Higashinagayasawa (Loc. 5) - Sanchu Group: Barremian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Anthozoa
- Scleractinia
- Stylinidae
|
|||||||
|
Anthozoa
- Scleractinia
- Montlivaltiidae
|
|||||||
| see common names | |||||||
Geography
| Country: | Japan |
| Coordinates: | 36.0° North, 138.7° East (view map) |
| Paleocoordinates: | 46.1° North, 146.3° East (Wright 2013) |
| Basis of coordinate: | estimated from map |
| Geographic resolution: | local area |
Time
| Period: | Cretaceous | Epoch: | Early Cretaceous |
| Stage: | Barremian | 10 m.y. bin: | Cretaceous 2 |
| Key time interval: | Barremian | ||
| Age range of interval: | 125.77 - 121.4 m.y. ago |
Stratigraphy
| Geological group: | Sanchu | Formation: | Ishido | ||
| Local section: | Higashinagayasawa | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: The "Sanchu Cretaceous" has been subdivided by many workers into component formations in ascending order: Shiroi (non-marine), Ishido, Sebayashi, and Sanyama Fms. The present author uses a three part numbering scheme based on Hisada et al., (1992), for which this collection is derived from unit 1. The Ishido Fm (correlated by the PBDB enterer to unit 1) contains a Late Hauterivian to Late Barremaian ammonite fauna. Upper units may range from Barremian to Early Aptian based on ammonite and radiolaria faunas (Sashida et al., 1989). | |||||
Lithology and environment
| Primary lithology: | fine lithified silty,conglomeratic sandstone |
| Secondary lithology: | medium sandstone |
| Includes fossils? | Y |
| Lithology description: Conglomerate, massive muddy fine-grained sandstone and thin-bedded fine- to medium-grained sandstone, accompanied with limestone. Judged to be lithified based on quality and texture of specimens in photographic plates. | |
| Environment: | marine indet. |
| Geology comments: No environmental data reported. | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | good |
Collection methods and comments
| Collection methods: | selective quarrying,field collection |
| Reason for describing collection: | taxonomic analysis |
| Collection method comments: Collected by the authors (Yamagiwa, Hisada, and Tamura) during mid-1990's. Collections reposited in National Science Museum, Tokyo, Japan. | |
| Taxonomic list comments:Exhaustive for hexacorals, with modern nomenclature. | |
Metadata
| Database number: | 55541 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2005-10-31 12:59:54 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2005-10-31 12:59:53 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 15003. | N. Yamagiwa, K. Hisada, and M. Tamura. 1998. Early Cretaceous Hexacorals from the western part of the Sanchu area, Kanto Mountains. Bulletin of the Natural Science Museum, Tokyo, Series C 24(1-2):55-66 [A. Miller/A. Hendy] |