6: U.S. Geological Survey collections—Preserving the past to inform the future: Tour three federal repositories— Core Research Center, Paleontological Collection, and the NSF National Ice Core Laboratory
Published:September 07, 2016
- PDF LinkChapter PDF
Natalie Latysh, 2016. "U.S. Geological Survey collections—Preserving the past to inform the future: Tour three federal repositories— Core Research Center, Paleontological Collection, and the NSF National Ice Core Laboratory", Unfolding the Geology of the West, Stephen M. Keller, Matthew L. Morgan
Download citation file:
This 2016 Geological Society of America (GSA) Annual Meeting trip will explore the Core Research Center, Paleontological Collection, and National Science Foundation National Ice Core Laboratory—three collections of major national significance managed by the U.S. Geological Survey (USGS). Since its inception in 1879, USGS has collected, preserved, and managed physical collections for scientific investigations of Earth’s systems. The Core Research Center is the largest federal core repository in the United States, where over 74 million meters (242 million feet) of the subsurface are represented by the collection of rock cores and well cuttings, available for use by researchers investigating resource potential, tectonics, structures, aquifers, and more.
The USGS has conducted paleontological research for more than 110 years to inform geological mapping, biostratigraphy, paleoecology, paleoclimate, and other research. Most of these paleontological samples are at the Smithsonian Institution National Museum of Natural History (NMNH) and USGS Denver facilities. The USGS Denver paleontological collection includes ~1.2 million samples. Ancillary materials consisting of handwritten ledgers, index cards, field reports, maps, and other information produced by USGS investigators provide profound knowledge about the specimens and associated geological systems. The USGS is working with NMNH to systematically digitize the collection to preserve and expose samples and data to research.
The National Science Foundation (NSF) National Ice Core Laboratory (NICL) is the nation’s repository for preserving, archiving, and sampling meteoric ice cores collected from the world’s ice sheets, ice caps, and glaciers, mostly from Antarctica and Greenland. NICL’s primary mission is to store and curate ice cores, primarily collected during NSF-sponsored projects, for present and future sample investigations.
At the Denver Federal Center, in Denver, Colorado, the U.S. Geological Survey (USGS) supports three large and diverse physical collections in a 12,000-m2 (130,000-ft2) facility open to the public. The collections include: (1) rock cores and cuttings representing millions of meters of Earth’s subsurface, collected at various depths; (2) paleontological samples collected over 110 years by USGS scientists; and (3) ice cores supported by the National Science Foundation (NSF, award number 1306660) and collected from the world’s ice sheets, ice caps, and glaciers. These collections have informed scientific research, resulting in significant published interpretations and results and discovery of vital energy and mineral deposits. Preservation of these valuable subsurface materials ensures that the collections will continue to inform and spawn additional inquiry and discovery. Storage and availability of these collections for future investigation averts duplicative collection efforts, saves resources by eliminating recollection costs, and ensures continued availability of materials that may no longer be collected due to cost and lack of accessibility. The USGS is striving to preserve, digitize, and expose these federal collections and associated data to the public to promote their discovery and use.
In fall 2016, the GSA tour participants will learn about the large physical sample collections managed by the USGS, which continue to inform scientific investigations and are available for study by the public. Visitors will be introduced to USGS’s paleontological holdings. Participants will learn the history of the fossil collections, access the unique specimens used to delineate stratigraphic boundaries and inform other studies, and learn about the efforts to transform analog materials to digital form. Trip participants will tour the co-located USGS Core Research Center to view the massive rock and cuttings collection. Information about the National Ice Core Laboratory will be presented, and tour participants will have the opportunity to step inside the archive freezer, which is kept at an ambient temperature of -38 °C.
Itinerary and Logistics
9:00 a.m. Participants meet at the Core Research Center front entrance.
9:00–9:45 a.m. Tour Core Research Center with John Rhoades (Core Research Center lead).
9:45–11:00 a.m. Tour Paleontology Collection with Kevin (Casey) McKinney (museum specialist).
11:00–12:30 p.m. Tour the National Ice Core Laboratory with Richard Nunn (curator).
The Core Research Center is located at the Denver Federal Center in Building 810, which houses the three collections shown during the tour. Participants may drive to the facility or take public transportation (direct bus or light rail) from downtown Denver, a distance of ~14 km (9 mi). Directions to the facility are available at http://geology.cr.usgs.gov/crc/location.html, and a map of the Denver Federal Center, showing Building 810 and the CRC front entrance, can be found at http://geology.cr.usgs.gov/crc/images/dfcmap%20CRC.jpg. There is ample parking in front of the building. Visitors may walk from the Federal Center Station park-and-ride, which will take ~15 min, or they may take a bus (www3.rtd-denver.com) from the park-and-ride to the CRC. A valid identification is required to enter the Denver Federal Center and must be shown at the security gate. International visitors may use a passport. Participants may take photographs of the USGS collections, which are stored in a climate-controlled warehouse. A warm clothing layer is recommended for visiting the ice core freezer, which is kept at a temperature of -38 °C. Participants will spend less than 5 min in the freezer. Comfortable, closed toe shoes for walking on the concrete floors and stepping into cold freezer conditions are recommended. The group will be escorted through the areas containing USGS collections in the facility. The three collections are housed in one building. Therefore, visitors will not have to consider travel between the tour stops. Visitors will leave the facilities through the CRC front entrance.
Stop 1. USGS Core Research Center
The USGS manages the Core Research Center (Fig. 1), which was established in 1974 by the USGS to preserve valuable samples of Earth’s subsurface for use by scientists and educators representing government, industry, and academia. The CRC collections include full-diameter rock cores, slabbed cores (cut in half longitudinally), well cuttings, thin sections, and associated analytical data. The majority of the material was donated to the CRC by private industrial companies, although some cores and cuttings were collected by the USGS and other government agencies. Rock cores were collected from ~9500 drilled borehole locations representing ~610,000 m (2 million ft) of subsurface strata in 35 states (Fig. 2). Many of the boreholes represented in the collection were drilled for research, and energy and mineral exploration. Most of the boreholes are located in the Rocky Mountain region. However, because the samples were collected in diverse geologic settings and geographic localities, many in areas with rich resource potential, the CRC has become one of the largest and most frequently used public core repositories in the United States. The well cuttings, which are rock particles chipped by a bit during well drilling operations and brought to the surface, were collected at almost 53,000 drilled borehole locations and represent ~73 million m (240 million ft) of subsurface strata in 28 states. Additionally, more than 27,000 rock thin sections, numerous core photographs, and a large volume of analytical data are accessible for approximately half of the boreholes represented in the collection. Analytical data include chemical and physical analyses, core descriptions, stratigraphic interpretations, and other analyses acquired by researchers studying the samples.
In addition to cores collected for mineral and energy exploration, the CRC maintains cores extracted for geoscientific research focused on complex earth science dynamics, such as tectonics, geologic structures, orogenesis, ore deposits, aquifers, and geothermal resources. These invaluable cores were collected in unique and restricted areas that will most likely not be drilled again. Examples of scientific investigations for which cores were collected include:
determining stress at the contact of two plates along the San Andreas fault;
characterizing overlapping lava flows of Mauna Loa and Mauna Kea volcanoes of Hawaii;
evaluating uranium resources across the United States;
understanding the dynamic properties of strategic-scale nuclear detonations and their effect on geologic structures as part of the Pacific Enewetak Atoll Crater Exploration Program;
studying rock formations and aquifer systems of the Denver Basin;
defining the geologic origin, history, and structure of Long Valley caldera in California, to determine the potential for economically viable geothermal power generation; and
testing the roots and margins of the hydrothermal system responsible for the deposition of the epithermal silver and base-metal ores of the Creede mining district in Colorado.
The cores, cuttings, and thin sections are available for continued examination and testing. The CRC customers may sub-sample the cores and cuttings for further analysis, provided that copies of the analytical data are given to the CRC. In addition, core and thin section photographs, well reports, and other auxiliary artifacts are available for viewing and download on the CRC website (http://geology.cr.usgs.gov/crc). The CRC has an ongoing policy to accept sample donations from companies and government agencies and to make these materials available for research and other customer interests. The CRC encourages use of its facility by all interested parties. The CRC is often used by private companies, conference workshops, and schools to educate and explore subsurface processes demonstrated by the characteristics of CRC’s physical samples. Use of CRC resources and tours of the facility are available by appointment.
GSA tour participants will view the large CRC cores and cuttings collection stored in a warehouse. Cores collected for scientific investigations will be shown, as well as demonstration cores exhibiting varying depositional environments and geologic characteristics. Examples of successful scientific investigations using CRC materials will be discussed.
Stop 2. USGS Paleontology Collection
Since its inception in 1879, the USGS has collected and preserved geoscience data and sample collections, which include millions of paleobiological specimens stored in USGS facilities and at the Smithsonian Institution National Museum of Natural History (NMNH) in Washington, D.C. As one of the largest paleontological collections in the world, the USGS paleontology collection is invaluable, as many specimens may no longer be collected due to high field collection costs or inaccessibility to sampling sites, which have been restricted, urbanized, or modified via landscape processes. The USGS Denver Paleontology Collection includes ~1.2 million specimens stored in 1000 Smithsonian museum cases (Fig. 3). The primary collections stored in the Denver repository include: Paleozoic trilobites, graptolites, fusulinids, and brachiopods; Mesozoic ammonites, inoceramids, and vertebrates; and Cenozoic non-marine molluscs and vertebrates. The specimens represent life throughout the Phanerozoic and have served to determine and delineate temporal and spatial events in geologic maps, stratigraphy and ecology interpretations, climate change, faunal diversity, and extinction events. Because dinosaur fossils are not informative for stratigraphic studies, the study of dinosaurs was not historically pursued by the USGS.
In addition to the 1.2 million fossils, the Denver collection includes a vast amount of metadata recorded in locality and taxo-nomic cards, ledgers, supplementary identification reports, field notes, and maps. Specimens in the USGS Paleontology Collection were collected from 1879 to 1995, by hundreds of researchers and field technicians working for various USGS projects focused on geologic mapping and interpretation, energy and mineral development, water resources, and other research topics. Collection of the specimens followed standardized protocols for data recording and reporting. However, the collection was not amalgamated into a single database. Presently, the USGS is partnering with the NMNH to inventory and standardize processes to preserve, digitize, and provide access to the USGS collections stored in USGS and NMNH facilities. The USGS and NMNH are working to convert analog data into digital data by coupling the information derived from inventory, georeferenced fossil localities, field reports, notebooks, and maps in an online database.
History of the USGS Paleontology Collection
Between 1867 and 1878, four federally funded topographic expeditions led by Clarence King, Ferdinand Hayden, John Wesley Powell, and George Wheeler explored the West. Having lenient jurisdictional boundaries, the surveys overlapped and competed for limited congressional resources. Recognizing the duplication of efforts, in 1878, Congress tasked the National Academy of Sciences to make recommendations for a plan to survey and map the Territories of the United States at the least possible cost. Subsequently, Congress created the USGS in the Organic Act of 1879 per the recommendations of the National Academy of Sciences, for “the classification of the public lands, and examination of the geological structure, mineral resources, and products of the national domain” (43 U.S. Code §31). The legislation stipulates that paleontologic specimens collected by the USGS shall be bequeathed to the National Museum (now NMNH) when they are no longer needed for scientific investigation (Evans and Frye, 2009). John Wesley Powell, the second director of the USGS (1881–1894), initiated paleontologic and stratigraphic studies within the USGS to inform the geologic mapping program (Rabbitt, 1989). Geologic formations were identified and correlated by the use of existing fossil remains, aiding USGS geologists in delineating formations and creating geologic maps.
Prior to formalizing the National Museum as the official repository, specimens collected during government surveys and expeditions were unofficially deposited at the National Museum, which received limited and sporadic congressional appropriations. In 1872, the federal government agreed to annual appropriations to pay the National Museum for the management of collections acquired during survey expeditions and collections transferred to the National Museum from the Patent Office’s National Institute, which was one of the first congressionally supported museums (Rye, 2013; Smithsonian Institution Archives). From the inception of the USGS, its paleontologists worked at the Smithsonian to identify and age fossils to inform geologic mapping; caring for specimens acquired by the USGS, survey expeditions, and other donations; and performing curation tasks for the museum. In the late 1800s, the Smithsonian had few permanent staff, and for many years USGS paleontologists working at the Smithsonian outnumbered Smithsonian staff (Rye, 2013).
As a result of a reorganization of the USGS Geologic Branch, in 1900, the Division of Paleontology was established. In the succeeding years, the branch’s name was modified several times prior to its final designation as the Paleontology and Stratigraphy Branch (P&S Branch) in 1949. The P&S Branch reached its apex in the 1970s-1980s, employing more than 100 paleontologists, geologic mappers, energy and mineral geologists, and other researchers and support staff stationed at USGS and Smithsonian facilities (Dutro, 2004). Research focused on diverse animal and plant phyla to characterize biostratigraphy across the Pha-nerozoic and study a wide range of topics, including evolution, paleoecology, environmental analyses, modern reef analogues of ancient reef systems, fresh-water lake assemblages, coal-swamp features of the Carboniferous, and others. In its 55-year history, the P&S Branch is credited with the publication of more than 5000 manuscripts and tens of thousands of in-house administrative reports, known as Examine and Report on Referred Fossils (E&Rs). These written materials served to clarify evolutionary processes for fossil groups, investigate taxonomy, refine the geologic time scale, inform sedimentary basin studies and associated regional geotectonics, and contribute to a better understanding of plate-tectonic controls on paleobiologic systems (Dutro, 2004). In 1995, changes in priorities and reorganization resulted in the elimination of paleontological studies within the USGS. The P&S Branch was eliminated and most USGS paleontologists left the NMNH.
The USGS paleontological collections are located in various facilities across the United States. Until the 1980s, the USGS managed several paleontology collections housed where the P&S Branch had stationed research scientists, including USGS facilities located in Denver, Colorado; Reston, Virginia; Menlo Park, California; Anchorage, Alaska; and at NMNH. In 1987, approximately a fifth of the paleontology collection belonging to the P&S Branch was moved from NMNH to Denver, where other biostratigraphic collections were located. In 1997, the Menlo Park USGS Invertebrate Collection was accessioned to the University of California Museum of Paleontology, located in Berkeley, California (Clites, 2013). Currently, significant paleontology collections that remain under the purview of the USGS reside at NMNH, Denver, and Anchorage. A rare and not yet cataloged pollen collection is also housed in Denver for future curation. NMNH manages the largest number of specimens acquired from the USGS, including donations from retiring USGS scientists, accessioned type specimens (which characterize the defining features of a specific organism), and specimens used in published figures.
Future of the USGS Paleontology Collection
While USGS paleontological holdings (databases, reports, maps, publications) are available to researchers, they are difficult to locate and discover. Recent mandates instructing federal agencies to provide open access to government data, along with enhanced developments in data management practices and web technology, have introduced opportunities to advance and digitally distribute paleontological data to promote their dissemination and use by researchers.
Today, ~1.2 million and 8 million paleontological samples collected by USGS researchers are stored at the USGS Denver facilities and at NMNH, respectively. Presently, the collections are being actively inventoried at both locations. To date, approximately half of the collections have been inventoried. For the remaining collections, the inventory process is expected to be completed in five years. Field localities from which specimens were collected are being digitally georeferenced. Maps, E&Rs, field notebooks, and other paper records are being scanned and converted to digital records for long-term preservation. In conjunction with conducting an inventory of the collection, USGS and NMNH are constructing a data model mapped to Darwin Core standards (Taxonomic Databases Working Group, 2009) for building an online shared database to record information about the paleontological collection. Information compiled by the USGS, including stratigraphic and geological information recorded in field notebooks, field maps marking sampling localities, and taxonomic identifications assigned in physical sample inventories, is being formatted to a metadata schema developed for describing paleontological collections and specimens. Future plans include use of standards-based web servicing techniques to distribute USGS paleontological data to other users and online systems.
The strong partnership between the USGS and NMNH will continue to benefit the care of the collection. The NMNH has first right of refusal to the USGS’s paleontological holdings. In the future, if needed, following USGS geologic collections management protocols, remaining specimens may be donated to other interested institutions for additional scientific research. Access to the Denver Paleontology Collection may be requested by appointment (http://geology.cr.usgs.gov/crc).
GSA tour participants will visit the USGS Paleontology Collection stored in a warehouse. Visitors will view fossil specimens stored in museum case drawers, as well as ancillary materials affiliated with the collection, including field notebooks and maps, reports, publications, specimen labels (some from as early as 1900), and more. Visitors will learn about the numerous collections, spanning the Cambrian to the Quaternary, collected by multiple investigators for various USGS projects. The specimen inventory process will be demonstrated. History of the collection and the P&S Branch will be discussed, and intriguing research informed by the paleontological collections will be presented.
Stop 3. National Ice Core Laboratory
The U.S. National Ice Core Laboratory (NICL) is the nation’s repository for preserving, archiving, and sampling meteoric ice cores collected from the world’s ice sheets, ice caps, and glaciers, mostly from Antarctica and Greenland. The NICL was established in 1993 and is located at the Denver Federal Center. The NICL’s primary mission is to safely and securely store and curate ice cores primarily collected during NSF-sponsored projects. Availability of the ice cores enables present and future sample investigations. The NICL is funded by the NSF Division of Polar Programs and operated by the USGS; and the NICL’s science operations are managed by the University of New Hampshire (Adrian, 2013). The NICL’s central location in Denver allows researchers to easily visit the facility, barring the need to travel to remote field sites, which is expensive and seasonally limited.
The 1557 m3 (55,000 ft3) NICL facility stores the world’s largest ice core collection available to researchers (Pfeffer and Fitzpatrick, 1993). The NICL is dedicated to the storage of meteoric ice samples only; no seawater, soil, or other potentially contaminating samples are stored in NICL facilities. New ice samples generally arrive at the NICL annually. The NICL includes a storage freezer housing the ice cores at a temperature of -38 °C (Fig. 4). An adjacent 12,000 ft3 workroom is used for examination, handling, and cutting of ice cores at an ambient temperature of -24 °C. Currently, the NICL stores over 18,300 1 m and 1.5 m tubes of ice cores collected from more than 100 boreholes drilled in Antarctica, Greenland, and North America. The collection of cores includes some of the oldest and deepest ice cores recovered, including Summit Greenland (~110,000 yr old) and Vostok (~450,000 yr old). Cores recovered from as far back as 1958 to the present are stored at the NICL (Hinkley, 2003).
Visiting NICL scientists examine and subsample the ice cores, seeking to understand past climatic variations, volcanic eruptions, sea-level changes, and fundamental processes in ice mechanics and associated characteristics affected by extreme glaciated environments. For example, polar ice is often layered in an undisturbed, year-by-year sequence of deposited snow in which atmospheric gases and aerosols are captured and preserved, providing a continuous annual record of paleoclimate atmospheric composition (Ad Hoc Panel on Polar Ice Coring, 1986). Trapped gas bubbles reflect the composition of contemporaneous air. Determining their oxygen and hydrogen isotopes and trace gases, such as carbon dioxide and methane, enables reconstruction of atmospheric chemistry and determination of paleoclimate characteristics (Bender et al., 1997).
Operations of the National Ice Core Laboratory
During field operations, ice cores are brought to the surface in lengths up to 6 m then cut into 1 m lengths, dried to remove drilling fluid covering the exterior of the core, bagged, and stored in aluminized cardboard tubes. Generally, for Antarctic studies, the ice samples are transported (typically flown by helicopter or military cargo plane) from the field collection site to McMurdo Station, where the samples are stored in 12 m (40 ft) freezer shipping containers, which have backup cooling units and generators to safeguard against failure. The containers are loaded onto a container cargo vessel, shipped to Port Huen-eme, California, and trucked to the NICL facility in Denver. To ensure that the temperature is maintained at or below -30 °C in the shipping containers, a refrigeration specialist accompanies the ice from McMurdo Station to Denver. Upon arrival at the NICL, new ice is unpacked from the shipping boxes, cataloged, inventoried, and added to the existing ice core collection. Subsequently, the ice cores are processed via a core-processing line (Fig. 5), which is established to coordinate preparation, cutting, and subsampling of the cores by scientists. Cores are subdivided, often requiring complex cutting plans, to enable allocation of appropriate samples to multiple investigators and for archiving purposes. Visiting scientists and students use band saws to cut samples from the ice cores, then pack and ship the samples to their institutions or laboratories for analyses.
NICL is operated using redundant power and cooling and freezing system components, including generators, compressors, evaporators, and condensers. A dedicated refrigeration contractor routinely checks, maintains, and performs scheduled upkeep on the facility. The contractor is on call 24/7, 365 days a year to respond to emergencies. Alarm systems for power, temperature, air monitoring, and mechanical systems are dedicated to quickly identifying and communicating problems. Triggered alarms generate phone messages to the refrigeration contractor, federal security offices, and NICL staff to ensure continuous operation.
History of the National Ice Core Laboratory
In the early 1950s, modern ice core drilling was initiated by the U.S. Army Corps of Engineers (USACE) (Langway, 2008). During the International Geophysical Year (IGY), 1957-1958, the U.S. National Academy of Sciences/National Committee for the IGY recommended pursuit of deep core drilling of polar ice sheets for scientific purposes. Leveraging ice drilling expertise, the NSF tasked the USACE to pursue this goal (Langway, 2008). The USACE had already successfully tested drilling ice cores in Greenland, at Camp Century, and turned their attention to successfully pursuing drilling of deeper cores in Antarctica (Ad Hoc Panel on Polar Ice Coring, 1986; Twickler and Souney, 2008). The USACE established the fundamental technology required to drill and retrieve deep ice core samples for climatologic studies and was initially solely tasked with developing the U.S. ice core drilling research program, including field support logistics (Langway, 2008). Success of the United States’ efforts to extract continuous ice cores promoted the flourishing of international research programs and development of ice core analysis techniques. In 2008, recognizing the need for holistic coordination to conduct ice core investigations in remote regions, the NSF established the Ice Drilling Program Office (IDPO) and Ice Drilling Design and Operations (IDDO) group to conduct short- and long-term planning in collaboration with the scientific community for ice drilling and coring efforts sponsored by the NSF (Albert et al., 2010). Information about the IDPO and IDDO is available at www.icedrill.org/.
During initial core drilling projects conducted in the 1960s, ice cores were temporarily stored in the field and distributed to laboratories and USACE facilities in the United States. Until 1975, the USACE Cold Regions Research and Engineering Laboratory provided limited long-term storage for ice cores. Prior to the establishment of the NICL in Denver, from 1975 to 1992, the Ice Core Storage Facility and Information Exchange of the Department of Geological Sciences at University at Buffalo, State University of New York, served as the principal ice core repository in the United States under a peer-reviewed contract with the NSF Division of Polar Programs (Ad Hoc Panel on Polar Ice Coring, 1986; Langway, 2008). In the early 1990s, the contract for an ice core storage facility was re-competed and awarded to the USGS. Some factors favoring the USGS for successfully receiving the contract included: Denver’s central location, geographic placement in close proximity to a commercial airport and major transportation routes, and NICL’s refrigeration unit placement inside a building for additional security and safety. Furthermore, the deliberate co-location of the NICL with the CRC leveraged the USGS’s expertise in collection curation and management.
Future of the National Ice Core Laboratory
The NICL facility uses the refrigerant R-22 Freon (HCFC-22), which due to its harmful effects to the ozone layer, is being phased out by 99.5% below baseline by 2020. The R-22 Freon cannot be easily replaced in the NICL refrigeration system without major modification (Twickler and Souney, 2014). The need to modify the existing refrigeration unit and expand the refrigeration storage, which is currently at 95% of capacity, has prompted the NSF to explore options to establish an additional refrigeration unit in the NICL facility. The new additional unit will be used to store existing ice cores, while the primary unit is retrofitted with more environmentally friendly refrigerant. Subsequently, the new unit will become the long-term archival storage for older cores, while the retrofitted unit, which includes the examination and processing room, will become the archive for the newer cores.
Tours of the NICL facility are available by appointment. The NICL Science Management Office coordinates access to the ice cores and use of NICL facilities by visiting scientists. Additional information is available on the NICL website: http://icecores.org/.
GSA tour participants will visit the warehouse that houses the NICL. A presentation will describe the background and operations of the NICL, including field collection processes; and ice core transportation, sampling, and storage at the Denver facility. An overview of scientific investigations researching climate and atmospheric conditions informed by ice core analysis will be presented. Visitors will have the opportunity to view the sampling room where ice cores are processed and sub-sampled and step into the NICL freezer to view the stored ice cores. In the NICL freezer, ice cores displaying unique characteristics will be shown, including ash layers and diurnal fluctuations.
Geoscientific samples and data provide the foundation for understanding Earth processes. Preservation of and public accessibility to physical samples managed by the USGS provide the opportunity for researchers to confirm and advance scientific findings and pursue new investigations. The large CRC, Paleontology, and NICL collections were acquired over many years, at great expense, involving complicated field and collection logistics and a large workforce. Ready availability of these valuable collections promotes research and investigations that enhance scientific acuity to benefit the nation. The physical collections managed by the USGS have informed a wide breadth of science and will continue to serve as a valuable resource for future research.
The author wishes to acknowledge John Rhoades, Kevin McKinney, Geoffrey Hargreaves, and Richard Nunn, with the USGS, for their dedication to preserving valuable national assets and avidly promoting the collections to researchers and the public. All photographs within this paper have been provided by the USGS.
Figures & Tables
Unfolding the Geology of the West
Prepared in conjunction with the 2016 GSA Annual Meeting in Denver, Colorado, this volume contains sixteen guides to field trips in this rich geologic region. The four “Great Surveys” of the late 1800s ventured west to explore and document the region’s unknown natural resources and collect valuable geologic information. Many of the field guides in this volume, aptly titled Unfolding the Geology of the West, will cover the same hallowed ground as the early geologic expeditions. Organized into four sections, this volume spans some of the major subdisciplines of geology: (1) stratigraphy, sedimentology, and paleontology; (2) structure and metamorphism; (3) Quaternary landscape evolution; and (4) engineering and environmental geology.