Looking for Ediacaran Life in Death Valley: Linking the Shuram Excursion to the Onset of Animal Biomineralization

Cloudina

Cloudina were shelled animals that grew in shallow water. They were sessile and prostrate. They are an index fossil of the Ediacaran period.

Figure 1: Reconstruction of Cloudina, taken from Becker-Kerber et al., (2017).

Cloudina from Namibia

These represent some of the oldest Cloudina fossils.

Figure 2: Cloudina interlayered with microbial mats.

Figure 3: Cloudina on the surface of microbial mats.

The Shuram Excursion in Namibia

The Shuram Excursion represents the greatest negative carbon isotope anomaly in Earth’s history. The excursion has been linked to orogeny and weathering that increased the alkalinity and phosphorus concentrations of seawater.

Figure 4: Graphic representation of the Shuram Excursion in Namibia. Image adapted from Wood et al., (2015).

Figure 5: WDS elemental stage map showing elevated concentrations of phosphorus outlining Cloudina shells (right and left) and within a putative sponge (top right).

Figure 6: Isotopic map showing the carbon (yellow) and oxygen (pink) isotopic ratios in 24 locations (blue).

The Shuram Excursion in Death Valley

Death Valley is another location in which the Shuram Excursion is preserved, as well as Cloudina fossils. The purpose of this NSF proposal is to investigate if the Shuram Excursion can be globally linked to the onset of biomineralization, by searching for phosphatic Cloudina shells at the end of the Shuram Excursion in Death Valley.

Figure 7: Graphic representation of the Shuram Excursion in Death Valley. Image taken from Verdel et al., (2011).

Map of Field Site

Figure 8: Map of potential research site. Image taken from Verdel et al., (2011).

Logistics

Budget: $70,000 to $75,000

NSF Program: Sedimentary Geology and Paleobiology (SGP) Program