2008 APR 14 - (VerticalNews.com) -- "Horodyskia is one of the earliest known macroscopic life forms, with a fossil record dating from c. 1.4 Ga. Palaeopascichnus represents a key Ediacaran element with world-wide distribution," scientists writing in the Journal of the Geological Society report.

  "However, their body constructions and affinities are poorly understood, partly because previously described species are mostly preserved as casts and moulds in siliciclastic rocks. Silicified specimens from the upper Ediacaran Liuchapo Formation in eastern Guizhou, South China, are described as Horodyskia minor sp. nov. and Palaeopascichnus jiumenensis sp. nov. Their taxonomic assignments are based on their uniserial arrangement of spheroidal or discoidal units, which are connected by a filament and surrounded by a quartz halo. They are unlikely to be brown algae, animal traces, faecal pellets, colonial metazoans, or giant sulphide-oxidizing bacteria. Instead, we propose that Horodyskia and Palaeopascichnus may be phylogenetically related, and their collective morphologies allow tentative comparison with agglutinated foraminifers: the segments can be compared with cytoplasm-filled chambers, connecting filament with small passage between chambers, and quartz haloes with agglutinated tests. However, their ontogeny appears to be distinct from that of modem foraminifers," wrote L. Dong and colleagues, Virginia Polytechnic Institute ...read more

  2008 APR 14 - (VerticalNews.com) -- According to recent research from Leicester, the United Kingdom, "We provide the most detailed sedimentological log to date through the Phyllopod Bed of the mid-Cambrian Burgess Shale Formation of British Columbia, based on millimetre-scale logging of a suite of thin sections. The sedimentary facies is dominated by alternations of homogeneous mudstone and a coarser-grained, laminated, variably sandy and shelly mudstone that is locally micronodular. ...read more

  2008 APR 14 - (VerticalNews.com) -- "In the Agly Massif (Pyrenees), two Variscan plutons, the Saint-Amac pluton and the Ansignan chamockite, intrude different levels of a c. 10 km thick crustal section. The Saint-Amac pluton intrudes through upper crustal rocks and the Ansignan charnockite cuts mid-crustal country-rocks," investigators in Toulouse, France report.

  "A structural study of these plutons based on the anisotropy of magnetic susceptibility technique, combined with a kinematic study of the country-rocks, shows that the structures and emplacement modes of the plutons are compatible with those of the other plutons of the Pyrenees emplaced during the D-2 transpressive phase. U-Pb dating on zircons from the Saint-Arnac pluton yields a 308.3 +/- 1.2 Ma age for a diorite and a 303.6 +/- 4.7 Ma age for a granodiorite. The chamockite was previously dated at 315 Ma. The emplacement ages of these two intrusions are thus separated by at least 5 Ma. First, numerous sills and laccoliths, such as the Ansignan laccolith, were injected in the middle crust, and this induced heating and thickening," wrote P. Olivier and colleagues, University of Toulouse ...read more