Stirling Quartzite Formation
| Stirling Quartzite Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geologic formation |
| Sub-units | "Upper", "Middle" and "Lower" Members |
| Underlies | Wood Canyon Formation |
| Overlies | Johnnie Formation |
| Thickness | 100–1,600 metres (330–5,250 ft)[1] |
| Lithology | |
| Primary | Quartzite |
| Other | Siltstone, Sandstone, Feldspars, Carbonate rock, Pebble Conglomerate |
| Location | |
| Region | Mojave Desert, California and Nevada |
| Country | United States |
The Stirling Quartzite Formation is a geologic formation in the northern Mojave Desert of Inyo County, California and Nye County and Clark County, Nevada.[2]
It can be seen in the Panamint Range and Funeral Mountains adjoining Death Valley within Death Valley National Park; and in the Spring Mountains in Clark County.[2] It also preserves rare fossils dating back to the Ediacaran period of the Neoproterozoic Era.[3]
Geology
[edit]The formation underlies the Wood Canyon Formation and overlies the Johnnie Formation. The formation itself, as the name suggests, mainly consists of quartzite rocks, interbedded with varying sandstones, siltstones, carbonate rocks and occasional pebble conglomerates. It is also noted that the mineral feldspars appears throughout the formation, which are weather from rounded to sub-angular grains.[1]
Dating
[edit]Whilst most studies agree that the Stirling Quartzite Formation is firmly Ediacaran in age due to the base of the overlying Wood Canyon Formation being aged at the latest Ediacaran and the lower strata of the Johnnie Formation having a recovered date of 640±0.09 Ma,[4] the Stirling Quartzite has not been properly dated, excluding provenances within the formation.[1]
Using detrital zircon geochronology on two zircon sample groups, NR9 and NR30, collected from the aforementioned provenances within the Upper and Lower members of the Stirling Quartzite Formation respectively. The age range recovered for the NR9 samples was between 2729±0 Ma and 573±0 Ma, whilst the age range recovered for the NR30 samples was between 2754±0 Ma and 927±0 Ma.[1]
Paleobiota
[edit]The Stirling Quartzite Formation is home to very few and rare Ediacaran fossils, with assignments to all fossils found within being tentative at best.[5]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
incertae sedis
[edit]| Genus | Species | Notes | Images |
|---|---|---|---|
| Cloundina[6][5] |
|
Tubular organism, tentative assignment. |  |
| Nimbia[6] |
|
Discoidal organism, tentative assignment. |  |
See also
[edit]
- List of fossiliferous stratigraphic units in California
- List of fossiliferous stratigraphic units in Nevada
References
[edit]- ^ a b c d Schoenborn, William A.; Fedo, Christopher M.; Farmer, G. Lang (June 2012). "Provenance of the Neoproterozoic Johnnie Formation and Stirling Quartzite, southeastern California, determined by detrital zircon geochronology and Nd isotope geochemistry". Precambrian Research. 206–207: 182–199. doi:10.1016/j.precamres.2012.02.017.
- ^ a b USGS.gov: "Stratigraphy and Structure Death Valley, California"; U.S. Government Printing Office; 1966.
- ^ Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
- ^ Verdel, C.; Wernicke, B. P.; Bowring, S. A. (1 July 2011). "The Shuram and subsequent Ediacaran carbon isotope excursions from southwest Laurentia, and implications for environmental stability during the metazoan radiation". Geological Society of America Bulletin. 123 (7–8): 1539–1559. doi:10.1130/B30369.1.
- ^ a b Smith, E. F.; Nelson, L. L.; Tweedt, S. M.; Zeng, H.; Workman, J. B. (12 July 2017). "A cosmopolitan late Ediacaran biotic assemblage: new fossils from Nevada and Namibia support a global biostratigraphic link". Proceedings of the Royal Society B: Biological Sciences. 284 (1858): 20170934. doi:10.1098/rspb.2017.0934.
- ^ a b Hagadorn, James W.; Waggoner, Ben (2000). "Ediacaran Fossils from the Southwestern Great Basin, United States". Journal of Paleontology. 74 (2): 349–359. ISSN 0022-3360.