Winner of the John C. Frye Memorial Award

2011 Holocene River Alluvium along the San Pedro River, Aravaipa Creek, and Babocomari River, Southeastern Arizona: A Framework for Understanding an Important Riparian System

On 25 April 2011, Harvey Thorleifson, Director of the Minnesota Geological Survey, announced the 2011 winners of the John C. Frye Memorial Award, for the best nominated environmental geology paper published by the Geological Society of America (GSA) or a state survey in one of the three previous calendar years:

Joseph P. Cook, Ann Youberg, and Philip A. Pearthree, Jill A. Onken, Bryan J. MacFarlane, David E. Haddad, Erica R. Bigio, and Andrew L. Kowler, 2009, Mapping of Holocene River Alluvium along the San Pedro River, Aravaipa Creek, and Babocomari River, Southeastern Arizona, Arizona Geological Survey.

Congratulations to Joe Cook, Ann Youberg, Phil Pearthree and their co-authors for this acknowledgment of the quality and importance of this work.

The Award will be announced and presented at the GSA Annual Meeting, this autumn in Minneapolis, at the Sunday evening Awards ceremony and at the Tuesday morning AASG Mid-Year meeting. The winning publication was chosen from six nominations, all of which the committee deemed excellent – making the selection process a challenging one.

The following paragraph from the submittal letter to the John C. Frye Memorial Award Committee showcases the relevance of the San Pedro Holocene mapping to the larger community. 

 “Because the San Pedro work focuses on the extent and relationships of Holocene and Pleistocene alluvium it is an indispensible tool for hydrologists and water managers in understanding the riparian system and implementing sustainable use policies. For fluvial sedimentologists, the alluvial architecture inferred from the finely delineated Holocene and Pleistocene sequences provides a medium for exploring river behavior – avulsion, branching, and river response to changes in climate and land use. Biologists investigating riparian ecology can consider plant assemblages in the context of geologic units of different age and composition, providing insight into influences of water availability and substrate on plant distribution.  And for archaeologists, these maps offer a geologic framework for their studies of prehistoric peoples of the San Pedro River valley.”

The San Pedro River report and maps are freely distributed to our target audience – the science community, civil authorities, conservationists, water managers, and the general public – as high-quality PDF downloads at the Arizona Geological Survey’s Document Repository (

Acknowledgment:  We thank Rich Burtell (formally of the Arizona Dept. of Water Resources) and Jeanmarie Haney (The Nature Conservancy) for writing compelling letters supporting the candidacy of this work. Funding for San Pedro mapping project was provided by the Arizona Department of Water Resources as part of the Gila River System adjudication to delineate subflow zones in the San Pedro River Watershed.

AZGS Back Pages

Arizona Geology is published by the Arizona Geological Survey. | © The Arizona Geological Survey, 2011. All Rights Reserved.
Editor: Michael Conway