The Future of Continental Scientific Drilling U.S

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THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING U.S. PERSPECTIVE

Proceedings of a workshop | June 4-5, 2009 | Denver, Colorado

DOSECC WORKSHOP PUBLICATION 1 Front Cover: Basalts and rhyolites of the Snake River Plain at Twin Falls, Idaho. Project Hotspot will explore the interaction of the Yellowstone hotspot with the continental crust by sampling the volcanic rocks underlying the plain. Two 1.5 km holes will penetrate both the surficial basalt and the underlying rhyolite caldera-fill and outflow deposits. A separate drill hole will explore the paleoclimate record in Pliocene Lake Idaho in the western Snake River Plain. In addition to the understanding of continent-mantle interaction that develops and the paleoclimate data collected, the project will study water-rock interaction, gases emanating from the deeper curst, and the geomicrobiology of the rocks of the plain. Once scientific objectives and set, budgets are developed, and funding is granted, successful implementation of projects requires careful planning, professional on-site staff, appropriate equipment, effective logistics, and accurate accounting.

Photo by Tony Walton

The authors gratefully acknowledge support of the National Science Foundation (NSF EAR 0923056 to The University of Kansas) and DOSECC, Inc. of Salt Lake City, Utah.

Anthony W. Walton, University of Kansas, Lawrence, Kansas Kenneth G. Miller, Rutgers University, New Brunswick, N.J. Christian Koeberl, University of Vienna, Vienna, Austria John Shervais, Utah State University, Logan, Utah Steve Colman, University of Minnesota, Duluth, Duluth, Minnesota edited by Cathy Evans. Stephen Hickman, US Geological Survey, Menlo Park, California covers and design by mitch favrow. Will Clyde, University of New Hampshire, Durham, New Hampshire document layout by Pam Lerow and Paula Courtney. THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING, A US Perspective

EXECUTIVE SUMMARY

Many fundamental and exciting scientific problems can only be solved by drilling. Problems for which drilling is essential encompass a wide range of themes: global environmental and ecological change; geodynamics, including related earthquake and volcano hazards; the geobiosphere; and natural resources and related environmental concerns. Intellectually coherent topics lie within these themes or cross theme boundaries. Themes include geologic records of coupled climate, sea level, and environmental change; history of the magnetosphere; melting processes of mantle plumes and their interaction with continental crust; fault and earthquake source mechanics; evolution of volcanic systems; extraterrestrial impact structures and processes; subsurface ecosystems; ground water; hydrothermal processes, geothermal energy and ore deposition; and CO2 sequestration, to mention a few. Drilling is necessary to access, for example, key structures, rock bodies and active processes that are not exposed, but lie within range of the drill bit; time series where surface outcrops are unavailable or not usable; or fluids and microbes at depth. The future of scientific drilling was considered at a workshop in Denver, Colorado, on June 4 and 5, 2009. The workshop emphasized the future of drilling under US auspices, although it had international participation. The goal of the workshop was to identify key scientific issues that could be addressed by drilling and to foster new scientific drilling projects within the US-based community, in cooperation with the International Continental Scientific Drilling Program (ICDP). Drilling into continental sediments and rocks complements drilling in ocean basins. The continental record potentially extends our knowledge of deep time to the Archean, while ocean drilling generally provides information only back to the age of the oldest oceanic crust. Continental drilling can elucidate uniquely continental processes and structures, as well as provide alternate but complementary views to observations made in the oceans. However, many problems require drilling in both the continental and oceanic realms, so cooperation and coordination between the continental and marine drilling community is critical. The community interested in continental scientific drilling is large, intellectually engaged, and thematically diverse. It is important to foster this community and to promote intellectual discourse among members with differing but potentially syngergistic interests. It is also important to reach outside the drilling community to groups that use different methods to approach the same problems. For example, most drill holes have the potential for investigating the subsurface microbial community, but this capability is underutilized. Many processes within the Earth’s interior are investigated by geophysics, analog studies, and modeling as well as through samples and data from drilling. The general view of the workshop participants was that collaboration should be encouraged with such parallel groups as well as within the scientific drilling community wherever possible and appropriate As drilling is expensive, it is important to identify objectives carefully and to optimize individual campaigns or holes. Optimization requires planning at two levels. At one level it is necessary for specialists in particular research topics to optimize available technology and research opportunities to develop key projects that have significant potential to advance the science in their particular discipline using as many different toolsand experimental approaches as possible. At a different level, individual drilling projects are very expensive and thus require development of a broadly based community of specialists in diverse fields who will make use of the samples and data from the drilling project. Such planning should include efforts to bring forth the maximum involvement of interested parties, including those from disciplines outside the traditional bounds of the geosciences. Both individual drilling projects and general research themes can benefit from technological advances to obtain better samples, downhole measurements and long-term monitoring that enable a wide array

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 1 of cutting-edge scientific issues to be addressed in a broader range of environments. Close interactions between scientists, drilling contractors, and designers of tools and equipment are necessary to continuously advance the science that can be addressed through drilling. The workshop came to several recommendations for the community interested in drilling in continental environments. First, the continental drilling community must broaden itself by educating other geoscientists in the advantages of drilling as a means of getting key samples and data for important problems. Second, the community must develop a broadly based science advisory committee that acts to focus the community, provides scientific leadership, and invites participation by all interested parties within the Earth sciences. Third, that science advisory committee must encourage disciplinary planning workshops that have strong participation of parallel groups not traditionally involved in drilling in addition to members of the continental drilling community. Fourth, the community should identify general needs for technological advances in capabilities or facilities and work together to meet those needs. Fifth, the community should develop instrumentation and protocols for use of drill holes in long-term monitoring of active processes at depth. Sixth, there should be well-established routes to carrying out preliminary site characterization studies to facilitate development of scientific and operational plans for drilling projects and to verify that the sites selected for these projects are optimal for achieving their scientific objectives. Seventh, the community must provide open and ready access to all data, cores, and publications that result from drilling after appropriate moratorium periods through public databases, repositories, site reports and publications in the general literature. Cooperation with ocean drilling in these activities is desirable. Finally, a facility is necessary to assist PIs in preparing realistic drilling plans and cost estimates for proposals. This facility should also have the capabilities to carry out successful drilling campaigns, including operational and support staff, logistics, drilling equipment and suitable on-site laboratories. The facility can provide staff support for community activities, and should be managed in coordination with technological, database and other support capabilities currently provided by the ICDP and IODP. The authors gratefully acknowledge support of the National Science Foundation (NSF EAR 0923056 to The University of Kansas) and DOSECC, Inc. of Salt Lake City, Utah. Anthony W. Walton, University of Kansas, Lawrence, Kansas Kenneth G. Miller, Rutgers University, New Brunswick, N.J. Christian Koeberl, University of Vienna, Vienna, Austria John Shervais, Utah State University, Logan, Utah Steve Colman, University of Minnesota, Duluth, Duluth, Minnesota Stephen Hickman, US Geological Survey, Menlo Park, California Will Clyde, University of New Hampshire, Durham, New Hampshire

2 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Anthony W. Walton1, Will Clyde2, Steve M. Colman3, Stephen Hickman4, Christian Koeberl5, Kenneth H. Miller6, and John Shervais7

INTRODUCTION: EXCITING SCIENCE THROUGH DRILLING Discovering new life forms, understanding how faults and mantle plumes operate, deciphering climate change and its effects on the biosphere, describing the processes of bolide impact and astrobleme formation, and documenting instability in the orbits of Mars and the Earth (Fig. 1) are some of the topics where vital information can only come through drilling into continental sediments and rocks. Drilling projects offer an opportunity for addressing multiple topics in single efforts—origin of magmas and diversity of the geobiosphere in a single project or both Pleistocene climate records and impact crater formation from a single lake. The various cores, fluid samples and measurements from the deep subsurface are of interest not only to geochemists, mineralo- gists, petrologists, sedimentologists, and geobiologists who study them, but also to specialists who use different methods to approach the same problems—seismologists, tectonicists, and experimental petrologists, for example. Therefore, drilling is a means of uniquely addressing key geologic problems that are the focus of investigations by several different specialties either within the drilling community or in parallel communities.

Figure 1. Wavelet spectra in time for orbital interactions within the Solar System for Late Triassic, derived from long cored stratigraphic records (Olsen and Kent, 1999), and Neogene, based on current celestial mechanics (Laskar et al., 2004). The interaction of Venus and Jupiter appears to be close to constant at 405 Ka, but the Earth-Mars interaction has shifted from about 1.75 Ma in the Triassic to about 2.37 Ma in the Neogene because of chaotic diffusion in the gravitational interaction between the two planets. Drilling of long sedimentary records can test fundamental models of the dynamics of the solar system, produce insolation curves for any arbitrary time period, tune isotopic decay constants, constrain the possible Velikovskyish behavior (Batygin and Laughlin, 2008) of the inner planets, and, ideally, test general relativity itself. (courtesy of Paul Olsen)

Drilling, including planning for and operating drilling projects, is not in the normal spectrum of skills taught to geoscientists during their education; most of us do best when concentrating on the science we know rather than dealing with technical and management issues in an unfamiliar field. Drilling projects require specialized equipment and personnel, neither of which are available at most universities or research institutions. Samples and data from drilling projects require careful storage and curation because they will have value to other investigators in the future, and the expense of reproducing them is prohibitive. The broad interest in drilling projects and the requirements for management, personnel, equipment, and reten- tion of materials mean that those interested in such projects should act as a community to make the process of developing and implementing drilling projects as straightforward as possible and to get the maximum possible return for the rather large investments required.

1 University of Kansas, Lawrence, Kansas 2 University of New Hampshire, Durham, New Hampshire 3 University of Minnesota, Duluth, Minnesota 4 U.S. Geological Survey, Menlo Park, California 5 University of Vienna, Austria 6 Rutgers University, New Brunswick, New Jersey 7 Utah State University, Logan, Utah

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 3 To further that community, and to publicize the funda- ics are not of necessity rigidly or uniquely assigned to mental and exciting science achievable with samples particular themes. and measurements from drilling projects, a workshop, The Future of Continental Scientific Drilling: A U.S. Global Environmental and Ecological Change Perspective (FSCD), took place in Denver, Colorado, Global Environmental and Ecological Change is a June 4–5, 2009. The workshop strove to bring together theme that deals with the history of the Earth in the a diverse representation of U.S. scientists whose re- broadest sense and its biota, mainly through studies search depended upon materials from drilling and in- of time series that are based optimally on drill cores. cluded some international representatives and a num- Such history has been a major focus of investigation ber of scientists whose main interest lay with parallel for over two centuries, but modern insights and tech- groups, such as the Incorporated Research Institutions niques now provide more detailed information and for Seismology (IRIS) and the Integrated Ocean Drill- allow more sophisticated analyses. Furthermore, our ing Program (IODP). The workshop was well attended understanding of Earth history may affect our view (55 participants registered, Appendix) and featured of the future, especially our view of climate change. excellent keynote presentations and lively discussion. Within GEEC (if it may be called that), two initiatives This document is a summary of the deliberations and emerged from the workshop. conclusions of the workshop. The first initiative involves high-resolution climate re- THEMES AND TOPICS cords obtained from lake sediments, especially from long-lived lakes that record Plio-Pleistocene history Drilling is a tool for obtaining samples or emplac- (see breakout report by Colman and Johnson). Other ing instruments to provide data that is applicable to a ancient systems also may provide similar resolution. broad and diverse range of geologic problems (Harms Although the lake sediments contain climate prox- and Emmermann, 2007; IODP, 2001). Continental ies—not direct measurements—of temperature, wind drilling uniquely provides highly resolved, unweath- field, and precipitation, new and emerging tools make ered records from the subsurface. Drilling projects interpretation of the proxies ever more robust and use- also allow emplacement of monitoring equipment and ful, and the records are accurate to decadal or even an- collection of subsurface fluid or biological samples. nual scale under ideal circumstances. A clear overlap Information from continental drilling projects not only exists between lake cores as records of climate history stands on its own but complements information from and their importance as a source of information on the ocean drilling, seismology, surface measurements and process and rate of evolution of lacustrine biota (see samples, or other sources. breakout report by Cohen, Michel, and Wilke). De- tailed paleoclimate records from lake sediments and Themes on-land sites may shed insight onto the factors that influenced evolution of humans, their ancestors, and Four themes encompass the range of continental sci- associated faunas, as in the case of African lakes (see entific drilling (CSD): 1) aspects of the history of breakout report by Cohen, Campisano, and Feibel). Earth, climate, and life, broadly grouped as global In addition, lake records also contain information environmental and ecological change; 2) the Earth as about the history of the Earth’s magnetic field, a topic an operating system, loosely geodynamics; 3) the geo- in geodynamics (see breakout report by Stoner). biosphere of the present day; and 4) the interaction of humanity and the Earth through understanding natural The second initiative focuses on Deep Time re- resource systems and related environmental concerns cords. In a longer-term sense, GEEC includes study (Table 1). of Deep Time, extending back through all sequences of supracrustal rocks. Here the records are generally Each of the themes has a number of topics to which less precise—Milankovitch or millennial scale com- drilling has provided key information or where it has monly—than those of recent lakes, but they do con- the potential to do so. The topics, or certain group- tain important information about the Earth from times ings of them, are natural organizing foci for planning when boundary conditions were quite different from workshops that rank scientific priorities, identify par- those of today. In addition, Deep Time continental ticular steps toward solving them, and promote col- records, which in individual cores may cover 10 Ma laboration with parallel communities. Table 1 lists a or more, are the only sedimentary source of informa- selection of such topics; others certainly exist or are tion for pre-Jurassic events and for detail of pre-Cre- emerging as the science advances. Furthermore, top- taceous events because of the subduction of oceanic

4 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE TABLE 1. Themes and Topics for Continental Scientific Drilling.

Themes Topics

High-resolution Plio-Pleistocene climate records time-series Evolution in isolated lake systems records Climate and evolution of hominins and associated faunas (History of the magnetosphere)

Climate history Sea-level history Paleoceanography Global Atmospheric history Environmental and Cryospheric history from near-field sub-ice records Ecological Change Deep-Time Stratigraphic architecture and crustal deformation records Evolution and extinction Dynamics of the Solar System Continents as the only source of information for pre-Late Jurassic historical records (History of the magnetosphere) (Antarctic deep time records)

Geodynamics Impact processes and structures Crustal evolution Hotspots, mantle plumes, and large igneous provinces Processes and hazards at volcanoes Fault mechanics History of the magnetosphere Ice sheet history and dynamics

Geobiosphere Microbiology Biogeochemistry Ichnofossils

Natural resource Hydrothermal resources and ore deposits systems and related Ground water environmental Hydrocarbons concerns CO2 sequestration

lithosphere. Topics of particular interest include past discussion and study for centuries among geologists climates, the history of the atmosphere, evolutionary and philosophers. For this area of research, drilling history, stratigraphic architecture and crustal defor- can provide samples and measurements that reveal the mation, the Earth’s magnetic field, sea level history time sequence of events related to a particular process, (Fig. 2), and paleoceanography (see breakout report the composition of subsurface fluids, the rate of strain, by Miller and Clyde). Deep Time records can even the composition of key zones, and evidence of the re- constrain orbital dynamics of the Solar System (Fig. sults of geologic processes. 1). Drilling in the Antarctic, such as is conducted or Exploration of the crustal structure and history of its proposed by ANDRILL, provide unique Deep Time evolution are obvious places for interaction of conti- records, potentially including an extensive history of nental scientific drilling with seismologists and ocean the Antarctic Ice Sheet (see breakout report by Powell drillers. The current U.S. Array efforts within Earth- and Vogel). scope are providing unprecedented information on in- Geodynamics terfaces within the crust of the United States and properties of the blocks those interfaces define but not their Geodynamics—broadly, the way the Earth works, in composition, age, and deformation history. Drilling in Peter Wyllie’s (1976) phrase—has also been a topic of ocean basins has yielded key information on the tim-

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 5 Figure 2. This Deep Time record, sea-level curves for the past 100 Ma, represents an integration of continental and ocean drilling efforts in the continental slope, continental shelf, and coastal plain of Delaware and New Jersey (Miller et al., 2005; Kominz et al., 2008). Verifying these results and extending them back in time require additional high-quality cores with good age control and reliable indicators of sea level. (Figure courtesy of Ken Miller, personal communication, 2009)

6 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE ing and movement of mantle plumes with associated of the Antarctic continent by drilling through the ice hotspots and large igneous provinces in the marine sheet promises to elucidate ice dynamics and history, realm, but only drilling the rock succession on land explore the subglacial hydrology and possible eco- can provide the evolutionary history of a plume (see system, and provide information on makeup and his- breakout report by Shervais and Christiansen). The tory of the Antarctic Continent (see breakout report by Hawaii Scientific Drilling Project (HSDP) was an el- Powell and Vogel). egant experiment designed to deconvolve the melting The emphasis in the Geodynamics Theme is on how history of a mantle plume and deduce aspects of the things work, although time series of samples may be structure of the mantle. Future projects will attempt the main source of information. FEMA and other plan- to elucidate the effects of plumes on continents and ners are interested in time series of earthquakes. The vice versa. history of Earth’s magnetic field is perhaps a key to Advances in physical volcanology over the past 40 understanding how the field works in a geodynamic years have led to models of eruption dynamics that sense, but may best be addressed by studying the de- bear testing through actual sampling, as in the recent tailed recent sedimentary records, described above, Unzen Drilling Project, which explored the conduit of and integrated across the Earth. Sedimentary accumu- a recently active volcano. As a by-product of drilling lations record the subsidence history of crust to form volcanic edifices, we can learn more about their al- basins, indicating driving forces of vertical move- tered core and their propensity for sector collapse and ments and their characteristic rates. Sedimentary accu- other catastrophic hazards as well as plumbing the hy- mulations sampled for studies of Deep Time also tell drothermal systems that lie within and below them, a us about source areas long vanished. topic that overlaps into natural resources (see breakout report by Zierenberg and Shanks). The Geobiosphere Drilling of potentially active faults also is of interest The geobiosphere has come to the attention of sci- to the ocean-drilling and seismological communities ence only recently, in contrast to Geodynamics and and to those who prepare structures and cities for fu- to GEEC. However, the possibility that the geobio- ture earthquakes, who are especially interested in time sphere—the section of the biosphere that lies beneath series of earthquakes (see breakout report by Hick- the Earth’s surface—is comparable in complexity and man, Brodsky, and Evans). Impacts are the second biomass to the biota of the surface gives it special im- most important surficial process on most solid bodies portance for research (see breakout report by Walton in the solar system and were important on the early and Kieft). This topic is investigated through micro- Earth as well. Although the effects of impacts are glo- biology, through biogeochemistry, and through trace riously visible on the surfaces of other planets (Fig. 3), fossils (Fig. 4). Study of the geobiosphere of the conti- study of three-dimensional structure of impact sites, nents is just beginning: even the extent of the geobio- and the deduction of processes from that structure is in sphere in space and time is not known, let alone the its infancy and requires earthly drilling (see breakout taxonomy, metabolic pathways, and mineralogical and report by Koeberl and Plescia). Finally, exploration geohydrologic effects of the organisms or consortia of them. Drilling through Antarctic ice sheet to subglacial lakes and sedimentary basins may reveal new realms of life (see breakout report by Powell and Vo- gel). The potential for truly transformational science is significant in studies of the geobiosphere. A deep biosphere workshop occurred in Potsdam in Septem- ber 2009 (http://www.icdp-online.org/contenido/icdp Figure 3. Impact cratering is the dominant surficial process on rocky bodies in the Solar System. Morphology of impact cra- The Environment and Natural Resources ters depends upon the size of the crater and therefore the energy of the impact, nature of the target, and gravity of the impacted Today’s world depends upon availability of plentiful body. While craters of each form—simple (L), complex (center), and inexpensive natural resources, but their use com- and complex with central peak ring (R)—are easily observed in monly leads to problems of local and worldwide pol- images of the surface of the Moon and other rocky planets, erosion, sedimentation, and subduction on the Earth has concealed lution. Some areas of this realm of interaction between characteristic features of many impact structures or effaced them humanity and the natural environment are clearly entirely. To understand the processes of crater formation and the within the purview of scientific drilling. Hydrothermal resulting structures, it is necessary to drill earthly examples. (Im- systems, as sources of geothermal resources, have long ages courtesy of David Kring)

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 7 STATE OF THE ENTERPRISE

Continental scientific drilling, as a program, prob- ably dates from the beginning of drilling on the Kola Peninsula project (1970–1992) by the Soviet Union and Russia. In 1987, Germany began to drill the pilot hole for the KTB (Kontinentales Tiefbohrprogramm) project. CSD began in the United States with Depart- ment of Energy’s (DOE) exploration of hydrothermal resources in the 1970s and, more broadly, with the workshops that led to the founding of DOSECC (Deep Observation and Sampling of the Earth’s Conti- nental Crust1) in 1984. In its early days (1984–1988), Figure 4. Euendolithic microborings, i.e. microbial ichnofossils, DOSECC evaluated proposals, dispersed funds for extend from a fracture in a hyaloclast from a depth of 2092.3 m drilling and research that had been granted by the Na- below sea level in the Hawaii Scientific Drilling Project #2 core. tional Science Foundations (NSF), and maintained a Such microborings are common in basalt glass from the ocean crust and ocean islands, and are being sought in continental pil- drilling office. At that time, DOE and the U.S. Geo- low lavas and hyaloclastites. Such structures are known to be biological Survey (USGS) were also active in CSD and genic because they display chemical, biochemical, and isotopic coordinated with the academic drilling community anomalies; have morphological resemblance to known microbial through an interagency coordinating group set up by structures; and give evidence of behavior, here seeking olivine crystals (upper right and lower left). However, the taxonomy and Public Law 100-441, the Continental Scientific Drill- metabolism of the organisms that made them are unknown. (Scale ing and Exploration Act, on September 22, 1988. This bar: 20mm. Photo courtesy of A.W. Walton) arrangement led to a number of small to very large been a target of drilling to characterize their properties projects, most of which were highly successful. Af- and capacity and are enjoying renewed interest today ter DOSECC was removed from any funding role and (see breakout report by Zierenberg and Shanks). DOE ceased drilling activity, the U.S. program contin- Similar hydrothermal systems have been sites of ac- ued by fits and starts with funding from various sourc- cumulation of ore deposits, which provide many of es. Early U.S.-led efforts were national efforts, which the necessary metals and other natural resources we perhaps involved international collaboration. demand. Sometimes the results are unexpected; the With the founding of the International Continental HSDP, for example, changed the understanding of cir- Scientific Drilling Program (ICDP) in 1994 (formal- culation of groundwater in Hawaii. Similar discover- ized in 1996), continental drilling became explicitly ies seem less likely in well-known areas on shore, but international, although national efforts have continued opportunities exist for spin-off science that will lead with smaller projects. NSF, along with other national to a better understanding of the groundwater system science-support agencies, contributes to ICDP, which or other natural relationships. then grants money for drilling costs and provides The Mallik Project explored one of the great resources various on-site and data management services. NSF of fixed organic carbon, that in gas hydrates. Other has supported the infrastructure of scientific drilling problems of the origin of hydrocarbons exist, such as through the DOSECC corporate office, which pro- the role of microbes in the conversion of marine or vides planning, project management, and operational terrestrial origin into kerogen. Serious proposals ex- services to drilling projects as well as fostering a community of interested scientists. NSF also provides for ist to practice carbon sequestration by injecting CO2 from power plants into deep, saline aquifers, especial- curating and storage of cores from lake drilling proj- ly those beneath the continental shelf and slope (See ects and facilities for their study, through LacCore. report by Miller). Drilling is necessary to ensure the Progress in scientific drilling depends upon well- properties of the reservoir and long-term stability of thought-out proposals with reasonable goals, suitable the seal as well as to provide avenues for displaced infrastructure, and adequate funding for both drill- water to escape. Any such exploratory drilling may ing and science. Scientific investigations by U.S. in- provide better understanding of the Earth. The latter vestigators must be funded from sources other than two areas, origin and distribution of hydrocarbons and 1 CO2 sequestration, would seem to invite industrial Now called Drilling, Observation, and Sampling of the Earth’s Continen- tal Crust, reflecting a broadening of emphasis to include smaller projects participation in drilling projects. involving shallow drilling.

8 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE TABLE 2. Stages and timing of a drilling project as illustrated by the Lake El’gygytgyn project.

Stages of Lake El’gygytgyn (Courtesy of Brigham-Grette and Mellis) Development Planning and Operational Activities Funding and Permitting History Posing of question July 1994: Investigators learn of Lake El’gygytgyn. or discovery of which fills the depression of an early Pleistocene Fall 1995: Proposal submitted to NSF; Not situation that demands impact crater funded investigation

Summer 1996: SGER awarded Fall 1996 to Fall 1997: Permits requested from Russian authorities, granted 1 year later. Preliminary research March 1998: New permits in place. and site survey May 1998: First coring campaign with SGER and funds from Alfred Wegener Institute January 1999: NSF proposal for coring and July 1998: Study of initial cores science: Not funded August 2000: Second coring campaign Scientific planning workshops, developing January 2001: ICDP Workshop; Impact community interest in collaborative joins project at ICDP suggestion. and parallel communities Fall 2001, 2002: NSF proposals not funded Build community, January 2004: ICDP preproposal develop science plan, January 2005: ICDP proposal, funded develop drilling plan, develop project budget, Summer 2006: NSF and German BMBF write proposals proposals funded Fall 2006: Planning meetings in the United States, Germany, and Russia anticipating drilling campaign early 2008 Operational planning Summer 2007: Drilling postponed until early 2009 Spring 2008: NSF imposes project Drilling equipment shipped to Russia beginning in June management structure 2008. Summer and Fall 2008: Planning meetings and conferences. October, November 2008: On-land drilling (permafrost site) Implementation January-May 2009: Drilling of lake sediments and impact rocks through ice Fall 2009: Core study to begin. Cores clear customs in Science Summer, 2009

ICDP, such as NSF, other state and national sources, plan the project scientifically and operationally, to pre- and private industry. Many U.S. investigators have pare budgets and proposals, and to get any necessary participated worldwide in a range of drilling projects permits. Then, commonly, there is a calendar window over the past 15 years. However, anecdotal evidence that is more favorable for drilling, especially in lakes shows that U.S. scientists have been prevented from or shallow seas, and transit of equipment to the drill- participating in various drilling programs by a lack of ing site may take months. research funds, despite status as PIs in successful drill- The Lake El’gygytgyn project, where drilling was re- ing proposals to ICDP. cently completed, is an example (Table 2). The time from when the lake came to the attention of inves- Planning Projects: Long Lead Times tigators until the cores can be opened for study will Many drilling projects are complex, multifaceted, and be over 15 years. The formal process of developing a expensive efforts that require a commitment of years drilling program began with an ICDP-funded work- to bring to fruition. It simply takes time to build a com- shop in 2001, eight years before the drilling campaign. munity of interested parties across a range of different Equipment for drilling left Salt Lake City in June 2008 specialties, to gather necessary preliminary data, to so that it would reach the lake in time for the favorable

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 9 drilling window in late winter 2009, when the lake was adequately ice covered. While logistics of drilling in a remote area of easternmost Siberia are particularly complex, this example is not an outlier in terms of the time required; the period from inception of a large drilling project until scientific study can begin on the resulting samples and data is normally several years to well over a decade. Both the Hawaiian Scientific Drilling Project and the SAFOD (San Andreas Fault Observatory at Depth) project both took more than a decade from their first planning efforts.

Scientific Drilling: Expect the Unexpected Scientific holes are drilled and cored precisely because we cannot otherwise determine the local geological situation. In fact, scientists and drill crews are commonly surprised. The Iceland Deep Drilling Proj- ect (IDDP, http://www.iddp.is/about.php ) developed a plan to drill to 4–5 km depth to investigate rock and geochemical properties where water is a supercritical fluid, at a location at Krafla in the northern part of the island. Instead, rhyolite magma interrupted the drilling at a depth of 2104 m (Fig. 5). The Hawaii Scientif- ic Drilling Project (HSDP) #2 discovered unexpected groundwater resources at about 1 km depth, where a freshwater lens lay beneath an aquitard, a paleosol that overlay Mauna Kea lavas. The well also revealed a

Figure 6. We drill because we want to know what is there. While we have well developed expectations, surprises commonly await. The Hawaii Scientific Drilling Project #2 well has led to a major revision of the understanding of ocean island geohydrology, even beyond the discovery of the separate, stacked freshwater lenses in Figure 5. Vesiculated clear rhyolite glass from IDDP #1 at a depth Mauna Kea and Mauna Loa lavas. Profile: Temperature profile of of 2104 m. The well had been programmed for a total depth ex- HSDP #2 phase 1. Rapid circulation of seawater through porous ceeding 4 km, but unexpected rhyolite magma interrupted the rock cools the upper 700 m of the hole. Photo: Drill crew reacts plans (Image from IDDP website) to overpressured fresh to slightly brackish water that was encountered in pillow lavas at depths of over 2000 m. (Geothermal profile courtesy of D. Thomas, personal communication, 2001; Figure negative geothermal gradient to a depth of about 800 courtesy of D. DePaolo, personal communication, 2009) m because seawater effectively removes heat from volcanic sources and radioactive decay within the ba- lake drilling projects. While serendipitous discoveries salt (Fig. 6). may help justify drilling to explore the crust or to test specific hypotheses, drill sites should be well charac- Other downhole surprises have not been so fortunate, terized by whatever means appropriate to avoid any even to the point of threatening entire projects or lim- unpleasant possibilities. iting their success. Difficult drilling conditions due to poorly characterized sand layers have bedeviled some

10 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE The Need for Support Facilities At the beginning of CSD, when the holes were deep and the programs were expensive, long-term projects involved dedicated staff, contractors, and con- sultants to carry out the planning and operational phases. Beginning with the Newark Basin project in 1990, a model that proposed small to moderate-sized projects has produced excellent results on many topics. However, more programs mean more investigators who must either grapple with the intricacies of operating drilling programs or have planning, drilling, and project-management expertise available. Numerous small campaigns necessarily each have small resources, preventing investigators from en- Figure 7. Adequate support facilities are necessary for success- gaging specialized staff to implement the drilling ful drilling projects. The tiny black dot in eastern Siberia at the end of the arrow is Lake El’gygytgyn, which formed during a bo- project. Efficiencies of scale can only be achieved lide impact in the Pliocene. As the area was not glaciated during by integrating baseline costs for planning, project Plio-Pleistocene glacial advances, both the impact structure and management, equipment, and operations across a a long paleoclimate record in sediments lie below the lake. Most number of programs. equipment and supplies for a Spring 2009 drilling campaign had to travel to Pevek, a port on the Russian Arctic coast during its ice- The planning process, including background stud- free period in late summer 2008. Equipment, supplies, and spares ies and site surveys, takes years. Funding for pre- left Salt Lake City in June 2008 to travel, by way of Vladivostok, to Pevek. After the tundra was thoroughly frozen, materials moved liminary investigations is often difficult to obtain. across an ice road to the campsite on the shore of the lake. Plan- Preparing successful proposals requires a realis- ning and conducting this expedition tested the organizational ca- tic design of the holes to be drilled, knowledge of pabilities of the scientists, operators, and funding agencies, but the the equipment necessary, and reliable estimates of team prevailed with a successful drilling program concluding in the costs involved. Once proposals are approved, May 2009. (Illustration modified from Google Earth) whether funding is or is not in place, the complex breakout report by Ito and Snyder), including some programs require supervisory efforts that commonly that may require new drilling technology. For ex- including travel to distant places on short notice. ample, drilling on larger lakes would require a larger However, the planning process and pace of drilling barge and more rig capacity than the existing GLAD projects is such that baseline funding for a drilling 800 system. Higher temperatures in geothermal and facility is necessary to support a U.S. Continental sub-volcanic systems would require higher tempera- Scientific Drilling effort because PIs of small to ture down-hole assemblies, logging equipment, and moderate-sized drilling projects need to be free to sensors (Fig. 8). Equipment that could have many ap- focus on science without having to also manage plications includes a highly mobile system that drills complex operations on a one-time basis (Fig. 7). shallow holes. Finally, several adaptations for down- An effective support facility is key to smoothing hole sampling would also have many applications, the run-up to actual drilling operations. It is neces- such as sampling at formation pressure conditions for sary to develop satisfactory working relationships drilling gas hydrates and systems for obtaining bio- with local officials and get appropriate permits. It geochemical and microbial samples. An appropriate is necessary to arrange for banking or other transfer transportable, modular laboratory would open many of funds for local expenses. Drilling in remote ar- CSD sites to collaboration with geomicrobiological eas requires knowing local suppliers. Experienced investigations of the subsurface. Similar modular fa- project managers will see that the proper equipment, cilities would facilitate on-site measurements of mag- supplies, and spares are on site at key times. netic, chemical, radiological, and other properties of the core or samples. Workshop participants recommended significant improvements to the systems of Equipment Availability Now and in the Future geoinformatics and data management and their coor- Equipment available currently from commercial en- dination with existing systems. Such systems, plus a tities, ICDP, or DOSECC is adequate for many proj- repository for cores and other samples would go far ects. However, the workshop identified several areas to increase the payoff from drilling projects by open- where additional equipment may be necessary (see ing the information and materials to other investiga-

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 11 tors for other uses. More important than a list of necessary or desirable improvements to equipment and facilities is a procedure for measuring the need for improvements of capability, designing the necessary equipment or facility, and securing funding for its acquisition and, if appropriate, operation.

FOCUS ON THE FUTURE: WHERE DO WE GO FROM HERE? This report highlights the fundamental and exciting science that can be achieved only through samples and measurements derived from drilling into continental crust and sediment records. Though broad and diverse, the U.S. continental scientific drilling community has common needs and offers many opportunities for collaboration, both within that community and with parallel communities that share overlapping interests. How- ever, the community and its subsets need focus to move ahead to achieve full scientific potential. The workshop organizers recommend several specific steps.

10 FOOT OUTER TUBE 1. Foster a culture of drilling among USED WITH ALL INNER ASSEMBLIES geological investigators as a HPC SAMPLER ALIEN SAMPLER means of getting key data for a PUSH SAMPLER EXT. CASE SAMPLER variety of important problems. NON-CORE ASSEMBLY Investigators should be aware that Figure 8. GLAD 800 lake-sediment sampling tools. These coring tools were developed drilling is appropriate in many cir- by Marshall Pardey of QD Tech for a special purpose: sampling lake-bottom sediments cumstances and that the support to achieve nearly 100 % core recovery. They have been highly successful. As the com- facilities and equipment are avail- munity identifies needs, a mechanism must exist to provide the engineering design and fabrication of special purpose equipment for drilling, sampling, logging, and on-site able. Developing such a culture analysis. (Courtesy of DOSECC, Inc.) requires that the community be open and accessible. DOSECC, goals, fostering collaboration, and speaking out on as a representative focus of the drilling community, community needs and accomplishments as well as can take steps to increase involvement among geo- advising DOSECC. Alternatively, the committee can logical researchers, including more professional edu- be otherwise constituted. The science planning and cation and outreach, better communication through advisory committee would include active partici- newsletters and websites, through workshops and pants from several fields of interest. This committee planning efforts, and by becoming more open as a can sponsor efforts by various interest groups to de- consortium. fine their goals and identify their needs (item 3). It, or a specialized technical advisory committee, can also 2. Develop a science planning and advisory group that develop means of identifying technical and infra- represents the entire U.S. CSD community. The structure needs and the means to fulfill them (item 4). DOSECC Science Planning Committee is currently a membership committee that advises the Board of 3. Encourage disciplinary planning workshops that in- Directors on scientific matters. It is possible that this clude likely collaborators as well as CSD commu- committee could be reconstituted to represent the en- nity members. The committee in item 2 above can tire community and serve as a focus for identifying develop a series of workshops that focus segments

12 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE of the drilling community on specific topics or istrative cracks. Some projects require preliminary groups of topics within or across themes (Table surveys that cost more than Eager or Rapid grants 1). The lakes community, which is now especial- can provide, but proposals to do the surveys do not ly interested in Plio-Pleistocene climate, organic review well on their own. Furthermore, new facili- evolution in lake systems, and climatic controls on ties and equipment are necessary and might be fund- evolutionary events, had a successful workshop in ed in anticipation of community needs (build it, and 1995 under the sponsorship of ICDP and the Past they will come). Global Changes (PAGES) project of the Interna- 7. Project investigators should have access to data, tional Geosphere-Biosphere Program. The work- samples, and cores gathered during drilling projects shop report (Colman, 1996) focused the efforts of during an appropriate moratorium period. However, that community for the next decade. The commu- the immediate results of drilling projects have long- nity now can benefit from an effort to update the term value and replacing them is not cost effective. report of that workshop. Those interested in fault- Those materials and data that result from the drilling have participated in several recent workshops, ing and subsequent sampling of the hole should be including a joint IODP-ICDP workshop (Tobin, et appropriately curated, stored, and made available to al., 2007). A recent IODP workshop on large ig- the scientific public for use in other investigations. neous provinces developed themes and objectives Permanent storage and appropriate access require for plume-related volcanism (Neal et al., 2008). a significant organizational effort and an enduring The impact community, the geobiosphere commu- commitment of appropriate resources. nity, the volcanological community, and the igneous processes community may each profit from a 8. Retain the capability to assist PIs in preparing drill- workshop. Furthermore, various areas of natural ing plans that are parts of proposals for submission resources, including carbon sequestration, do not to ICDP, NSF, and other agencies. Retain the many have a current overview consensus. capabilities necessary to carry out a successful scientific drilling campaign, including scientist participa- 4. Develop a system to issue requests for develop- tion in creation of drilling plans; on-site inspection ment of key equipment or facilities that will meet for suitable topography; evaluation of infrastructure needs expressed for furthering the capability of and support at proposed location; calculation of drilling. Develop or enhance the facilities for cu- what has to be where and when; and development rating and storing the cores, samples, and data that of a local professional team for many necessary result from drilling projects, and making them tasks. These tasks include transferring money and available for further study. Physical products and arranging permits; packing equipment, supplies, and data from drilling projects are of likely use in fu- spares; arranging for shipping and transit of customs; ture investigations by new techniques or as infor- recruiting knowledgeable drilling crews; and provid- mation for new kinds of study, but are prohibitive- ing project supervision, logistical support, and drill- ly costly to reproduce. Storing them and making them accessible for future investigators is a better ing equipment. approach. CONCLUSION 5. Develop protocols for use of holes as monitoring points on sampling networks. Some holes are in Scientific drilling is a tool that provides unique and geological situations very favorable for monitor- vital data and samples for a very broad range of key ing of stress and strain, fluid composition and flow geological problems, including many stated in a re- rates, or earthquake shocks. Other holes may not cent National Academy of Science study (Committee have any such use. However, the utility of any on Solid Earth Sciences, 2008). Continental scientific holes for short- or long-term monitoring sites, drilling in particular addresses numerous problems and the costs associated with their use, should be a consideration in the preparation of proposals that cannot be addressed by drilling in ocean basins. and design of the holes themselves. Investigators However, maintaining a viable community that takes need guidance on whether to include post drilling advantage of this tool requires education, planning, down-hole activities as part of the justification of and resources. This document aims to summarize the their research. current scientific themes that could most benefit from 6. Work with NSF to develop a focus or some coor- CSD and act as a launching pad for more in-depth dis- dination on CSD. Without some structure at NSF, ciplinary efforts. U.S. Scientists are at disadvantage in developing In addition to providing the samples and measure- projects because their projects commonly cross ments that are the objective of the immediate project, disciplinary lines so that funding is scattered in drill holes are a resource for continuing observation. several programs. Without leadership at NSF during the review process, strong, but diverse, pro- Repeated sampling of temperatures and fluids become posals may review poorly or fall through admin- possible, with appropriate designs of the well comple-

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 13 tion. Holes can host microcosms for geomicrobio- allel communities that use different approaches to the logical research. Some drill holes can be dedicated same problems or to communities that would other- to downhole seismometers and strain meters. Borings wise not be engaged. Such engagement improves the can become sources of fresh water, hot water, and min- possibilities for success and favors the most efficient eralized fluids. Cores can be the objects of study long use of resources. We make plans, and then we figure after the initial measurements and sampling are done. out what are going to do as reality and opportunities present themselves. Two caveats are appropriate. First, communication among the various communities is vital to optimize Plans, equipment, and infrastructure do not appear the return on various efforts to plan and develop in- spontaneously; like drilling operations themselves, the frastructure. Each project has the potential to get data background elements necessary for a successful CSD or samples that are of interest to other communities. effort require financial resources. Availability of re- Second, no plan or group of plans should be allowed sources in turn depends upon sound proposals that not to exclude efforts not specifically listed; the funding only explain the science but justify the investment in process strives to support proposals to do the best sci- it by knowledgeable funding agencies. A strong com- ence rather than the ones that seek to check off some munity can foster topical planning and better justify preordained boxes. investment in equipment, facilities, and infrastructure. The next items for the Continental Scientific Drilling So why plan, given the second caveat? Planning iden- Community should be community building and topi- tifies not only key questions but also the resources cal planning. (e.g. equipment, facilities, infrastructure, and support) that make any drilling effort possible with the great- Acknowledgments est return on investment. Where currently available equipment or technology is insufficient to achieve key This workshop was primarily funded by NSF through goals that communities have identified, supporting fa- grant EAR 0923056. DOSECC provided additional cilities or investigators can invent or acquire the nec- support. The staff at the Brown Palace and Comfort essary improvements or develop the new elements of Inn were helpful and efficient. The organizers would infrastructure. Many items of equipment and elements especially like to thank the keynote speakers and the of support or infrastructure are applicable across the reporters of the breakout groups for their contribu- entire continental drilling community. Planning also tions. Dave Zur of DOSECC provided on-site man- provides an opportunity to open the questions to par- agement for the event.

14 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE WORKSHOP DELIBERATIONS Breakout groups at the workshop considered a number of topics to identify the key avenues of advance, the possible collaborations within the drilling community and with parallel communities, and the infrastructure, support, and equipment necessary to accomplish them. Not all of the topics listed in Table 1 were addressed in breakouts. In fact, many of them came out in discussions surrounding the workshop. The following items summarize the sense of planned discussion sessions and some other topics.

CONTENTS

Continental Drilling for Records of Past Climates and Environments: A Look to the Future Steven M. Colman and Thomas Johnson ...... 16

Drilling to Understand Biological Evolution in Lakes Andrew Cohen, Ellinor Michel, and Thomas Wilke ...... 18

Human Evolution and Scientific Drilling Andrew Cohen, Christopher Campisano, and Craig Feibel ...... 20

Geomagnetic Opportunities through Continental Drilling Joseph Stoner ...... 22

The Future of Continental Scientific Drilling: Deep Time Kenneth Miller and Will Clyde ...... 25

Antarctic Sub-Ice Geological Coring and Drilling Compiled by Ross Powell and Stefan Vogel ...... 29

Continental Drilling to Examine Igneous Processes and Geodynamics John Shervais and Eric Christiansen ...... 32

Mechanics of Faulting and Earthquakes Stephen Hickman, Emily Brodsky, James Evans ...... 35

Impact Craters, Ejecta, and Processes: Scientific Rationale and Possible Targets Christian Koeberl and Jeff Plescia ...... 39

Geomicrobiology Anthony W. Walton and Thomas Kieft ...... 42

Natural Resources and the Environment: Fluid Flow, Fractures, Water-Rock Interaction, and Hostile Environments Robert Zierenberg and Pat Shanks ...... 45

CO2 Capture and Sequestration Kenneth Miller ...... 47

Drilling as a Teacher: Education & Outreach and the Future of Continental Scientific Drilling David M. Zur and Kirk Johnson ...... 48

Facilities, Equipment, and Infrastructure Emi Ito and Walter Snyder ...... 51

References Cited ...... 54 Appendix ...... 57 Workshop Schedule ...... 58

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 15 CONTINENTAL DRILLING FOR RECORDS OF PAST CLIMATES AND ENVIRONMENTS: A LOOK TO THE FUTURE Steven M. Colman1 and Thomas Johnson1

Efforts to obtain long continental records of terrestrial climates and environments have yielded significant results since the mid-1990s. Much of this success reflects interactions among the International Continental Drill- ing Program (ICDP), the Past Global Changes (PAGES) project of the International Geosphere-Biosphere Pro- gram, and DOSECC, beginning with a ICDP-PAGES co-sponsored workshop in 1995. Since then, DOSECC developed the GLAD 800 (Global Lake Drilling to 800 m) drill rig that filled an enormous technological hole in our ability to obtain long continental records. The sedimentary records of sizable number of lakes have now been drilled, including Baikal, Hovsgol, Great Salt, Bear, Titicaca, Bosumtwi, Malawi, Peten-Itza, Qinghai, Potrok Aike, and El’gygytgyn. Initial publications from these projects, in journals including Science, Nature, PNAS, and GRL, have made major scientific advances. We now stand on the verge of what was envisioned in the early workshops and planning meetings: a well sampled global network of continental drilling sites. Rather than broad, generalized goals such as simply obtaining long-term records of climate change, we can now begin to address specific scientific needs. These specific questions, discussed below, require a synoptic network of high-temporal-resolution climate records from the continents. Drilling sediments beneath extant lakes has several advantages, including the ability to test paleoenviromental proxy measurements in the modern system and the ability to span a continuous record from the present back to a period of interest (Fig. 9). Much of the scientific need for long continental sedimentary records stems from a desire for better understanding of how the climate system has behaved in the past as a guide to future climate behavior. The relevance of paleoclimate records stems from the fact that some of the best tests of numerical models, which are used to forecast future climate change, come from assessments of the ability of the models to reproduce past climate changes documented by paleoclimate records. Paleo-records are also useful for calibrating the sensitivity of the climatic models. These model-data comparisons serve not only to test the models, but to guide selection of sites for additional paleoclimate studies. Also, understanding how the climate system has behaved in the past, especially during abrupt changes and transitions, is inherently useful for understanding the climate system as a whole. Beyond immediate societal relevance, major scientific questions can be addressed with continental records of environmental change. Such questions are as fundamental and scientifically exciting in their own right as any

The Value of Multiple Proxies

Figure 9. Sedimentary records from lakes contain numerous classes of in- direct indicators, proxies for past climate. Normally, sequential sampling of cores of those sediments shows the indicators vary in a coordinated fashion as a function of depth and, therefore, time. Magnetic, isotopic, and kinetic dates provide a useful chronology. Lack of bioturbation in many lake records allows highly precise time resolution. Drilling sediment records from modern lakes allows some verification of the various proxies. (Illustration courtesy of James Russell, personal communication, 2009)

1 University of Minnesota, Duluth, Minnesota

16 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE in the earth sciences. They are embodied, for exam- gested as periods of interest for continental climate ple, in the some of the foci of NSF programs such as studies because of their transitions or because of their Paleo-Perspectives on Climate Change (P2C2): potential as analogs for the present and the future; • What were the regional responses of coupled these include MIS stages 5 (a, e), 11, and 3. River fans climate systems like ENSO, monsoons, and the and deltas are attractive targets because such sedi- North Atlantic Oscillation during past climate ments commonly contain both marine and terrestrial changes? components, allowing comparisons of these realms. • What does the geologic record tell us about past New paleoclimate records, especially from Africa, climate sensitivity and the impacts of abrupt cli- lead to intriguing questions about the relationship be- mate changes under different boundary conditions, tween hominid evolution and the co-existing climate past climate states, or large, rapid changes in forc- and environment. The Lake Malawi Drilling Project, ing? for example, revealed the existence of major droughts, These questions imply a need for better understand- far exceeding the aridity of the last glacial maximum, ing of a number of critical aspects of the climate impacting tropical East Africa on a precessional fre- system, some of which can only be addressed with quency prior to 75,000 years ago, which undoubtedly drill-core sediments. One such aspect is the need to affected the welfare and migration of early man. Some define regional variations in climate on the continents, critical African records are available by drilling lacus- the so-called synoptic view of climate. High spatial trine sequences on dry land, which is inherently more resolution needs to be paired and balanced with high economical than lake-based drilling (see breakout re- temporal resolution of the climate record at any one port by Cohen, Campesano, and Feibel). The ques- site. It is clear that both modern climate and anthro- tion of the environment during hominid evolution also pogenic changes in climate vary considerably across leads to the broader question about biological evolu- individual continents, and that these patterns are in- tion of lacustrine and terrestrial species that co-occu- structive about climate mechanisms that are involved. pied the surrounding landscape (see breakout report Another critical aspect of climate reconstruction is its by Cohen, Michel and Wilke). utility for examining climate variability during times Much potential scientific advancement involves col- of different boundary conditions, including glacial laboration between the paleoclimate community and maxima and intermediate glacial-interglacial states. other disciplines in planning and executing lake drill- A number of time intervals are of particular interest ing projects. Spectacular successes have come from either because they represent climate extremes (e.g. drilling crater lakes (e.g., Bosumtwi and El’gygytgyn) the last interglacial or the last glacial maximum), or that contain both a record of impact processes and a because they appear to be times of climate instabil- paleoclimate record in the post-impact crater lake. ity (e.g. marine isotope stage (MIS) 3). Considerable Drilling in active rift basins (e.g., Baikal and Malawi) interest exists in late Pliocene climates, a time during has led to insights about the interaction of tectonics which CO was last higher than present anthropogeni- 2 and sedimentation in such basins. Much more could cally elevated levels. be done to involve other communities, including those This may be an appropriate time to develop a major that deal with biological evolution, such as those re- new drilling initiative involving Plio-Pleistocene sedi- lated to hominid evolution in relation to climate, dis- ments on the continents. There have been several ex- cussed above, and more broadly, those that study the citing breakthroughs in paleoclimate proxies and tech- organisms in lacustrine ecosystems. Finally, microbial niques in recent years that are yielding new insights life in extreme environments, including deep within into the history of rainfall, temperature, and wind sedimentary sequences, remains little explored. regime with impressive temporal resolution (Fig. 9). Several technological improvements would greatly Scanning X-ray fluorescence has revolutionized our help to advance the science. Incremental upgrades to ability to generate high-resolution records at relatively GLAD 800 drilling system would improve the opera- low cost. New organic biomarkers for temperature tion of many projects. Drill rigs bigger than the GLAD (TEX86 and MBT) and for rainfall (deuterium and 800 system are needed to drill the largest, deepest carbon isotopic composition of plant leaf waxes) are lakes in the world, which are targets of great scientific providing fascinating new insights into past climate interest. And of course, improved dating methods are dynamics on the continents. Rapid sedimentation rates always helpful. Progress is being made along these in most lakes are attractive because of the correspond- lines in, for example, paleomagnetic stratigraphy. ing time resolution for deciphering climatic events. Several of the marine isotope stages have been sug-

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 17 DRILLING TO UNDERSTAND BIOLOGICAL EVOLUTION IN LAKES Andrew Cohen1, Ellinor Michel2, and Thomas Wilke3

Species that diversified on islands formed the genesis of Darwin’s ideas on evolution; subsequent studies of similarly insular isolated habitats such as caves, springs and lakes have formed the basis for much of our understanding of speciation processes and rates of evolution. The investigation of evolution of endemic organisms, those restricted to a particular habitat and area (Fig. 10), allows evolutionary biologists to ask questions about the underlying causes of the diversity of life, which documents diversification rates and correlation with physical and ecological variables with a degree of precision and insight unavailable in groups of organisms with wider distributions. The evolution of species flocks in lakes (i.e. clusters of closely related species whose ancestor was also endemic to that lake) lends itself uniquely to collaborative investigation by biologists and earth scientists interested in scientific drilling (Michel et al., 2003). This is because drill cores from lakes can provide both a record of changing geological/environmental context for interpreting the evolutionary history, and can also yield fossils of the species flocks under study.

The most spectacular examples of intralacustrine speciation known from modern lakes come from ancient lake basins where water bodies have persisted for millions of years, making them sufficient for the evolution and diversification of extraordinary groups of organisms (Rossiter and Kawanabe, 2000; Albrecht and Wilke, 2008). Several of these lakes either have been drilled (Lakes Baikal, Titiacaca, Malawi) or are under serious consideration for future drilling projects (Lake Ohrid, see http://www.icdp-pnline.org/contenido/icdp/front_content. php?idcat=1277, and Lake Tanganyika). Furthermore, several paleolake basins with extraordinary but now extinct species flocks have also been drilled (e.g. the Newark Basin [McCune, 2004] and Paleolake Idaho of the Snake River Plain [Smith, 1987]). Drilling lakes with living and ancient species radiations presents exciting research opportunities, such as: • Studying the limnological origin of the lake and, therefore, the origin of its biotic elements. • Determining rates of speciation and diversification and timing of evolution and extinction events in fossil lineages documented from drill cores (e.g. Khursevich et al., 2000; Karabanov et al., 2004). • Documenting the rates of coevolutionary processes (for example, escalatory “arms races” between mollusks and their predators, e.g. West and Cohen, 1996), which are well known from ancient lakes (Fig. 11). • Constraining the timing of severe environmental catastrophes, such as dramatic lake level falls and volcanic eruptions, or the subsequent refilling of lakes, which in turn allows calibration of molecular clock estimates for diversification histories (Cohen et al., 2007). • Relating repeated diversification events within a lake basin to cyclic processes such as Milankovitch processes.

Figure 10. SEM image of an endemic and undescribed cyp- Figure 11. A unique biogenic habitat in Lake Tanganyika ridopsine ostracode from Lake Malawi drill core MAL05-1c, showing a branching sponge on a shell bed made of remains dating from approximately 129ka. Many lakes are isolated from the endemic gastropod Neothauma tanganyicense and ecosystems and ideal natural laboratories for studies of evolu- the bivalve Coelatura burtoni. This habitat is additionally tionary processes, rates, and interaction with external factors. home to endemic fish, crabs, and bryozoans, some specialized to this habitat. (Photograph courtesy of John Mischler/ 1 University of Arizona, Tucson, Arizona Nyanza Project) 2 Museum of Natural History–London, and ICZN 3 Justus Liebig University, Giessen, Germany

18 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE • Studying concordance between major geological/ address questions of fundamental interest to the evo- limnological/environmental changes and evolu- lutionary biology community and offer new oppor- tionary events (see Fig. 12). tunities for interdisciplinary collaborations between • Inferring the driving forces for the evolution of biologists and earth scientists interested in evolution endemism (i.e., the influence of environmental (Fig. 12). stability vs. rapid changes). Long drill cores from ancient lakes, such as those currently proposed for Lake Ohrid, have the potential to

Figure 12. Proof of principal for testing whether environmental factors drive intra-lacustrine diversification in Lake Ohrid. The broken red lines show the estimated constant speciation rate from a molecular phylogeny of 16 Dina leech species and its modelled standard deviation. The blue line shows actual changes in speciation rates in those species based on a lineage-through-time plot. These changes in speciation rates are attempted to link to major geological, limnological, and environmental changes inferred from sediment cores (indicated as hypothetical red squares). (Figure courtesy of Tom Wilke)

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 19 HUMAN EVOLUTION AND SCIENTIFIC DRILLING Andrew Cohen1, Christopher Campisano2, and Craig Feibel3

Understanding the evolution of humans and our close fossil relatives is one of the enduring scientific issues of modern times. Scientists have long speculated on how and when we evolved and what conditions drove our evolution. The research needed to address these questions is interdisciplinary, involving anthropologists, biologists, and earth scientists. In addition to the difficult task of finding, describing, and interpreting hominin fossils (the taxonomic tribe that includes Homo sapiens and our close fossil relatives from the last 6 Ma), much of modern geological research associated with paleoanthropology involves understanding the geochronologic and paleoenvironmental context of those fossils. When did they live? What were the climatic conditions they experienced? How did both local and regional climate processes combine with regional tectonic boundary conditions to influence their food resources, foraging patterns, and demography? How and when did these conditions vary from humid to dry, or cool to warm? And can the history of those conditions be related to the evolution, diversification, stasis, or extinction of hominin species (Fig. 13; Vrba, 1988; Potts, 1996; Campisano and Feibel, 2007; Kingston et al, 2007)?

Figure 13. The Lake Malawi Scientific Drilling Project drilling barge in 2005. Results from this project provide evidence for extraordinary early Late Pleistocene megadroughts in tropical Africa, which may have significantly impacted early modern human distribution in the region.

Most of the efforts to address these questions to date have centered on evidence available from the outcrops where the hominin and other fossils have been collected. Earth scientists have made great strides in understanding these contextual questions using fluvial, paleosol, and marginal lacustrine sediments associated with hominin fossils. However, this approach has its limitations. Outcrops, for example, cannot normally provide us with continuous, unweathered stratigraphic sections needed to address many questions relating events in hominin evolution and environmental change (Fig. 14). The places where hominins actually lived, for example, above the water table, tend to have only discontinuous and relatively low resolution lithostratigraphic records of climate and other aspects of environmental change. For these reasons the paleoanthropology community has turned to drill cores as a potential source of more highly resolved paleoenvironmental information. This concept is not new. Almost 30 years ago, the NSF sponsored a workshop to examine how long sediment drill cores from the deepest and oldest of the modern African rift valley lakes might inform our understanding of the environmental context of early hominin evolution (Lewin, 1981). DeMenocal (1995) demonstrated how the Northeast African paleoclimate could be inferred from dust records encased in DSDP drill cores collected in the Gulf of Aden. This paper, as well as subsequent ones by the same research group (deMenocal, 2004; Feakins et al., 2005), provided the first more-or-less continuous offshore record of Neogene climate for hominin evolution occurring nearby terrestrially and also set out a research agenda for investigating the possible role of orbital forcing mechanisms on the timing of hominin evolution. The idea of drilling the African Great Lakes ultimately came to fruition in 2003 with the successful completion of the Lake Malawi Drilling Project (Scholz et al., 2006), which had important paleoclimate implications for hominin evolution and the expansion of anatomically

1 University of Arizona, Tucson 2 Arizona State University, Tempe 3 Rutgers University, New Brunswick, N.J.

20 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE modern humans out of Africa (Fig. 13; Cohen et al., 2007). These successes have motivated the paleoanthropology community to join forces with the scientific drilling community to seek out new opportunities for using drill core records to address paleoclimate and paleoenvironmental questions of fundamental importance to the interpretation of human origins, and several workshops have been held in recent years to explore the potential of drilling for these purposes (Cohen et al., 2006; Cohen and Umer, 2009). Such records could come from a variety of sources, including marine cores and deep lakes as discussed above, but also from paleolake sediments now exposed on land or just below the surface. The Hominin Sites and Paleolakes Drilling Project initiative (HSPDP), which is already underway (http://www.icdp-online.org/ contenido/ icdp/front_content.php?idcat=1225), seeks to collect cores from lacustrine sediments in sedimentary basins around East Africa that span key intervals in hominin evolution and that are located adjacent to important hominin fossil and archaeological sites. As with Lake Malawi, these paleolake deposits hold the key to obtaining high-resolution earth history, records during intervals and in places of particular interest to paleoanthropology. Similar research opportunities exist in other key regions for hominin evolutionary history, such as lake deposits in central China or the extant but Figure 14. A ~1.5 Ma hominin trackway in marginal lake deposits from the Koobi For a Formation, Turkana Basin, northern Ke- ancient lakes of Sulawesi, Indonesia. Many ancient nya. The Turkana Basin is one of the areas currently under active lake basins also offer the potential to examine earth consideration for new scientific drilling to address human-origins history influences on human evolution, such as vol- questions. canic eruptions and tectonic history and even impact events. Thus, an outstanding potential for collaboration exists between the paleoanthropology community and a wide range of other groups of scientists who can benefit from continental scientific drilling.

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 21 GEOMAGNETIC OPPORTUNITIES THROUGH CONTINENTAL DRILLING Joseph Stoner1

We study the paleomagnetic record for many reasons, with the most fundamental being the reconstruction of the past history of the geomagnetic field and understanding the geodynamo that creates it. Paleogeomagnetic observations provide increasingly precise models of the core and geodynamo that cannot otherwise be obtained. Change is the one geomagnetic constant, and understanding geomagnetic change is likely the key to deciphering the geodynamo. Geomagnetic change is also a critical component of Earth’s near-space boundary conditions that govern Earth’s influx of cosmic radiation. However, as a community our knowledge of what governs geomagnetic change is rudimentary at best. Geomagnetic change is the basic component of magnetic stratigraphy. The Geomagnetic Polarity Time Scale (GPTS) has been called the backbone of Cenozoic stratigraphy, with its use in earlier times continuing to be developed. Yet, we still do not know why the polarity reverses and we currently have no predictive power to tell when it will do so again. Polarity reversals of short duration (< a few thousand years), known as excursions, are now known to be a common component of geomagnetic field history; they are often poorly resolved and, therefore, poorly understood. Relative paleointensity, which measures change in the strength of the magnetic field, as opposed to its polarity, is a grow- ing and improving stratigraphic technique covering, at present, the last few million years. Linked to other time scales, it permits more ever more precise dating of past events. A global and historical observational data set would provide a clear path toward progress on all of these questions, with the objective of developing theory to explain and predict geomagnetic change not out of the question. Rarely are geomagnetic objectives considered when initiating a drilling program. However, the use of the paleomagnetic record for stratigraphy is often relied upon, and it will only Figure 15. Relative paleointensity (RPI) stratigraphy in the marine be improved through a better understanding of the realm. Top: Three recent compilations: The Equatorial Pacific pa- geomagnetic field and the processes that govern its leointensity stack, EPASIS-3, covering the past 3Ma (Uamazasaki & recording in rocks and sediments. Many different Oda, 2005), the PISO-1500 paleointensity stack compilation for the drilling projects would provide the necessary pre- past 1.5 Ma, combining oceanic data from from 13 sites worldwide, but mostly in the North Atlantic (Channell et al., 2009), and Sint-2000, cise geomagnetic record to contribute to the overall based upon 10 sediment cores worldwide and covering the past 2 Ma geomagnetic record. (Valet et al., 2005). B. High resolution global paleointensity stack of the past 75 kyr (GLOPIS-75; Laj et al., 2004). Data from cores of lake Drilling provides the unique opportunity to sample sediments and other high-resolution continental sites can improve both otherwise inaccessible archives. From a paleogeo- resolution and spatial distribution of the data sets. magnetic standpoint, continental drilling can provide needed observations from a global prospective to move the field closer to a theory of geomagnetic change. Observations from distributed locations would include the development of long high-resolution paleomagnetic (directions and intensity) time series, the recovery of deeply buried geomagnetic features of interest (reversals, excursions) recorded at a high temporal resolution, and provision of unique paleomagnetic observations from the distant past. Ocean drilling has provided some initial intriguing observations; continental drilling could

1 Oregon State University, Corvallis, Oregon

22 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Figure 16. Full vector geomagnetic reconstruction for the last 70,000 yrs from ultrahigh resolution sediments of the Chilean Margin drilled during ODP Leg 202 (Stoner et al., 2008). take this much further by providing many more high at resolution relevant to society is the Holy Grail of resolution records over a range of time intervals. And paleomagnetism. Such records are needed as they pro- together there are unique opportunities than can be vide a paleomagnetic output that well approximates exploited as the magnetic field and magnetic stratig- geomagnetic input without the smoothing that has raphy does not care if it is recorded at land or at sea. greatly affected much of the sedimentary paleomagnetic record. Few such records exist beyond the Holo- Relative Paleointensity cene, those that do are changing the way we view the geomagnetic field. Figure 16 shows a full vector geo- Variations in the past strength of the geomagnetic magnetic reconstruction for the last 70,000 yrs from field have been reconstructed from marine sediment ultrahigh resolution sediments of the Chilean margin acquired from every ocean basin. This record is now drilled during ODP Leg 202 (Stoner et al., 2008). The tightly constrained to marine oxygen isotopes going 135-mcd u-channel-derived directional paleomagnet- back 1.5 Ma (Channell et al., 2008; Fig. 15) and to the ic secular variation (PSV) and relative paleointensity Greenland GISP2 ice core for the last 100 kyr (Stoner (RPI) records from ODP Site 1233 (41.0 S, 74.26 W, et al., 2000). While few terrestrial records are avail- water depth 838 m) recovered sediments with excep- able, the high quality record from Lake Baikal (e.g., tionally high sedimentation rates of ~ 2 m/kyr during Peck et al., 1996) shows that there is great potential. the last glacial. The directional PSV records resolve a Obtaining globally dispersed records will allow us to cyclical pattern and comparison between that and RPI study the differences as well as use the similarities for are just beginning to be made. The most remarkable stratigraphy. feature is the Laschamp excursion found centered at 41,000 BP. The Site 1233 chronology indicates that Ultra-high Resolution Paleomagnetic Records the Laschamp event and has a duration of reversed Obtaining high quality observations of the geomag- polarity of only 600 years, with polarity transitions netic field (direction and intensity) back into the past occurring in less than 200 years within a 1500 year-

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 23 long interval of low RPI. The path of virtual geomag- terrestrial synchronization of paleoclimate records. As netic pole (VGP) positions show a large clockwise an initial proof of concept we have been working on VGP loop that, unlike any prior observations, begins the synchronization of sediment records from in and and ends at approximately the same Alaskan location around Iceland. Figure 17 illustrates initial declination with a complete around-the-world tour in between. comparisons between marine cores MD99-2269 and This ability to dissect an excursion at this resolution is 2265 on the Iceland shelf and Icelandic lake sediment unique, but it does not have to be. If we are to under- from Haukadalsvatn (HAK) and Hvitarvatn (HVT), stand the processes that generate excursions, a global collected as part of the GLAD4 drilling of Icelandic distribution of sites are needed, with records from lakes in 2003. The identification of tephra layers and lakes being an excellent target. numerous radiocarbon dates permit assessment of the accuracy of the correlations. Similar studies could be Marine-Terrestrial Correlations undertaken in many parts of the world. Paleomagnetic records are not limited to marine or terrestrial settings and therefore are optimal for marine-

Figure 17. Initial declination comparisons between marine cores MD99-2269 and 2265 on the Iceland shelf and Icelandic lake sediment from Haukadalsvatn (HAK) and Hvitarvatn (HVT), collected at part of the GLAD4 drilling of Icelandic lakes in 2003.

24 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: DEEP TIME Kenneth Miller1 and Will Clyde2

The Earth system has undergone remarkable changes over deep geological time. Climates have varied from “snowball Earth” conditions to extreme “greenhouse” conditions. The biosphere has undergone numerous mass extinctions and adaptive radiations. Continents have been inundated by high sea levels, and biogeochemical cycles have evolved in tandem with the biosphere and the chemical composition of the Earth. These changes have imprinted the geological record in unique ways providing Earth scientists a way to reconstruct them and understand their interconnections. A rigorous understanding of geological processes operating over various time scales and under a wide range of boundary conditions offers important perspective on the current state of the Earth system and how it may change under anthropogenic influences. The deep time Earth science community has benefited tremendously from the well-organized ocean drilling program over the last several decades. Despite many individual successes, continental scientific drilling has been relatively underutilized to investigate deep time. During the Future of Continental Scientific Drilling (FCSD) workshop, there was a clear consensus among the participants that an organized and vibrant continental scientific drilling program would lead to better resolved, better quality, and better archived geological records with which to investigate deep time. These records in turn could lead to fundamental breakthroughs in our understanding of many key scientific questions that have also been identified in other recent community-based, agenda-setting documents (e.g., “Earth, Oceans, and Life,” IOPD 2001; “The Importance of Deep-Time Geologic Records for Understanding Cli- mate Change Impacts,” Ongoing National Research Council Project).

Climate Change Orbital Influences on the Earth System— The recognition that relatively small and predictable changes in Earth’s orbit strongly influenced the Earth system over recent geological time intervals has initiated significant interest in understanding the role of orbital variations in shaping the Earth system over Figure 18. Scanned gamma-ray (left scale), neutron (dashed on right scale), long geological time intervals. Geological and resistivity (solid on right scale) log from the Rains and Williamson Oil, Inc. Becker “B” #1 oil well in Russell County, Kansas, shows the Middle and records of orbital variations potentially can Upper Pennsylvanian (Upper Carboniferous) strata of the region. Alternation be used to develop a precise astronomical of limestone and red, gray, or black shale in the Pennsylvanian and Permian of time scale for the entire Phanerozoic (e.g., the U.S. mid-continent has long been thought to reflect orbital cycling. Succes- Westerhold et al., 2007) and to test sensitiv- sions like this may help test the ideas of Olsen & Kent (1999) and Laskar et al. (2004) about stability of orbital interaction among planets of the solar system. ity to climate forcing under a wide range of (Depth in feet; log from Kansas Geological Survey Website) boundary conditions. Hypotheses to be test-

1 Rutgers University, New Brunswick, New Jersey 2 University of New Hampshire, Durham, New Hampshire

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 25 ed include: 1) orbital variations during greenhouse pe- drilling. Cores provide the stratigraphic continuity and riods of Earth history differ in expression and periods unweathered samples necessary to reconstruct the kind from icehouse periods because they are driven by car- of detailed geochemical and biological records nec- bon cycle, not the cryosphere; 2) orbitally controlled essary to rigorously address these questions. Recent climate changes were an important influence on biotic advances in the precision of isotopic dating methods changes (e.g., Van Dam et al., 2006); 3) orbital param- provide new opportunities to test alternative hypoth- eters obtained from deep time can be used to constrain eses relating to orbital forcing. The geochronological the dynamics of the solar system over long time scales methods themselves may be further improved by the (Fig. 18; Olsen and Kent, 1999). ability to astronomically tune isotopic decay constants (e.g., Kuiper et al., 2008). All of these fundamental questions of Earth history require the development of high-resolution stratigraph- “Abrupt” Climate Change—Abrupt (e.g. < 10,000 ic records that are best obtained through continental years) changes in climate are an important feature of

Figure 19. Top: Summary of plant turnover in the Bighorn Basin of Wyoming across the PETM. Composite basin-wide record of carbon isotope values from paleosol carbonates is shown at left (PDB = Pedee belemnite standard) with macrofossil record in center and microfossil (pollen) record at right. DCA scores are from detrended correspondence analysis of sites-by-species matrix of presence/ab- sence data. Notice the large magnitude yet transient change in floral composition associated with the PETM carbon isotope excursion. All plant data are from Wing et al., 2005. (Clyde and LeCain, in review; figure courtesy of Will Clyde). Bottom: Summary of mammal turnover in the Bighorn Basin of Wyoming across the PETM. Composite basin-wide record of carbon isotope values from paleosol carbonates (left) shows characteristic negative excursion at PETM (PDB = Pedee belemnite standard). The peak in first appearances coincident with the PETM represents the influx of Wasatchian immigrants (FAD = first appearance datum, LAD = last appearance datum). Immigrant species represent ~20% of fauna (shaded area) upon their immigration yet come to represent ~50% of all individuals (white area) soon after their first appearance. Species richness rises dramatically in response to immigration event and then declines to levels in Wasatchian that are still higher than during preceding Clarkforkian (Clarkf.) time. Mean species size increases dramatically at PETM due to influx of larger bodied immigrants whereas mean individual size decreases temporarily during brief warming of PETM due to dwarfing of many lineages. Trophic structure also undergoes significant turnover across PETM, herbivores and frugivores become more important in new Wasatchian community structure (PC-1 = score on first principal component). Dashed lines represent 95% confidence intervals. Figure modified from Clyde and Gingerich, 1998. (Clyde and LeCain, in review; figure courtesy of illW Clyde)

26 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Earth history. They include both warming (e.g., Pa- • Defining the sedimentary and sequence strati- leocene/Eocene Thermal Maximum or PETM; Fig. graphic responses to eustatic change in siliciclas- 19) and cooling (e.g., Oi-1) events that may illustrate tic, carbonate, and mixed-depositional settings. fundamental behaviors of the Earth system. Under- This also necessitates deciphering the complex standing the causes and effects of these anomalous interactions between eustasy and local processes, particularly rates of vertical tectonism (uplift, sub- events in a world with different boundary conditions sidence) and sediment supply. from today could lead to the identification of thresh- olds or feedbacks in the Earth system that would Continental scientific drilling is an essential tool for otherwise go unnoticed by studying only more re- achieving these objectives because sediments repre- cent geological time. Core records of these events in senting key paleoenvironments and time periods are rapidly subsiding continental basins and continental seldom adequately exposed in outcrop. Furthermore, margins would offer expanded stratigraphic records outcrop sections cannot sufficiently constrain the third with which to reconstruct cause and effect of these dimension of stratigraphic architecture that is charac- events and compare to the biogeochemical proxies teristic of passive margins and other sedimentary ba- from deep marine records. sins.

Carbon Cycle Dynamics—The carbon cycle has Evolution and Extinction played an important role in modulating the evolution of the Earth’s surface, yet its behavior over The most unusual characteristic of the Earth’s sur- long time scales remains poorly constrained. For face compared to other planets is the presence of a instance, what are the major controls on the balance biosphere. Deciphering the evolutionary dynamics of of carbonate precipitation and burial of organic car- the Earth’s biosphere over geological time scales has bon? Atmospheric concentrations of carbon-based long been an important focus of Earth scientists and biologists. By understanding the fundamental con- greenhouse gases (e.g., CO2 and CH4) have been important climate drivers throughout Earth history, but trols on evolution and extinction, we can better pre- the controls on their concentrations and the sensitiv- dict and manage the response of modern ecosystems ity to climate change are hotly debated. The geologi- to anthropogenic influences and develop an integrated cal record has abundant evidence of carbon cycle understanding of Earth system feedbacks. Many of the dynamics in the form of carbonate precipitation and most reliable and spatially integrated biological prox- organic carbon deposition. There are also many in- ies (e.g. fossil pollen, taxon-specific biomarkers, mi- stances where the carbon cycle was perturbed over crofossils) are best recovered from cores because they relatively short time intervals (e.g., Ocean Anoxic are unweathered and stratigraphically more complete Events, PETM) providing natural geological experi- than outcrop records. The most interesting evolution- ments with which to investigate the rates and feed- ary questions today are interdisciplinary and many of backs of carbon-cycle dynamics. them intersect other major continental drilling foci listed above. For instance, the following hypotheses Sea-level Change—One of the objectives of the can be tested: 1) diversification and extinction rates earth sciences most relevant to society is to under- were controlled by orbitally paced climate change; 2) stand the history and impact of global sea-level (eu- evolution has shaped the carbon cycle over long time static) fluctuations at different time scales. A recent scales with various feedbacks; and 3) sea-level change Joint Ocean Leadership, ICDP, IODP, DOSECC has deeply affected the evolution of marine organ- and Chevron Sponsored Workshop was held on isms (e.g., Katz et al., 2005). Continental drilling can Drilling to Decipher Long-Term Sea-Level Changes provide the detailed and pristine stratigraphic records and Effects (http://www.oceanleadership.org/files/ needed to address these questions in a systematic and Sea_Level_Workshop_Report.pdf). This workshop rigorous way. identified two main goals: • Determining the pattern of global sea-level Developing a Deep Time Coring Culture change (eustasy) through Earth history and identifying and quantifying the mechanisms Much of the Deep Time discussion at the FCSD work- responsible for eustatic change through geo- shop was focused on the fact that the Earth history logical time. Determination of eustatic timing, community is unfamiliar with, and often intimidated amplitudes, and rates are essential prerequisites by, continental scientific drilling despite the obvious to assessing mechanisms, as is incorporation of scientific advantages that it could offer. Aside from results derived from proxy records. the improved quality, resolution, and consistency of samples, continental drilling could serve as a positive

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 27 sociological node for scientific exchange among di- the development and support of numerous low cost/ verse colleagues in much the same way that DSDP/ low risk Deep Time drilling projects, in addition to the ODP/IODP has done for the marine sciences commu- more traditional large scale projects, could help en- nity. It is not hard to imagine how a healthy conti- gender a culture, and later heritage, of drilling in the nental drilling program would draw together existing community. Only with this culture in place will the Deep Time initiatives (e.g., Geosystems, Earthtime, full benefits of continental drilling for answering Deep MARGINS). With experience comes familiarity so Time questions be achieved.

28 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE ANTARCTIC SUB-ICE GEOLOGICAL CORING AND DRILLING Compiled by Ross Powell1 and Stefan Vogel1

Recent sub-ice drilling programs such as ANDRILL and Lake Elgygytgyn are showing that long geological records of ice sheet dynamics and high-latitude paleoclimate are invaluable for integrating with lower latitude records of past climatic and sea level changes. They not only add dimension and provide constraints on the more common lower latitude data, but they also provide new, unique understanding of the global dynamics involved with such changes. These subglacial targets are now at a stage where they are potentially accessible through a combination of ice and geological drilling. Current high-latitude drilling projects have made important steps in technology development that point the way toward achieving these goals. Some further development of technologies is necessary, and new workshops will be needed to advance the ideas stemming from those that already have been held. Subglacial geological drilling holds huge potential for the future of high-latitude geoscience.

Sub-ice environments are notoriously difficult to access for data to constrain ice dynamics models, thus data sets are few. At this point, most of our knowledge about subglacial systems derives from geophysical remote sensing with isolated local data from access holes to the bed or sub-ice-shelf cavity. However, rigorous inferences about these systems require broader and more detailed data sets, better coverage of different conditions of the systems, and quantitative analyses especially for testing ice sheet models. These unknowns about ice dynamical responses to warming led the IPCC, in their 2007 report, to place lower bounding limits on predictions of future sea level rise rather than being more definitive, and they urged the need for more data collection.

Over the last decade or so, scientists have further recognized the complexity of sub-ice environments Figure 20. Modern Antarctica showing potential subglacial drainage systems and known subglacial relative to the microbial lakes where sediment may host a unique geobiological community as well as preserving archives of ecosystems they host. In Antarctica’s ice sheet (and inferred global sea level) and climatic history. (Courtesy of Zina Deretsky, NSF, http://www.nsf.gov/news/news_images.jsp?cntn_id=109587&org=NSF) this regard, there is intense scientific and public interest in the large subglacial lakes that are being documented, especially below the Antarctic Ice Sheet (Fig. 20). Data from such systems broaden our understanding of the phylogenetic and physiological nature of subsurface microorganisms that exist under dark and cold conditions on earth, and also inform predictions used in exploration for extra-terrestrial life.

Geological and Tectonic History The geological and tectonic history of Antarctica is far from fully known due to the continent being almost entirely covered by thick ice. Yet the continent and its lithospheric plate play important but poorly understood roles in global tectonic architecture. Antarctica is considered aseismic, making it anomalous in comparison with other continents. Furthermore, its plate is surrounded by mid-ocean-ridges and hence should be under compression, yet there are active extensional regimes. The West Antarctic Rift System, one of the largest on

1 Northern Illinois University, DeKalb, Illinois.

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 29 Earth, has the unique attributes of having only one worth, may contain sedimentary records of ice-sheet rift shoulder and being largely below sea level. Con- dynamics extending far back to the initiation of the straints on composition and age of basement rocks ice sheet. In West Antarctica, the stratigraphic record of interior East Antarctica would place better con- in various basins and probable rifted grabens will constraints on Precambrian provinces and the evolution tain a mid-late Mesozoic(?) and Cenozoic history of of the Antarctic shield for verifying current models. West Antarctic evolution and paleoclimate history. The stress state in basement rocks provides greatly Two low-lying regions within the Wilkes Land sector needed information for evaluating seismicity and of East Antarctica (Aurora and Wilkes Subglacial Ba- extensional regimes. Drill holes into crustal rocks sins) appear as broad down-warped epeirogenic basins would allow passive and active seismic experiments filled by marine and non-marine strata. They may well for delineating crustal structure. contain evidence of the much debated past dynamics and paleoclimate of the East Antarctic Ice Sheet. A significant control on glaciation is continental topography, with rising mountains and higher eleva- Access holes are required to recover longer sedimen- tions focusing snow accumulation and becoming tary rock cores comparable to those from the continen- nucleation centers for ice sheets. Sampling bedrock tal margins. Technological developments are required to determine its age and uplift history is important to integrate geological-drilling technologies with for reconstructing paleo-topography for modeling those of ice drilling, including clean access. Geologic Antarctic Ice Sheet history. drilling beneath an ice sheet requires access holes to remain open for an extended period and consideration Borehole access to the ice sheet bed is required to of differential movement of ice over the bed. recover rock and sediment cores for these studies. A number of workshops have resulted in a list of Paleo-ice Surface Elevations, Paleo-land Surface high priority targets. However, as bedrock samples Topography & Ice-sheet History from beneath the Antarctic Ice Sheet are currently limited to debris in the ice, any sample of opportu- Estimates of ice-volume evolution and associated sea- nity recovered from bedrock and analyzed will pro- level change depend on knowledge about paleo-ice vide valuable information. Locations for targeted surface elevation and bed topography. Geological de- sampling should be selected based on best estimates posits found around continental mountains and nuna- of bedrock geology, paleo-topography and plausible taks provide information about paleo-ice-sheet thick- ice sheet extents based on models. ness during previous ice-sheet maxima and retreat. Ice-sheet models also rely on bed topography because Deep-time Paleoclimate ice sheets nucleate on highlands and basal melting that lubricates the ice sheet bed occurs within deep basins Records of glaciation in Antarctica occur in scat- and troughs. Due to the lack of paleo-topographic tered terrestrial deposits and sedimentary basins and data, ice-sheet models currently use existing topogra- can be compared with offshore records. New long phy adjusted for isostatic rebound. geological cores are being collected near the ice sheet margin by the ANDRILL and SHALDRIL pro- Dating and analyses of subglacial rock samples will grams. Interior subglacial basins also likely contain provide time constraints and a better understanding of proxy records of paleoclimate and ice-sheet history tectonic and igneous events leading to the formation of to complement these records from the continental highlands and basins throughout Antarctica’s history. margins. Three main categories of sedimentary tar- Furthermore, radiogenic exposure dating of subglacial gets are subglacial lakes, West Antarctic rift basins, samples can establish the timing of ice-sheet fluctua- and East Antarctica epeirogenic basins. Individual tions and for constraining numerical ice-sheet models. targets within these categories can potentially pro- Incorporating such information into ice-sheet models vide a unique record of past ice sheet and climatic allows for more realistic reconstructions of paleo-ice- changes based on their geographic location, distance sheet behavior and sea-level change. from the ice-sheet margin, and frequency and mag- Tectonic processes such as uplift and subsidence sig- nitude of ice-sheet fluctuations. Thus they are prob- nificantly influence ice-sheet dynamics and crustal ably valuable libraries, and complementary pictures loading/unloading from changes in ice volume drive of past ice-sheet and climatic changes. subsidence/uplift that modulate land-surface topog- Of special interest are subglacial lakes, which occur raphy. Surface elevation influences temperature and throughout the continent. Subglacial lakes, such as accumulation rates, and whether ice sheets are frozen Subglacial Lake Vostok and Subglacial Lake Ells- to, or sliding at, their bed. Regional structural basins

30 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE may be locally forced below sea level or be formed subglacial lakes and other areas of hydrological inter- as narrow troughs by rifting processes, and pre-exist- est. Hole diameter requirements vary depending on ing faults weaken local rocks to allow easier erosion. instrumentation required; clean access technology is Changes in continental elevations over time signifi- required and the hole may need to be maintained open cantly change bed conditions on tectonic time-scales. for days. Consideration needs to be given to the differential ice motion when accessing the subglacial bed. Access holes to the ice-sheet bed are required to recover short rock and sediment cores for these studies. Sub-ice Microbial Ecosystem and Biogeochemistry Sites should be based on best estimates of bedrock geology, bed paleo-topography, and their location with Subglacial and basal zones, where both water and respect to the ice sheet margin. mineral matter come in contact with ice, sediment, or bedrock, represent environments for microbial life Subglacial Lakes and the Sub-ice Hydrological under otherwise frozen conditions. Ice sheets provide System one of the best matrices for studies on microbial lon- gevity, genome recycling, and environmental control Subglacial hydrology has been of interest to glacial on biotic diversity and evolution. Microbial cells and geologists and glaciologists ever since eskers were DNA should also provide valuable information that recognized as being sediment accumulations from can be linked to paleoclimatic change. Such life forms subglacial fluvial conduits. More recently sub-ice hy- may be the only biological survivors in areas covered drological systems piqued scientific interest as being by glaciations for millions of years and may provide important forces in ice dynamics, fast ice flow and crucial terrestrial analogs for extraterrestrial life sur- surges; subglacial weathering and erosion; sediment viving and persisting on icy planetary bodies in our transport and jokulhlaup events; hosting microbial solar system, such as Mars, Europa, or Ganymede. ecosystems; and maintaining subglacial lake systems. Transfer of significant volumes of water and sediment Investigating life forms, and the distribution, activity, occurs through these systems to the ocean. Subglacial and evolution of life within subglacial aquatic envi- meltwater may also play a role in Antarctic bottom ronments and their sediment, are a first-order goal of water formation and consequent global ocean circula- the U.S. polar microbiology community. Of particu- tion. lar interest are the characteristics of biological niches; biogeochemical cycling; evolutionary histories of mi- Although critical for ice-sheet stability, models of sub- crobial communities in subglacial lakes; the spread of glacial hydrology are rudimentary due to a lack of ba- isolated microbiological communities through the flux sic data on their nature, magnitude of flux, and degree of water; and the forward motion of thick layers of and rates of change. Hidden beneath kilometer-thick water-saturated till beneath fast-flowing ice streams. glacial ice, subglacial hydrological systems are diffi- A complex symbiotic system of biogeochemical pro- cult to characterize and quantify. cesses and chemotrophic life may exist beneath the About 150 subglacial lakes have been discovered in ice, mobilizing nutrients and subsequently transport- Antarctica, with Subglacial Lake Vostok being the ing them to and discharging them into the Southern largest. These lakes are interconnected through a sub- Ocean. It has been suggested that this nutrient supply glacial hydrological system of creeks and rivers simi- may influence chemistry of the polar ocean and per- lar to any other continental hydrological system, yet haps contributes positively to its fertility. confined by the overlying ice sheet. Studies of particu- The study of subglacial microbial communities and lar importance for subglacial lakes are those focusing the bio/geochemical processes are an important com- on spatial variability of life, the degree of hydrologi- ponent of studies investigating subglacial environ- cal interconnectivity between individual lakes, influ- ments and their role in the ice-ocean-lithosphere sys- ence of lakes on the rest of the subglacial hydrological tem. Similar to studies of the deep biosphere, proper system, and linkages with the Southern Ocean. Fur- integration of this component into an interdisciplinary thermore, as described above, some subglacial lakes drilling project at an early stage is fundamental. Spe- appear to house important sedimentary libraries of cial attention needs to be given to contamination is- ice-sheet and geological histories and climate change. sues (forward and backward) and the development of Access holes to sample basal ice and subglacial wa- appropriate clean access and sampling technologies. ter and sediments are required at selected sites over

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 31 CONTINENTAL DRILLING TO EXAMINE IGNEOUS PROCESSES AND GEODYNAMICS John Shervais1 and Eric Christiansen2

The fundamental processes by which planets evolve chemically, thermally, and tectonically involve the production of magma and the movement of this magma from deeper levels toward the surface. The formation of magma by partial melting chemically fractionates the source region into melt and refractory residue, and the subsequent movement of this melt to the surface transfers both heat and the chemically fractionated magma from one part of a planet to another creating its chemically stratified internal structure. On Earth, igneous processes operate on length scales that range from a few centimeters to the depths of the mantle—thousands of kilometers. At the shorter length scales (up to a few kms or tens of kms) the processes of interest are volcanic or sub-volcanic: how do volcanoes work? What are the hazards associated with a given volcano or class of volcanic structures? At the longer length scales (tens of kms to thousands of kms) the processes relate to geodynamics—the chemical and physical differentiation of the Earth on timescales of millions to thousands of millions of years. The National Research Council recently completed a report entitled “Origin and Evolution of Earth” (Com- mittee on Solid Earth Sciences, 2008), which outlines a series of ten grand research questions that should be addressed in the coming decades, including: How does Earth’s interior work and how does it affect the surface? Why does Earth have plate tectonics and continents? What causes climate to change? How has life shaped Earth—and how has Earth shaped life? Can earthquakes, volcanic eruptions, and their consequences be predicted? And finally, how do fluid flow and transport affect the human environment? Continental scientific drilling is not only an effective tool to address these questions (directly on the shorter-length scales and indirectly on the longer ones), but in many cases it is the only tool that can provide the data needed to address these questions systematically. Below, we reflect on the role of continental scientific drilling in the study of magmatic processes and of the broader geodynamic processes which govern them.

Magmatic Systems The study of magmatic systems in the crust may be divided into active volcanic systems and volcanic structures, including volcano-pluton connections. These topics overlap and interconnect but are most easily discussed separately. Active volcanic systems—Active volcanic systems are important both to science and society; hazards to human populations associated with volcanic eruptions are significant in many parts of the world and have in the past resulted in tens to hundreds of thousands of deaths. Understanding the life cycle of typical volcanic systems is crucial to managing the risk associated with their eruptions. Of particular interest are volatiles, both juvenile and meteoric, which drive most explosive volcanic eruptions and are the primary risk factors in post-eruptive hazards such as lahars and the mass failure of hydrothermally altered volcanic edifices (sector collapse). Under- standing these risk factors is critical to the prediction and monitoring of hazardous eruptions. Drilling in active volcanic systems has been demonstrated to be feasible and rewarding in terms of its scientific return by the Unzen Drilling Project in Japan, which intersected a volcanic conduit at depth beneath the volcano (Fig. 21). Volcanic-plutonic structures—Many targets crucial to understanding magmatic processes do not require drilling in active volcanic systems; they can also be found in older volcanic terranes that have not been breeched by erosion, which preserve their original stratigraphic and structural relationships. These structures occur in a range of distinct tectonic settings and include stratovolcanoes, shield volcanoes (both large and small), calderas (which may form in arc, rift, or plume settings), flood basalts and volcanic rift basins and their plutonic equivalents. How are volcanoes and plutons constructed and how do they evolve through time chemically and structurally? How are volcanic systems linked to their sub-volcanic roots?

1 Utah State University, Logan, Utah 2 Brigham Young University, Provo, Utah

32 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Figure 21. Core of conduit from Unzen Volcano, Japan. In 2004, drilling penetrated a dike that fed the 1991–1995 lava domes at a depth of 1975 to 1977 m or 1.3 to 1.4 km below the crater of the volcano and at an elevation of about 100 m above sea level. Information from such penetrations can help understand the physical state of the magma and the degassing process, which control the nature of the eruption and thus the form of the volcano and the danger of its eruptions to life and property. Volcanoes also may have hydrocthermal systems that affect the durability of the cone against catastrophic failure, and they may be the sites of formation of metal deposits. (From the Unzen Scientific Drilling Project website, http://hakone.eri.u-tokyo.ac.jp/vrc/usdp/new_e.html)

Geodynamic and Geochemical Evolution of crusts form and evolve. Even on Earth, plume-derived Earth—LIPS and Arcs magmas have a significant impact on the origin and evolution of continental crust and lithosphere. The The geodynamic and geochemical evolution of the replacement of sub-continental lithosphere by deep Earth are intimately linked to two dominant processes plume material may accompany flood-basalt volca- of heat transfer: plate tectonics (driven by the sinking nism, which will itself drive internal differentiation of of cold lithospheric plates in subduction zones to form continental crust by underplating or inflating the crust volcanic arcs and the rise of hot asthenospheric man- with mafic magma, by removing silicic melts from tle below midocean ridges to form oceanic crust) and lower crust and erupting them on the surface, and by the rise of thermally (and possibly compositionally) buoyant mantle to form hotspots with their associated ocean island basalts and flood basalts. The magmas formed in these distinct environments tell us about the nature of the source material and the processes that affected it during melting. In particular, plume-related magmas have been implicated in the breakup of continents and super continents and may contain information about the composition and even the structure of the deep mantle. In contrast, volcanic arcs typically represent processes in the upper 200 kilometers of the mantle that form continental crust. Volcanoes in either setting can have significant impacts on the Earth’s atmosphere and climate and vice versa. Plumes and LIPS—The connection between deep- seated mantle plumes, ocean island basalts, and large igneous provinces (LIPS) is becoming relatively robust as new techniques in mantle tomography establish visible connections between hotspot volcanoes and deep thermal anomalies. Because mantle plumes are inferred to initiate near the core-mantle boundary, it has been proposed that plume-derived magmas represent our best (or only) samples derived from the Figure 22. Schematic of mantle plume rising toward the Hawaii base of the mantle, and they may even contain com- hotspot potentially carrying material from base of the mantle or ponents from the core (Fig. 22; DePaolo and Weiss, the core-mantle boundary area and entraining material from low- 2007). On other planets, plumes may be the dominant er mantle. (From Bryce et al., 2005, Geochemistry, Geophysics, tectonic process and the principal way in which their Geosystems vol. 6, doi:10.1029/2004GC000809)

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 33 recycling hydrothermally altered rhyolites formed evolution of a volcanic province through time is one during earlier episodes. There is also the potential for of the most powerful tools we have for understanding lateral flow or delamination of the lower crust in re- the time-integrated response of these complex systems sponse to heating and inflation. and the processes that control them. Plume-derived magmas are least contaminated by crust Many of the projects or types of projects envisioned in the ocean basins, where they form ocean-island ba- here could be best approached through collaborations salts like Hawaii (sampled by the successful Hawaii with other programs, in particular ocean-based drill- Scientific Drilling Project and the Koolau Drilling ing programs like IODP. Other potential collabora- Project); however, the ocean basins are nowhere older tions include paleoclimate or impact studies, deep- then 180 Ma. Thus, if we want to study the occurrence time initiatives, and alternative energy resources such of plume-derived magmas and LIPS through time, we as geothermal power prospecting. There are many need to understand how these magmas interact with issues related to geobiology and the deep biosphere continental lithosphere, how this interaction changes that could be addressed in conjunction with continen- the chemical and isotopic composition of the resulting tal scientific drilling for igneous processes. The origin magmas, and how this interaction changes the chemi- and evolution of life are fundamental questions whose cal and isotopic composition of the subcontinental key may lie in the drilling of volcanic and hydrother- mantle lithosphere and continental crust. Large vol- mal systems. The short-term ecosystem responses and canic systems such as LIPS may also have significant long-term evolutionary implications of large volcanic implications for short-term climate change that can af- eruptions also could be studied with well-constrained fect biotic evolution and extinctions. These questions stratigraphic sequences sampled by drilling. We also are the subject of the proposed Project Hotspot, which need to identify igneous processes that are biological- focuses on plume-continent interactions associated ly important energy sources and the ecosystems they with the Yellowstone plume. support. The depth and temperature limits of the biosphere in igneous crust has not been established but Arcs—The large-scale evolution of volcanic arcs is could be examined in collaboration with studies of ig- fundamental to understanding how continental crust neous processes. forms. What magmatic processes create intermediate magmas? What roles do lateral accretion and mag- Practical Implications matic intrusion play in the growth of arc crust? Is the lower mafic crust of the arc recycled back into the Facilities and Equipment—To be successful, conti- mantle and, if it is, how is this accomplished? How nental scientific drilling needs to maintain a permanent much of the magma at a convergent margin is new ju- infrastructure that includes facilities, equipment, and venile addition to the crust and how much is recycled most importantly, trained personnel who are adept at older crust? What causes the intrinsically high water scientific drilling and know how to make each project and oxygen fugacities of arc magmas? These large as successful as possible. It would be inefficient and scale questions have not been addressed by continen- indeed reckless to let each project develop and imple- tal drilling but some have been addressed by ocean ment its own drilling infrastructure without the benefit drilling projects that sample the non-emergent parts of trained personnel in a dedicated support facility that of these systems. But there are many questions about could bring its own expertise and specialized equip- how arcs form and evolve that can only be addressed ment to bear. Continental drilling needs a facility simi- by drilling projects that look at the long-term life cy- lar to JOIDES that has the trained personnel, the spe- cle of magmatic arcs whose older roots are buried by cialized equipment, and the logistic capability to plan younger activity. and carry out a successful drilling campaign. Outreach & Education—It is critical that we educate Why Drill? the public about why continental scientific drilling is The rationale for continental scientific drilling to ad- important. We need to harness the public’s existing dress igneous processes and geodynamics is much interest in volcanoes (e.g., super eruptions) to engage the same as for other scientific drilling targets: many them in our research. And we need to emphasize the problems require continuous stratigraphic records that role of discovery in science—that breakthroughs in cannot be obtained by other approaches, especially scientific knowledge can’t be predicted, and that dis- in young volcanic provinces where uplift and ero- coveries involve risk. sion have not exposed these rocks in cross-section, or where they are poorly exposed due to surface weath- “if we knew what we were doing ering. The ability to study the chemical and isotopic it wouldn’t be research”

34 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE MECHANICS OF FAULTING AND EARTHQUAKES Stephen Hickman1, Emily Brodsky2, James Evans3

Earthquakes pose immediate risks to over a hundred million people (UNDP, 2004). Great progress has been made in the last century in identifying earthquake-prone regions, rapidly locating and measuring the size of earthquakes, and mitigating their disastrous effects on buildings. However, further progress in understanding earthquakes, fault-related fluid flow, and a range of earthquake-related problems is seriously hampered by a lack of understanding of the fundamental physics of earthquakes. The absolute stresses on faults before, during, and after earthquakes are unknown. The ways in which earthquakes interact and trigger new events is uncertain. The controls on partitioning of stress between large, damaging earthquakes and small, inconsequential ones or gradual creep are poorly understood. Many processes have been suggested as important in controlling the dynamics of earthquakes based on theoretical, laboratory, and geological studies. Most of these suggestions make specific predictions for measurable properties, long-term history, and behavior within active faults at depth. Yet, actually testing these theories is challenging from the surface of the Earth. Boreholes are required to retrieve samples from the depths of active faults, measure stresses, fluid pressures, and physical properties at seismogenic depths, and record signals close to the source from earthquakes as they happen. Only in this way can we truly understand the strongly coupled mechanical, thermal, hydrological, and chemical systems operating in active fault zones at depth.

Scientific Questions to be Addressed by Fault-Zone Drilling Drilling, sampling, and downhole measurements within active faults can substantially advance our understanding of the mechanics of faulting and earthquakes by providing direct observations on the composition, physical state and mechanical behavior of active faults at seismogenic depths (see reviews by Zoback et al., 2007; and Reches and Ito, 2007). As discussed at this workshop, fault-zone drilling allows us to address a number of first-order questions related to fault zone structure and mechanical behavior, including: • How do earthquakes start, keep going, and stop? By measuring the frictional strength of faults through direct borehole stress measurements and proxies, like heat dissipation, stresses on faults and their resistance to sliding can be determined throughout the earthquake cycle. Drilling is necessary because earthquakes initiate at depth—where processes leading to earthquake nucleation can be studied most directly—and frictional resistance during earthquake rupture is predicted to be measurably high at depth. Direct sampling of fault-related rocks also enables us to measure frictional properties in the laboratory. • How do faults evolve between earthquakes? By measuring the evolution of permeability and seismic velocity from repeated cross-hole experiments and downhole monitoring, we can capture the restrengthening of faults in preparation for the next earthquake. Drilling is necessary to separate the evolution of the surficial units, which are known to evolve strongly post-seismically, from the fault-zone evolution at the depths where earthquakes actually originate. • Why do some faults creep and others produce earthquakes? By recovering samples from creeping and non-creeping faults at depth and comparing their frictional, composi- tional, and microstructural properties in the lab we can identify the similarities and differences between them and identify processes controlling seismogenic versus stable (creeping) behavior. Drilling is necessary to reach the nucleation depths of faults that are known to have earthquakes, so that seismogenic faults and creeping faults can be directly compared. • Are earthquakes predictable? What factors control the size and recurrence of large earthquakes? By measuring the timing, location, and local stress fields of small earthquakes, the triggering stresses can be determined and thus the criteria for initiation constrained. Also, by reconstructing paleoseismic histories, the long-term patterns of earthquake recurrence can be elucidated. We can extend the paleoseismic record of ancient earthquakes obtained using traditional methods (e.g., on-land trenching) with lake drilling where the sedimentary record is

1 U.S. Geological Survey, Menlo Park, California 2 University of California, Santa Cruz, California 3 Utah State University, Logan, Utah

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 35 nearly complete. Drilling is necessary to measure By measuring fluid pressure, permeability, and flu- variations in seismicity, strain, fluid pressure, and id/rock composition across faults, the roles of faults other properties immediately before earthquakes as both barriers and conduits to fluid migration can that are not observable from the surface and to cap- be clarified. Drilling is necessary because hydro- ture the dynamic interaction between earthquake logic properties of faults are expected to change initiation and rupture and the local stress field. To markedly with stress, temperature, and local geo- extend the paleoseismic record further back in time, logic/geochemical conditions and, thus, active fluid drilling is needed to reach otherwise inaccessible flow systems need to be sampled at depth. Common lake and other deposits, allowing calibration against industry practice during drilling is to avoid faults fault trenches and high-resolution seismics. (or drill through them rapidly without sampling or measurements); thus, basic information on fault • How do new faults form and then evolve? properties and behavior in reservoirs is missing. By measuring the architecture of faults formed during discreet events like mining-induced earth- Drilling, downhole measurements, and direct sam- quakes, extraterrestrial impacts, or nuclear blasts, pling within active fault zones provide critical tests we can identify structures and processes related to of hypotheses arising from seismologic observations, the initial generation and evolution of faults as op- laboratory rock deformation experiments, and geo- posed to the reactivation of mature faults. Drilling logical observations of exhumed fault zones. Drill- is necessary to reach these structures at depth under ing provides the only direct means of measuring pore geologically relevant stresses and temperatures. pressure, stress, permeability, and other important pa- • Do faults and earthquakes stimulate or affect mi- rameters within and near an active fault zone at depth. croorganisms? What role, if any, do microbes play It is also the only way to collect fluid and rock sam- in fault-zone sealing and fluid pressure evolution? ples from the fault zone and wall rocks at seismogenic Is there a bio-tectonic fault zone cycle? depths and to monitor time-dependent changes in the By sampling fault zone fluids and mineral surfaces seismic wave field, fluid pressure, fluid chemistry, de- at depths, the possible feedbacks between life and formation, temperature, and other properties at depth faults can be investigated. Drilling is necessary be- during the earthquake cycle. cause biological processes are expected to change with depth and are not easily preserved in outcrop or contaminated mines. Also, fault zones are con- Recent Fault Zone Drilling Projects and Work- duits for exotic fluids and gases, and thus are likely shops hosts for biota not observed in other geological fea- A number of fault zone drilling projects have been tures. undertaken over the past several years to address the • Why do earthquakes happen far from plate bound- topics outlined above (Table 3; Fig. 23). The scientific aries? What controls intraplate earthquake distri- goals and accomplishments of these projects along bution in space and time? with the technological challenges facing fault-zone By measuring absolute stress, fluid pressure, and drilling in general were the topic of a joint ICDP/IODP heat flow in boreholes penetrating tectonically ac- Workshop on Fault Zone Drilling held in Miyazaki, tive intraplate faults and obtaining samples from Japan, in 2006. The proceedings from this workshop these faults, we can ascertain their similarities and were published as a special issue of Scientific Drilling differences with plate-boundary faults. Drilling is (Ito et al., 2007). Discussions at the Miyazaki work- necessary to determine absolute stress, fluid pres- shop highlighted a number of areas in which future sure, and heat flow in seismically active intraplate advances and cooperation in fault-zone drilling were areas and to obtain rock and fluid samples from urgently needed, including: active intraplate faults. Drilling is especially important for sampling, since intraplate earthquake • Developing or modifying drilling/coring tech- faults do not commonly break the surface. Drilling niques, mud systems, directional control, downhole and sampling within intraplate faults can also help measurements, and casing/cementation to maxi- reconstruct earthquake histories through dating of mize success in highly deformed and unstable fault veins and other deformation structures, which is zone environments. particularly important on these faults because they • Convening joint workshops and advisory panels to only rupture rarely. develop “best practices” for core orientation, core • What role do faults play in localizing or trapping handling, ephemeral gas/fluid sampling, and analy- oil, gas, and geothermal energy resources? How ses of cuttings and fluids. might faults affect the subsurface storage of natural • Strengthening ongoing information exchange on gas or geologic sequestration of CO ? 2 scientific, technical and logistical issues between

36 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE TABLE 3. Major recent or currently active fault zone drilling projects (after Ito et al., 2007; ICDP website, June 2009). Projects with asterisks (*) have had planning and/or scoping workshops and are in various stages of seeking funding or developing science plans.

Project Location/Earthquake Tectonic Setting Funding Agencies

NSF-Earthscope, SAFOD: San Andreas San Andreas Fault, Continental Transform ICDP, USGS, Fault Observatory at Depth Central California Stanford Univ. Chelungpu Fault, TCDP: Taiwan Chelungpu Arc-Continent Taiwan, Japan- Taiwan. 1999 Chi-Chi Fault Drilling Project Collisional Thrust MEXT, ICDP Earthquake

CRL: Gulf of Corinth Rift Helike Fault Zone, Continental Back-Arc EESD-European Laboratory Corinth, Greece Rift Union, ICDP

NanTroSEIZE: Nankai Nankai Trough, Subduction Zone Trough Seismogenic Zone IODP Southwestern Japan Megathrust Experiment

1995 Kobe Intraplate Strike-Slip NIED, GSJ, Japanese Nojima Fault Drilling Earthquake, Japan Fault Universities

NELSAM: Natural Mining-Induced Reactivated Intraplate ICDP, NSF, NRF- Earthquake Laboratory in Seismicity, TauTona Faults South Africa, MEXT South African Mines Gold Mine 2008 Wenchuan Wenchuan Fault Scientific Continent-Continent Earthquake Fault, Chinese Government Drilling Program Collisional Thrust China

CRISP: Costa Rica Errosional Subduction Costa Rica IODP Seismogenesis Project* Zone

Deep Fault Drilling Alpine Fault, New Exhumed Continental ICDP Project* Zealand Transform

Sevier Desert Drilling Sevier Desert Basin, Low-Angle Normal ICDP Project* Basin & Range, Utah Fault MOLE: Multidisciplinary ICDP, Instituto Intraplate seismicity, Observatory and Low- and High-Angle Nazionale di Central Apennines, Laboratory for Normal Faults Geofisica Italy Experiments* e Vulcanologia ICDP, Greek Forearc, Hellenic Crete* Greece Institutes & Subduction Zone Government

Eger Rift* Czech Republic Continental Rift Zone ICDP

GONAF: Geophysical North Anatolian ICDP, GFZ, Turkish Observatory North Continental Transform Fault, Turkey Government Anatolian Fault*

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 37 IODP, ICDP, and national (e.g., DOSECC) drilling communities. • Identifying and developing robust sensor and deploy- ment systems for long-term monitoring of strain, seismic waves, temperature, fluid pressure, and fluid chemistry in active faults at temperatures of >120ºC and under chemically hostile conditions. • Fostering new fault-zone drilling proposals in different geologic and tectonic settings through workshops and networking with existing scientific teams. Figure 23. Recent fault zone drilling projects have emphasized the synergy of using a combina- • Developing plans for rapid tion of techniques to identify the principal slip surface and identify the mechanical significance of drilling into faults imme- the extracted samples. For instance, in the Taiwan Chelungpu Drilling Project (TCDP), grain size diately after a large earth- analysis of the core was combined with seismic data from the 1999 Mw 7.6 Chi-Chi earthquake to quake, at the national and determine the energy budget of the fault (Ma et al., 2006; Figure courtesy of K.F. Ma). international level.

Following on this final recom- Solve by measuring: Seismic velocity, permeabil- mendation, a joint ICDP/SCEC Workshop on Rapid ity, deformation, and fluid chemistry. Response Drilling was convened in Tokyo, Japan, in • 2008 (Brodsky et al., 2009). Although the technologi- How do earthquakes trigger other earthquakes? cal, logistical, and financial hurdles for drilling into a Solve by measuring: Location, timing, and stress fault soon after a major (M ≥ 7) earthquake are for- interactions between aftershocks. midable, such a project would answer key questions • What are the geological properties necessary for about the initiation, propagation, arrest, and recur- nucleating an earthquake? rence of major earthquake ruptures. The scientific Solve by measuring: Mineralogy, deformation goals to be addressed by rapid response drilling into a micrsotructures, and frictional properties of fault major earthquake fault and the types of measurements rocks recovered from hypocentral depths. needed are as follows: As discussed in detail by Brodsky et al. (2009), • What is the frictional resistance during an earth- achieving these important objectives requires drilling quake? into an active fault at depths of 2 km or more within Solve by measuring: Temperature, hydrogeology, two years after an on-land earthquake with more than fault zone structure, and stress field at depth and 1 m of surface slip. mechanical properties in the laboratory. • How does a fault zone heal and prepare for the next earthquake?

38 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE IMPACT CRATERS, EJECTA, AND PROCESSES: SCIENTIFIC RATIONALE AND POSSIBLE TARGETS Christian Koeberl1 and Jeff Plescia2

Impact craters are important targets for deep continental drilling because they provide the types of data and samples necessary to address a broad spectrum of scientific questions. The study of impact structures and their associated deposits are an absolute prerequisite for understanding fundamental processes of Earth and planetary sciences. Processes to be examined include not only how impact craters form and their influence on the terrestrial environment, but, for example, the paleoclimate because they often provide depositional basins. Even though several impact structures have already recently been drilled by ICDP and DOSECC (Chicxulub, Mexico; Chesapeake Bay, USA; Bosumtwi, Ghana, and El’gygytgyn, Russia), much of that scientific work has focused on non-impact questions and the coring to date has been insufficient to answer many questions specific to crater formation. There are approximately 180 recognized impact structures on Earth rang- ing in size from ~300 km to a few tens of meters in diameter. Impact structures can be classified into three types: simple craters (e.g., Meteor Crater; Fig. 24), complex craters (e.g., Bo- sumtwi, Chesapeake Bay), and multi-ring basins (e.g., Chicxulub, Vredefort). Some structures are young, exposed, and easily accessible (e.g., Meteor Crater); others are completely buried and can be studied only by drilling and geophysical techniques. But, understanding all aspects of the cratering processes requires significant subsurface information even for craters exposed at the surface. Much of our understanding Figure 24. Meteor Crater, Arizona, and a schematic of a simple impact crater. Cratering is the most common surficial process on nearly all rocky bodies in the solar system, but knowledge of the about crater formation is processes and effects of cratering comes mostly from studies of configurations of well preserved based on surface morphol- craters on bodies other than Earth. (Courtesy of Jeff Plescia) ogy of extraterrestrial impact craters and on large chemical and nuclear explosions on Earth. In the case of the extraterrestrial examples, there is no subsurface information. While subsurface information is available for explosion craters, they are typically orders of magnitude smaller in energy. The largest nuclear event, Castle Bravo, released energy comparable to that of the Meteor Crater event. However, the Castle Bravo explosion did not produce a significant crater because it was detonated on a tower. Our current understanding, as revealed by direct examination of the subsurface character of terrestrial impacts and their deposits, is limited in most cases to data from a single drill hole. A single core has been obtained

1 University of Vienna, Austria 2 Johns Hopkins University, Baltimore, Maryland

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 39 through the entire section of the ejecta blankets of a simple crater (Meteor Crater), central peak crater (Ries), and a peak ring crater (Chicxulub); a single core has been obtained through the breccia lens on the floor of a simple crater (Brent, Canada). And few rather shallow cores have been obtained on the margins of the Chicxulub structure. A single drill hole represents, for a 50 km diameter structure, 1 x 10-10 % of the area or 1 x 10-4 % of the diameter (a small sample indeed!). No cores extend through or deeply into the central uplift or the floor deposits (allochthonous and au- Figure 25. Schematic of a complex impact crater with a central tochthonous fragmental material with and without uplift. Understanding the structure of such impact craters would melt or the melt sheet) of complex craters or the guide understanding of the processes involved and the extent of effects. In addition to forming the crater, the ejecta blanket and bounding faults of complex craters. No cores have any internal breccias and melt sheets, the impact causes an event been obtained into the walls of craters or sufficiently of shock-related deformation and fracturing of the target rock, set- deep through the floor, and away from the rim, that ting up potential for fluid circulation and development of micro- would make it possible to examine the manner in bial ecosystems. However, no type of craters (simple, complex, complex with peak rings) has been systematically drilled to exam- which the shock effects are attenuated with distance ine their configuration and the effects of their formation on nearby (Fig. 25). rocks.. (Courtesy of Jeff Plescia) Scientific questions at terrestrial impact structures cant depth below the crater and remain at shallow lev- that require drilling include: els after the impact. Within the central uplift, rocks • transient crater geometry at simple craters that were originally at greater depth are exposed, al- • central uplift geologic relations as a func- lowing access, in large structures, to lower crustal tion of depth and connection with deep rocks that would otherwise not be accessible. crater flow and spatial accommodation and Impact craters can produce relatively long-lived hy- how the observed structure is modeled drothermal systems. The studies of such systems have • central uplift collapse application to commercial mineralization, hydrother- • bounding fault geometries at depth—merg- mal alteration processes, and extremophile habitats. ing of bounding faults into a decollement or Because impacts excavate deep “holes,” they act as some type of distributed brittle deformation depositional centers. In a marine environment, such as Chesapeake Bay, the excavated basin allows for • nature of ring structure of large impact basins a thicker, hence higher-resolution, continental margin section that provides a more detailed record of • melt sheet—basement contact relations changes in a climate, ocean chemistry, and influx of • effects of water-bearing or volatile-rich interplanetary dust particles. Similar excavated basins rocks on the impact process on land host lakes that provide a long-term record of • spatial decay of shock effects and rock terrestrial climate change. Because there are local, re- damage and the temporal rates of fracture gional, and global variations in climate, records from healing. multiple locations need to be acquired and compared. This has implications not only for paleoclimate stud- Much of the data that would be acquired by exami- ies (e.g., Quaternary climate), but also for human ori- nation of these problems are relevant to other geo- gins studies. logic questions. Faulting associated with impact craters provides information on the inception of faults Ages of impact events are poorly known and can only in unfaulted rocks, rheology of granular flow, and be directly determined by analysis of melted material cataclastic deformation. The manner in which the produced by the impact, both in terms of radiomet- ejecta is deposited onto the surrounding surface and ric ages and biostratigraphic ages. Age data provide the collapse the ejecta cloud mimic process of a py- insight into the cratering rate on Earth and the cor- roclastic flow and collapse of ash columns. relation of impact events to terrestrial extinctions and the possibility of periodic increases in the crater rate. The center of complex impact craters typically has While there is a clear temporal association between a central uplift. There, rocks are raised from signifi-

40 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE the K-T boundary and its extinction and the Chicxulub minerals. The Cantarell oil field in Mexico, the world’s impact, the specific causality mechanism of the im- eighth largest, is associated with the Chixculub struc- pact has not yet been defined. Additional drilling at ture. Impact structures in the Williston Basin (US/ the Chicxulub impact could shed light on the target Canada), Ames (Oklahoma), Avak (Alaska), and oth- materials and the manner in which they were altered ers are important hydrocarbon reservoirs. by the impact and modified the global environment Drilling operations have been essential in linking nu- (Fig. 26). A particularly relevant question with respect merical models and geophysical data on impact struc- to impact-extinction correlations regards differences tures and their formation with the actual behavior of in the target rocks and how alteration of that material the rocks. No other methods can provide information changes the atmosphere composition and atmospher- on these important points that help to understand the ic thermal regime. Answers could come from a joint impact process. Many details are still unclear, in part project with IODP. because of the large variety in target lithology and Some impact structures are associated with significant impact parameters and the very small number of im- economic deposits. Sudbury (Canada) hosts Ni-Cu-Pt pact structures that have so far been studied in detail. Therefore, it is important to continue drilling at impact structures in order to test numerical models and provide ground-truth for geophysical interpretations. Scientific drilling of large craters provides essential petrologic, structural, geochronologic, and geophysical data, allowing a quantum leap forward in our understanding of the evolution of large impact structures and the physical, chemical, and biological processes that have operated within these craters over time. Links to other important topics in continental drilling (such as fault studies, paleoclimate, human origins, deep biosphere, natural resources) allow for joint projects. Determination of the energy relationships of impacts, their effects on the environment, and the impact Figure 26. Cross-section of the Chicxulub impact structure, Yu- catan, Mexico, showing possible borehole locations for a future hazard assessment provide essential socio-economic drilling project to unravel basic questions of the nature of the tar- reasons to use drilling in the study of impact processes get and the effects of the impact on the target. A combined on- on Earth. shore and off-shore drilling campaign would provide a much more complete image of the structure and the state of the surrounding rocks. (Courtesy of David Kring)

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 41 GEOMICROBIOLOGY Anthony W. Walton1 and Thomas Kieft2

The biosphere is now known to extend into the Earth’s crust to depths of at least 4 km in some locations, but the full extent of life at depth and its evolutionary and geochemical implications remain poorly understood (Fig. 27). Subsurface marine and terrestrial prokaryotes (bacteria and archaea, which comprise the bulk of the deep biosphere) make up 30 to 50% of the Earth’s living matter (Whitman et al, 1998). The uncertainty in the amount is due to the sparsely studied state of the terrestrial subsurface. The continental subsurface biosphere has been estimated to contain 22 to 215 Pg biomass C whereas the marine counterpart comprises 303 Pg biomass C (Whitman et al, 1998). The terrestrial subsurface biosphere has been sampled at a few sites in deep mines and wells drilled for various purposes, but has otherwise not been systematically studied. Drilling is the only way to get samples and measurements that describe the terrestrial subsurface biosphere. The lower depth limit of the biosphere is currently unknown but may be constrained primarily by temperature. The known upper temperature limit for life is approximately 121°C (Kashefi and Lovley, 2003) or perhaps even higher with elevated pressure (Takai et al., 2008). Energy sources also control the distribution of subsurface microbes. While the majority of subsurface ecosystems studied to date are supported by organic C derived from photosynthesis at the surface, exciting studies have revealed chemosynthetic subterranean ecosystems that gain

energy from geochemically generated inorganic energy sources, e.g., H2 (Stevens and McKinley, 1995; Cha- pelle et al., 2002; Lin et al., 2006). Far from being passive survivors, microbes shape their subsurface environs;

Figure 27. Almost every time the deep geobiosphere is sampled, new organisms are discovered, such as Henderson Group 1, which appears to be independent of all known divisions of bacteria (Sahl et al., 2008). The figure shows abundance of microbial divisions in water samples from a fracture in the Henderson Molybdenum Mine, Colorado. Sample 7025-D1 (left) was taken before inserting a packer into the drill hole accessing a water-filled fracture; the other samples, containing abundant new forms, were taken from boreholes after sealing them from the mine atmosphere with a packer (Redrafted from Sahl et al., 2008)

they extract nutrients, precipitate and dissolve minerals, create biogeochemical signatures, and generate important gases such as methane. The Integrated Ocean Drilling Program, IODP, identified three broad scientific themes in their Initial Science Plan, the first of these being “The deep biosphere and the subseafloor ocean” (http://www.iodp.org/isp/). Pursu- ant to this theme, the IODP includes drilling cruises that are primarily driven by biological objectives and encour- ages geobiological add-ons to projects with other goals. Recommendations exist for at least one dedicated geomicrobiological expedition annually (Subsurface Life Task Force, 2008). The task force report outlines efforts to characterize the habitability of the deep marine biosphere, metabolic rates, availability and fluxes of electron donors and accepters, and the abundance of microbial cells. Further, they seek to have samples fixed and frozen to -80˚C for post-cruise study of distribution of biomass and activity of organisms, diversity and composition of the community, and habitability of the subsurface. Dissolved microbial reactants and products can be measured in expressed interstitial waters from cores and, with information on inorganic constituents and formation factor, allow studies of microbial energetics and reaction rates (Subsurface Life Task Force, 2008). The IODP’s inter-

1 The University of Kansas, Lawrence, Kansas 2 New Mexico Institute of Mining and Technology, Socorro, New Mexico

42 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE est in geomicrobiology has in- creased their funding base and has led to high-profile discoveries and publications. Similarly, the International Continental Scientific Drilling Program (ICDP) lists “Geobio- sphere and early life” as one of its eight themes (Harms and Emmermann, 2007). Howev- er, no on-shore or lake drilling program to date has had the facilities for chemical analysis and sample handling that are envisioned in the IODP program and are required for quantitative studies of the subsurface biosphere, and only a few (Mallik, Chesapeake Bay, Peten Itza, and Eger Rift) have strong geomicrobiological components (Horsfield and Kieft, 2007). Few continental projects have even intended to establish the presence of deep biosphere organisms or their remains although some accidental discoveries have Figure 28. Number of microbes per gram of sediment (dry weight) plotted against depth in the core from the Chesapeake Bay Impact Structure. Microbial abundance declines with depth to occurred (Fisk et al, 2003; about 1000m, but rises to about 106/g in impact breccia and underlying schist. Microbes below Walton and Schiffman, 2003). 1500 m must have re-colonized the area after the sterilizing effects of the impact. (From Cockell Sediments, sedimentary rocks, et al., in press, reproduced with permission.) and even crystalline rocks are potential targets for geomicro- life or as a refuge from Hadean bombardment. Fur- biological investigation. Studies of Deep Time and of thermore, it is important to know the rates of evolution climate records in lakes also present obvious oppor- in subsurface environments and how organisms have tunities as do studies of hydrocarbon systems like the adapted to the extreme circumstances that subsurface Mallik project. life represents. Collectively, the marine and terrestrial geobiosphere, with up to half of the total biosphere, Science Objectives may have a profound effect on global geochemical cycles and on climate (Horsfield and Kieft, 2007). The first major science objective is determining the types, abundance, metabolic processes, and growth rates of organisms in the subsurface (Fig. 28). In par- Operational Matters allel with this are determining the sources and fluxes While geoeomicrobiological sampling adds somewhat of nutrients and other components, the variation of the to the cost of a drilling project, it can also consider- subsurface biota with space and time, the ability of ably enhance the scientific payoff. First and foremost organisms to alter or form minerals, and the role of is the need to insure that samples collected are truly subsurface organisms in formation and destruction of representative of the subsurface, both chemically and natural resources, especially oil and natural gas. As in- microbiologically. For down-hole operations, estab- formation emerges about the terrestrial and lacustrine lished protocols make it possible to obtain cores while subsurface biota, the results can be compared with minimizing contamination from the surface and drill- those from the land surface, the marine realm, and the ing fluids and to use a combination of sub-coring and underlying marine subsurface realm, and applied to tracers to quantify the contamination (Kieft et al., question of the subsurface as a site of the origin of

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 43 2007). Geomicrobiological objectives may influence Procedural, Equipment, and Infrastructure Needs the style of drilling/coring selected, e.g., sub-coring 1. The scientific deep drilling community should en- techniques require the core diameter to be adequate to courage the development of drilling projects that are provide a meaningful volume of rock for study after intended primarily to address objectives related to removal of surface layers. The exact method of qual- the deep biosphere at appropriate sites, as well as to ity assurance/quality control of samples that is chosen encourage the inclusion of geomicrobiology in other depends upon the cost, available facilities, and desired project plans as appropriate. Communication between results. Geomicrobiological studies also require sup- project leaders and potential investigators of the geo- porting geochemical analyses, which have their own microbiological community are necessary at an early needs in terms of sample collection and analyses. The stage. As the opportunities exist for collaboration with geochemical data may help to meet other scientific ob- so many projects that have non-biological objectives, jectives as well. Sample handling for core studies of it is important that projects be evaluated for their living microbes is facilitated by dedicated and appro- potential new understanding of the subsurface. Fur- priately equipped lab space, which could be a portable thermore, having such consultations at an early stage laboratory as used for this purpose by the IODP. would enable the geomicrobiological investigators to Sampling for geomicrobiology requires decisions on contribute to shaping the project so that all objectives which sample to take long before other analyses can are most efficiently met. be undertaken. An important consideration for com- 2. IODP accepts ancillary program letters (APL), bining geomicrobiological studies with deep time or proposals to participate in particular cruises where paleoclimate studies is that subcoring might require additional equipment or sampling activities may be destruction of a sample containing a key time or event required. APLs are reviewed and funded based upon marker or a significant number of annual layers. How- their merit. Some system of this kind may be desirable ever, such overlapping needs can be managed by pri- for geomicrobiological activities on continental drill- oritization of objectives, splitting cores lengthwise, ing projects. duplicate holes, or other means. 3. A containerized laboratory that could be used at Not all drilling projects necessarily require a geomi- drill sites where geomicrobiological investigations oc- crobiological component; stratigraphically oriented cured. IODP has such a facility module that could be drilling projects may penetrate strata that have been placed on board ship for appropriate cruises. A similar fully investigated for subsurface microbes and thus facility would enable scientists at on-land or lacustrine may unnecessarily repeat earlier results. Investiga- drilling sites to do on-site preparation of geomicrobio- tions of environments where subsurface temperatures logical samples and some simple laboratory analyses. exceed the range of living organisms will not yield living organisms for study, although trace fossils, both 4. Means of freezing samples on site and transporting textural and chemical, may be present in suitable sub- frozen samples to laboratories for study is necessary. strates. However, after drilling is complete on most or 5. Access to completed holes for placing microcosms all projects, it is possible to extract fluids for analysis and for sampling fluids. This use requires that the and to emplace microcosms that organisms may colo- holes be uncased and steps be taken to avoid contami- nize. nation. However, the boreholes already exist and the added experiments make the cost benefit ratio of their Opportunities for Interaction drilling more favorable. Upon completion of all ex- Virtually all drilling projects offer an opportunity for periments, the holes could be either plugged or turned geomicrobiological sampling of the subsurface for over to other groups of investigators who were moni- relatively small cost in money and time. However, toring other things. some projects would yield little new information, as 6. One or more workshops could be organized to deter- mentioned above. Those projects that do offer prom- mine what equipment to include in a mobile DOSECC ise of significant geomicrobiological results should be biogeochemical laboratory (possibly patterned after encouraged to collaborate to get the maximum of pos- that of the IODP), to decide how to secure funding for sible results. In addition to the ICDP geobiosphere op- this investment in infrastructure, and to familiarize the portunities, collaborations are possible with numerous continental scientific drilling community with the op- groups interested in subsurface life. portunities that could accrue from investment in this infrastructure.

44 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE NATURAL RESOURCES AND THE ENVIRONMENT: FLUID FLOW, FRACTURES, WATER-ROCK INTERACTION, AND HOSTILE ENVIRONMENTS Robert Zierenberg1 and Pat Shanks2

Important resource issues that can uniquely be understood through scientific drilling on the continents include: 1) fundamental controls on the movement of water in the deep crust; 2) elemental fluxes and potential energy and mineral resources of geothermal and hydrothermal systems; 3) Energy related issues such as formation and disruption of clathrates, C sequestration, and nuclear waste, and; 4) understanding and quantifying the distribution and function of the deep biosphere Understanding fluid flow through rock and water-rock interaction is fundamental to many aspects of scientific problems that can be addressed by drilling, but this understanding also has important practical benefits for society in terms of better knowledge of the resources upon which modern cultures depend for a high quality of life, including water, energy, and metals. Continental scientific drilling, particularly projects planned and executed in cooperation with resource agencies (DOE, USGS) and industry (oil and gas, geothermal, minerals), has the potential for not only intellectual advancement, but can, in many instances, have a direct pay-back to the public at large who funds these efforts in terms of more reliable access to resources that results from better understanding of the fundamental processes controlling the formation of energy and metal deposits. Resources for which scientific drilling may be a necessary approach to obtain in situ data and further our understanding of the genesis and availability include water, oil, gas, gas hydrates, geothermal energy, minerals, and even geologically confined pore-space for sequestration and/or remediation of carbon dioxide or other pollut- ants. Knowledge of subsurface fluid flow paths, the development and maintenance of permeability, and rock re- activity are fundamental constraints on understanding and quantifying thermal and chemical fluxes in the Earth.

Fundamental Scientific Questions Important scientific questions that require drilling include the relationship between porosity and permeability in different geologic environments and how permeability varies depending on the scale of investigation. Fundamentally important scientific questions include the relationship and feedbacks between fluids and rock deformation; the initiation and propagation of fractures; the cyclical development and destruction of fracture permeability in crack/seal veins; the composition of fluids that alter rocks and transport dissolved solids; and the relationship of the deep biosphere to all these factors. Study of these problems requires access to the subsurface via drilling. Many of these questions are best addressed in active systems, such as fault zones or geothermal systems, and in situ observation and experimentation in drill holes may be the best approach to advance our knowledge. In some cases, development of new tools may be needed to move forward. In particular, the present limited availability of logging cables, geophysical instruments and tools, and downhole fluid samplers that function at the elevated temperatures encountered in active geothermal systems or ore-forming environments limits our ability to investigate these systems. Similarly, there is a need for development of robust seismometers, strain meters, and packers that can be used for subsurface observatories in tectonically active areas. When thinking about the justification for scientific drilling, it is important to see beyond the value of the core material recovered as the drill hole itself is a potentially important resource.

Scientific Results from Iceland Drilling One example of the potential contribution of scientific drilling to resource issues is the Iceland Deep Drilling Project (http://www.iddp.is/), which is, in part, supported by ICDP. The primary goal of this project is to drill the depths where temperature and pressure conditions should be in the supercritical region for aqueous fluids in order to evaluate the potential for producing geothermal energy at much higher efficiencies as well as to ascertain the composition of supercritical fluids and the nature of the associated wall rock alteration. The initial drill hole (IDDP-1; Fig. 29) for this project in the Krafla geothermal field in northern Iceland failed to reach the deep objectives when a rhyolite magma body was encountered at 2104 m. This hole is presently being prepared

1 University of California, Davis, California 2 US Geological Survey, Denver, Colorado

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 45 for a flow test and may provide important information copyrite and sphalerite, with significant enrichments on high temperature fluid/rock reaction. It also has the of precious metals, in production pipes (Hardardót- potential to be developed as an enhanced geothermal tir, 2004). Drilling at this site is anticipated to reach system (EGS) that directly utilizes magmatic heat to the deep reaction zone that controls the composition produce superheated steam for electrical power gen- of seafloor hydrothermal vents, a long-standing goal eration. of the RIDGE and IODP research communities that is Future drilling is planned in the Reykjanes geother- beyond the capabilities of ocean drilling vessels. Proj- mal field in southern Iceland. This geothermal field is ects such as this provide an excellent opportunity for recharged by seawater and has similarities to “black scientific collaboration with other research programs smoker” systems developed on seafloor spreading cen- (InterRIDGE, IODP, Society of Economic Geologists) ters. The fluids transport significant amounts of metals as well as important information relevant to the under- and deposit massive sulfide scale composed of chal- standing of, and exploration for, metallic ore deposits.

Figure 29. IDDP-1 drilling in Krafla, Iceland. The project to explore for supercritical water had to be aborted when rhyolite magma was encountered at 2104 m. However, supercritical water remains a worthwhile objective in the hydrothermal power industry because of its great energy content. Scientific objectives of such projects include understanding water-rock interaction and fluid flow under such conditions.

46 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE CO2 CAPTURE AND SEQUESTRATION Kenneth Miller1

Addressing the energy needs of a population that will reach nine billion people by 2100 will require not only conservation, renewable energy, and nuclear power, it will require conventional energy sources, particularly coal. The developing world is building coal-fired power plants at an unprecedented rate, and the U.S. is gener- ating half of its electricity from this most abundant of fossil fuels. To address environmental and climatic concerns, Carbon Capture and Sequestration (CCS) will be necessary for large point sources,y such as coal plants.

Extraction of CO2 from a flume stream is possible with only a 25% loss of energy; state-of-the-art power plants could achieve 90% carbon capture with better efficiency than the aging coal fired fleet currently in production.

The captured CO2 could be sequestered either in expended oil/gas fields or in saline aquifers as a supercritical fluids, with the latter required to provide necessary volumes close to point sources. The equation of state of supercritical CO2 would require sequestration at depths of >800 m in reservoir sands capped by impermeable beds. Drilling would be required to evaluate the reservoir and capping potential of possible geological sequestration sites and for future monitoring of sequestered CO2.

Onshore sites are being investigated throughout the country by the DOE, and ongoing studies of such sites will require continuous coring and logging. However, models show that sequestration of supercritical CO2 is best done offshore where cold bottom waters limit the mobility of supercritical CO2. The first industrial-scale coal power plant with CCS is likely to be built on the U.S. east coast where electricity rates are high and the potential exists for offshore sequestration that maximizes current infrastructure (trains and transmission lines) and minimizes impact by sequestering offshore. Planning for this effort and future projects along the east coast will require a concerted drilling program both onshore and offshore.

1 Rutgers University, New Brunswick, New Jersey

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 47 DRILLING AS A TEACHER: EDUCATION & OUTREACH AND THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING David M. Zur1 and Kirk Johnson2

Continental scientific drilling enables the collection of samples to reconstruct past geologic history, allowing collection of mountains of information which has led to wondrous discoveries that capture the imagination of all—young and old alike (Fig. 30). Discoveries such as mass extinctions and plate tectonics have informed our sense of place on this planet. News reports of massive earthquakes, volcanoes and landslides tell the story of constant geologic change. Human origins and early human migration are thought to be linked with climate change. The possible need for carbon sequestration and the search for new water resources remind us that our planet, though big, has limits. Drilling on the continents has played an integral and indispensable part of these discoveries. A science-literate public is essential to our response to evolving Earth systems.

The public has an existing interest in science—we are explorers; that is what we do. Informing disparate groups of people—scientists, policymakers, children, the public at large—is key to fostering support for continental scientific drilling. Education and outreach (E&O) comes in many forms; it is anything we want it to be, from a presentation at a large international science society conference to a talk to a Girl Scout troop, from contacting a local politician to discuss his opinion on climate change to a chat with a friend about the earthquake liquefaction potential of the area where she wants to buy a home. While most project proposals submitted to funding agencies require an E&O component, more needs to be done to inform the public about the fascinating science enabled by continental scientific drilling.

Societal benefits, including earthquake and landslide preparedness, fault mapping, ground surface liquefaction potential, and mineral resources evaluation are all part of the data gathered through drilling. Only through a robust E&O program will the public be made aware of how drilling plays a role in gathering data to address these geologic phenomena.

Develop an Education and Outreach Culture: Start with more E&O in Our Own Scientific Community During the Future of Continental Scientific Drilling workshop, there was a consensus among the participants that DOSECC, as a U.S.-based consortium, is the logical place to spearhead a U.S.-based continental scientific drilling E&O effort. As such, principal investigators (PIs) are encouraged to involve DOSECC in not only their drilling plan but in their E&O plan as well. Some scientists consider undertaking a drilling project too costly or complex. The scientific community needs to be encouraged to explore the options available through continental scientific drilling. This has been enabled through drilling-project-specific scientific sessions at major conferences (GSA, 2006) and exhibit booths by DOSECC at large national conferences like AGU and GSA, an annual DOSECC/ICDP Town Hall Meeting held during AGU’s Fall Meeting, publications, newsletters, short films, and internet videos. All of these forms of communication must be continued to keep the potential users of continental scientific drill- Figure 30. Youngsters explore a drilling rig at an exhibit. This particular rig drilled lava lakes in Hawaii half a century ago. Me- ing aware of their options. chanical devices and scientific investigation appeal to the public in general and to youth in particular. As the drilling community 1 DOSECC, Inc., Salt Lake City, Utah conveys its science to the public, interest and support will follow. 2 Denver Natural History Museum, Denver, Colorado

48 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Once PIs are aware of the drilling options and formulate a project plan, E&O needs to be integrated as an important part of their project. For example, the U.S. National Science Founda- tion (NSF) requires that “broader impacts” are addressed in each proposal. This requires fore- thought on E&O during the pre-proposal stage. NSF wants specific details of E&O on projects; PIs should plan on asking for coordinated help with these efforts. PIs must recognize that com- municators of the science to the public must have access to resources such as drill sites, project partners to learn about project details and see how the drilling is done. Graduate and undergraduate students in the geosciences should be aware of the power of drilling to collect samples. This does not need to involve huge drilling rigs and large budgets; it could be Figure 31. Dennis Nielson, President of DOESCC, Inc., the 56-member accomplished with small portable drilling units of consortium of universities and research institutions, speaks to Rep that are easily transported and collect many sam- Rush Holt, D-NJ. during a Capitol Hill reception sponsored by the Co- ples quickly. The depth of these samples would alition for National Science Funding. obviously not be as great as with a large rig, but small units are great for collecting unweathered samples that could be compared to outcrop samples. new findings, or links to interesting articles regarding A small unit could be used during a teaching unit in data collected by drilling. Meet with your U.S. Rep- geology field camp or incorporated into a classroom resentative or Senator in their home district or attend exercise and would help remove the perception that one of the national science “fly-ins” to Washington drilling is only for big projects with big budgets. This DC. Then follow-up with those political contacts to would be hands-on education and outreach to our own make sure they know someone in their district is in- scientific community in its purest form. volved in a cool science project. Avail yourself to the politician for questions they may have on your area of Distinguished lecture series involving scientists from expertise. Go to a local school board meeting to see continental drilling projects have proven popular and what the next science textbook looks like. More sci- successful. Lecture programs are currently sponsored entists need to be aware of upcoming policy through by DOSECC, IODP, GSA, and others and provide an AGI, GSA, AGU, and the Coalition for National Sci- arena for researchers to publicize their results to both ence Funding (CNSF). scientific and lay audiences. In addition, offering scholarships or internships to Educate the Public graduate and undergraduate students and primary and secondary schoolteachers would provide incentive Continental drilling is the only scientific drilling pro- for drilling-related science and educational programs. gram accessible to public. Logistics to a drill site can Research grants, awards, and internships conducted be tricky but not as difficult as creating public access by GSA, AGU, DOSECC, and others should contin- to an ocean drilling platform. This access should be ue, and a culture of sharing resources between them leveraged into opportunities for the public and media should be fostered. to see the drilling, learn about how the drilling is done, talk about the science that will come from it, and open an avenue for discussion of other science topics. Get Educate the Policymakers to know the science reporter at your local newspaper Communication with policymakers is an important as- or television stations and invite them to the site. For pect of E&O (Fig. 31). There should be a fostering of remote sites, use of satellite connectivity and the inter- relationships between scientists and their local, state net for on-line chats, video blogs, and teleconferences and federal elected representatives. This can be as can serve to inform the public in a technologically ap- simple as e-mailing them with quick project details, pealing way.

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 49 Other ideas include: the public through collaboration. These venues are • Involving the public or industry, where pos- often looking for new ideas to present science to the sible, in research and education activities. public, and projects conducted with drilling are full of interesting science. • Giving science and engineering presentations to the broader community (e.g., at museums The aforementioned groups (GSA, AGI, AGU, IODP, and libraries, on radio shows). the National Earth Science Teachers Association, and • Making data available in a timely manner by many others) have well-developed E&O resources. means of databases, digital libraries, or other Establishing relationships with their E&O personnel venues, such as CD-ROMs. could lead to cooperative use of their products and ideas, and provide an avenue for continental drilling • Publishing in diverse media (e.g., non-tech- to become more visible in their products. For example, nical literature, newspapers, websites, CD- ROMs, press kits) to reach broad audiences. IODP operates a shipboard learning opportunity for teachers called the School of Rock. IODP may be able • Presenting research and education results in to send teachers to continental scientific drilling sites formats useful to policy-makers, members of for training and to provide them with an opportunity Congress, industry, and broad audiences. to compare and contrast the different drilling environ- • Participating in multi- and interdisciplinary ments, challenges, and data. In addition, NSF has a conferences, workshops, and research activi- dedicated E&O person within the Earth Sciences Di- ties. rectorate (EAR) to provide input and, possibly, fund- • Integrating research with educational activities ing for educational activities. in order to communicate in a broader context. Teaming with local and state government should also be encouraged. Project scientific collaborators can Collaborate also include the general scientific community, funding agencies, industry, water managers, outreach partners, Partnering with museums, nature centers, science cen- museum visitors, and school kids. Local arts and parks ters, and similar institutions to develop exhibits in sci- taxes can fund geo-art grants or installations. ence, math, and engineering is a great way to educate

50 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE FACILITIES, EQUIPMENT, AND INFRASTRUCTURE Emi Ito1 and Walter Snyder2

The facilities, equipment, and infrastructure needs of a continental drilling program are dictated by the science objectives. There is a wide range of needs for new or enhanced drilling technologies, on-site analysis activities, core and sample storage and curation, geoinformatics, and other resources. Many of the specific needs have been mentioned in the various breakout reports. In general, there is a consensus that we need integrated facilities that support: 1) specialized drilling needs that are not available commercially; 2) site surveys that are the first step in moving forward with projects that require scientific drilling; 3) data and sample curation, including standardized logging at drill-site that captures necessary metadata; 4) several mobile labs for initial whole core description that offer a “clean” environment for geobiologists; and 5) an easy to use data management system that will meets all the requirements of collaborative science, data dissemination to the public, and applications to K-16 education.

Meeting these diverse needs could take a variety of forms, but an integrated suite of facilities, whether in the formal or informal sense, is needed. A core or central facility, which could be DOSECC, that has the expertise, equipment, and staff to undertake the drilling and core processing, or have the expertise to work with principal investigators in brokering outside contracts for services, would be the first element of the integrate suite. This facility could also be viewed as a repository for much of the equipment that could be utilized by various funded projects. For example, while the core facility would manage the drilling operations of major drilling projects, it would check out equipment to researchers for simpler drilling projects that only required such results as shallow drilling.

It is recommended that a task force be assembled to more fully research and obtain specifications and costs for the various items outlined in this section, and prioritize their acquisition and/or development.

Drilling Technology Technologies need to support both short and deep bedrock sediment and ice core drilling and also have the capability for drilling in extreme environments and handling geo- biologic samples. Capable, Figure 32. Glad 800 drilling system on Lake Titicaca. This system has been very successful in affordable technology that is drilling sedimentary and impact successions in lake basins. Its design was a compromise that maintained and available to a met many, but not all, objectives laid out in the Colman (1996) PAGES report. While this system wide community of research- will continue to be useful, a larger system with a bigger platform and a higher capacity drilling ers is required. The following rig will be necessary to work in larger, deeper lakes. (Photograph courtesy of DOSECC) options were discussed: • An improved GLAD 800 drilling system. The current barge system cost approximately $750,000, but with a need to drill deeper lakes, a $3M to $5M investment in a new modular system that includes the barge, new drilling rig, etc., was discussed (Fig. 32). • The capability to log while tripping out of the hole. ICDP is developing such a system, but it may be two years out.

1 University of Minnesota, Twin Cities, Minneapolis, Minnesota 2 Boise State University, Boise, Idaho

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 51 • Drilling systems with the capability to obtain a “Continental Drilling Data System” and adhere to biogeochemical/microbial samples (solid and community sampling protocols. These facilities need fluid) without contamination. long-term support. LacCore is presently the only or- • Technology that can drill, log, and monitor in ganized facility for NSF-funded continental drilling extreme environments, including to tempera- and focuses on lake cores. A similar hard rock (includ- tures of 300°C or more. ing cuttings) facility is needed. Previous attempts to • A number of easily transported, easy-to-use establish such a facility at the Texas Bureau of Eco- drills rigs for shallow drilling (150-300 m) nomic Geology’s Houston facility might be revived, that could be checked out by researchers. The or similar facilities approached. Minex Winkie Drill is an example of such a drill (limited to 150m depth). This equipment On-site Core Logging could also be used by field camps to instruct students in drilling methodologies. This would A series of mobile labs that could be deployed to drill help to expand opportunities and, therefore, sites would greatly enhance core handling and analy- the size of the community who could apply sis. Technicians would be needed for some of these drilling to their research projects; this would labs. These mobile labs would target different needs; be important for changing the culture so re- some would be combined, while others would require searchers could see the new possibilities that separate vans. Recognized needs for hard rock and continental drilling brings to their science. soft rock drilling and for geobiological studies differ • Develop the ability to support long-term ob- in subtle to not-at-all subtle ways. Examples of needs servatories through the placement of relevant include: surface and subsurface monitoring tools. • A whole core NRM (Natural Remanent Mag- • Fluid sampling systems and the ability to con- netization) systems (for strategic drilling de- duct pumping tests are needed. cisions). • The ability to take over-pressured core sam- • A whole core MSCL (Multi-Sensor Core ples (e.g., gas hydrates). Logger), already deployed in ICDP-supported projects. Site Survey Capability and Funding • A geobiology and geochemistry mobile lab that includes the ability to freeze samples, is a Site surveys are a basic requirement of many drilling “clean lab,” and includes equipment for trans- projects, and there is a need for a consistent mecha- porting frozen samples (Fig. 33). nism for funding them. Presently, many such surveys Finally, on-site data (metadata, logging data, etc.) are funded by EAGER awards, but this is an ad-hoc should be collected and automatically uploaded, or approach that may not provide sufficient levels of captured and uploaded later once Internet connection funds. Some site surveys require expensive reflec- becomes available, to a “Continental Drilling Data tion seismic data, some “only” need more affordable System.” ground penetrating radar (GPR) studies, while others might include a comprehensive regional geologic syn- Geoinformatics and Data Management thesis. The cost of such surveys might be reduced by cooperation with other groups, such as IRIS, for seis- Data generated before, during, and after drilling proj- mic surveys. Regardless, there is a pressing need to ects need to be accommodated by a geoinformatics pursue the discussion of how to facilitate site surveys system. This data capture, and its management and in view of the fact that such surveys are necessary for archiving, could be facilitated through a “Continen- strong proposals, but such projects do not review well tal Drilling Data System” (CDDS). The CDDS would on their own. need to accommodate regional framework studies, site surveys, on-site and post-drilling data. Such a Core and Sample Storage Facilities system would also help meet existing and emerging agency data requirements. Community standards and Core and samples from drilling projects must be stored protocols for handling cores, samples, and heteroge- in easily accessible, properly documented and curated neous sets of data from post-drilling analyses should facilities so future work can be done on them as de- be accommodated by the CDDS. The CDDS would sired by the research community. In the past, many not need to be one centralized system but be totally cores have been lost, and this must be avoided in the distributed, including portals, to the core and sample future. All such repositories should be linked through storage facilities. This would avoid reinventing data

52 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Figure 33. Exterior and interior views of containerized, transportable geobiology laboratory at Apsö, Sweden. A similar laboratory opti- mized for on-site use at drilling projects would allow careful studies of geobiology. (Photographs courtesy of T.C. Onslott and Karsten Pedersen) centers and databases that already exist and have long- This requires a more thorough study and discussions term support. The system should provide turnkey data with many existing facilities, and, as examples, it was solutions for drilling projects, freeing the PIs from noted that we need to: this task. It could be a central component for educa- • Improve precision of and develop new prox- tion and outreach efforts and provide a mechanism for ies for climate and environmental change broader community participation in drilling projects studies. by allowing wider access to information. It could be • Improve methodologies to provide high res- designed to accept legacy data compiled for proposed olution chronologies for all time scales but, projects and, in general, provide better integration of in particular, for those time frames that fall outcrop and core studies. The CDDS could initially in-between standard radiometric dates and ra- be provided by GeosciNET—a collaboration of Core- diocarbon ages. Wall, Geoinformatics for Geochemistry (GfG), SES- • Improve and develop new biological tracers. AR, GeoStrat, and the ICDP DIS. However, this team could be broadened as needs dictate. We expect these improvements will be part of the natural outcome of new research projects that require Analytical Facilities and Methodologies scientific drilling. New and improved post-drilling analytical facilities and methodologies are needed to support the science.

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56 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE APPENDIX

Workshop Participants

Shelton Alexander Emi Ito Alexander Prokopenko Melissa Berke Kirk Johnson James Russell Margaret Blome Thomas Johnson Peter Schiffman Emily Brodsky Thomas Kieft Doug Schnurrenberger Laurie Brown Christian Koeberl Daniel Schrag Christopher Campisano David Kring Pat Shanks Eric Christiansen Jochem Kueck John Shervais Will Clyde H. Richard Lane Walter Snyder Andrew Cohen Stephen Lund Joseph Stoner Steve Colman Andrew Manning Ellen Thomas Ann Cook Kenneth Miller Alexander van Geen Don DePaolo Lisa Morgan Dick van Klaveren David Dinter Dennis Nielson Stefan Vogel James Evans Anders Noren Anthony W Walton Craig Feibel Paul Olsen Philippe Wyffels Barry Hanan Robert Phinney Robert Zierenberg Stephen Hickman Jeffery Plescia David Zur Yasufumi Iryu Ross Powell

Organizing Committee Keynoters Reporters Conveners Christopher Campisano Emily Brodsky Anthony W. Walton Don DePaolo Christopher Campisano Kenneth Miller Stephen Hickman Eric Christiansen Christian Koeberl Kirk Johnson Andrew Cohen Stephen Hickman Steve Colman Other members: Thomas Kieft David Kring James Evans John Shervais Craig Feibel Paul Olsen Steve Colman Stephen Hickman Will Clyde James Russell Emi Ito Dan Schrag Thomas Johnson Kirk Johnson Thomas Keift Christian Koeberl Other contributors to reports Kenneth Miller Ellinor Michel Jeffery Plescia Joseph Stoner Ross Powell Thomas Wilke Pat Shanks John Shervais Walter Snyder Stefan Vogel Anthony W. Walton Robert Zierenberg

THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE 57 WORKSHOP SCHEDULE

Thursday, June 4, 2009 Plenary Session I Convener: Ken Miller Central City Room (2nd Floor, Brown Palace) 8:00 Welcome, introductions, and purpose of the workshop Tony Walton 8:15 A View from NSF Rich Lane 8:30 Keynote: Deep Time Paul Olsen 9:00 Keynote: Climate Change and Human Origins Chris Campisano 9:30 Keynote: Fault Structure and Mechanics Stephen Hickman 10:00 Break & posters 10:30 Breakout sessions Deep Time with long-term climates Leadville. Leaders: Miller, Clyde Climate and human origins Georgetown. Leaders: Cohen, Feibel Fault structures & mechanics Silver Plume. Leaders: Evans, Brodsky 12:00 Lunch Oryx Room Plenary Session II Convener: John Shervais Central City Room 1:00 Review of morning breakouts 1:30 Keynote: Magmas, Hotspots, and the Mantle Don DePaolo 2:00 Keynote: Quaternary Climate Change James Russell 2:30 Keynote: Impact Processes and Structures David Kring 3:00 Break & posters 3:30 Breakout sessions Igneous processes Leadville. Leaders: Shervais, Christianson Quaternary climate change Centeral City. Leaders: Colman, Tom Johnson Impact processes Georgetown. Leaders: Koeberl, Plescia Antarctic drilling Silver Plume. Leaders: Powell, Vogel 5:15 Adjournment. Dinner on your own Friday, June 5, 2009 Plenary Session III Convener: Chris Koeberl Central City Room, Brown Palace 8:00 Review of afternoon breakouts 8:30 Keynote: The Deep Biosphere Tom Kieft

9:00 Keynote: CO2 sequestration Dan Schrag 9:30 Keynote: Public education and outreach Kirk Johnson 10:00 Break and posters 10:30 Breakout sessions Education and outreach Leadville. Leaders: Kirk Johnson, Zur The Deep Biosphere Silver Plume. Leaders: Walton, Kieft Natural Resources: water, metals, energy, and waste Georgetown. Leaders: Shanks, Zierenberg Facilities, equipment and infrastructure Central City. Leaders: Snyder, Ito 12:00 Lunch Oryx Room Plenary session Convener: Tony Walton Central City 1:00 Review of morning breakouts Group discussion: Facilities, equipment, and infrastructure A Science Plan for Continental Drilling? 2:30 Closing

58 THE FUTURE OF CONTINENTAL SCIENTIFIC DRILLING: A U.S. PERSPECTIVE Back Cover: Cores of lake sediments are housed at the LacCore facility at the University of Minnesota Twin Cities. Cores are from (left to right) Great Salt Lake, Utah, USA; Haukadalsvatn, Hestvatn, and Hvitarvatn, Iceland; Lake Malawi, Malawi; and Lake Titicaca, Bolivia. Coring lake sediments provides detailed paleoclimate records for the Pleistocene and, in longer-lived lakes, Pliocene. Tech- nological advances are improving the precision of the analysis to the annual level, where adequate geochronological control is possible. Lake sediments also provide detailed records of the intensity and inclination of the Earth’s magnetic field, which may either provide more precise age control or information about the history and, therefore perhaps, mechanics of the magnetic field. Many lake-drilling projects have multiple objectives, including effects of climate on humans and other elements of the nearby biota, impact structures, and understanding of rates and processes of evolution in isolated settings. Cores must be handled correctly to ensure that they are maintained in the appropriate state, properly documented, and available to the investigators. Samples and data from drilling projects are important resources for future studies with new techniques or new objectives.

Images courtesy Anders Norden, LacCore