| Nature forms over time, e.g. believed due to weathering, mineralization or crystallization, landscapes and rocks in which the human imagination identifies often strange formations out of the real world. An example of this are agates that, generally outwardly unattractive pose, in their interiors of ... moreNature forms over time, e.g. believed due to weathering, mineralization or crystallization, landscapes and rocks in which the human imagination identifies often strange formations out of the real world. An example of this are agates that, generally outwardly unattractive pose, in their interiors often true works of art. |
| In 1978 the US - American geologist Walter Alvarez gained a narrow pattern red clay in the Italian Apennines and certain age these samples to approximately 65 million years , ie at the end of the Cretaceous period and the beginning of the Tertiary period. This very thin lime- clay layer lies between ... moreIn 1978 the US - American geologist Walter Alvarez gained a narrow pattern red clay in the Italian Apennines and certain age these samples to approximately 65 million years , ie at the end of the Cretaceous period and the beginning of the Tertiary period. This very thin lime- clay layer lies between two calcareous sediments and showed a different fossil record , which to a mass extinction ( faunal ) hinted . While further analysis Alvarez noted a high iridium concentrations; a typical ... An article by Peter Seroka (written in german) |
| Betrachtet man die Struktur von Kristallen, erkennt mam meistens verschiedene Arten von Symmetrien, wie Translationen, Spiegelungen oder Drehsymmetrien. Der Grund für das Auftreten dieser Symmetrien liegt darin, daß bestimmte Atomanordnungen in der Struktur besonders stabil sind; eine hohe Symmetrie ... moreBetrachtet man die Struktur von Kristallen, erkennt mam meistens verschiedene Arten von Symmetrien, wie Translationen, Spiegelungen oder Drehsymmetrien. Der Grund für das Auftreten dieser Symmetrien liegt darin, daß bestimmte Atomanordnungen in der Struktur besonders stabil sind; eine hohe Symmetrie erlaubt dann die ständige Wiederholung dieser besonders stabilen Konfigurationen in der Struktur. Die Beschäftigung mit der Symmetrie von Kristallen in der Kristallographie ist aus mehreren Gründen besonders wichtig - Ein Beitrag von Erik Hock |
| Report about a geologic - and geology of deposits excursion through central and southern Namibia as well as the Namaqualand bordering to the South and parts of the Northern cape in autumn, 2009., Amongst other localities in Namibia the author visited the tin deposit Uis, the explorations project Na ... moreReport about a geologic - and geology of deposits excursion through central and southern Namibia as well as the Namaqualand bordering to the South and parts of the Northern cape in autumn, 2009., Amongst other localities in Namibia the author visited the tin deposit Uis, the explorations project Namib Lead near Swakopmund, as well as the important mines Rosh Pinah and Scorpion Zinc in the south of Namibia. In the Republic South Africa the trip led to the copper mining region of Okiep as well as the lead zinc mines of Aggeneys and, finally, to the Kalahari manganese ore districts of Postmasburg and Kuruman. (Full text in german) |