Mineralienatlas - Fossilienatlas
Steckbrief
USA / Illinois / Grundy Co. | ||
Verkürzte Mineralienatlas URL |
https://www.mineralienatlas.de/?l=48985 |
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Verkürzte Pfadangabe |
Grundy Co., Illinois, US |
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Wichtig: Vor dem Betreten dieser wie auch anderer Fundstellen sollte eine Genehmigung des Betreibers bzw. Besitzers eingeholt werden. Ebenso ist darauf zu achten, dass während des Besuches der Fundstelle die erforderlichen Sicherheitsvorkehrungen getroffen und eingehalten werden. |
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Bilder mit Lokationsbezug (2 Bilder gesamt)
Aufrufe (File: ): 328
Mazon Creek Lagerstätte Fig. 1. aus aus Clements, Purnell & Gabbott (2018): (a) Locality of the Mazon Creek (brown box) in relation to major cities and towns in Illinois. (b) Illinois during the Pennsylvanian showing the epeiric sea and approximate landmasses in relation to the Mazon Creek Lagerstätte (brown box). (c) Illinois (highlighted) and surrounding US states (grey outline) during the Late Carboniferous. (d) Map of the current Mazon Creek area. The strip mines (or ‘pits’) are marked with their designate numbers. It should be noted that many of these are now infilled and no longer visible on topographical maps. To the NE, the hypothesized palaeo-coastline is marked. The inset photograph is marked as (e) on the Mazon River. Based on Baird et al. (1986). (e) Photograph of the type locality along the Mazon River banks (see (d) for location). Copyright: Clements, Purnell & Gabbott; Beitrag: oliverOliver Fundort: USA/Illinois/Grundy Co./Morris/Mazon Creek Bild: 1559130582 Lizenz: Creative Commons - Namensnennung (CC-BY) V.3.0 |
Mazon Creek Lagerstätte |
Fig. 1. aus aus Clements, Purnell & Gabbott (2018): (a) Locality of the Mazon Creek (brown box) in relation to major cities and towns in Illinois. (b) Illinois during the Pennsylvanian showing the ... |
Copyright: | Clements, Purnell & Gabbott |
Beitrag: oliverOliver 2019-05-29 |
Aufrufe (File: ): 4422
Mazon Creek - Schema zur Entstehung der Konkretionen und Verteilung der Fossilien Fig. 2 aus Clements, Purnell & Gabbott (2018): (a) A geophantasmogram of the Mazon Creek Lagerstätte showing shore to marine distribution of fossils. The Francis Creek Shale Member was deposited largely from sediment washout from rivers, which created a shallow-dipping (2°) terrigenous wedge that extended out into the shallow sea and buried the previously drowned forest of the Colchester Coal Member. Proximally to the palaeo-coast the sediment was dominated by silts (lighter grey) whereas a large fan-shaped arc of distal sediment was dominated by finer clays (dark grey) (Baird 1997b). The literature divides the Mazon Creek into two distinct faunas: the freshwater Braidwood, a brackish community, and the marine Essex fauna (i). This is not supported by geology or fossil assemblages: we advocate categorization of fossils into those that were transported and washed out (including terrestrial plants) (ii) and organisms that inhabited the marine environments and colonized under the shifting freshwater plume (iii). In areas distal to the palaeo-coast, ‘dud’ (unfossiliferous) concretions are often found (iv). In areas where the Francis Creek Shale Member pinches out, ‘normal’ Carboniferous marine fauna fossils are found; however, they are not preserved within concretions (v). (b) Schematic stratigraphic sequence of the lower metres of the Francis Creek Shale Member and the associated members of the Carbondale Formation. The fossiliferous concretions can be found in the lower 3–8 m of the Francis Creek Shale Member. The fossiliferous Mazon Creek concretions are found in the lower 3–5 m of the Francis Creek Shale. Concretions found below this are typically pyrite rich. Higher order synodic neap–spring cycles can be seen on the right. Tidal cycles created the characteristic silt–clay paired laminae throughout the Mazon Creek Lagerstätte. These laminae are also commonly preserved within the siderite concretions (Kuecher et al. 1990). uc, underclay unit; CC, Colchester Coal No. 2 Coal Member; FCSM, Francis Creek Shale Member. Based on Baird et al. (1985a), Kuecher et al. (1990) and Shabica & Hay (1997). Scale left in metres and right in millimetres (mm). (c) Hypothesized sequence of events required for preservation in siderite concretions. (i) After rapid burial, decay of the organisms creates a geochemical microenvironment around the carcass and depletes interstitial sulphate. (ii) Siderite precipitation creates a ‘proto-concretion’ that acts to entomb the organism and resists compaction. (iii) Lithification of the concretion completes. Syneresis within the concretions can cause septarian fractures to occur. Secondary minerals may precipitate and fill voids left by decaying tissues. Tidal laminae are often compressed around concretions, suggesting that compaction of the sediment occurred after lithification of the proto-concretion (Kuecher et al. 1990). Based on Baird et al. (1986). (d) A schematic illustration of the so-called ‘taphonomic discontinuity’ seen in the Mazon Creek. Increased geographical distance from the river mouth correlates with an increase in the percentage of ‘dud’ or barren concretions (Fig. 2a (iv)). Similarly, soft-tissue preservation also dramatically decreases with distance from the shore. The most distal zone has no fossils found in concretions but poorly preserved ‘normal’ Carboniferous marine shelf fauna (Fig. 2a (v)). It is postulated that, in the distal region, high bioturbation and/or presence of epifaunal animals may have prevented or limited the formation of siderite concretions, increasing likelihood of pyritic cores forming and obliterating fossiliferous remains. Copyright: Clements, Purnell & Gabbott; Beitrag: oliverOliver Fundort: USA/Illinois/Grundy Co./Morris/Mazon Creek Bild: 1559130971 Lizenz: Creative Commons - Namensnennung (CC-BY) V.3.0 |
Mazon Creek - Schema zur Entstehung der Konkretionen und Verteilung der Fossilien |
Fig. 2 aus Clements, Purnell & Gabbott (2018): (a) A geophantasmogram of the Mazon Creek Lagerstätte showing shore to marine distribution of fossils. The Francis Creek Shale Member was deposited la... |
Copyright: | Clements, Purnell & Gabbott |
Beitrag: oliverOliver 2019-05-29 |
Mineralbilder (1 Bilder gesamt)
Aufrufe (File: ): 289
Mazon-Creek Fossilien Fig. 3. aus Clements, Purnell & Gabbott (2018): A selection of fossils within siderite concretions from the Mazon Creek Lagerstätte. (a) Rhabdoderma sp. (ROM56774). (b) Chiton Glaphurochiton concinnus (PE29045). (c) Rhabdoderma (exiguum?) (Burpee/Lauer Foundation LF836). (d) Polychaete Esconites zelus (ROM47529). (e) Priapulid Priapulites konecniorum (FMNHPE25135). (f) Actinopterygian Platysomus circularis (FMNHPF7333). (g) Unidentified trigonotarbid arachnid, most probably Aphantomartus pustulatus. (BMRP2014MCP850). (h) The seed fern Alethopteris sp. (ROM43584). (i) Asterophyllites sp. ROM 43576. (j) Annularia stellate(?) that has been overgrown with sphalerite (LEIUG83622). (k) Chondrichthyan tooth; Phoebodus? (ROM56812A) demonstrates, that despite an absence of large fossils, larger animals lived in the Mazon Creek area. (l) Concretion with pyritic core from pit 11 (not accessioned). (m) Holothurian Achistrum? (P69TG22a). (n) Saurerpeton obtusum (ROM56804B). Scales: 20 mm. Copyright: Clements, Purnell & Gabbott; Beitrag: oliverOliver Fundort: USA/Illinois/Grundy Co./Morris/Mazon Creek Mineral: Siderit Fossil: unbestimmt / fehlend Bild: 1559130296 Lizenz: Creative Commons - Namensnennung (CC-BY) V.3.0 |
Mazon-Creek Fossilien |
Fig. 3. aus Clements, Purnell & Gabbott (2018): A selection of fossils within siderite concretions from the Mazon Creek Lagerstätte. (a) Rhabdoderma sp. (ROM56774). (b) Chiton Glaphurochiton concin... |
Copyright: | Clements, Purnell & Gabbott |
Beitrag: oliverOliver 2019-05-29 |
Mehr | MFoF |
Mineralien (Anzahl: 2)
Gesteine (Anzahl: 1)
Fossilbilder (1 Bilder gesamt)
Aufrufe (File: ): 289
Mazon-Creek Fossilien Fig. 3. aus Clements, Purnell & Gabbott (2018): A selection of fossils within siderite concretions from the Mazon Creek Lagerstätte. (a) Rhabdoderma sp. (ROM56774). (b) Chiton Glaphurochiton concinnus (PE29045). (c) Rhabdoderma (exiguum?) (Burpee/Lauer Foundation LF836). (d) Polychaete Esconites zelus (ROM47529). (e) Priapulid Priapulites konecniorum (FMNHPE25135). (f) Actinopterygian Platysomus circularis (FMNHPF7333). (g) Unidentified trigonotarbid arachnid, most probably Aphantomartus pustulatus. (BMRP2014MCP850). (h) The seed fern Alethopteris sp. (ROM43584). (i) Asterophyllites sp. ROM 43576. (j) Annularia stellate(?) that has been overgrown with sphalerite (LEIUG83622). (k) Chondrichthyan tooth; Phoebodus? (ROM56812A) demonstrates, that despite an absence of large fossils, larger animals lived in the Mazon Creek area. (l) Concretion with pyritic core from pit 11 (not accessioned). (m) Holothurian Achistrum? (P69TG22a). (n) Saurerpeton obtusum (ROM56804B). Scales: 20 mm. Copyright: Clements, Purnell & Gabbott; Beitrag: oliverOliver Fundort: USA/Illinois/Grundy Co./Morris/Mazon Creek Mineral: Siderit Fossil: unbestimmt / fehlend Bild: 1559130296 Lizenz: Creative Commons - Namensnennung (CC-BY) V.3.0 |
Mazon-Creek Fossilien |
Fig. 3. aus Clements, Purnell & Gabbott (2018): A selection of fossils within siderite concretions from the Mazon Creek Lagerstätte. (a) Rhabdoderma sp. (ROM56774). (b) Chiton Glaphurochiton concin... |
Copyright: | Clements, Purnell & Gabbott |
Beitrag: oliverOliver 2019-05-29 |
Mehr | MFoF |
Fossilien (Anzahl: 14)
Untergeordnete Seiten
IDs
GUSID (Globale ID als Kurzform) | yJOBUGCdNEWe0fVNSGeE3Q |
GUID (Globale ID) | 508193C8-9D60-4534-9ED1-F54D486784DD |
Datenbank ID | 48985 |