Vol. 5, No. 2 February 1995 INSIDE • Honorary Fellows, p. 30 GSA TODAY • Rocky Mountain Section Meeting, p. 37 A Publication of the Geological Society of America • Cordilleran Section Meeting, p. 40

Farthest North: Ocean Drilling in the Arctic Gateway Region Leg 151 Shipboard Scientific Party

ABSTRACT The Ocean Drilling Program (ODP) recently recovered the first deep-drilled sediment sequences from the Arctic Ocean, on Leg 151 in July–September 1993. The ODP drill- ship Resolution took advantage of late summer low-ice conditions in the region northwest of Svalbard to drill three sequences on the Yermak Plateau at lat ~80°N and long 5°–8°E. Despite being chased away several times by advancing sea ice, ODP Leg 151 successfully obtained the northernmost long sediment cores (>500 m) ever drilled. The sediment Figure 1. Left: Finnish icebreaker Fennica patrolling sea ice on the Yermak Plateau in the Arctic Ocean at lat ~80°N. Photo by Suzanne O’Connell, Wesleyan University. sequences obtained provide the first Above: Laminated biosiliceous oozes from the late Eocene on the East Greenland opportunity for high-resolution margin (site 913), showing rich green and blue surficial coloration attributed to the records of arctic climates and paleo- presence of vivianite. Photo by ODP Operations Superintendent Gene Pollard. ceanography from the mid-Pliocene to present. Surprisingly high sedi- mentation rates involving high fluxes of glacially derived dropstones and terrigenous detritus attest to relying on the transpolar drift of the circumarctic continental ice sheets and Current, making this area inaccessible dynamic circumarctic continental sea ice. As chronicled in Nansen’s the arctic sea ice, and their subsequent for deep-sea drilling by ships without ice sheets at least episodically since (1899) account of the journey and evolution in Quaternary glacial-inter- icebreaker capabilities. These surface the mid-Pliocene. “Overconsoli- subsequent scientific papers, the Fram glacial cycles. current systems create a strong east- dated” Quaternary sediments at site drifted toward Fram Strait in the north- Reconstructing pre-glacial arctic west asymmetry in surface-water tem- 910 suggest that a massive ice sheet ernmost North Atlantic over the course environments will provide insights peratures and strongly influence the may have been grounded on the of 3 yr, providing the first scientific into possible future arctic environ- climate of the surrounding lands, Yermak Plateau during at least some information from the Arctic Ocean. A ments that may develop in response to accounting for mild climates in Scandi- glacial intervals, perhaps derived century after the Fram expedition, the greenhouse warming. Very warm Arctic navia at latitudes where glacial condi- from the Barents Sea shelf and but- ODP drillship Resolution (SEDCO/BP Ocean climates have been suggested for tions prevail on Greenland. tressed by Svalbard. The oldest drop- 471), administered by the Joint Ocean- the mid-Pliocene, on the basis of fossil In the present day, the North stones in the Arctic gateway region, ographic Institutions for Deep Earth faunal distributions including plank- Atlantic–Arctic gateway region is also recovered at Fram Strait site 909, Sampling, drilled the first sites in the tonic foraminifera (Herman, 1970, a center for deep-water exchange were late Pliocene in age. At site 907 Arctic Ocean proper and its main gate- 1974), sea otters and mollusks (Carter between the Arctic and North Atlantic on the Iceland Plateau, however, an way at Fram Strait. et al., 1986), as well as elevated sea- Ocean, and the Norwegian-Greenland earlier appearance of dropstones One of the long-standing questions level terraces (Brigham-Grette and Sea is an important locus for deep- during the late Miocene suggests about Arctic Ocean climates is the his- Carter, 1992). Documenting the pre- water formation. The only deep individual ice sheets had different tory of the arctic cryosphere, including glacial arctic paleoenvironment and its connection between the Norwegian- histories. Other ODP Leg 151 cores the circum-arctic continental ice sheets subsequent evolution will illuminate Greenland Sea and the Arctic Ocean from Fram Strait, the East Greenland and the Arctic sea ice. The Fram expedi- its sensitivity to future anthropogenic is through the narrow Fram Strait, with margin, and the Iceland Plateau pro- tion documented that the present-day climate change. a sill depth of ~2600 m. In the cyclonic vide important information on the sea-ice cover is a pervasive feature of gyre of the Norwegian-Greenland Sea, Cenozoic paleoceanographic history the Arctic Ocean, which Nansen felt REGIONAL surface waters derived in part from the of the Norwegian-Greenland Sea and had existed “since the earliest dawn of OCEANOGRAPHY warm, salty Norwegian Current are its relation to global climates. In time.” Today, considerable uncertainty sufficiently cooled to become dense, particular, late Miocene laminated The ability of the Resolution to con- exists about the onset of an extensive to sink, and to form cold deep waters. biosiliceous sediments on the Iceland duct operations in the Yermak Plateau Arctic sea-ice cover (e.g., Thiede et al., These waters fill the series of basins Plateau suggest that active deep con- region is directly tied to surface-water 1990). Estimates of its age range from that comprise the Norwegian-Greenland vection did not occur in this area oceanography in this area. Relatively middle to late Miocene (Clark, 1982) Sea, enter the Arctic Ocean through until ca. 7 Ma. warm surface waters derived from the to late Quaternary (Herman, 1985). Fram Strait, and spill over sills in the warm Norwegian Current flow north Based on the appearance of planktonic Denmark Strait (~600 m) and Iceland- INTRODUCTION through the Norwegian Sea and enter foraminiferal assemblages similar to Faeroe Channel (~1100 m) to con- the Arctic Ocean as the West Spitsber- Leg 151 of the Ocean Drilling modern communities, sea ice may tribute to the formation of North gen Current through the Fram Strait Program (ODP) has ushered in a new have become a permanent feature as Atlantic deep water. Deep-water west of Svalbard. This current melts era of scientific exploration of the arc- recently as ca. 0.9 Ma (Herman, 1970, exchange thus occurs through both extensive sea ice and icebergs in this tic region by recovering the first deep- 1974, 1985). Ice-rafted detritus in Arc- the northern gateway through Fram area in the summer, including the drilled sediment cores (>500 m) from tic Ocean sediments suggests that the Strait and the southern gateway to the area over the Yermak Plateau. Corre- the Arctic Ocean. The sediment se- circumarctic ice sheets have existed North Atlantic across the Greenland- spondingly, cold surface waters of the quences recovered, featuring high since at least the early Pliocene (Her- Iceland-Faeroe ridge. East Greenland Current flow south sedimentation rates with abundant ice- man, 1970; Margolis and Herman, The present-day system in the along the east coast of Greenland and rafted dropstones, indicate a dynamic 1980). These paleoclimatic interpreta- Norwegian-Greenland Sea of surface- enter the North Atlantic Ocean history for the arctic cryosphere since tions are based exclusively on short water inflow and deep-water outflow through Denmark Strait west of at least the mid-Pliocene. An integral piston cores (<10 m in length) in areas represents a lagoonal-style circulation Iceland. Thus, much of the western part of a long-term effort for renewed with low sedimentation rate, which Greenland Sea receives arctic sea ice study of the arctic region, ODP Leg provide greatly condensed records. A transported by the cold East Greenland Drilling continued on p. 31 151 sailed exactly 100 yr after Fridjof major advantage of deep-sea drilling in Nansen’s famous expedition across areas of high sedimentation rate is that the Arctic Ocean. Nansen and his long sediment sequences (>500 m) may Each month, GSA Today features a short science article on fast-breaking items or crew allowed their ship the Fram be obtained for greater stratigraphic current topics of general interest to the 15,000 members of GSA. What do you think to be frozen into the arctic sea ice coverage and high-resolution sediment of these articles? Do you have an idea for an article that you would like to see pub- in the Laptev Sea north of Siberia records. Specifically, such records lished in GSA Today? If so, please contact Eldridge Moores, Science Editor, GSA Today, in order to transit the Arctic Ocean, should document the formation of the (916) 752-0352, fax 916-752-0951. Drilling continued from p. 25 cover prevented drilling at two impor- tant sites (proposed sites Yerm-1 and that results in nutrient-depleted surface Yerm-5), ODP Leg 151 recovered the waters and oxygen-rich deep waters. first deep-drilled sedimentary sequences This circulation system plays a signifi- from the Arctic Ocean in August and cant role in heat transport to the high September 1993. The JOIDES Resolution northern latitudes and contributes drilled three sites in a depth transect directly to North Atlantic deep-water on the Yermak Plateau northwest of formation, thereby representing an Svalbard at lat ~80°N and long 5°–8°E. important driving force of the deep- Leg 151 also recovered material from ocean “conveyor belt” that transits two sites in Fram Strait between Sval- the world ocean. bard and Greenland, and from one site each on the East Greenland Margin DRILLING RESULTS: and the Iceland Plateau (Fig. 2). Nearly ODP LEG 151 3500 m of section were drilled, ranging in age from middle Eocene (~45 Ma) to ODP Leg 151 is part of the North present (Fig. 3). Atlantic–Arctic gateway (NAAG) pro- The sites successfully drilled on the ject, a coordinated effort to study the Yermak Plateau were the first drillsites paleoceanographic evolution of the in the Arctic Ocean proper, and are of Arctic Ocean, Norwegian-Greenland particular interest to the scientific com- Sea, and northern North Atlantic dur- munity. These sites were selected to ing the Cenozoic. This research effort study the Neogene evolution of arctic consists of two ODP drilling legs to this glacial conditions and to examine ver- area, Leg 151 in the summer of 1993 tical differences in sediment properties, and Leg 162 in the summer of 1995. accumulation rates, and surface- to These ODP drilling efforts are also deep-water circulation. Sites 910, 911, linked to the Nansen Arctic Drilling and 912 were drilled in water depths Program, dedicated to studying the of ~556, 902, and 1037 m, respectively. long-term climatic evolution of the The drilling program included triple Arctic Ocean. Obtaining long sediment hydraulic piston coring, rotary coring, sequences from the Arctic Ocean and and well logging. The sediments recov- the northern North Atlantic is central ered are silty clays and clayey silts with to documenting the Cenozoic evolu- a large component of terrigenous mate- tion of climate and ocean circulation in rial including glacial dropstones, and the northern and southern gateway re- are Pliocene–Quaternary in age. Bio- gions. The major objectives of this pro- genic material occurs sporadically ject are (1) to study the Cenozoic pale- throughout the sequences but is oceanography of the Nordic seas, abundant only in the upper Quater- Figure 3. ODP Leg 151 drilled sequences vs. depth, grouped north to south as sites from the including the history of surface- and nary. Carbonate contents are very Yermak Plateau, Fram Strait, East Greenland margin, and Iceland Plateau. Location, water depth deep-water exchange through the low, ranging from 1.5%–6%, and in meters below sea level (m bsl), age, major unconformities, and magnetic polarity records are northern and southern gateways; (2) to organic carbon values are high for shown for each site; llM = lower lower Miocene, llO = lower lower Oligocene and uuO = upper investigate the role of the tectonic evo- such an open shelf setting, ranging upper Oligocene. lution of the North Atlantic–Arctic from 0.7%–1.4%. The upper Quater- gateways in regional and global cli- nary is also marked by enhanced matic change; (3) to examine the late preservation of color banding; thin, Neogene evolution of arctic and sub- ~500 m below sea floor (m bsf) at sea-ice cover and/or increased stability very dark gray layers alternate with arctic sea ice and continental ice both sites 910 and 911, the sediments of circumarctic ice sheets. Refining the olive-gray sediments. The Yermak sheets; and (4) to document the latest were still Pliocene in age (Fig. 3). Sedi- timing of this change in sedimentation Plateau sequences are interpreted as Quaternary climatic history of the mentation rates based on magneto- rates and establishing the environmen- nearly uniform hemipelagic sediments northern North Atlantic through high- stratigraphy at Site 911 range from tal changes that caused it may be key with a significant component of ice- resolution studies of Milankovitch- to ~17 cm/ka during the late Pliocene to reconstructing the glacial evolution rafted terrigenous material, including millennial-scale variability. to ~10 cm/ka during the past 1 m.y. of the Arctic gateway region during the terrestrial organic carbon. High organic NAAG I drillsites were planned These rates are distinctly higher than Quaternary. carbon contents are attributed to a to take advantage of late summer sea- those based on piston cores from the combination of terrigenous flux and ice–free conditions in the Norwegian- area; sedimentation rates for the last “Overconsolidated” marine organic carbon supply associ- Greenland Sea and Arctic Ocean. Ice- glacial-interglacial cycle on the Yermak Sediments at Site 910 ated with sea-ice edge productivity. free conditions are essential to the Plateau range from 1.6 to 5 cm/ka The puzzle of relatively high operation of the drillship JOIDES (Gard, 1986, 1990, Baumann, 1990), High Sedimentation Rates Pliocene–Quaternary sedimentation Resolution. In order to drill hundreds and rates in the central Fram Strait on the Yermak Plateau rates is compounded by apparent of meters below the sea floor in water average ~3 cm/ka (Eisenhauer et al., “overconsolidation” of the sedimentary depths of several hundreds to thou- Obtaining long sediment 1990; Köhler and Spielhagen, 1990). section within the Quaternary at site sands of meters, the ship must be able sequences from the Yermak Plateau to The remarkable thickness of the 910, which constitutes an important to remain stationary for several days document the onset of arctic glacial Yermak Plateau sequences relative to change in physical properties observed to a week or more. Consequently, the conditions proved to be a difficult task, upper Quaternary sediments from pis- in the Yermak Plateau sites. Coring at Finnish icebreaker Fennica was con- not only because of sea-ice conditions, ton cores, and their large terrigenous site 910 met with “overconsolidated” tracted to protect the drillship from but mainly because of an unexpectedly component, need explanation. High silty clays and clayey silts, at ~19 m bsf, any advancing sea ice or icebergs thick Pliocene–Quaternary sedimentary sedimentation rates suggest that the which were very difficult to penetrate (Fig. 1). Although extensive sea-ice section. When drilling terminated at Yermak Plateau was a locus of deposi- with the hydraulic piston corer. Ship- tion for hemipelagic and terrigenous board measurements of physical prop- sediments, including ice-rafted mate- erties of these sediments (from ~9 to rial, during most of the Quaternary. Figure 2. Map of North Atlantic– 20 m bsf) revealed a sharp increase in When and how did conditions change Arctic gateway region showing sediment strength with depth from such that hemipelagic sedimentation location of ODP Leg 151 drill <100 to >300 kPa, an increase in wet and supply of ice-rafted material to sites and important basins, bulk density from 1.7 to 2.2 g/cm3, and ridges, and plateaus in the Yermak Plateau decreased during an abrupt decrease in porosity from the area. Also shown the late Quaternary? One possible 50% to 35%. One possible explanation are Fram Strait, Sval- explanation is that decreased transport for such overconsolidation prior to the bard, and the Yer- and melting of sediment-laden sea ice latest Quaternary is that an expanded mak Plateau. Y1 and icebergs derived from circumarctic Barents ice shelf buttressed by Svalbard is proposed land masses was due to changing site YERM-1. may have repeatedly become grounded surface current systems. In the present Contour in certain Quaternary glacial intervals day, the transpolar drift funnels sea interval is and overcompacted shallow sediments ice from the circumarctic across the 1000 m. on the Yermak Plateau. This possibility Yermak Plateau through the narrow has implications for models of Barents Fram Strait, where the warm West Sea shelf glaciation in particular (e.g., Spitsbergen Current accelerates sea-ice Elverhøi et al., 1990) and ideas about and iceberg melting and sediment the possibility of a large arctic ice sheet deposition. Decreased strength of during the Pleistocene (e.g., Hughes et either the transpolar drift or the West al., 1977). A fourth hydraulic piston Spitsbergen Current could account for core hole was drilled for more detailed such a decrease in detrital sedimenta- shore-based geotechnical and strati- tion rates. Alternatively, decreased sup- graphic studies, which are underway ply of ice-rafted material could reflect the establishment of a semipermanent Drilling continued on p. 32

GSA TODAY, February 1995 31 Drilling continued from p. 31 Cenozoic Deep-Water tively high organic carbon values Neogene evolution of the arctic cryo- Circulation in the (~0.7%–2.2%), confirming that the sphere. Further drilling within the Arc- to determine the mode and timing of Norwegian-Greenland Sea early rifting phase in Fram Strait tic Ocean proper by the Nansen Arctic sediment compaction. featured only limited deep-water Drilling Program awaits intensive The oldest sediments drilled during exchange between the Arctic Ocean efforts to develop a platform suited Leg 151 were middle Eocene in age Late Neogene and Norwegian-Greenland Sea. The to the arctic pack ice. from site 913 on the East Greenland Dropstone Input sequence at site 909 (~1060 m in margin. The sediments are finely lami- length) provides a continuous lower SUMMARY Dropstones are found throughout nated, highly organic and carbon rich Miocene–Quaternary record in Fram the sequences recovered from the (reaching peaks of >2%), and contain Despite logistical problems includ- Strait. The presence of laminated and Yermak Plateau, which extend to the many sediment-gravity deposits. Bio- ing dynamic sea-ice cover, ODP Leg color-banded sediments through the mid-Pliocene (site 910). Increases in silica content was very high in the late 151 recovered the first deep-drilled middle Miocene, with organic carbon dropstone input and siliciclastic abun- Eocene at this site, at a similar age to sequences (>500 m) from the Arctic values ranging from ~0.7% to 1.5%, dances in these sequences suggest that that observed elsewhere in the Atlantic Ocean on the Yermak Plateau, as well suggests low oxygen and high carbon glacial conditions in the Arctic gateway Ocean (e.g., Berggren and Van Couver- as from Fram Strait, the East Greenland dioxide levels in deep waters, indicative region became especially intense at ca. ing, 1974). Laminated upper Eocene margin, and the Iceland Plateau. Mate- of sluggish deep-water circulation dur- 1 Ma. The onset of arctic glacial condi- biosiliceous sediments are locally very rial from these sites, ranging in age ing this interval in Fram Strait. tions in this region is inferred from the colorful greenish blues and purplish from middle Eocene (ca. 45 Ma) to Biosilica-rich deposition continued first consistent occurrence of drop- blues, attributed to the presence of present, allow investigation of the pale- at site 907 on the Iceland Plateau stones at Fram Strait sites 908 and 909 vivianite (Fig. 1B). These laminated oceanographic and tectonic history in (~1800 m water depth) well into the during the early Pliocene. Increased sediments with high amounts of ter- several important areas and intervals late Miocene until ca. 7 Ma. Accumula- glacial conditions are indicated at ca. rigenous organic matter and biosilica in the North Atlantic–Arctic gateway tion of biosiliceous material until ca. 2.5 and ca. 1 Ma. The oldest ice-rafted indicate a restricted basin with high region. 7 Ma at this site suggests that nutrients dropstones in the Leg 151 sites were surface productivity in close proximity Shipboard results from piston cores were concentrated in deep waters and seen in the late Miocene ca. 6.4 Ma at to a continental source during the ini- indicate much higher sedimentation upwelled to foster surface-water pro- site 907 on the Iceland Plateau, signifi- tial phase of rifting in the Greenland rates on the Yermak Plateau and Fram ductivity. This pattern of circulation cantly earlier than in the Fram Strait basin. Site 913 also recovered upper Strait in the Pliocene–Quaternary than marked by deep-water inflow and region. This finding is consistent with Eocene–lower Oligocene sediments in the late Quaternary. A decrease in surface-water outflow suggests an estu- the age of the oldest dropstones known with abundant biosiliceous material glacially derived sediments in the late arine-style system, in contrast to the from the Vøring Plateau in the Norwe- that will allow examination of the Quaternary may have resulted from modern anti-estuarine circulation in gian Sea at ca. 10 Ma (Jansen et al., response of biosiliceous plankton in some combination of decreased supply the Norwegian-Greenland Sea, which 1988, 1991; Krissek, 1989) and in the the Norwegian-Greenland Sea to high- from the circumarctic continental ice is marked by deep convection. This Greenland Sea in the late Miocene at latitude cooling at this time. sheets, changes in surface circulation inferred circulation history in the ca. 7 Ma (ODP Leg 152). The glacial Laminated sediments with signifi- patterns, and possibly the establish- Norwegian-Greenland Sea suggests record in the Greenland-Iceland-Nor- cant biosilica contents recovered in ment of a semipermanent sea-ice cover. that deep convection could not have wegian Seas clearly extends farther several upper Oligocene and lower Overconsolidated Quaternary sedi- been a major contributor to North back in time than in the North Miocene sections suggest poor ventila- ments at site 910 on the Yermak Atlantic deep-water formation until Atlantic, where the onset of ice-rafted tion of deep waters continued into the Plateau suggest that a massive ice sheet after ca. 7 Ma. This result needs to be terrigenous material occurred in the Neogene. An unconformity encompass- may have become grounded in certain reconciled with previous findings that late Pliocene ca. 2.5 Ma (Shackleton et ing much of the early Miocene–early Quaternary glacial intervals, perhaps northern component water formation al., 1984). Differential glacial histories Pliocene is present at site 908, below derived from the Barents Sea shelf and has been significantly enhanced since of the source areas involved may which are found biosilica- and biocar- buttressed by Svalbard. ca. 12.5 Ma (Woodruff and Savin, 1989, account for these discrepancies in tim- bonate-bearing upper Oligocene–lower The oldest dropstones recovered 1991; Wright et al., 1992). One possible ing. Post-cruise research will attempt to Miocene sediments from ~190 to 330 m. from Leg 151 sites were of late Miocene resolution is that during the interval address the individual histories of the These sediments are commonly lami- age at site 907 on the Iceland Plateau, from ca. 12.5 to 7 Ma, northern com- circumarctic ice sheets. nated and color banded and have rela- consistent with previous results from ponent water could have been derived the Norwegian-Greenland Sea. How- mainly from other source areas such ever, the first appearance of dropstones as the Labrador Sea, or from shallower in Fram Strait was during the early depths in the Norwegian-Greenland Pliocene, which may reflect differential Sea. histories of the circumarctic ice sheets. ª ODP Leg 151 also recovered mate- Important increases in dropstone input GeoExplorer GPS rial from distinctly warm intervals of were observed throughout the region at the Cenozoic, including the mid- Pocket-sized GPS mapping system ca. 2.5 and ca. 1 Ma. Pliocene at sites 907, 909, and 910, Laminated sediments with signifi- The smallest, lightest, most powerful and most the late Oligocene–early Miocene at cant biosilica and terrestrial organic affordable GPS mapping system available. site 908, and the middle–late Eocene matter recovered in several middle at site 913. Records from these STANDARD FEATURES: Eocene–middle Miocene sections sug- sequences will help refine climate • Integrated six-channel GPS receiver and antenna gest poor ventilation of deep waters • 2 to 5 meter accuracy after differential correction models by allowing comparison of during the early rifting phase in the • Memory for storage of over 9,000 positions northern polar and subpolar paleo- Norwegian-Greenland Sea. Termination • GEO-PC software for planning, differentially environments to global climates. processing and outputting to GIS databases of laminated, biosiliceous sedimenta- • Full navigation functions tion in the Norwegian-Greenland Sea • Real-time differential GPS ready FUTURE DRILLING in the late Miocene also suggests that SYSTEM UPGRADES: Sequences drilled by ODP Leg 162 active deep-water convection did not • Decimeter Processor software for SUB-METER in the summer of 1995 as part of NAAG occur until perhaps ca. 7 Ma. DIFFERENTIAL GPS ACCURACY • PFINDER software for feature and attribute II will improve the stratigraphic and data collection geographic coverage of sediment ACKNOWLEDGMENTS • External power kit records from this region. Two sites This article is contributed by on the Yermak Plateau (proposed sites Benjamin P. Flower on behalf of the Yerm-1 and Yerm-5) not drilled on Leg SPECIAL EDUCATOR SYSTEMS AND Leg 151 scientific party. Shipboard 151 because of ice cover are high-prior- GSA PRICING AVAILABLE scientists were co-chiefs Annik Myhre ity targets for NAAG II. The major aim and Jörn Thiede, ODP staff scientist at these sites is to reach preglacial arctic John Firth, and Naokazu Ahagon, sequences. A site proposed from the Kevin Black, Jan Bloemendal, Garrett Scout and southern Svalbard margin is situated to Brass, James Bristow, Nancy Chow, better document the history of the ScoutMaster GPS Michel Cremer, Linda Davis, Benjamin Svalbard and Barents Sea shelf ice Prices start at $739.00 Flower, Torben Fronval, Julie Hood, sheets. Sites on the Iceland Plateau are The ultimate land navigation tools Donna Hull, Nalan Koç, Birger Larsen, planned to study the dynamic history • Lat/Lon or UTM plus altitude Mitchell Lyle, Jerry McManus, Suzanne • 250-position storage of surface- and deep-water circulation O’Connell, Lisa Osterman, Frank Rack, • “Over & Up” feature for plotting on in the Norwegian-Greenland Sea dur- Tokiyuki Sato, Reed Scherer, Dorothee topo sheets ing the Neogene. Additionally, several Spiegler, Ruediger Stein, Mark Tadross, SCOUTMASTER ONLY high-sedimentation-rate drift deposits Stephen Wells, David Williamson, Bill • RS-232 data port near the southern gateway, including Witte, and Thomas Wolf-Welling. I • Real-time differential ready for 2-5 the Feni and Gardar drifts, are targeted thank all the ODP Leg 151 participants, meter accuracy to document the late Quaternary his- • Two available software utilities for including Captain Tom Ribbens and tory of surface- and deep-water transferring, logging and plotting data his crew, the ODP drilling team, and exchange across the Denmark Strait marine technical staff for their efforts, Free Earth Science Catalog Available and the Iceland-Faeroe Ridge. The and John Barron, Eldridge Moores, and NAAG II drilling program will continue Geerat Vermeij for thoughtful reviews (800) 272-4327 (619) 431-2655 the effort to address the paleoceano- of the manuscript. Fax (619) 431-0904 graphic and climatic history of the E-mail: [email protected] northern and southern gateway regions 2075 Corte del Nogal, Suite I, Carlsbad, CA 92009 during the Cenozoic, including the late Drilling continued on p. 33

32 GSA TODAY, February 1995 Majority or Minority, Geology Still Matters

Jill S. Schneiderman, 1994–1995 GSA Congressional Science Fellow

After the Republicans overwhelm- needed to steer the party. Quickly, I South Dakota. Constituents in the ingly won the November 8 elections, became familiar with the faces of regu- Pierre–Fort Pierre region had recently the media used geological vocabulary lars such as Senators Barbara Mikulski brought the matter to Senator Daschle’s to describe the election results— (D—Md.), Jay Rockefeller (D—W.Va.), attention. The issue interests me, as tsunami, landslide, tectonic shift— John Breaux (D—La.), Byron Dorgan a geologist and educator, for it occupies Power Administration to meet power lending irony to a Republican success (D—N.D.), and John Kerry (D—Ma.) the intersection of appreciation for the demands in the region during severe based on a promise, among many in Leadership races are notoriously cycles of Earth’s rock sphere and hydro- cold. The problem represents a difficult the Republican “Contract with Amer- personal elections; since voting is by sphere and the necessity of living deli- conflict between two important pur- ica,” to abolish the U.S. Geological Sur- secret ballot, promises for support may cately on an ever-changing, heavily- poses of the dam—flood control and vey. The personal impact of the elec- not be firm. Thus, when Senator populated Earth. Depending on one’s hydropower. tion results was to leave me working Daschle left our office the morning of approach, that intersection will be By speaking with professionals for the would-be minority, rather than December 2, we wished him good luck characterized by frustration in encoun- from the Corps of Engineers, the Nat- majority, leader, Senator Tom Daschle and waited anxiously for word on the tering obstacles or satisfaction in craft- ural Resources Conservation Service, (D—S.D.). vote. When the Senators met to hear ing durable solutions. the South Dakota Department of Envi- While other fellows contemplated the leadership nomination speeches in One of five major river basins in ronment and Natural Resources, and shifting their assignments, I delved the Old Senate Chamber (restored to its South Dakota, the Bad River originates South Dakota constituents, I was able into work in an office still in campaign 1859 appearance and open to the pub- in the South Dakota Badlands and to absorb different viewpoints on the mode. Senator Daschle’s leadership lic), where Dolley Madison listened to flows 130 miles east into the Missouri problem and to understand Senator campaign office was readjusting for his Daniel Webster, Henry Clay, and John River. It empties into the Lake Sharpe Daschle’s ability to facilitate a solution. race for minority leader against Senator Calhoun debate the issues of their day, Reservoir at Pierre six miles down- Residents and city officials consider Christopher Dodd (D—Ct.) who had a proxy vote made Senator Daschle the stream from the Oahe Dam. The Bad the situation untenable because storm stepped into the race since Jim Sasser new Democratic leader with a 24 to 23 River drainage encompasses approxi- sewers back up, streets flood, water (D—Tn.) was not reelected. Sasser, and count. Posted outside the Chamber, mately 3120 square miles in western inundates house foundations, leaking then Dodd, were the favored candi- our staff person called the office to South Dakota which consist of easily into basements, and water-supply well dates for leader among the senior report the news. We cheered, not eroded claystone and siltstone. The houses have been flooded, a threat to Democratic Senators who figured my knowing the tumult into which it watershed, almost entirely privately municipal water supplies. boss too young for the job. Daily until would send our office. owned land, is approximately 65% In a 1992 reconnaissance report December 2, the day set for the leader- While Senator Daschle and his pol- rangeland and 35% cropland. requested by Rep. Tim Johnson (D— ship race, four or five Senators came to icy advisers met with colleagues to craft The Bad River carries an average of S.D.), the Corps of Engineers investi- our office to meet with Senator Daschle an agenda that meets the challenges 3.25 million tons of sediment into Lake gated alternative solutions to alleviate to discuss direction for the Democrats sent by voters, I worked on the issue of Sharpe annually. Erosion and sediment the power constraints at the dam and and the nature of the leadership flooding along the Missouri River in accumulation from the drainage has control flooding. The corps suggested caused water-quality concerns in the levee construction as an economically region over the past 30 years. Cur- feasible means to provide flood protec- rently, aggradation of the Missouri tion. Water-resource management pro- River channel in the Pierre and Fort fessionals at the South Dakota Depart- Pierre area from heavy sediment influx ment of Environment and Natural Drilling continued from p. 32 Hughes, T., Denton, G. H., and Grosswald, M. G., has restricted the main channel and Resources view levee construction as 1977, Was there a late Würm Arctic ice sheet?: causes flooding. The Corps of Engi- a temporary measure that delays the Nature, v. 266, p. 596–602. REFERENCES CITED neers, though studying the problem, inevitable additional flooding or con- Jansen, E., and Sjøholm, J., 1991, Reconstruction has not offered a remedy. Thus, poten- struction of higher levees. Townspeople Baumann, M., 1990, Coccoliths in sediments of of glaciation over the past 6 myr from ice-borne tial flooding in winter months in Pierre object to levees because of their aes- the eastern Arctic Basin, in Bleil, U., and Thiede, deposits in the Norwegian Sea: Nature, v. 349, J., eds., Geological history of the polar oceans: p. 600–603. and Fort Pierre prompted constituents thetic and economic impact. Addition- Arctic versus Antarctic: Dordrecht, Netherlands, to contact Senator Daschle. Though ally, they recognize that levees would Jansen, E., Bleil, U., Henrich, R., Kringstad, L. , Kluwer, p. 437–445. and Slettemark, B., 1988, Paleoenvironmental aggradation results in increased river adversely affect high-quality aquatic Berggren, W. A., and Van Couvering, J. A., 1974, changes in the Norwegian Sea and the northeast stages throughout the year, during the and terrestrial habitats of two riverine The late Neogene: Biostratigraphy, geochronol- Atlantic during the last 2.8 m.y.: Deep-Sea Drilling winter, ice accumulation exacerbates islands used by wintering wildlife pop- ogy, and paleoclimatology of the last 15 million Project/Ocean Drilling Program sites 610, 642, 643 the problem by further restricting the ulations. Power plant releases would years in marine and continental sequences: and 644: Paleoceanography, v. 3, p. 563–581. Palaeogeography, Palaeoclimatology, Palaeoecol- flow of water discharged from behind produce higher stages and flood large Köhler, S. E. I., and Spielhagen, R. F., 1990, The ogy, v. 16, p. 1–216. the Oahe Dam. In order to control the areas of hardwood habitat and wet- enigma of oxygen isotope stage 5 in the central Brigham-Grette, J., and Carter, L. D., 1992, Fram Strait, in Bleil, U., and Thiede, J., eds., Geo- flooding during ice-affected conditions, lands in LaFramboise and Farm Islands Pliocene marine transgressions of northern logical history of the polar oceans: Arctic versus Oahe Dam power plant releases are to several feet (U.S. Army Corps of Alaska—Circumarctic correlations and paleocli- Antarctic: Dordrecht, Netherlands, Kluwer, reduced. This practice interrupts power Engineers, Omaha District, May 1992 p. 489–497. matic interpretations: Arctic, v. 45, p. 74–89. generation and is not a permanent report). In my opinion, after having Carter, L. D., Brigham-Grette, J., Marinkovich, L., Krissek, L. A., 1989, Late Cenozoic records of ice- solution; it imposes severe constraints rafting at ODP Sites 642, 643 and 644, Norwegian Pease, V. L., and Hillhouse, J. W., 1986, Late on the ability of the Western Area Geology Matters continued on p. 34 Cenozoic Arctic Ocean sea ice and terrestrial pale- Sea: Onset, chronology and characteristics of oclimate: Geology, v. 14, p. 675–678. glacial-interglacial fluctuations, in Eldholm, O., Thiede, J., Taylor, E., et al., Proceedings of the Clark, D. L., 1982, Origin, nature and world cli- Ocean Drilling Program, scientific results, v. 104: mate effect of arctic ice-cover: Nature, v. 300, College Station, Texas, Ocean Drilling Program, p. 21–26. p. 61–74. Eisenhauer, A., and eight others, 1990, High reso- Margolis, S. V., and Herman, Y., 1980, Northern CALL FOR APPLICATIONS AND NOMINATIONS FOR lution 10Be and 230Th stratigraphy of late Quater- Hemisphere sea-ice and glacial development in nary sediments from the Fram Strait (core 23235), the late Cenozoic: Nature, v. 286, p. 145–149. GEOLOGY CO-EDITOR in Bleil, U., and Thiede, J., eds., Geological history of the polar oceans: Arctic versus Antarctic: Dor- Nansen, F., 1899, Farthest north: New York, GSA solicits applications and nominations for the position of co-editor of Geology, drecht, Netherlands, Kluwer, p. 475–487. Harper and Brothers Press. to serve a three-year term, beginning in January 1996, as one of a two-editor Elverhøi, A., Nyland-Berg, M., Russwurm, L., and Shackleton, N. J., Backman, J., Zimmerman, H., team. Desirable characteristics for the successful candidate include: Solheim, A., 1990, Late Weichselian ice recession Kent, D. V., Hall, M. A., Roberts, D. G., Schnitker, in the central Barents Sea, in Bleil, U., and Thiede, D., and Baldauf, J., 1984, Oxygen isotope calibra- 1. Broad interest and experience in geology; international recognition J., eds., Geological history of the polar oceans: tion of the onset of ice-rafting and history of 2. Iconoclastic; willing to take risks and try innovations Arctic versus Antarctic: Dordrecht, Netherlands, glaciation in the North Atlantic region: Nature, Kluwer, p. 289–307. v. 307, p. 620–623. 3. Familiar with many earth scientists and their work 4. Sense of perspective and humor Thiede, J., Clark, D. L., and Herman, Y., 1990, Late Gard, G., 1986, Calcareous nannofossil biostratig- 5. Organized and productive raphy of late Quaternary arctic sediments: Boreas, Mesozoic and Cenozoic paleoceanography of the v. 15, p. 217-229. northern polar oceans, in Grantz, A., et al., eds., 6. Willing to work closely with GSA headquarters staff The Arctic Ocean region: Boulder, Colorado, Geo- 7. Able to make decisions Gard, G., and Backman, J., 1990, Synthesis of arc- logical Society of America, Geology of North tic and sub-arctic coccolith biochronology and America, v. L, p. 427–458. 8. Sense of fairness history of North Atlantic drift water influx during 9. Familiar with new trends in geoscience the last 500,000 years, in Bleil, U., and Thiede, J., Woodruff, F., and Savin, S., 1989, Miocene deep- 10. Willing to consider nontraditional research in geosciences eds., Geological history of the polar oceans: Arctic water oceanography: Paleoceanography, v. 4, versus Antarctic: Dordrecht, Netherlands, Kluwer, p. 87–140. This is not a salaried position, but GSA pays the expenses for secretarial assis- p. 417–436. Woodruff, F., and Savin, S., 1991, Mid-Miocene tance, mail, telephone, and travel to GSA headquarters. Herman, Y., 1970, Arctic paleoceanography in late isotope stratigraphy in the deep sea: High- Cenozoic time: Science, v. 169, p. 474–477. resolution correlations, paleoclimatic cycles, If you wish to be considered, please submit a résumé and a brief letter describing and sediment preservation: Paleoceanography, why you should be chosen. If you wish to nominate another, submit a letter of Herman, Y., 1974, Arctic Ocean sediments, micro- v. 6, p. 755–806. fauna and the climatic record in late Cenozoic nomination and the individual’s written permission and résumé. Send nomina- time, in Herman, Y., ed., Marine geology and Wright, J. D., Miller, K. G., and Fairbanks, R. G., tions and applications to Donald M. Davidson, Jr., Executive Director, Geological 1992, Early and middle Miocene stable isotopes: oceanography of the arctic seas: New York, Society of America, P.O. Box 9140, Boulder, CO 80301, by April 14, 1995. Springer-Verlag, p. 283–348. Implications for deepwater circulation and cli- mate: Paleoceanography, v. 7, p. 357-389. Herman, Y., 1985, Arctic paleoceanography in late THE GEOLOGICAL SOCIETY OF AMERICA Neogene time and its relationship to global cli- Manuscript received March 30, 1994; revision received mates: Inter-Nord, v. 17, p. 99–14. June 21, 1994; accepted July 28, 1994. ■

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