OBSERVATION & SAMPLING OF THE EARTH’S NEWSNEWS · 1000 meters and counting! March 1, 2006. L to R – Jason Curtis, Dave Hodell, James Cranmer, Ed Brown, Mark Brenner, Doug Schnurrenberger,

Lake Petén Itzá, a 165 m deep lake in northernGuatemala, is the deepest lake in the lowlands ofCentral America. Because of its great depth, itheld water during full glacial periods of thePleistocene when arid climate persisted in theregion. The objective of the PISDP was to recov-er complete lacustrine sequences to study climatevariability in lowland Central America during thelate Pleistocene and Holocene on time scalesranging from decades to millennia.

Tools used to collect core included DOSECC’s

Hydraulic Piston Coring (HPC) system andextended-nose bit coring tools. A total of 1327 mof sediment was recovered at seven sites rangingin water depth from 30 to 150 m. Core recoveryaveraged 93.4%. Multiple holes were drilled atmost sites and cores were logged in the field fordensity, p-wave velocity, and magnetic suscepti-bility using the ICDP GEOTEK core logger.Complete stratigraphic recovery was verified innear-real time using Splicer, an IODP softwareprogram that aligns features among holes usingcore logging data.

Smear-slide analysis of core catcher samplesindicates similar lithostratigraphies among deep-water sites in the central basin. All cores show anabrupt transition from Late Glacial dense gyp-sum sand interbedded with silty clays, toHolocene gray clay, representing a shift from aridglacial to moist early Holocene conditions.High-frequency variations in bulk density occurthroughout the last glacial period and can be cor-

DRILLINGOBSERVATION &SAMPLINGOF THE EARTH’SCONTINENTALCRUST

VOL 3 NO 2 / MAY 2006

NEWSNEWS 1.3 km of SedimentRecovered by theLake Petén ItzáScientific DrillingProjectCONTENTS

Lake Petén Itzá 1Scientific Drillling Project

Drilling K-T and Chicxulub 3Event Strata in Texas

Deep Corehole Completed 4in the Chesapeake BayImpact Structure

Paleoclimate and Human 8Evolution Workshop

Upcoming Conferences 9

Workshops 10

Iceland Deep Drilling 11Project

Congratulations to the 122006 DOSECC InternshipAwardees

www.dosecc.org

FOR THE CONTINENTALSCIENTIFIC DRILLINGCOMMUNITY

1000 meters and counting! March 1, 2006. L to R – Jason Curtis,

Dave Hodell, James Cranmer, Ed Brown, Mark Brenner, Doug

Schnurrenberger, and Kent Thomas.(Photo: PISDP)

DOSECC NEWSLETTER May 06 5/8/06 2:07 PM Page 1

2 MAY 2006

Drilling locations on Lake Petén Itzá,Map courtesy of PISDP.

related among sites in the deep basin. Below thegypsiferous interval is a thick sequence ofdiatom-rich gray clay. Radiocarbon and U/Thdating are under way to determine the age of thesediments recovered.

Downhole logging was conducted by theICDP Operational Support Group (OSG) at fivesites using slimhole tools, which will permit cor-relation of core and downhole logs and their inte-gration with seismic profiles. Samples from atleast one hole at each site were squeezed for porewater geochemical analysis, and ephemeral prop-erties such as alkalinity and pH were measuredon site. One unexpected finding was the occur-rence of elemental sulfur in several cores.

The cores were shipped from Guatemala in arefrigerated container and arrived safely at theNational Lacustrine Core Repository at theUniversity of Minnesota where they will bestored. We, the members of the Petén Itzá

All cores show an abrupt transition fromLate Glacial dense gypsum sandinterbedded with silty clays, toHolocene gray clay, representing a shift from arid glacial to moist earlyHolocene conditions. (Photos: PIDSP)

Scientific Drilling Party, express our sincerethanks and appreciation to the DOSECC drillingteam and ICDP-OSG whose hard work and goodhumor made the project such a success. We haverecovered a wealth of high-quality core materialthat will permit us to study the sediment biogeo-chemistry of Lake Petén Itzá and reconstruct theclimate and environmental history of the region.

David Hodell, Department of Geological Sciences, University of Florida, Gainesville, FL

Flavio Anselmetti, ETH Zurich, Geological Institute, ZurichDaniel Ariztegui, Institute F.- A. Forel,

Univesity of Geneva, VersoixMark Brenner, Department of Geological Sciences,

University of Florida, Gainesville, FL Jason Curtis, Department of Geological Sciences,

University of Florida, Gainesville, FL and members of the Petén Itzá Scientific Drilling PartyAdditional input from David Zur, DOSECC

Between Feb 3 and March 11, 2006, drilling was conducted byDOSECC on Lake Petén Itzá using the Global Lake Drilling(GLAD800) drill rig, mounted on the “superbarge” R/V Kerry Kelts. (Photo: PISDP.)


DRILLING PROJECTSDRILLING PROJECTS

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Drilling K-T and Chicxulub Event Strata in TexasIn March 2005, DOSECC drilled the Cretaceous-Tertiary (K-T) boundary sequences in two local-ities along the Brazos River, Falls County, Texas.The project was organized by Professor GertaKeller (PI), Geosciences Department, PrincetonUniversity, and funded by NSF-EAR. The BrazosRiver area was chosen to test the current contro-versy over the age of the Chicxulub impact:whether this impact was the K-T killer as com-monly believed or predated the K-T boundary by300 k.y., as suggested by the new Chicxulubcrater core Yaxcopoil-1 and outcrops in NEMexico (Keller et al., 2003, 2004).

The Brazos River area provides a simple andinexpensive test of these results by drilling acouple of 100 feet deep holes across the K-Tboundary. This area was chosen because of thecomplete stratigraphic sequences, which arecomparable to the K-T boundary stratotype sec-tion at El Kef, Tunisia, the location about 1000km from the impact crater, and the presence ofboth the K-T Ir anomaly and “event deposit” withChicxulub impact ejecta spherules in widely sep-arated stratigraphic intervals. These attributes

mark the Brazos River area as the most importantK-T impact locality outside Mexico and criticalto resolving the current controversy regardingthe age of the Chicxulub impact and its potentialkill-effect.

The cores recovered the K-T boundary in un-disturbed dark laminated mudstones 90 cm abovethe 30 cm thick “event deposit”, which consists ofreworked Chicxulub impact spherules, glauconite,shell hash and mudclasts at the base followed bybioturbated laminated and hummocky sandstones.Between the event deposit and the K-T boundaryare upward fining silty mudstones (first 10 cm)followed by 80 cm monotonous laminated shalesand mudstone with shells and burrows infilledwith pyrite. The stratigraphic separation of the K-T boundary and event deposit provides the mostpromising test for the K-T and Chicxulub impactevents. Initial results presented at the May 23-25,AGU, in Baltimore.

Gerta Keller, Princeton University

Brazos KT Drilling participantsinclude:

Gerta Keller (PI) Princeton University,Princeton, NJ

Gerald R. Baum, Maryland Geological Survey, Baltimore, MD

Thomas Yancey, Texas A & MUniversity, College Station, TX

Thierry Adatte, Geology Department,University of Neuchatel, Switzerland.

Michael Prauss, Free University, Berlin, Germany

References:Keller, G., Stinnesbeck, W., Adatte, T.and Stueben, D., 2003. MultipleImpacts across the Cretaceous-Tertiaryboundary. Earth Science Reviews, 62,327-363

Keller, G., Adatte, T., Stinnesbeck, W.,M. Rebolledo-Vieyra, J. UrrutiaFuccugauchi, U. Kramar and D.Stueben, 2004. Chicxulub impact predates the K-T boundary mass extinction. PNAS 101(11): 3753-3758

Examining core recovery at Brazosdrill site: Gerta Keller and Jerry Baum.(Photo montage by Gerta Keller)

Drilling of three 75-100 feet deepholes was done with DOSECC’sCS-500 rig and was completed in four days. The highly professional and incredibly hard-working two-man drillingcrew (Chris Delahunty and Vance Hiatt) did a fantastic job and succeeded with nearly100% core recovery. —G.K.


4 MAY 2006

The Chesapeake Bay Impact StructureThe late Eocene Chesapeake Bay impact struc-ture is located in southeastern Virginia, USA, andis among the largest and best preserved of theknown impact structures on Earth. This buriedcrater structure consists of a deep, 38-km-widecentral zone surrounded by a shallower outerzone of sediment collapse known as the annulartrough, which extends the structure to a totaldiameter of about 85 km and gives it a distinctiveshape that is generally referred to as an “invertedsombrero.” It is the seventh largest impact struc-ture recognized on Earth.

The Chesapeake Bay structure is distinctiveamong impact structures on Earth for several,scientifically important reasons. At 35.5 Ma, it isa relatively young structure and, in comparison toother known impact structures of similar size, isvery well preserved. Its location on a passivecontinental margin prevented the tectonic distor-tion that has affected many large terrestrialimpact structures. Also, its location on a relative-ly deep continental shelf allowed marine deposi-tion to resume immediately following the impact,which rapidly and completely buried the crater,thereby preventing subsequent erosion. Its targetzone consisted of multiple layers (water, sedi-ment, rock) that varied in strength; this rheologi-cal variation appears to have controlled the finalsize and shape of the structure to a large extent.

The presence of an oceanic water column in thetarget resulted in a thick section of sedimentarybreccias within the upper part of the crater pro-duced by catastrophic resurge currents and per-haps impact-generated tsunamis; ocean-resurgesediments obviously are not a feature found in“dry” continental impacts. Finally, theChesapeake Bay impact structure is the source ofthe North American tektite strewn field.

The post-impact late Eocene to Pleistocenesediments that cover the structure also are of sig-nificant interest. This section of fine-grainedmarine sediments documents the post-impact,middle to late Cenozoic sea-level history, strati-graphic sequences, and climate variability of theMid-Atlantic segment of the U.S. Atlantic conti-nental margin.`

A further prime research issue is the hydroge-ology of the impact structure. The presence ofsalty groundwater throughout the structure is ofsignificant interest to those studying the avail-ability of fresh water in the densely populatedand rapidly growing urban corridor located alongthe southwestern and southern margins of theimpact structure. This project also presented anopportunity for deep biosphere research, whichwas carried out using appropriate drill-site anti-contamination protocols (including tracer gasand microbead additions to the drilling mud) dur-ing core retrieval.

The ICDP-USGS Chesapeake BayStructure Drilling ProjectIn September 2003, a workshop funded by theInternational Continental Scientific DrillingProgram (ICDP) and hosted by the U.S.Geological Survey (USGS) was held nearReston, Virginia, to create scientific, operational,and funding plans for the drilling of a deep core-hole into the central area of the Chesapeake Bayimpact structure. The workshop was attended byover 60 scientists from ten countries.

A funding proposal resulting from the work-shop was submitted to ICDP in January 2004 andaccepted by ICDP in late 2004. The USGS alsoauthorized funding for the deep drilling in 2004.Hence, ICDP and USGS provided the initialfunds for the drilling budget. Supplementary

Deep Corehole Completed in the Chesapeake Bay Impact Structure

Suevitic and lithic breccia in core box;Eyreville - B Corehole; 1445 - 1448m(Photo: David Powars)


CBIS DRILLING PROJECTCBIS DRILLING PROJECT

5

drilling funds were provided by ICDP, USGS,and the NASA Science Directorate in November-December 2005. DOSECC, Inc., served as thegeneral contractor for the field operations, andMajor Drilling America, Inc., drilled the deepcorehole under contract to DOSECC. Seven sci-ence teams organized at the 2003 workshop con-stitute the Project’s research group.

The drill site is located on private land ownedby the Buyrn family and is known locally asEyreville Farm. This site is in NorthamptonCounty, Virginia, between the villages ofEastville and Cheriton.

Preliminary Corehole StratigraphyCoring was completed to a total depth of 1,766 mduring September-December 2005. Cores wererecovered from two parallel coreholes, asdescribed in the following section.

The geologic section consists of 1,322 m ofcrater-fill impactites overlain by 444 m of post-impact sediments (Table 1). The lowest craterunit encountered in the core consists of a ca. 216-m-thick section of mica schist and pegmatitewith minor gneiss and impact-generated dikerocks. A ca. 157-m-thick section of suevitic andlithic breccias overlie the schists and pegmatitesand underlie a 275-m-thick megablock ofgranitic rock. The granitic megablock is overlainby a thick section of impact-disrupted pre-impactsediments; the upper part of this section includesa sedimentary breccia known as the Exmorebreccia, which contains sediment clasts and crys-talline-rock clasts. The cored post-impact sec-tion consists of upper Eocene, Oligocene, andMiocene fine-grained marine sediments.

Drilling HistorySite operations began in late July 2005 when alocal well-drilling company, Somerset Drilling,Inc., installed a water-supply well at the site.They also began the deep corehole by rotarydrilling to a depth of about 128 m (no coring) andinstalling large-diameter steel casing to a depthof 125 m. The Virginia Department ofEnvironmental Quality acquired a set of geo-physical logs in the corehole before casing wasinstalled.

www.dosecc.org

The drill crew and equipment from MajorDrilling America arrived in early September, andcoring began in the deep hole at a depth of about125 m on September 15th using a CP-50 wirelinecoring rig. Drilling proceeded in good fashionusing a PQ sampling system (Table 2) to a depthof 591.0 m when mud circulation was lost onSeptember 23rd and the CHD-134 (“PQ”) rodsbecame trapped in the hole.

Coring resumed on September 24th using anHQ coring system (Table 2) and continued to adepth of 940.9 m on October 8th when mud cir-culation again was lost. At that time, the drillerspulled the HQ rods and bit up into the CHD-134rods at 591.0 m depth. Repeated attempts to reamthe hole back to 940.9 m depth continued fornearly two weeks because of repeated loss ofmud circulation due to expanding and slidingred-clay sections (“clay boots”) in the sediment-clast breccia (Table 1). The bit finally returned toa depth of 940.9 m on October 20th. However,during the reaming process, the bit had deviatedfrom the original hole at a depth of 737.6 m. Asa result, duplicate cores were collected betweendepths of 737.6 m and 940.9 m. Hence, twocoreholes are designated at the Eyreville site, theEyreville A corehole and the Eyreville B core-hole (Table 2).

Coring in Eyreville B continued with the HQsystem to a depth of 1,100.9 m where the HQ bitwas deliberately stuck within a section of graniteon October 26th. Thus, the HQ rods were inten-tionally left in the hole to serve as casing againstthe troublesome red clays in the sediment-clastbreccia. Coring with an NQ coring system(Table 2) started on October 27th at 1,100.9 mand continued without major problems to thefinal depth of 1,766.3 m on December 4th.

The uppermost 125 m of the geologic sectionwere not cored in 2005. The USGS will drill a

TABLE 1. Preliminary generalized lithologic column (composite for two coreholes)

0 to 444 m Post-impact sediments444 to 1,096 m Sediment-clast breccia and sediment megablocks1,096 to 1,371 m Granitic megablock(s)1,371 to 1,393 m Lithic blocks in sediment1,393 to ca. 1,550 m Suevitic and lithic brecciaca. 1,550 to 1,766 m Schist and pegmatite; breccia veins

View of CBIS drilling operation. (Photo: David Powars)

ABOVE: Recovering the core barrel.(Photo: Greg Gohn)


Core Storage and Sampling PartyThe cores were taken to the USGS NationalCenter in Reston, Virginia, during and after thedrilling operations in 2005. The cores from theimpactite section will reside there for the nearfuture. Cores from the post-impact sedimentarysection will be moved to Rutgers University, NewJersey, in May 2006.

The entire core was displayed at a samplingparty that was held on March 19-22, 2006 at theUSGS National Center. At that time, theProject’s Science Team members examined thecores and marked sample intervals. Presentationof preliminary results is tentatively planned forspring 2007 at an international meeting to bedetermined.

Drill-Site StaffThe success of the Chesapeake Bay impact struc-ture drilling program is directly attributable tohard work by numerous dedicated individuals(Table 4) during the long days and nights at thedrill site. Chief among this group are the field-operations staff from DOSECC, the drillers fromMajor Drilling America, and the dozens of scien-tists and technicians from universities and agen-cies in Austria, Canada, Finland, Germany,Norway, South Africa, Spain, the UK, and theUSA, who served as the site geologists.

Gregory S. Gohn, U.S. Geological Survey, USAChristian Koeberl, University of Vienna, AustriaKenneth G. Miller, Rutgers University, USAWolf Uwe Reimold, Univ. of the Witwatersrand,

South Africa, & Humboldt University, Germany

6 MAY 2006

corehole to about 140 m depth at Eyreville inMay 2006 to recover this section, which is antic-ipated to consist of upper Miocene, Pliocene, andPleistocene sediments.

Unfortunately, the geophysical logging pro-gram was compromised significantly because ofthe trapped steel rods in the corehole, equipmentmalfunctions, and bridging of the open hole afterthe NQ rods were removed. A planned interimlogging run to about 1 km was not attemptedbecause of the reaming problems in the red clayand the subsequent permanent placement of theHQ rods in the hole. Only three logs wereacquired after the coring was completed onDecember 4th, despite considerable effort. TheUSGS logger collected a natural gamma log anda temperature log inside the NQ rods for nearlythe entire length of combined holes A and B. Atemperature log collected using a probe fromKarlsruhe University, Germany, also was run atthat time.

The top of the hole is closed with a removableshort section of modified HQ drill rod fitted witha pressure gauge and hose connection. The holemay be accessed only through the HQ rods. Theuncased hole below 1,100.9 m probably cannotbe accessed. Four sets of steel casing or rodsremain in the hole (Table 3).

TABLE 2. Corehole information

Total depth: 1,766.3 mCored interval: 125.6 m to 1,766.3 mCore recovery: Very good, but percentage not calculatedLatitude: 37 19 17 N (preliminary) Longitude: 75 58 30 W (preliminary) Location: Eyreville Farm, Northampton County, Virginia, USAFirst core: September 15, 2005Last core: December 4, 2005Core sizes: PQ, 125.6 to 591.0 m in Eyreville A corehole, 85 mm diameter

HQ, 591.0 to 940.9 m in Eyreville A corehole, 63.5 mm diameterHQ, 737.6 to 1,100.9 m in Eyreville B corehole, 63.5 mm diameterNQ, 1,100.9 to 1,766.3 m in Eyreville B corehole, 47.6 mm diameter

Geophysical Logging: July 27, 2005Virginia Dept. of Environmental Quality logging truck

December 4-5, 2005USGS logging truck, Denver, ColoradoKarlsruhe University temperature logging trailer

TABLE 3. Post-drilling corehole configuration

Steel casing, diameter 35.56 cm 0 to 16.8 mSteel casing, diameter 16.83 cm 0 to 125.6 mCHD-134 (“PQ”) rods, inside diameter 103.2 mm 0 to 591.0 mHQ rods, inside diameter 77.8 mm 0 to 1,100.9 m

Extruding a new core from the samplebarrel.

Suevite - ~4825' (1524m) - 11/17/05


U.S. GEOLOGICAL SURVEY, USAWilma Aleman GonzalezCarlos BudetLaurel BybellEugene Cobbs, Jr.Eugene Cobbs, IIIBarbara CorlandColleen DurandLucy EdwardsGregory GohnJ. Wright Horton, Jr.Julie KirshteinThomas KraemerMichael KunkNancy McKeown (Canada)Michael LowitRoger MorinJames MurrayRuth Ortiz MartinezHerbert PierceDavid PowarsDavid QueenDonald QueenWard SanfordEllen SeefeltJean Self-TrailMary VoytekJustin WadeDaniel WebsterBrendan Zinn

RUTGERS UNIVERSITY, USAJames BrowningAurora ElmoreAshley HarrisAndrew KulpeczKenneth MillerSvetlana MizintsevaAimee PuszBridget Wade

DOSECC, INC., USADennis Nielson, PresidentChris Delahunty,

Operations ManagerJohn Joice, Operations ManagerBeau Marshall,

Operations ManagerDavid Zur, Education and

Outreach Manager

MAJOR DRILLING AMERICA,INC., USAJeff Riley, Drilling SupervisorPaul Horschel, Lead DrillerChris Jensen, Lead DrillerDavid Long, Lead DrillerKenneth Cook, Drill HelperShane Crooks, Drill HelperMilford Hayes, Drill HelperRichard Nehring, Drill HelperRyan Wilson, Drill Helper

www.dosecc.org 7

DRILL-SITE STAFFUNIVERSITIES AND AGENCIESOleg Abramov,

Univ. of Arizona, USANicole Bach,

Old Dominion Univ., USAT. Scott Bruce, Virginia Dept.

Environmental Quality, USACharles Cockell,

Open University, UKHenning Dypvik,

Univ. of Oslo, NorwayJohn Eckberg,

Univ. of Houston, USASascha Eichenauer,

Free Univ. Berlin, GermanyTiiu Elbra, Univ. Helsinki, FinlandJennifer Glidewell, Geoscience Earth& Marine Services,

Houston, TX, USAAaron Gronstal,

Open University, UKPhilipp Heidinger,

Karlsruhe Univ., GermanySarah-Catherine Hester,

Univ. Northern Colorado, USAKevin Jones, Univ. Arizona, USAAmanda Julson,

Blinn College, USADavid King, Auburn Univ., USAChristian Koeberl,

Univ. Vienna, AustriaTomas Kohout,

Univ. Helsinki, FinlandDavid Kring, Univ. Arizona, USADaniel Larson,

Univ. Memphis, USAUlli Limpitlaw,

Univ. Northern Colorado, USAPeter McLaughlin, Delaware

Geological Survey, USAJared Morrow,

Univ. Northern Colorado, USAJens Ormö,

Centro de Astrobiologia, SpainLucille Petruny,

Astra-Terra Research, USAJeffrey Plescia, Johns Hopkins

Univ. Applied Physics Lab., USA

Uwe Reimold, Univ. of the Witwatersrand, South Africa, and Humboldt Univ. Berlin, Germany

David Vanko, Towson Univ., USAVladimir Zivkovic,

Univ. Memphis, USA

Henning Dypvik (University of Oslo) and Jean Self-Trail (USGS) examine a newcore. (Photo: Greg Gohn)

ABOVE: Night Shift! Geologists clean the new core from a depth of 3,090 ft (942 m).(Photo: Greg Gohn)

CBIS DRILLING PROJECTCBIS DRILLING PROJECT


Over the past two and a half decades, new tech-niques for studying climate change, applied espe-cially to deep-sea drill core records, have driventhe development of environmental forcinghypotheses of human evolution. These hypothe-ses link specific climate transitions during thelast 5 to 10 million years or changes in climatevariability over that same time period to events inhominin physical and adaptive evolution andspecies diversification [e.g., Vrba, 1988; Potts,1996; Bobe and Behrensmeyer, 2004].

Key developments in hominin evolution, andespecially in the human genus Homo with itsunique array of behavioral characteristics, may betied to specific climate ‘events’ or to the increaseor decrease in climate variability in particulartime intervals. The key forcing factors mightinclude the stepwise aridification of Africa duringthe late Pliocene and early Pleistocene (about 3 to1.5 million years ago), or changes in the variabil-ity of climate (and the food and water resourcesaffected by the new climate regime) driven bychanges in the Earth's orbital precession, obliqui-ty, and eccentricity, (Milankovich insolation forc-ing) or millennial-scale climate fluctuations.

Simultaneously, there has been a tremendousgrowth in interest in documenting climate changein those regions of the world where major eventsin human evolution occurred. This interest hasbeen spurred by efforts to complement the pale-oanthropological record [e.g., Cerling, 1992;Quade et al., 2004] and, more broadly, to under-stand climate dynamics in the tropics [e.g.,deMenocal, 1995].

The convergent interests of geologists, pale-oanthropologists, archaeologists, and paleoclima-tologists, coupled with recent developments in

the acquisition of long drill cores from LakesMalawi and Bosumtwi in tropical Africa, formedthe backdrop for a recent workshop on paleocli-mates and human evolution. Workshop partici-pants gathered to consider current knowledge ofthe relationship between human evolution and cli-mate history over the last 25 million years and tochart promising directions for future research andinterdisciplinary collaborations in this rapidlydeveloping field.

Linking Deep Sea and Lake Cores toEvolutionary History

Workshop participants debated the challengesto understanding the role of climate in humanevolution. Although correlation of events cannotdemonstrate causation, comparative temporalanalyses of paleoclimate versus hominin andother vertebrate fossil records are at least a firststep in researching this linkage, and severalresearchers presented such data.

Workshop participants recognized that funda-mental difficulties exist in integrating dataderived from very different sources, as these datarepresent very different temporal and spatialscales of resolution and completeness. In particu-lar, discussion focused on how to better use envi-ronmental history data that are appropriatelyscaled to the hypotheses being evaluated [e.g.Behrensmeyer, 2006].

Drill core records from the deep sea currentlyprovide the most temporally complete record ofenvironmental variability in East Africa over thelast five million years; and this record shows somestriking correlations with major episodes ofhominin and other mammalian evolution

Paleoclimate and Human Evolution Workshop

8 MAY 2006

MEMBERSHIP NOWINCLUDES 54 INSTITUTIONSDOSECC welcomes the University of Massachusetts at Amherst as its 54th member!Julie Brigham-Grette is theUMass representative. DOSECC continues to increase its membership as a way of gathering input and guidancefrom as broad a cross section of the scientific community as possible. Participation of the membership on DOSECCcommittees and at membershipmeetings is critical to chart thedirection for the organization. To become a member, the institution is required to pay aone-time membership fee of$3,000. The membership feesbecome part of a corporatereserve account, the interestfrom which provides funding for the annual student internship awards.


WORKSHOPSWORKSHOPS

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[deMenocal, 2004]. Marine records indicate thatAfrican climate has been influenced by a combina-tion of high-latitude teleconnections (~100-kilo-year glacial/interglacial cyles), variability in tropi-cal insolation (driven by the precession cycle), seasurface temperatures [e.g., Schefuss et al., 2003],and monsoon intensity. Drying cycles apparentlybecame larger and longer after 2.8, 1.7, and 1.0million years ago (Ma), following the predominantorbital beats of global climate variability.

New drill core records from African lakes andthe promise of identifying future drill sites pro-vide an exciting opportunity to address this scal-ing problem by opening up new combinations ofspatial/temporal resolution and stratigraphic con-tinuity during key intervals in human evolution,conference participants noted. Potential targetsmight be situated in existing lakes, in thedepocenters of ancient lake basins, or even in theoutcrop belts where hominin fossils and artifactshave been recovered. Tropical lakes, with theirlong-recognized sensitivity to subtle changes inprecipitation/evaporation ratios, and their fre-quent accumulation of annually varved deposits,are ideal for producing such records [e.g.,Johnson et al., 2002; Scholz et al., 2005].

Another challenge discussed during theworkshop is to link reconstructed changes inpaleoclimate to the patterns observed in fossilbones and stone tools. Part of this involvesassessing which behaviors and anatomical traitsmake sense as evolutionary responses to chang-ing climate and habitat.

Conference participants discussed howchanges in diet, evidenced from hominin jaw ordental evolution within a species of hominin,might suggest a particular directional shift invegetation cover and/or climate over the time orin the geographic range of the species in ques-tion. Participants also showed that microscopicpatterns of wear on fossil teeth related to differ-ent types of food consumed could provide evi-dence that among early hominins, selective pres-sures favored generalists capable of falling backon less preferred foods during arid intervals,when preferred food types were scarce. In addi-tion, conference attendees showed that skeletaldifferences between humans living under differ-ent climatic regimes are evident even betweenmodern populations of Homo sapiens. Similarclimate response arguments may help in theunderstanding of major transitions betweenAustalopithecus and Homo, between species ofHomo, or even within those hominin speciessuch as A. afarensis that have a rich and long

www.dosecc.org

DOSECC RIG AND TOOLSDISPLAYED AT GSAWith the annual GeologicalSociety of America meeting inSalt Lake City in 2005, DOSECCdecided to display our CS500drilling rig at the convention. We also displayed some of our drilling tools and bits.

fossil record [Wood and Richmond, 2000].Given the limited species diversity of homininstoday (n = 1), models linking skeletal or size dif-ferences both within and between species andsexes to climate or vegetation differences inother types of modern mammals, especially pri-mates can also be developed.

Defining time intervals for study andsubjects for interdisciplinary researchThere was a consensus among workshop partici-pants that improved climate reconstructions forAfrica and the hominin expansion corridors inEurasia are an immediate, pressing goal. Withcontinuous African continental drill core records,researchers now can test ideas linking culturalinnovation and human dispersal with the timingof specific climate events (e.g., wetter periods orperiods of greater or lesser climate variability). InEurasia, where regional climate reconstructionsfor the middle to late Pleistocene transition aremore broadly available, this approach has alreadypaid off in a better understanding of the differ-ences in habitat and climate range between mod-ern Homo sapiens and Neanderthals.

There was also a consensus concerning theneed for interdisciplinary research on key timeintervals. These are intervals when there are bothdata supporting extremely important evolutionaryevents and the potential to obtain much morehighly resolved climate records than we have atpresent. Three intervals stood out as noteworthyfor future intensive, integrative study:

● 3.0–2.4 Ma: Onset of 41-kiloyear glacial cycles in Arabian Sea dust records, origin of stone toolsand the genus Homo, evidence of faunal changein East Africa

● 2.0–1.5 Ma: Evolution of Homo erectus, expan-sion of Homo out of Africa, evidence for expan-sion of grassland habitats

● 0.4–0.05 Ma: Diversification of Homo, originof anatomically modern humans, beginning of Middle Stone Age and major transition in stonetool and other technological innovations, dispersal of modern humans out of Africa

In taking a time-slice approach, the challengefor the paleoclimate/human evolution communitywill be to better integrate outcrop, marine, andlake core data and modeling results, in order toreconcile their very different temporal and spatialscales and resolutions. Conference participantsagreed that a research consortium of like-mindedscientists could provide an umbrella of symposia,

UPCOMING CONFERENCESSociety of Economic GeologistsMay 13-16, 2006Keystone, CO, USA

Geological Society of AmericaOctober 22-25, 2006Philadelphia, PA, USA

American Geophysical UnionDecember 11-15, 2006San Francisco, CA, USA

(Photo: DMZ)


UPCOMING WORKSHOPS

ICDP Workshop: Snake RiverScientific Drilling Project Twin Falls, Idaho, USAMay 18-21, 2006

IODP- ICDP Workshop on Fault Zone Drilling: Developing a Global PerspectiveMiyazaki, Japan May 23-26, 2006

ICDP Workshop: Lake Van Drilling Project Van, TurkeyJune 6 – 9, 2006

ICDP Workshop: The Magma-Hydrothermal Connection MutnovskyVolcano and the MutnovskyGeothermal ReservoirPetropavlovsk-Kamchatsky, RussiaSeptember 2006

10 MAY 2006

databases, and Web sites or publications to pro-mote such an effort. It would also sharpen thefocus on where improved climate records mightbe obtained on the continents, specificallythrough scientific drilling technology. Suchrecords might come from a range of possible tar-gets, from drilling existing fossil/artifact outcropsites in order to sample unweathered strata, todrilling depocenters near such sites for morecomplete records, to drilling extremely long con-tinental records in areas such as Lake Tanganyikain central Africa, where a continuous record ofthe span of human evolution might be obtained.

Regardless of the approach, the workshopmade clear that this is only the beginning ofwhat promises to be an exciting time for collab-orative efforts to understand the climatic contextin which our species and our close relativesevolved.Paleoclimates and Human Evolution: A Workshop on IntegratingContinental Drilling Research with Paleoanthropology and OtherGeological Records, held 17–20 November 2005 at theSmithsonian’s Conservation and Research Center in Front Royal,Va., was sponsored by the U.S National Science Foundation; theSmithsonian Institution's National Museum of Natural History'sHuman Origins Program; and Drilling, Observation and Sampling ofthe Earth’s Continental Crust (DOSECC), Inc. Additional workshopinformation can be found athttp://www.geo.arizona.edu/web/HumanEvolutionWorkshop/

Andrew S. Cohen, Department of Geosciences, University of Arizona, Tucson; E-mail: [email protected]

Gail M. Ashley, Department of Geological Sciences, Rutgers University, Piscataway, N. J

Richard Potts, Human Origins Program, National Museum of Natural History, Washington, D. C.;

Anna K. Behrensmeyer, Department of Paleobiology, National Museum of Natural History, Washington, D. C.

Craig Feibel, Departments of Geological Sciences and Anthropology,Rutgers University, Piscataway, N. J.

Jay Quade, Department of Geosciences, University of Arizona, Tucson.

ReferencesBehrensmeyer, Anna K. (2006) Climate change and human

evolution. Science 311:476-478.Bobe, R., and A. K. Behrensmeyer (2004) The expansion of

grassland ecosystems in Africa in relation to mammalian evolution and the origin of the genus Homo, Palaeogeogr. Palaeoclimatol. Palaeoecol., 207, 399–420.

Cerling, T. E. (1992) Development of grasslands and savannas inEast Africa during the Neogene, Palaeogeogr. Palaeoclimatol. Palaeoecol., 97, 241–247.

deMenocal, P. (1995) Plio-Pleistocene African climate, Science,270, 53–59.

deMenocal, P. B. (2004) African climate change and faunal evolutionduring the Pliocene-Pleistocene, Earth Planet. Sci. Lett., 6976, 1-2.

Johnson, T. C., et. al. (2002) A high-resolution paleoclimate recordspanning the past 25,000 years in southern East Africa, Science,295, 113–114, 131–132.

Potts, R. (1996) Evolution and climate variability, Science, 273, 922–923.

Quade, J., et.al. (2004) Paleoenvironments of the earliest stone toolmakers, Gona, Ethiopia, Geol. Soc. Am. Bull., 116, 1529–1544.

Schefuss, E., et.al. (2003) African vegetation controlled by tropicalsea surface temperatures in the mid-Pleistocene period, Nature,422, 418–421.

Scholz, C. A., et.al. (2005) Initial results of scientific drilling on Lake Malawi, East African Rift, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract PP13C-03.

Vrba, E. S. (1988) Late Pliocene climate events and hominid evolution, in Evolutionary History of the “Robust” Australopithicines, edited by F. E. Grine, pp. 405–426, Aldine, New York.

Wood, B., and B. G. Richmond (2000) Human evolution: Taxonomyand paleobiology, J. Anat., 196, 19–60.

This article originally appeared in EOS, Transactions, AmericanGeophysical Union, Vol. 87, Number 16, page 161, 18 April 2006.Copyright 2006 American Geophysical Union.

DOSECC – SCEC Workshop: Originand Depth Extent of Pulverized RockAlong Active Continental Faults inSouthern California: Insights to beGained from Shallow BoreholesPalm Springs, CA, USASeptember 2006

10th International Paleolimnology SymposiumDuluth, Minnesota, USAJune 25-29,2006

12th International Symposium onDeep Seismic Profiling of theContinents and their MarginsShonan Village Center Hayama, JapanSeptember 24-29, 2006

LINKS TO ALL WORKSHOPS AT

WWW.DOSECC.ORG


NEWSNEWS

11www.dosecc.org

Published bi-annually by DOSECCthrough funding provided by NSF.

Dennis L. NielsonPresident and Treasurer(801) [email protected]

David Zur Education and Outreach Manager(801) [email protected]

Bob KeefeOperations Manager(801) 581-5572, [email protected]

Jennifer BircumshawAccountant / Office Manager(801) [email protected]

Doug SchnurrenbergerStaff [email protected]

Vance Hiatt Drilling Supervisor

James CranmerDrilling Supervisor

John JoiceDrilling Supervisor(801) 581-3376

Mailing AddressP.O. Box 58857Salt Lake City, Utah 84158-0857Fax: (801) 585-9386

Newsletter edited by David Zur

Newsletter designed by Easton Design

Iceland Deep Drilling Project UpdateIn December 2003, Hitaveita Sudurnesja Ltd (HS)offered one in a series of several production wellsthey planned to drill at Reykjanes as a candidatefor deepening to 5 km by the IDDP, once the pro-duction characteristics of these wells had beentested. Accordingly the drillhole RN-17 atReykjanes became the prime candidatefor deep drilling by the IDDP. HSintended to release this drillhole,or another well of opportunity,to IDDP for deepening, pro-vided enough steam for a100 MWe power plant hadbeen secured before mid-year 2006. However aflow test of RN-17 inNovember 2005 was cutshort when it becameplugged by rock debris andattempts to clean and condi-tion this drillhole failed inFebruary 2006. A caliper logrevealed that there has been extensivecaving, therefore drillhole RN-17 is no longer acandidate for deep drilling by the IDDP.

In February 2005, RN-17 was completed to 3.1km depth, the deepest drillhole in the Reykjanesfield. As it was then the prime candidate for deep-ening by the IDDP, all daily reports and wellreports on RN-17 were written in English and, fol-lowing the ICDP protocol, made available at theICDP website. ICDP agreed to finance a spot corein this well. However, by the time funding becameavailable RN-17 had already been completed andso the core was collected from the bottom of well

RN-19, another “well of opportunity” that wasbeing drilled at that time. In 2005 the IDDP dis-tributed samples of drill cuttings from RN-17 andcore from RN-19, for study by the internationalscience team. At the moment several groups inItaly, France, Germany, USA, Russia and Iceland

are studying this material as well as drillcutting samples from other wells at

the Reykjanes geothermal field.Other teams were waiting for

fluid samples from the flowtest of RN-17 of lastNovember that endedabruptly due to collapseof the formation, as men-tioned above. Losing RN-17 is most unfortunate for

Hitaveita Sudurnesja, asthat company has borne the

financial loss of drilling awell that had to be abandoned.

This situation has created theopportunity for IDDP to re-evaluate

future plans. At the moment we are discussingthe advantages of drilling a deep well in search ofsupercritical fluid in a different location, at theKrafla geothermal field, instead of at Reykjanes,while maintaining the objectives and momentumof the project. Expect a new announcement on thismatter shortly.

Wilfred Elders

DOSECC Provides Drilling Tools for Antarctica ProjectDrilling tools are one of the most important partsof a drilling program. DOSECC has recentlysupplied downhole coring tools for the ShallowDrilling on the Antarctic Continental Margin(SHALDRIL) Project.

The SHALDRIL Project will use DOSECC’sLake Coring System (DLCS) suite of tools. Thesuite includes a push sampler for soft sediments,the extended nose case sampler for stiffer sedi-

ments, DOSECC’s proprietary hydraulic pistoncorer, the DOSECC-designed Alien sampler, anda non-coring assembly for fast drilling wherecore is not collected.

In addition, DOSECC has proposed to providedrilling tools for the Antarctic GeologicalDrilling Program (ANDRILL).


P.O. Box 58857Salt Lake City, UT 84158-0857

Congratulations to the 2006 DOSECC Internship Awardees!

Brandon Mijal Western Washington University

Brandon is studying Holocene glaciation ofcentral Idaho’s Sawtooth Mountains. Hisstudy involves intensive glacial mappingand alpine lake sediment coring throughoutthe Redfish Lake drainage. By linking out-wash sediments to moraine sequences, lakecore sediments can provide a proxy recordof glacial fluctuations of the range. Lakesediment stratigraphy, 14C AMS radiocar-bon, and tephra analysis from each corewill outline glacial fluctuations throughoutthe area, leading to the first detailedHolocene glacial chronology for the range.His faculty sponsor is Dr. Douglas Clark.

Andrew KulpeczRutgers University

Andrew’s study will evaluate the post-impact stratigraphic evolution of the lateEocene Chesapeake Bay Impact Structureusing integrated sequence stratigraphy.Lithologic, Sr-isotopic, and biostratigraph-ic analyses will be used to establish tempo-ral hiatuses and determine sequence distri-bution within the crater. One-dimensionalbackstripping will be used to quantify in-crater tectonics and allow for an evaluationof the processes that control sequence dis-tribution (eustasy, tectonics, sediment sup-ply) across the mid-Atlantic coastal plain.This study will use core from theDOSECC/USGS/ICDP Eyreville-1 core-hole, the USGS Langley and Exmore core-holes, and regional geophysical logs. Hisfaculty sponsor is Dr. Kenneth G. Miller.

Kristen MarraUniversity of Oklahoma

Kristen’s project will examine the origin,composition, and depositional history ofsediment fill within Unaweep Canyon, COin order to help constrain the canyon’s unre-solved genesis. The fill from the innercanyon includes a thick lacustrine sectionthat will provide a high resolution climaterecord for an upland setting for the earlyand mid Pleistocene. Sedimentological andgeochemical analyses will be conducted oncore collected from the canyon’s innergorge in June, 2004. Her faculty sponsorsare Dr. Michael J. Soreghan and Dr. G.S.Soreghan.

DOSECC annually makes available funding from its membership reserves to promote student involvement in projects where drilling has provided data and material for study.Since 2000, DOSECC has supported 11 internships.

DOSECC thanks all the applicants for their interest in the internships, and congratulates the awardees on their success. We look forward to the presentation of the results of their studies at DOSECC’s Eleventh Annual Continental ScientificDrilling Workshop in June 2007.


Documents

OBSERVATION & SAMPLING OF THE EARTH’S NEWSNEWS · 1000 meters and counting! March 1, 2006. L to R – Jason Curtis, Dave Hodell, James Cranmer, Ed Brown, Mark Brenner, Doug Schnurrenberger,