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The Hunsrück Slate (German: Hunsrück-Schiefer) is a Lower Devonian lithostratigraphic unit, a type of rock strata, in the German regions of the Hunsrück and Taunus. It is a lagerstätte famous for exceptional preservation of a highly diverse fossil fauna assemblage.
The Emsian stratigraphy of the southern Rhenish Massif can be divided into two lithological units: the older slates of the Hunsrück-Schiefer and the younger sandstones of the Singhofener Schichten. Stratigraphically below the Hunsrück Slates is the (older) Taunus quartzite.All these metasedimentary rocks were originally deposited in the marine Rhenohercynian Basin, a back-arc basin south of the paleocontinent of Laurussia.
The Hunsrück Slate roughly comprises the Sauerthal-Schichten, Bornich-Schichten and Kaub-Schichten. These are 408–400 Mya old, making them part of the Latest Pragian to Early Emsian stages of the Devonian.
Beecher's Trilobite Bed is a Konservat-Lagerstätte of Late Ordovician (Caradoc) age located within the Frankfort Shale in Cleveland's Glen, Oneida County, New York, USA. Only 3-4 centimeters thick, Beecher's Trilobite Bed has yielded numerous exceptionally preserved trilobites with the ventral anatomy and soft tissue intact, the soft tissue preserved by pyrite replacement. Pyritisation allows the use of X-rays to study fine detail of preserved soft body parts still within the host rock.Pyrite replacement of soft tissue is unusual in the fossil record; the only Lagerstätten thought to show such preservation were Beecher's Trilobite Bed, the Devonian Hunsrück Slates of Germany, and the Jurassic beds of La Voulte-sur-Rhône in France, although new locations are coming to light in New York state.
Although BTB is famous for gold bugs, my personal collection from this site are on the contrary, focusing only on those non-trilobite arthropods and soft-bodied creatures. Most of them are still undescribed, please enjoy.
The Weeks Formation in Utah is the youngest (c. 499 Ma) and least studied
Cambrian Lagerstätte of the western United States. It preserves a diverse exceptionally preserved fauna that inhabited a relatively deep-water environment at the offshore margin of a carbonate platform, resembling the setting of the underlying Wheeler and Marjum formations. Yet, the Weeks fauna differs significantly in composition from the other remarkable biotas of Cambrian Series 3 of Utah, suggesting a significant Guzhangian faunal
restructuring. This bioevent is regarded as the onset of a transitional episode in the history of life, separating the two primary diversifications of the Early Palaeozoic. The Weeks fossils have been strongly affected by late diagenetic processes, but some specimens still preserve exquisite anatomical details.
The Wheeler Shale (named by Charles Walcott) is a Cambrian (c. 507 Ma) fossil locality world-famous for prolific agnostid and Elrathia kingii trilobite remains (even though many areas are barren of fossils) and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna (including Naraoia, Wiwaxia and Hallucigenia) and preservation style (carbonaceous film) normally associated with the more famous Burgess Shale.As such, the Wheeler Shale also represents a Konservat-Lagerstätten.
Together with the Marjum Formation and lower Weeks Formation, the Wheeler Shale forms 490 to 610 m (1,610 to 2,000 ft) of limestone and shale exposed in one of the thickest, most fossiliferous and best exposed sequences of Middle Cambrian rocks in North America.
At the type locality of Wheeler Amphitheater, House Range, Millard County, western Utah, the Wheeler Shale consists of a heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and thin, flaggy limestone. The Wheeler Formation (although the Marjum & Weeks Formations are missing) extends into the Drum Mountains, northwest of the House Range where similar fossils and preservation are found.
The Spence Shale is the middle member of the Langston Formation in southeastern Idaho and northeastern Utah. It is exposed in the Bear River Range, the Wasatch Range and the Wellsville Mountains. It is known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils.
The type locality is Spence Gulch in southeastern Idaho, near the town of Liberty. It was first described by Charles Doolittle Walcott in 1908.