Английская Википедия:Illtyd Formation

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The Illtyd Formation is an up to 1000-m thick geologic formation in Yukon. It preserves fossils dating back to the Dyerian subdivision of the Cambrian period, which spans the Stage 3 / Stage 4 boundary; it's considered to belong to the mid-upper Bonnia-Olenellus trilobite Zone. Top of the unit corresponds, more or less, to the top of Stage 4.[1][2] These fossils include Lower Cambrian trilobites'.[3]

The type section is in the Wernecke Mtns; it corps out also in and to the S/SW of the Rochardson Moutnars. It possibly corresponds to the Sekwi Fm in the Macxkenzie mtns.[1]

Lowermost of the Palaeozoic strata west of the Richardson Mountains, angular unconformity at base, overlying various Precambrian strata. Silty limestones and massive dolomites. In places rhythmically bedded. Colour: Tan, brownish grey muds; sandier layers orange. Upper layers include oolites and oncolites. Trace fossils include burrows and 'worm trails'. In some places unit is massively faulted and altered / weathered, approaching marble grade metamorphism near faults.[1]

See also

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References

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External links


Шаблон:Canada-geologic-formation-stub Шаблон:Cambrian-stub Шаблон:Yukon-stub