Biostratigraphy of the Roberts Mountains Allochthon Helps to Resolve Many Regional and Global Geological Problems

Stan Finney, a graptolite biostratigrapher, has been investigating the rocks of the Roberts Mountains allochthon (RMA) in north-central nevada since 1987. His results are used to address a variety of problems, for example:

• 1) the stratigraphy, sedimentology and structure of the Roberts Mountains allochthon
  
• 2) the nature of the Sauk-Tippecanoe Sequence boundary
  
• 3) the late Ordovician global climate change and mass extinction
  
• 4) Ordovician biostratigraphy and chronostratigraphy
  

Some important research results are:

• 1) the post-Sauk, pre-Tippecanoe unconformity across North American was produced by mantle dynamics leading to increased buoyancy of the continent rather than by eustatis sea-level changes as generally assumed
  
• 2) the voluminous quartz sands composing much of the RMA were derived from the North American craton, demonstrating that the RMA is not an exotic terrance
  
• 3) the Vinini Formation, within the RMA in the Roberts Mountains, includes outstanding reference sections for boundaries between the Ordovician and Silurian Systems and the Lower and Middle Ordovician Series.

These Ordovician sections were visited in June 1995 by field trips associated with the 7th International Symposium on the Ordovician System held in Las Vegas and the 5th International Graptolite Conference held at CSULB. Many undergraduate and graduate students have participated in research projects on the RMA; much of the research is multi-disciplinary and involves collaboration with colleagues from academia, government, and industry, and represents a wide range of research specialities.

Click here to return to Stan Finney's home page

Click your Mouse on "Back to the Beach!" below if you want to return to the California State University at Long Beach (CSULB) home page

Back to the Beach!

Or click here to return to the Department of Geological Sciences home page