The Mount Tallac roof pendant is the largest and best exposed body of metavolcanic rocks in the Sierra Nevada, contains rocks that predate the intrusion of the Jurassic-Cretaceous granitic batholith, and is cut by the Sierra Nevada boundary fault. Thus, these rocks record a comprehensive record of the pre-, syn- and post geologic history of the Sierra Nevada. While the petrology of both the metavolcanic rocks and the plutons have been widely studied, relatively little is known regarding the structural fabrics in the roof pendant. Reconnaissance mapping within the Mount Tallac pendant in the eastern portion of the Desolation Wilderness Area in the summer of 2012 documented an interesting array of structural fabrics. Here strata of the Tuttle Lake Formation are penetratively deformed, involved in open folds, and are cut by an array of fractures that have accommodated varying degrees of sinistral offset. A detailed interpretation of these fabrics will undoubtably provide new insights into the modes of pluton emplacement within the pendant and deformation associated with uplift of the Sierra Nevada.

In collaboration with:
Scott Giorgis, SUNY New Paltz
Anthony Pivarunas, USGS
Allison Jones, Sierra College

Managing environmental and academic components of the cognitive load associated with field activities presents a challenge for many students. Indeed, under certain circumstances considerable environmental loads associated with personal factors (e.g., experience, knowledge, health, culture, gender, race, identity, and family influence) can cause anxieties that may threaten pedagogical success and even field safety. Pre-activity statements are designed to help students cope with these environmental loads by providing them with information about potential risks and strategies for mitigating associated hazards. While effective, these statements rely upon a students ability to visualize field conditions that they may not have the experience to do so effectively. We are exploring the use of annotated, three-dimensional photospheres imbedded in a virtual field trip as a way to help students navigate their personal environmental loads, the anxiety associated with increased loads, and to keep them cognitively focused on the learning outcomes. To date, we have explored the application of this approach with much success at the Wasatch-Uinta field camp and in field methods courses at Sacramento State University. In the coming year, we plan to expand this research to include 2YC students at Sierra College.

In collaboration with:
Ryan Petterson, Stanford University
Allison Jones, Sierra College
Chris Atchison, University of Cincinnati
Kevin Bohacs, KM GEOconsulting

Insufficient subsurface data (e.g., seismic surveys and well logs) hinder interpretations of the structural architecture of the post-Taconic northern Appalachian fold-thrust belt. To partially address this need, I examined the structural architecture of the fold-thrust belt near Kingston, NY. This region is significant because it is in the transition between the central (Pennsylvanian Valley and Ridge) and northern (Hudson Valley) segments of the Appalachian fold-thrust belt. I combined results of detailed geologic mapping (Fig. 1) and serial cross sections to create a 3-D model for the structural architecture of the fold-thrust belt. This model illustrates a two-tiered duplex system similar to that of the central Appalachians, but at a much smaller scale. The dramatic contrast in structural scale between the central and northern segments of the Appalachian fold-thrust belt is likely the result of along-strike thinning of the mechanically significant stratigraphic units within the deformed Siluro-Devonian sequence. The results of this work are relevant to ongoing efforts to characterize natural gas deposits in the Appalachian Plateau and adjacent areas.

In collaboration with:
Scott Giorgis, SUNY New Paltz
Frederick Vollmer, SUNY New Paltz
Stephen Marshak, University of Illinois
M. Scott Wilkerson, DePauw University

I developed a passion for the history of natural cement production in eastern New York. Dolostone mined from the Hudson Valley fold-thrust belt near Rosendale is widely regarded as the source of the highest quality natural cement ever produced in North America. Rosendale cement was used in the construction of landmarks including the Brooklyn Bridge, US Capitol, and the Washington Monument. These mines associated with the production of natural cement created unique bedrock exposures that have attracted geologists for nearly 200 years. Interestingly, Federal laws requiring the use of original materials in the restoration these and other historical landmarks is sparking a renewed interest in Rosendale natural cement. Unfortunately, many of the details associated with the complicated manufacturing process have been lost over time. I worked in collaboration with a local historical society (the Century House Historical Society) to co-author an overview history and economic geology of the Rosendale natural cement industry for a special volume published by the American Society for Testing and Materials – International (Werner and Burmeister, 2007).

In collaboration with:
Alex Bartholomew, SUNY New Paltz
Jeffrey Lee Benjamin, Columbia University

Century House Historical Society
Delaware & Hudson Canal Historical Society

Exposures of strata deposited within the Namurian Basin in County Clare, western Ireland, offer a truly outstanding opportunity to examine the formation, fill and closure of a Carboniferous sedimentary basin at a range of scales. These excellent exposures, together with the range of deep sea-terrestrial environments preserved within its stratigraphy, have helped the region become an extremely popular area for geological teaching and research – particularly in fields related to the hydrocarbons industry. Despite this interest, there is still much to be resolved regarding the sedimentology, paleoecology, and evolution of this basin. In particular, it is unclear how much horizontal shortening was accommodated within the basin in association with the Variscan orogeny.

In collaboration with:
Chenliang Wu, Yonsei University
Jeffrey Nittrouer, Texas Tech