Stirling Quartzite Formation
Geologic formation in the Mojave Desert
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The Stirling Quartzite Formation is a geologic formation in the northern Mojave Desert of Inyo County, California and Nye County and Clark County, Nevada.[3]
| Stirling Quartzite Formation | |
|---|---|
| Stratigraphic range: | |
Stirling quartzite from the Mojave desert. | |
| Type | Geologic formation |
| Sub-units | "Upper", "Middle" and "Lower" Members |
| Underlies | Wood Canyon Formation |
| Overlies | Johnnie Formation |
| Area | 40,000 km2 (15,000 sq mi)[1] |
| Thickness | 100–1,600 metres (330–5,250 ft)[2] |
| Lithology | |
| Primary | Quartzite |
| Other | Siltstone, Sandstone, Feldspars, Carbonate rock, Pebble Conglomerate |
| Location | |
| Region | Mojave Desert, California and Nevada |
| Country | United States |
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.[3] It also preserves rare fossils dating back to the Ediacaran period of the Neoproterozoic Era.[4]
Geology
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.[2]
Dating
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,[5] the Stirling Quartzite has not been properly dated, excluding provenances within the formation.[2]
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.[2]
Paleobiota
The Stirling Quartzite Formation is home to very few and rare Ediacaran fossils, with assignments to all fossils found within being tentative at best.[6]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
incertae sedis
Ichnogenera
| Genus | Species | Notes | Images |
|---|---|---|---|
| Planolites[7][8] |
|
Burrows, occur right at the top of the "Upper Member". | |
See also
