Tópico: Duvidas de geologia - Historia geológica para dummies!

[Geotecton]

Ouvi de uma professora que "o Brasil não tem serras, tem escarpas", isso procede?

As palavras "serra" e "escarpa" pertencem muito mais à Geomorfologia do que à Geologia e apresentam uma certa 'área nebulosa de definição'. De qualquer modo a sua professora está equivocada porque no Brasil existem as duas feições.

A "serra" é um conjunto aproximadamente linear na crosta superior, quase sempre oriunda de atividade tectônica, formada de blocos crustais pequenos delimitados por falhas normais de alto ângulo, geralmente com duas faces bem distintas no sentido transversal do seu comprimento, sendo uma com ângulo acima de 60º e a outra bem menos acentuada. Exemplos: Serras do Mar e da Mantiqueira.

A "escarpa" é uma feição quase sempre associada a uma erosão diferencial de alguma feição, inclusive de uma serra, com uma só face, geralmente com forte elevação (superior a 45º) o que resulta em uma encosta íngrime e que frequentemente separa diferentes 'províncias fisiogeográficas'. Exemplo: Escarpa de São Luis do Purunã.

[Buckaroo Banzai]

Há pouco tempo li que sob um exame geológico mais acurado, o que parecia ser enterro ceremonial neandertal, mais provavelmente é algo como um neandertal (ou mais, não lembro) que caiu num buraco e morreu lá, ou pixou num solo que afundou e ele morreu lá.

Você lembra qual é a fonte?

[...] The North Americans say their point of view was bolstered by the team’s excavations at the nearby Neandertal site of Roc de Marsal. There, a complete skeleton of a Neandertal child found in 1961 was long considered to be strong evidence for burial. But Dibble and his colleagues, including geoarchaeologist Paul Goldberg of Boston University, applied micromorphology—a relatively new approach that puts entire archaeological sites under the microscope to fi nd clues to how bones and artifacts were deposited—and concluded that Roc de Marsal may not have been a deliberate burial after all (Science, 20 November 2009, p. 1056, and 9 December 2011, p. 1388). In a paper published last year in the Journal of Human Evolution (JHE), Goldberg and some other team members argued from a microscopic and macroscopic study of the  sediments in and around the burial site that the pit in which the child was found was a natural depression, and that its body, which was lying face down, may have slid down into the pit from above.

Turq and team member Bruno Maureille of the University of Bordeaux in Talence, France, were not convinced, however, and declined to sign the JHE paper. “We completely agree with the observations, but we disagree on their interpretation,” Turq says. In Turq’s view, a skeleton found intact—as was mostly the case at Roc de Marsal—“automatically indicates the corpse was protected” by some sort of burial practice that included covering the body with earth. Maureille agrees, adding that parts of the skeleton such as the lower vertebrae would be particularly susceptible to coming apart once the soft body tissues disintegrated if it were not deliberately buried. Maureille adds that the issue of whether the pit was natural or dug by Neandertals is not relevant, because the body could have been deposited deliberately in a natural cavity. Pettitt, in recent publications, has argued that disposing of bodies in natural depressions is a form of “funerary caching,” and that the deliberate digging of graves may have developed later as a way of artifi cially creating such burial spaces [...]

http://www.unl.edu/rhames/neander-burial.pdf

Arqueo-CSI.