types on a depth strip chart that has drill times and chromatograph readings also recorded on it. Rock types are often correlated with the drill times for a particular rock type, e.g. fast drill time for a porous sandstone. Obviously properly recording what rock type is being drilled at what depth is not an exact science. Some factors that affect the accuracy are logger experience in an area, improper lag times, interbedded thin layers of multiple rock types, finely-ground rock fragments, sloughing of uphole rock material, and diligence of the logger.
Back to top
Liquids:
The logger analyzes for liquids primarily in two ways: chloride content and fluorescence. Chloride content of the mud is constantly monitored. An increase in chlorides from a certain depth can indicate a strong salt water flow from a permeable formation. Samples are also viewed under ultraviolet light to check for fluorescence because most oils fluoresce. In the event that fluorescence is detected. The sample is subjected to cleaning fluid to determine whether it is hydrocarbon or mineral fluorescence.
Gasses:
A key component of a mudlogging unit is a gas chromatograph. This unit continuously samples the gases coming out of the mud and analyzes them for methane and the heavier hydrocarbons. The presence of a 'show' of hydrocarbons on the chromatograph alerts the logger to be more alert for other evidences of hydrocarbons. Sometimes a separate "lag" must be determined for gasses as they may rise faster to the surface than the samples. A bag of carbide dropped down the drill pipe is usually used for this purpose.
Texaco and GRI conducted extensive research on ways to improve the sampling of gases from the mud stream.
sábado, 27 de outubro de 2007
Alimentos Transgênicos e seus Impactos na Saúde, na Economia e no Meio Ambiente
Temos a satisfação de convidá-lo a participar do Seminário Internacional - Alimentos Transgênicos e seus Impactos na Saúde, na Economia e no Meio Ambiente que será realizado no dia 31 de outubro, das 8h30 às 18h00, no Auditório da FGV - EAESP, localizado na Avenida 9 de Julho, 2029.O Seminário será uma oportunidade para a sociedade aprofundar o debate sobre os transgênicos e os possíveis impactos relacionados ao consumo de alimentos geneticamente modificados. Na ocasião, especialistas das áreas médica, jurídica e econômica apresentarão diferentes pontos de vista sobre os alimentos transgênicos de modo a enriquecer a discussão em torno do tema.
O evento é uma iniciativa do Centro de Estudos em Sustentabilidade da FGV - EAESP em parceria com a Ética da Terra com apoio da Secretaria Municipal de Verde e Meio Ambiente de São Paulo e da Universidade Aberta do Meio Ambiente e da Cultura de Paz - UMAPAZ.
A programação está no documento em anexo.
Clique aqui para fazer sua inscrição no evento.Contamos com sua presença. Centro de Estudos em Sustentabilidade - GVces
OK
sexta-feira, 26 de outubro de 2007
MINERAÇÃO & METALÚRGICABrasil tem maior potencial mineral do mundo
17/10/07 - 00:00 > MINERAÇÃO & METALÚRGICABrasil tem maior potencial mineral do mundoSÃO PAULO - O Brasil é o país com maior potencial mineral do mundo, alcançando a pontuação mais alta (98, em uma escala até 100) entre todos os outros países e regiões do planeta. A constatação é do Fraser Institute, entidade americana que acompanha o setor e divulga há 15 anos o PPI (Policy Potential Index), índice potencial da mineração.Segundo o instituto, o potencial brasileiro supera o de outras áreas importantes em mineração, como Canadá (incluindo Quebec e Ontário, que tiveram índice 97), Estados Unidos (Alasca, que também teve 97), e Austrália (a região oeste do país teve índice 97 e a norte, 96).Em outro estudo, o Metal Economics Group, que também acompanha o setor, verificou que o Brasil aumentou sua fatia nos investimentos globais em exploração mineral, de 3% para 4%, ficando no mesmo nível de países com potencial mineral semelhante, como Austrália, Canadá e África do Sul.Os investimentos das empresas no País indicam que essa fatia vai crescer ainda mais. Nos últimos dez dias, empresas como Companhia Vale do Rio Doce, Votorantim e Alcoa anunciaram aportes superiores a US$ 40 bilhões no setor nos próximos cinco anos, os mais altos da história.Em 2008, a Vale planeja investir mais de US$ 7,5 bilhões em minerais ferrosos e não ferrosos, além de alumínio. E a Votorantim tem planos de aportar cerca de US$ 6 bilhões em mineração nos próximos cinco anos.Projetos até em OmãOutro ponto ressaltado pelas análises do setor é a diversificação geográfica de áreas para investimento das empresas brasileiras de mineração.Além de projetos em países próximos, como o da Votorantim no Peru, há planos até para o Oriente Médio. A Vale, por exemplo, pretende desenvolver um usina de pelotização em Omã, com capacidade para a produção de 9 milhões de toneladas por ano. O investimento previsto é de US$ 546 milhões e o início de operações se dará no primeiro semestre de 2010.Segundo a Vale, o projeto em Omã levou em consideração "a expansão da indústria de aço no Oriente Médio, com usinas a forno elétrico."A companhia também tem um projeto na Nova Caledônia, no Pacífico Sul: o Goro, um dos maiores depósitos de níquel do mundo, com capacidade para produzir 60 mil toneladas por ano de níquel refinado e 4.600 toneladas anuais de cobalto.A Vale, que já é a maior produtora mundial de minério de ferro, planeja também aumentar sua capacidade no Brasil, para 450 milhões de toneladas, com três grandes projetos: Carajás, Carajás Serra Azul e Maquiné-Baú.Carajás Serra Azul será o maior projeto de minério de ferro do mundo, com capacidade de produção de 90 milhões de toneladas por ano e investimento total de US$ 10,094 bilhões.O projeto será implantado na serra Sul de Carajás, no Pará. Esse estado terá o maior número de investimentos em mineração: de acordo com levantamento do Instituto Brasileiro de Mineração (Ibram), existem 13 projetos previstos em território paraense, incluindo o projeto Juriti, da Alcoa, de mineração de bauxita.Além disso, a Alunorte prevê expansão da usina de beneficiamento de bauxita em Barcarena, também no Pará, com investimentos de US$ 850 milhões.Presença mundialDessa forma, o Brasil se prepara para aumentar sua importância no mercado externo. Na pauta mineral de exportação do País o destaque é o ferro, com 64% do total, seguido por bauxita, com 11%. O cobre aparece em terceiro lugar, com 3%, mas projetos de expansão fazem com que as previsões sejam de aumento do peso do produto nas vendas externas.O saldo da balança comercial do setor representa mais de 35% do superávit total do País, com um resultado superior a US$ 45 bilhões. Paulo Camillo Vargas Penna, presidente do Ibram, lembra que os principais importadores são Ásia (liderada pela China), Alemanha e Estados Unidos.
quarta-feira, 24 de outubro de 2007
Ciclo de Palestras do Departamento de Recursos Minerais no próximo dia 25 de outubro,
Caros Colegas.Informamos que estaremos retomando a edição 2007 do tradicional Ciclo de Palestras do Departamento de Recursos Minerais no próximo dia 25 de outubro, quinta-feira, no Auditório do DRM-RJ, a partir das 14 horas, abordando o tema "9ª Rodada de Licitações da ANP – A Importância para o Estado do Rio de Janeiro", com três apresentações de especialistas sobre a próxima rodada de licitações para concessão de blocos de exploração e sua importância para a economia do Rio de Janeiro. Após as apresentações, num segundo bloco, haverá de uma Mesa Redonda com os palestrantes e convidados, seguido de debate com os presentes.Este será mais um momento de divulgação de nosso Centro de Informações da Produção de Petróleo e Gás Natural do Estado do Rio de Janeiro - CIPEG, que coordena o evento. O Serviço Geológico do Estado do Rio de Janeiro sentir-se-á honrado em receber a todos.AtenciosamenteFlavio ErthalPresidenteServiço Geológico do Estado do Rio de Janeiro. CICLO DE PALESTRAS DO DRM-RJServiço Geológico do Estado do Rio de Janeiro
Niterói – 25 de Outubro de 2007Horário: 14:00 h às 17:10 h
“9ª Rodada de Licitações da ANP – A Importância para oEstado do Rio de Janeiro”
Niterói – 25 de Outubro de 2007Horário: 14:00 h às 17:10 h
“9ª Rodada de Licitações da ANP – A Importância para oEstado do Rio de Janeiro”
Programação14:00 - Abertura - Flavio Erthal - Presidente do DRM-RJ
14:10 - Palestra da ANP - “A 9ª Rodada de Licitações” - Paulo Alexandre - Superintendente de Licitações - Agência Nacional do Petróleo, Gás Natural e Bio-Combustíveis ANP (a confirmar)14:40 - Palestra do IBP - Representante do IBP (a confirmar)
15:10 - Pausa para o Café15:30 - Palestra do Centro de Informações da Produção de Petróleo e Gás Natural - CIPEG /DRM-RJ - “O Estado do Rio de Janeiro e a 9ª Rodada da ANP” - Francisco Dourado - Diretor de Geologia do DRM-RJ e Coordenador do CIPEG16:00 - Mesa Redonda e Debates17:10 - Encerramento
Local: Auditório do DRM-RJ Rua Marechal Deodoro, 351 – Centro - NiteróiInformações e inscrições prévias: Departamento de Recursos Minerais - DRM-RJtel: 21-2620-2525 r.: 2440 ou fax: 21-2620-9132wsally@drm.rj.gov.br / drm@drm.rj.gov.br
domingo, 21 de outubro de 2007
Quem corre para a praia mais próxima todo santo feriado pode não imaginar, mas foram necessários milhões de anos de evolução para que a humanidade finalmente conseguisse colonizar os ambientes costeiros do nosso planeta. Uma equipe internacional de pesquisadores acaba de mapear o que parece ser o primeiro passo dessa odisséia: uma caverna da costa da África do Sul que foi ocupada há 164 mil anos pelos mais antigos "ratos de praia" da pré-história.E mais: os pesquisadores também acharam restos de ferramentas completas e pigmentos minerais provavelmente usados para pintar o corpo e, quem sabe, as paredes da caverna. São indícios de uma mente relativamente sofisticada, capaz de conceber relações simbólicas -- capacidade que, para a maioria dos antropólogos, só teria aparecido dezenas de milhares de anos mais tarde entre nossos ancestrais.
"O legal da ciência é que algumas idéias podem ser testadas e falsificadas, ou seja, derrubadas, se não estiverem de acordo com os fatos", disse ao G1 o americano Curtis Marean, da Escola de Evolução Humana e Mudanças Sociais da Universidade do Estado do Arizona. "Bom, a idéia de que toda a complexidade comportamental humana apareceu de uma vez só há apenas 50 mil anos está derrubada, e nossos achados são uma nova prova disso", afirma o pesquisador, que coordenou a pesquisa que está na edição desta semana da revista científica "Nature".
The Mossel Bay Archaeology Project/Divulgação
A pesquisa de Marean e companhia é uma janela preciosa numa época durante a qual indivíduos fisicamente quase idênticos ao Homo sapiens atual já andavam pelo mundo. Ao que tudo indica, nossa espécie tem cerca de 200 mil anos de idade, mas esses primeiros humanos biologicamente modernos estranhamente eram, bem, um pouco menos que humanos, a julgar pelos traços de seu comportamento que chegaram até nós.
Explica-se: até hoje, praticamente não há indícios de ferramentas complexas (ou compostas de materiais que não sejam pedra ou madeira), arte, capacidade de entender o mundo com a ajuda de símbolos, linguagem e ocupação de áreas costeiras antes de, pelo menos, uns 100 mil anos atrás. É como se os primeiros Homo sapiens tivessem "demorado a engrenar" social e culturalmente.
Daí a importância dos achados de Marean e companhia. A caverna que eles escavaram fica perto do oceano Índico, numa região conhecida como Pinnacle Point pelos sul-africanos. Apesar de ficar perto do oceano, o lugar é relativamente alto, o que ajudou a protegê-lo das flutuações do nível do mar nas últimas centenas de milhares de anos -- do contrário, os restos desencavados teriam sido levados pelas ondas.
E os restos são um bocado significativos. A começar, por exemplo, de uma variedade considerável de espécies de mariscos e outros moluscos marinhos -- sim, esses humanos antigos aparentemente apreciavam frutos do mar, ao contrário de seus ancestrais, que só utilizavam recursos alimentares terrestres.
"Por que demoramos tanto para ocupar zonas costeiras? É uma ótima pergunta, e não sei se tenho a resposta", pondera Marean. Parte do problema, diz o cientista, pode ser o sumiço de sítios arqueológicos mais antigos e mais baixos, tragados pela elevação do nível do mar. Mas, para ele, o problema central pode ser outro -- a dificuldade natural de um primata acostumado com o interior de encarar o oceano e seus perigos e oportunidades.
Haja coragem
"Jonathan Swift, autor de 'As Viagens de Gulliver' tem uma frase engraçada. Ele diz que o primeiro homem a ver uma ostra como fonte de alimento só podia ser alguém muito corajoso", brinca Marean. Aliás, algumas das espécies de marisco são, na verdade, parasitas de baleias -- o que significa que os humanos, ou talvez humanas, de Pinnacle Point chegaram a se aproveitar até do cadáver dos grandes mamíferos marinhos para obter seus frutos do mar. Há também indícios de ferramentas de pedra extremamente delicadas, com lâminas de poucos milímetros de espessura de quartzo -- normalmente só encontradas muitos milênios depois.
O mais intrigante, no entanto, é o uso aparentemente abundante de ocre, um pigmento mineral avermelhado que teria muito futuro durante o florescimento cultural do Homo sapiens no fim da Era do Gelo. É verdade que o ocre também poderia ser usado como adesivo, para fixar pontas de pedra a cabos de madeira, mas a escolha das pedras mais avermelhadas para produzi-lo parece indicar que ele servia mesmo como pintura corporal.
Ora, isso é indício praticamente inequívoco de pensamento simbólico, dizem os pesquisadores. Se eles estiverem certos, a caverna sul-africana pode ser um dos primeiros degraus da escalada que acabaria transformando nossos ancestrais em humanos plenos.
sábado, 20 de outubro de 2007
Assinar:
Postagens (Atom)