User:SeismicShrimp/sandbox
| Manacapuru Formation | |
|---|---|
| Stratigraphic range: Late Silurian, Pridoli | |
| Type | Formation |
| Unit of | Trombetas Group |
| Underlies | Alter do Chão Formation |
| Thickness | 200 metres (660 ft) |
| Lithology | |
| Primary | shale, mudstone, sandstone |
| Location | |
| Region | Manacapuru |
| Country |  Brazil |
| Type section | |
| Named for | Manacapuru |
Manacapuru Formation is a geologic formation in Brazil preserving fossils from the Silurian-Devonian transition of the Amazonas Basin. It was originally described as a member of Trombetas Formation but was later elevated to it's own formation.[1]
Description
[edit]The Manacapuru Formation is named after the Brazilian State Manacapuru where outcrops of it is found. The formation itself is mostly made up of layers of fine to medium grained sandstones interbedded with grayish laminated siltstones along with littoral and neritic pelites. These layers occur alternatively with layers of shale where the fossils of the formation can be found.
Throughout the formation, there are layers attributed to offshore, coastal, shallow platform, and deltaic environments due to sea level changes in the area. Layers produced in the more fluvial environments are mostly contained in the lower unit and didn't produce macrofossils while the upper layers have records of fossils such as brachiopods.[2]These organisms where most likely preserved during frequent storm events.[3]
Paleobiota
[edit]Acanthodii
[edit]| Genus | Species | Notes | Image |
|---|---|---|---|
| Type 1 Spine[4] | These spines resemble those seen in the climatiid Ptomacanthus as well as Onchus punctuatus. | ||
| Type 2 Spine [4] | Spines that resemble what is seen in climatiids, these specimens contain both unpaired and pectoral fine spines | ||
| Type 3 Spine [4] | A single spine that resembles gyracanthids such as Gyracanthides, larger specimens show a thin, chevron-line ridge pattern |
Brachiopoda
[edit]| Genus | Species | Notes | Image |
|---|---|---|---|
| Lingula [2] | L.sp | ||
| Orbiculoidea[2] [5] | O. baini | A discinid with a circular shell shape along with large interspaces | _2_(48318644291).jpg) |
| O. bondenbenderi | |||
| O. excentrica | |||
| O. xinguensis | |||
| O. katzeri | |||
| Schellwienella [2] | S. amazonensis |  |
Chondrichthyes
[edit]| Genus | Species | Notes | Image |
|---|---|---|---|
| Type 4 spine[4] | Unornamented fin spines that resemble those seen in specimens found in the later Port Philomel Sandstone |
References
[edit]- ^ Carozzi, Albert V. (1979-07). "PETROLEUM GEOLOGY IN THE PALEOZOIC CLASTICS OF THE MIDDLE AMAZON BASIN, BRAZIL". Journal of Petroleum Geology. 2 (1): 55–74. doi:10.1111/j.1747-5457.1979.tb00692.x. ISSN 0141-6421.
{{cite journal}}: Check date values in:|date=(help) - ^ a b c d Aquino Corrêa, Luiz Felipe; Feijó Ramos, Maria Inês; de Rezende, João Marcelo Pais (2024-12-15). "Schellwienella amazonensis (Orthotetida, Brachiopoda): New species of the genus in the Lochkovian of the Amazonas Basin (Manacapuru Formation), northern Brazil". Journal of South American Earth Sciences. 150: 105253. doi:10.1016/j.jsames.2024.105253. ISSN 0895-9811.
- ^ Rocha, Patrícia Ferreira; Silveira, Rosemery Rocha da; Barbosa, Roberto Cesar de Mendonça (2019). "Age and palaeoenvironments of the Manacapuru Formation, Presidente Figueiredo (AM) region, Lochkovian of the Amazonas Basin". Brazilian Journal of Geology. 49 (4). doi:10.1590/2317-4889201920180130. ISSN 2317-4692.
- ^ a b c d Janvier, P.; Melo, J.H.G. (1992-06-17). "New acanthodian and chondrichthyan remains from the Lower and Middle Devonian of Brazil". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte. 1992 (4): 193–206. doi:10.1127/njgpm/1992/1992/193. ISSN 0028-3630.
- ^ Corrêa, Luiz Felipe Aquino; Ramos, Maria Inês Feijó (2021-01-01). "Discinoids (Brachiopoda: Lingulata) from the upper Manacapuru Formation (Early Devonian), south border of Amazonas Basin, Brazil". Journal of South American Earth Sciences. 105: 102960. doi:10.1016/j.jsames.2020.102960. ISSN 0895-9811.