The Mysterious Beirdneau Sandstone Layer in Ogden/Farmington

What can we learn from the Beirdneau sandstone layer in Ogden/Farmington?

What story does this unique layer of sandstone tell us about the ancient climate in the region?

Answer:

The Beirdneau sandstone layer among Devonian and Carboniferous limestone layers indicates a period of dryer climate or a shift from marine to terrestrial environment. The absence of fossils and presence of cross-bedding suggest a less hospitable environment for marine life and possible environmental changes in the ancient climate.

The presence of the Beirdneau sandstone between many layers of limestone from the Devonian and Carboniferous periods in the Ogden/Farmington area suggests a significant change in the depositional environment. Sandstone typically forms from sand deposited by water or wind, indicating that there may have been a period of drier climate or a shift from a marine to a more terrestrial or fluvial environment.

This could be reflective of changes in sea level, climate fluctuations, or tectonic activity that altered the landscape and sediment supply. Beautiful cross-bedded sandstones can result from water or wind action, suggesting environments such as rivers, beaches, or dunes.

The absence of fossils in the Beirdneau sandstone, when compared to the fossil fish found in the surrounding limestone layers, indicates a less hospitable environment for marine life during its formation. By comparison, the presence of fossiliferous shales, such as those from the Dom João Formation, indicates a marine environment.

Therefore, the Beirdneau sandstone layer tells a story of a deviation from the predominantly marine conditions evidenced by the limestone, perhaps indicating a time of environmental stress or transition that could have impacted the ancient climate and ecosystem in the region.