earth science

Wheeler Shale

Wheeler Shale is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wheeler Shale rather than just read about it. In short: 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 wi…

Key takeaways

Wheeler Shale belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Wheeler Shale to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Wheeler Shale from memory before moving on to harder problems.

Reference excerpt

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.

Taphonomy and sedimentology

Detailed work recognises a number of ~10 m thick lagerstätten sequences in the formation, each of which formed at a sea-level highstand in deep water. The lagerstätte were deposited by turbidities and mudslides onto an oxygenated sea floor. The productive layers comprise mud and clay particles, with a tiny fraction of wind-blown quartz.

Stratigraphy The Wheeler Shale spans the Ptychagnostus atavus and uppermost-Middle Cambrian Bolaspidella trilobite zones (See House Range for full stratigraphy).

Fauna

Incomplete list of the fauna of the Wheeler Shale: (Note: the preservation of hard bodied trilobite remains and soft bodied animals seems to be mutually exclusive within particular horizons.)

Protista Marpolia spissa - cyanobacteria or green algae Morania fragmenta - cyanobacteria

Arthropoda Alalcomenaeus cambricus - megacheiran Branchiocaris pretiosa - hymenocarine Branchiocaris sp. Cambropodus gracilis - possible myriapod Canadaspis perfecta - hymenocarine Dicerocaris opisthoeces Dicranocaris guntherorum - possible habeliid? Emeraldella brocki - vicissicaudatan Isoxys Leanchoilia superlata - megacheiran Megachelicerax - chelicerate Mollisonia symmetrica - mollisoniid chelicerate Perspicaris dilatus hymenocarine Pseudoarctolepis sharpi - possible hymenocarine Sidneyia inexpectans - vicissicaudatan Tuzoia? peterseni - hymenocarine Waptia fieldensis - hymenocarine

Dinocaridida Amplectobelua cf. A. stephenensis – radiodont Anomalocarididae gen. et sp. nov. - radiodont Buccaspinea cooperi? - radiodont Caryosyntrips durus - radiodont Caryosyntrips serratus - radiodont Peytoia nathorsti - radiodont Pahvantia hastata - radiodont Stanleycaris sp. - radiodont Utahnax vannieri - kerygmachelid lobopodian, possibly from Marjum Formation Utaurora comosa - opabiniid

Trilobita Naraoia compacta - naraoiid nectaspid Hypagnostus parvifrons - agnostid Peronopsis amplaxis - peronopsid agnostid Peronopsis bidens Peronopsis fallax Peronopsis gaspensis Peronopsis intermedius Peronopsis interstrictus Peronopsis montis Peronopsis segmentis Ptychagnostus atavus (= Acidusus atavus) - ptychagnostid agnostid Ptychagnostus germanus Ptychagnostus gibbus Ptychagnostus intermedius Ptychagnostus michaeli Ptychagnostus occultatus Ptychagnostus seminula Glyphaspis concavus - asaphid Bathyuriscus fimbriatus - dolichometopid corynexochid Bathyuriscus sp. Kootenia sp. - dorypygid corynexochid, perhaps a synonym of Olenoides Olenoides expansus - dorypygid corynexochid Olenoides nevadensis Olenoides serratus Tonkinella breviceps Zacanthoides divergens - zacanthoidid corynexochid Zacanthoides sp. Altiocculus harrisi - ptychopariid (specific name may be confused with Alokistocare) Alokistocare harrisi - alokistocarid ptychopariid Asaphiscus wheeleri - ptychopariid; second-most common species in the formation Bathyocos housensis - ptychopariid Bolaspidella drumensis Bolaspidella housensis Bolaspidella sp. Bolaspidella wellsvillensis Brachyaspidion microps Brachyaspidion sulcatum Cedaria minor - known from the Warrior Formation Elrathia kingii - alokistocarid ptychopariid Elrathia sp. Elrathina wheeleri = Ptychoparella wheeleri? - ptychopariid Jenkinsonia varga Modocia brevispina Modocia laevinucha Modocia typicalis Ptychoparella sp. - ptychopariid Ptychoparella wheeleri Spencella sp. - ptychopariid

Brachiopoda Acrothele subsidua

Chordata Hertzina sp. - conodont

Cnidaria Cambromedusa sp. - jellyfish

Mollusca Pelagiella sp. - pelagiellid helcionelloid

Echinodermata Castericystis sprinklei - solute Castericystis sp. Cothurnocystis sp. - stylophoran Ctenocystis sp. - ctenocystoid Gogia spiralis - eocrinoid Eocrinoid holdfasts believed to belong to Gogia spiralis; may belong to other species

Porifera Choia carteri - choiid protomonaxonid demosponge Choia utahensis Crumillospongia sp. - hazeliid protomonaxonid demosponge Diagonella sp.

Priapulida Ottoia prolifica - archaeopriapulid Selkirkia sp. - archaeopriapulid Selkirkia willoughbyi- archaeopriapulid

Unclassified Hallucigenia sparsa - hallucigeniid lobopod Allonnia cf. tintinopsis - a chancelloriid Chancelloria pentacta - chancelloriid Eldonia sp. - eldoniid cambroernid Skeemella clavula - Possible vetulicolian Hylolithellus sp. - annelid? Wiwaxia corrugata - halwaxiid? lophotrochozoan Yuknessia simplex - pterobranch Margaretia dorus - tube associated with the hemichordate Oesia

References

Illustrations

Worked examples

Example 1 — a first encounter with Wheeler Shale

Start with the simplest possible case. Write down what Wheeler Shale claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wheeler Shale before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wheeler Shale ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wheeler Shale

In research: Wheeler Shale appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wheeler Shale in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wheeler Shale is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cambrian System of North America, Cambrian geology of Utah, Geologic formations of Utah, so understanding it makes those chapters shorter.
In everyday life: Look for Wheeler Shale outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Wheeler Shale in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wheeler Shale means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Wheeler Shale out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wheeler Shale in simple terms?

Why does Wheeler Shale matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wheeler Shale?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wheeler Shale.