Vol. 6, No. 2 February 1996 INSIDE • Penrose Conference Reports, p. 14, 16 GSA TODAY • Rocky Mountain Section Meeting, p. 24 A Publication of the Geological Society of America • North-Central Section Meeting, p. 30

Alternate Origins of the Coast Range Ophiolite (California): Introduction and Implications

William R. Dickinson, Department of Geosciences, University of Arizona, Tucson, AZ 85721 Clifford A. Hopson, Department of Geological Sciences, University of California, Santa Barbara, CA 93106 Jason B. Saleeby, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125

ABSTRACT Correctly interpreting the tectonic evolution of the California continental margin requires understanding the ori- gin of the Jurassic Coast Range Ophio- lite, which represents a fragment of mafic-to-ultramafic crust of oceanic character lying depositionally beneath the western flank of the Great Valley forearc basin in fault contact with the Franciscan subduction complex of the California Coast Ranges. Three con- trasting hypotheses for genesis of the ophiolite as seafloor are each based on internally consistent logic within the framework of plate tectonics, but are mutually exclusive and lead to strikingly different interpretations of regional tectonic relations, even though each assumes that the Sierra Nevada batholith to the east represents the eroded roots of a magmatic arc linked to subduction along the Mesozoic continental margin. To encourage the further work or analy- Multiple basaltic sills of the sheeted dike and sill complex, Point Sal remnant of the Middle Jurassic Coast sis needed to develop a definitive inter- Range ophiolite. The ridge in background exposes sheeted sills and (to left of tree on the skyline) base of pretation, summary arguments for each the overlying pillow lavas. hypothesis of Coast Range Ophiolite genesis in mid- to late Jurassic time are presented in parallel: (1) backarc now incorporated within the continental larger than our area of disagreement. We spreading behind an east-facing intra- block (Bailey et al., 1970). The overall span each interpret the Coast Range Ophiolite oceanic island arc that then collided and of Middle to Late Jurassic radiometric ages layered assemblage as a profile of mafic amalgamated with the Sierran continen- for igneous components of ophiolite and crust and lithosphere of oceanic character, tal-margin arc; (2) paleoequatorial mid- postophiolite hypabyssal intrusions is and we infer that this profile was formed ocean spreading to form oceanic litho- ~170 to 155-150 Ma (Hopson et al., 1981, through magmatism induced by mantle sphere that was then drawn northward 1991; Saleeby et al., 1984; Mattinson and upwelling linked to lithospheric extension toward a subduction zone in front of Hopson, 1992). Understanding correctly or “spreading.” We each also argue for the Sierran continental-margin arc; and the origin and emplacement of the Coast emplacement of the ophiolite within the (3) forearc spreading within the forearc Range Ophiolite is essential for under- conceptual framework of plate tectonics, region of the Sierran continental-margin standing the Mesozoic evolution of the taking the Sierra Nevada composite batho- arc in response to transtensional defor- Cordilleran continental margin (Saleeby, lith to the east to be the deeply eroded mation during slab rollback. 1992). The time is long past when geosci- roots of Jurassic-Cretaceous magmatic arc entists could assume that all ophiolites belts, and regarding Franciscan rocks of INTRODUCTION formed in the same way or have the same the California Coast Ranges farther west Widely distributed exposures of the tectonic significance. as part of the subduction complex Jurassic Coast Range Ophiolite in the Cali- With the help of co-authors, we out- accreted near the trench that was paired fornia Coast Ranges represent deformed line here three divergent views on the ori- with the Sierran-Klamath arc assemblage and structurally dismembered segments gin of the Coast Range Ophiolite. We of oceanic crust and uppermost mantle emphasize that our areas of agreement are Ophiolite continued on p. 2 IN THIS ISSUE GSA TODAY February Vol. 6, No. 2 1996 Alternate Origins of the Coast SAGE Remarks ...... 20 Range Ophiolite (California): GSA TODAY (ISSN 1052-5173) is published Introduction and Implications .... 1 Environment Matters ...... 22 monthly by The Geological Society of America, Inc., Calendar ...... 23 with offices at 3300 Penrose Place, Boulder, Colorado. Washington Report ...... 10 Mailing address: P.O. Box 9140, Boulder, CO 80301- Rocky Mountain Section Meeting ...... 24 9140, U.S.A. Second-class postage paid at Boulder, Book Nook ...... 11 Colorado, and at additional mailing offices. Postmas- North-Central Section Meeting ...... 30 ter: Send address changes to GSA Today, Membership GSAF Update ...... 12 Services, P.O. Box 9140, Boulder, CO 80301-9140. 1995 Annual Meeting Revisited ...... 36 Copyright © 1996, The Geological Society of America, Penrose Conference Reports Inc. (GSA). All rights reserved. Copyright not claimed Fault-Related Folding ...... 14 GSA Meetings ...... 38 on content prepared wholly by U.S. Government Argentine Precordillera ...... 16 employees within the scope of their employment. Per- Classifieds ...... 39 mission is granted to individuals to photocopy freely all 1996 GeoVentures ...... 19 Northeastern Section Meeting Update . . . 39 items other than the science articles to further science and education. Individual scientists are hereby granted GSA on the Web ...... 19 permission, without royalties or further requests, to make unlimited photocopies of the science articles for use in classrooms to further education and science, and to make up to five copies for distribution to associates in the furtherance of science; permission is granted to Ophiolite continued from p. 1 We thank conveners R. G. Anderson, make more than five photocopies for other noncom- mercial, nonprofit purposes furthering science and edu- D. M. Miller, and R. M. Tosdal for arrang- cation upon payment of the appropriate fee ($0.25 per (Fig. 1). We concur that the east flank of ing the 1993 Penrose Conference on page) directly to the Copyright Clearance Center, 27 the Franciscan subduction complex was Jurassic Cordilleran magmatism at which Congress Street, Salem, Massachusetts 01970, phone (508) 744-3350 (include title and ISSN when paying). thrust beneath and otherwise faulted our opposing thoughts were pointedly Written permission is required from GSA for all other against the Coast Range Ophiolite , which juxtaposed, and we dedicate the following forms of capture, reproduction, and/or distribution of formed the westernmost segment of the discussions to the memory of E. H. Bailey any item in this journal by any means. GSA provides this and other forums for the presentation of diverse floor of the Great Valley forearc basin (who started it all). opinions and positions by scientists worldwide, regard- lying between Sierran arc and Franciscan less of their race, citizenship, gender, religion, or politi- trench. 1. COAST RANGE OPHIOLITE cal viewpoint. Opinions presented in this publication do not reflect official positions of the Society. We nevertheless ascribe generation of AS BACK-ARC–INTER-ARC the Coast Range Ophiolite to three differ- BASIN LITHOSPHERE ent tectonic settings: (1) Dickinson infers SUBSCRIPTIONS for 1996 calendar year: William R. Dickinson, Department of Society Members: GSA Today is provided as part of “backarc” seafloor spreading behind a Geosciences, University of Arizona, membership dues. Contact Membership Services at migratory east-facing intraoceanic island (800) 472-1988 or (303) 447-2020 for membership Tucson, AZ 85721 arc, which collided with the west-facing information. Nonmembers & Institutions: Free with Richard A. Schweickert, Department of paid subscription to both GSA Bulletin and Geology, Sierran arc along the continental margin Geological Sciences, University of Nevada, otherwise $45 for U.S., Canada, and Mexico; $55 else- (as intervening oceanic lithosphere was where. Contact Subscription Services. Single copies Reno, NV 89557 consumed), to lodge the migratory arc and may be ordered from Publication Sales. Claims: For Raymond V. Ingersoll, Department of Earth nonreceipt or for damaged copies, members contact its backarc seafloor against the continental and Space Sciences, University of California, Membership Services; all others contact Subscription margin; (2) Hopson infers “midocean” Services. Claims are honored for one year; please allow Los Angeles, CA 90024-1567 sufficient delivery time for overseas copies. seafloor spreading along an intraoceanic ridge crest, followed by tectonic transport The concept that the Coast Range STAFF: Prepared from contributions from the of the resulting seafloor to the continental Ophiolite was formed by backarc-interarc GSA staff and membership. margin (as Sierran subduction drew it ever spreading behind an east-facing intra- Executive Director: Donald M. Davidson, Jr. Science Editor: Suzanne M. Kay closer), until the ophiolite docked against oceanic island arc that was accreted to the Department of Geological Sciences, Cornell University, the continental margin prior to the onset continent in Jurassic time by arc collision Ithaca, NY 14853 of Franciscan accretion; (3) Saleeby infers along a suture within the Sierra Nevada Forum Editor: Bruce F. Molnia U.S. Geological Survey, MS 917, National Center, “forearc” seafloor spreading induced by foothills has persisted for 25 years (Moores, Reston, VA 22092 transtensional deformation within the 1970; Schweickert and Cowan, 1975; Managing Editor: Faith Rogers west-facing Sierran-Klamath arc system Moores and Day, 1984; Ingersoll and Production & Marketing Manager: James R. Clark Production Editor and Coordinator: Joan E. Manly (in response to rollback of the subducted Schweickert, 1986). Remnants of the Graphics Production: Joan E. Manly, Adam S. McNally slab during highly oblique convergence). intraoceanic arc complex are identified The three concepts have quite differ- as thick submarine successions of de- ADVERTISING ent implications for details of tectonic formed and disrupted Jurassic lavas and Classifieds and display: contact Ann Crawford history. For example, models 1 and 3 both pyroclastics, as much as 5000 m thick (303) 447-2020; fax 303-447-1133 involve varieties of so-called supra–sub- (Bogen, 1985), resting locally on shreds Issues of this publication are available electronically, in duction-zone ophiolite forming the floors of ophiolitic basement along the Sierran full color, from GSA as Acrobat “Portable Document of interarc basins, whereas model 2 envi- foothills belt. Eruptive activity in the Format” (PDF) files. These can be viewed and printed on personal computers using MSDOS or MSWindows, sions only “normal” seafloor spreading foothills arc was coeval with Jurassic on Macintoshes, or on Unix machines. You must use in an open ocean basin; models 2 and 3 phases of magmatism in the west-facing the appropriate Adobe Acrobat Reader, available for involve only a single west-facing Sierran Sierran continental-margin arc, whose axis free download from GSA and other online services. The more powerful Adobe Exchange program, available magmatic arc, whereas model 1 includes lay farther east along and beyond the Sier- from commercial software suppliers, may also be used. a separate east-facing arc that was accreted ran crest from mid-Triassic to mid-Jurassic Download the issues of GSA Today and/or the appropri- tectonically to the Cordilleran continental time (Schweickert, 1976; Busby-Spera, ate Readers using the Uniform Resource Locator (URL): http://www.geosociety.org. Issues of GSA Today are margin; models 1 and 2 both require 1988; Dilles and Wright, 1988). A strong posted about the first of the month of publication. tectonic transport of the ophiolite to case can be made that the Jurassic intrao- This publication is included on GSA’s annual CD-ROM the continental margin, whereas model ceanic and continental-margin arcs of the GSA Journals on Compact Disc. Call GSA Publication 3 envisions genesis of the ophiolite in Sales for details. place within an arc-trench system lying Printed with pure soy inks on recyclable paper in the U.S.A. along the continental margin. Ophiolite continued on p. 3

2 GSA TODAY, February 1996 Smartville complex, which is then inter- preted as the product of spreading in place within the west-facing Sierran forearc (Dilek, 1989a; Edelman et al., 1989), rely upon the presence in the northern foot- hills belt of Middle Jurassic (~165 Ma) granitoid plutons that cut thrusts placing Lower Jurassic elements of the foothills arc assemblage above metasedimentary melange. The resulting conclusion that accretion of the foothills arc complex was Figure 1. Geologic sketch map of part of complete by Middle Jurassic time is not California showing the robust, however, because the intruded regional relation of the melange unit is not tied firmly to the con- Coast Range Ophiolite tinent and underthrusting of the eastern to key lithotectonic belts; flank of an east-facing intraoceanic arc by SC—location of melange would be expected prior to final Smartville ophiolitic complex within foothills suturing to the continent. Arc plutons metamorphic belt; trend unrelated to the Sierran continental arc of Great Valley gravity- could thus cut arc-melange thrusts in the magnetic anomaly late phases of intraoceanic arc evolution (high) after Cady (1975). prior to accretion along the compound subduction complex of the foothills belt. Widespread Middle Jurassic deformation within the Sierran continental arc has been attributed in part to terrane accretion (Edelman and Sharp, 1989; Edelman et al., 1989), but could as well reflect intra-arc contraction. Several workers (Shervais and Kim- brough, 1985; Shervais, 1990; Stern and Bloomer, 1992) have concluded that the Coast Range Ophiolite has geochemical affinities with supra–subduction-zone Ophiolite continued from p. 2 The arc assemblage of the Sierran (SSZ) ophiolites (Pearce et al., 1984), foothills metamorphic belt (Fig. 1) may implying the influence of a subducted Sierra Nevada are genetically unrelated represent a complex of related but dis- slab on its generation. These workers (Dilek et al., 1990). rupted arc segments and remnant arcs and others (Evarts, 1977; Lagabrielle et Deformed and variably metamor- juxtaposed across fault contacts (Paterson al., 1986; Robertson, 1989) have variously phosed Paleozoic-Mesozoic marine strata et al., 1987; Edelman and Sharp, 1989). inferred backarc, forearc, or intra-arc set- (mainly chert-argillite sequences and Volcanogenic successions locally overlie tings of either east-facing or west-facing turbidites), exposed between and thrust ophiolitic sequences of both earliest arcs for its origin. Ophiolitic breccias beneath the two arc assemblages, are Jurassic (~210–200 Ma) and intra-Jurassic locally overlying the Coast Range Ophio- interpreted as a suture belt of compound (~165–160 Ma) age (Saleeby, 1982; Saleeby lite and resting concordantly beneath subduction complexes cut by multiple et al., 1989; Dilek, 1989b; Edelman et al., the Great Valley Group reflect local but fault zones and melange belts emplaced 1989). The best preserved remnant of widespread extensional deformation at during arc-arc collision (Schweickert and mafic crust occurs in the northwestern the sites of their formation (Robertson, Cowan, 1975). A modern example of a foothills within the Smartville ophiolitic 1990). Following initiation of Franciscan remnant ocean basin closing by face-to- complex (Fig. 1) formed by intra-arc rifting subduction to the west, Great Valley fore- face arc-arc collision is afforded by the and associated magmatism during Middle arc sedimentation was underway near the Molucca Sea (Ricci et al., 1985). In the to Late Jurassic time (Menzies et al., 1980; Kimmeridgian-Tithonian boundary Sierran foothills belt, metamorphosed Beard and Day, 1987); combined radio- (155–150 Ma). Upper Jurassic turbidites of the partly metric and fossil ages bracket the main Stern and Bloomer (1992) argued the volcaniclastic Mariposa Formation are interval of its formation as 165–155 Ma case for forearc spreading to produce the inferred to be an overlap assemblage (Day et al., 1985; Edelman and Sharp, Coast Range Ophiolite by drawing an deposited in part in a remnant ocean 1989). Widespread overlap of foothills analogy between the Jurassic Sierran arc basin but also onlapping the accreted volcanic units by the Mariposa Formation and early stages in the evolution of the intraoceanic arc complex (Ingersoll and near the Oxfordian-Kimmeridgian bound- modern Izu-Bonin-Mariana arc of the Schweickert, 1986). Once the foothills ary implies that the arc complex had western Pacific. As they note, however, arc-arc suture belt had fully closed, lodged along the foothills belt by ~155 Ma the analogy is not exact because the con- subduction stepped outboard to the in Late Jurassic time (Schweickert et al., cepts of “subduction-zone infancy” and California Coast Ranges, trapping 1984). Crosscutting plutons of the evolv- “infant-arc crust,” unquestionably applica- backarc-interarc Jurassic oceanic crust as ing Sierran arc were emplaced into foot- ble to the Eocene Izu-Bonin-Mariana arc, the Coast Range Ophiolite at the leading hills volcanogenic assemblages and cannot apply to the Sierran arc, for which edge of the overriding plate. With the melanges by latest Jurassic or earliest abundant radiometric ages for plutons onset of Franciscan subduction in the Cretaceous time (~150–140 Ma) indicate arc activity throughout the inter- California Coast Ranges, Sierran arc mag- (Saleeby et al., 1989). val 215–80 Ma (Stern et al., 1981; Chen matism also stepped westward to over- Recent interpretations that the foot- and Moore, 1982). Moreover, the Izu- print both the foothills suture belt and hills arc complex was accreted to the con- the accreted intraoceanic arc. tinental margin prior to formation of the Ophiolite continued on p. 4

GSA TODAY, February 1996 3 Ophiolite continued from p. 3

Bonin-Mariana arc is indisputably an intraoceanic arc, and geochemical anal- ogies between the Coast Range Ophiolite and igneous rocks of the Izu-Bonin-Mari- Pillow basalt with interpillow ana system can be interpreted as strong pelagic limestone. Volcanic evidence for origin of the former in close member of the Middle Juras- relation to an intraoceanic arc, rather than sic Coast Range ophiolite, Llanada remnant, southern to the Sierran arc along the continental Diablo Range, California. margin. Recent work near intraoceanic island arcs in the southwest Pacific has shown the difficulty of distinguishing geo- chemically among arc-related magmas erupted in backarc, intra-arc, and forearc settings (Hawkins, 1994). Accordingly, origin of the Coast Range Ophiolite by backarc spreading behind an precluding east-west transport behind an 2. COAST RANGE OPHIOLITE AS intraoceanic island arc that lodged in the arriving island arc. PALEOEQUATORIAL MID-OCEAN Sierran foothills late in Jurassic time Two residual questions remain. The LITHOSPHERE remains a viable hypothesis. Scraps of first pertains to relations between the Sier- remnant arc structures within the ophio- Clifford A. Hopson, Department of ran foothills belt and the Klamath Moun- lite are to be expected in this case, along Geological Sciences, University of California, tains, where the Josephine Ophiolite is with overall SSZ geochemistry. If forearc Santa Barbara, CA 93106-9630 inferred to have formed by interarc rifting of the Sierran arc (model 3) were Emile A. Pessagno, Jr., Programs in spreading along the continental margin the correct interpretation, one would Geosciences, University of Texas at Dallas, within the interval 165–155 Ma (Saleeby expect to find rifted fragments of prerift Richardson, TX 75083-0688 et al., 1982; Harper and Wright, 1984; Sierran foothills melange units within the James M. Mattinson, Department of Wyld and Wright, 1988). This interval Coast Ranges, but such has never been Geological Sciences, University of California, overlaps the time span inferred above for reported. Moreover, the Coast Range Santa Barbara, CA 93106-9630 arc rifting within an offshore intraoceanic Ophiolite is capped locally, as at Llanada, Bruce P. Luyendyk, Department of arc complex to form the Smartville com- by ~1500 m of intermediate volcaniclastic Geological Sciences, University of California, plex and Coast Range Ophiolite. In the rocks (Robertson, 1989; Hull et al., 1993), Santa Barbara, CA 93106-9630 Klamaths, however, the Rogue Volcanics which could readily be derived from a rift- Ward Beebe, Department of Geological form a frontal arc coeval with the interarc ing intraoceanic arc but are unlike chert- Sciences, University of California, basement of the Josephine Ophiolite, rich quartzolithic Upper Jurassic to Lower Santa Barbara, CA 93106-9630 whereas no analogous assemblage has Cretaceous sandstones derived from a Sier- Donna M. Hull, Programs in Geosciences, been discovered within the Coast Ranges. ran provenance and deposited in both the University of Texas at Dallas, Spreading to form the Josephine Ophiolite Mariposa Formation of the foothills belt Richardson, TX 75083-0688 may have been a response to arc-arc colli- and at lower horizons of the Great Valley Ivette M. Muñoz, Programs in Geosciences, sion in the Sierran region farther south forearc basin (Ingersoll, 1983; Short and University of Texas at Dallas, Richardson, (Ingersoll and Schweickert, 1986). Ingersoll, 1990). Upward transitions from TX 75083-0688 The second issue pertains to the time distal to proximal volcaniclastic strata Charles D. Blome, U.S. Geological Survey, of initiation of Franciscan subduction west above the Coast Range Ophiolite are inter- MS 919, Box 25046, Denver, CO of the Coast Range Ophiolite. Ages (K-Ar, preted here as the result of progradation 80255-0046 U-Pb, Ar-Ar) of high-grade blueschist from arc sources, rather than the record blocks within the Franciscan assemblage The igneous pseudostratigraphy, of tectonic transport toward the arc (as range from 140–145 to ~160 Ma (Wak- structure, seismic velocity profile, petro- in model 2). abayashi, 1992). The oldest ages appear to logy, and geochemistry of the mid-Jurassic If the Coast Range Ophiolite, as overlap with the final phases of formation (~170–165 Ma) Coast Range Ophiolite argued here, is an accreted fragment of of the Smartville complex and Coast seem consistent with tectonically thinned, backarc-interarc crust, then its formation Range Ophiolite, whereas the tectonic multiply altered oceanic crust, but provide at essentially the same time as the intra- model favored here holds that Franciscan no clear-cut guide to original tectonic set- arc Smartville complex of the Sierran foot- subduction should postdate accretion of ting. Lacking decisive evidence from the hills reflects the same general interval of those intra-arc and backarc features by igneous rocks, we turn to the associated extensional tectonism within an intra- arc-arc collision in the Sierran foothills. Jurassic sedimentary rocks. The succession oceanic arc-trench system. The rather Perhaps resolution of this paradox lies in of sediments entrapped within and accu- mafic crustal profile of the intervening a better understanding of the mechanisms mulating on top of the igneous crust of a Great Valley (Cady, 1975; Holbrook and by which subduction was arrested in the mobile oceanic plate make up its plate Mooney, 1987) can be understood as Sierran foothills and initiated in the Coast stratigraphy (Berger and Winterer, 1974), representing similar ophiolitic materials, Ranges to the west. Some overlap in the which is applicable to ophiolites and can perhaps telescoped by deformation during timing of those two events is not difficult provide a travel history for an ancient accretion and certainly overprinted by to envision as an intraoceanic arc system oceanic plate. For example, the plate subsequent Sierran plutonism. Recent gradually lodged firmly against the stratigraphy of ophiolites formed at a interpretations of paleomagnetic data continental margin. divergent plate margin (mid-ocean ridge) for several remnants of the Coast Range will reflect transport toward a convergent Ophiolite suggest paleolatitudinal concor- margin, marked by progressive increase dance with North America (Butler et al., in the sedimentary products of arc 1991; Mankinen et al., 1991; Hagstrum and Murchey, 1993), requiring no major north-south transport (model 2) but not Ophiolite continued on p. 5

4 GSA TODAY, February 1996 Ophiolite continued from p. 4 Figure 2. Tectonostratigraphic diagram compar- ing Coast Range Ophiolite (CRO) –VP– basal Great Valley Group (GVG) succession at Cuesta Ridge, volcanism. Arc-related ophiolites, born Point Sal, Stanley Mountain, and Llanada with behind convergent plate margins (i.e., the Josephine Ophiolite (JO)–Galice succession. above subduction zones), lie adjacent to Time scale from Gradstein et al. (1994); top of the arc volcanism from birth. Their travel his- Jurassic from Bralower et al. (1990); radiolarian tories might keep them close to the active zonation from Pessagno et al. (1993). Minimum arc (e.g., arc-parallel strike-slip transport) and estimated maximum possible ages of Coast Range Ophiolite remnants (only tops shown) are or take them farther away in the case of based on U/Pb and Pb/Pb isotopic ages, respec- prolonged back-arc spreading, but will tively (Mattinson and Hopson, 1992). The not carry them toward the arc from a Josephine Ophiolite age is from Harper et al. distant birthplace. (1994); Devils Elbow outlier (JODE) age from Jurassic plate stratigraphy at the Point Wyld and Wright (1988). Black intervals span the Sal, Stanley Mountain, Cuesta Ridge, and depositional hiatus between Coast Range Ophio- lite remnants and the overlying VP succession; Llanada Coast Range Ophiolite remnants also a hiatus within VP. VP spans time of vol- (Fig. 1) shows that the igneous oceanic canopelagic sedimentation including distal tuffa- crustal rocks originated beyond reach of ceous (VPt) and proximal sandy-fragmental (VPs) terrigenous or volcanic arc sedimentation facies, respectively. Terrigenous sedimentation on and were then carried progressively closer Coast Range Ophiolite–VP began with basal strata of the Great Valley Group in the latest Jurassic. to the coeval Jurassic arc that fringed west- The GALICE interval spans the terrigenous ern North America. The lithostratigraphic graywacke-mudstone sequence above Josephine succession begins with the sedimentary Ophiolite and thin VP strata. Nevadan orogeny rocks entrapped as small scraps within the (Klamath phase) from Harper et al. (1994). CT ophiolite volcanic member. These are interval spans sedimentation in Central Tethyan mainly basaltic rubble, red jasper (silicified Province, NT in Northern Tethyan Province, and SB in Southern Boreal Province; question-mark intervals lack diagnostic radiolarians. Asterisk wedges ferruginous hydrothermal sediment), and mark Late Jurassic magmatic (intrusive) and hydrothermal events. pelagic limestone. Limestone is the only externally derived sedimentary rock, indi- cating an open-ocean setting. Claims of arc-derived volcaniclastic strata interbed- ded with Coast Range Ophiolite lavas tephra) mixed in varying proportions facies) downwind of an active Jurassic are incorrect; those strata belong to the with radiolarian ooze. A thick upper sandy- arc, then partly into the proximal unconformably overlying Late Jurassic fragmental facies composed of up to 300 m volcaniclastic submarine apron (VP (volcanopelagic) (VP) succession (see of bedded pumiceous and lithic lapilli tuff, sandy-fragmental facies). below), locally isolated between subvol- volcaniclastic sandstone (including tur- The Coast Range Ophiolite–VP con- canic intrusive sheets (postophiolite sills, bidites) and conglomerate, with interbeds tact is unconformable: pillow lavas below mistaken for ophiolite lava flows) that of radiolarian tuffaceous mudstone, over- this contact carry interpillow limestone, commonly concentrate along and just lies the tuff-radiolarite facies at some cen- whereas VP strata immediately above are above the Coast Range Ophiolite–VP tral Coast Range localities (Llanada–Del mixtures of radiolarian ooze and volcanic contact in some Coast Range Ophiolite Puerto–Hospital Creek), and locally ash. The unconformity marks a deposi- remnants. (Llanada) grades up into an additional 500 tional hiatus (Fig. 2) that began when Resting depositionally on the ophio- m of cobbly to bouldery andesitic subma- spreading carried Coast Range Ophiolite lite lava is an Upper Jurassic (Oxfordian- rine debris-flow deposits capped by tuffa- oceanic crust below the calcite compensa- Tithonian) VP succession (Hull et al., 1993) ceous radiolarian chert. The tuff-radiolar- tion depth (CCD), ending carbonate depo- composed mainly of two original compo- ite facies represents the submarine distal sition, and lasted until its entry into the nents: radiolarian ooze and rhyolitic to tephra fringe of an active, emergent vol- tephra fringe of an arc. The Upper Jurassic andesitic volcaniclastic marine sediment. canic arc; the upper sandy-fragmental and Cretaceous Great Valley Group of ter- Most VP remnants consist of a thin facies is the corresponding coarser proxi- rigenous clastic marine strata overlies the (50–130 m) tuff-radiolarite facies of tuffa- mal submarine apron. This succession VP succession conformably. The upper- ceous radiolarian mudstone and chert, reflects transport of the oceanic plate most Jurassic lower portion of the Great and altered tuffs representing submarine (Coast Range Ophiolite) through the Valley Group, composed of mudstone deposits of pyroclastic fallout (airborne distal tephra fringe (VP tuff-radiolarite with interbeds of turbiditic siltstone and sandstone, plus local lenticular (channel- fill) pebble conglomerate well above the base of the succession (Bailey et al., 1964; Page, 1972; Suchecki, 1984), correspond to submarine slope deposits prograding over basin-plain deposits (Suchecki, 1984). These basal Great Valley Group strata, derived from Klamath-Sierran tectonic Interpillow pelagic (cocco- lithic) limestone near the top highlands at the North American accre- of the upper lava, Point Sal tionary margin (Dickinson and Rich, 1972; remnant of the Coast Range Ingersoll, 1983), represent a terrigenous ophiolite, Santa Barbara clastic apron that prograded over the deep County, California. ocean floor (Coast Range Ophiolite–VP succession) following onset of the Nevadan orogeny (Pessagno et al., 1996).

Ophiolite continued on p. 6

GSA TODAY, February 1996 5 Ophiolite continued from p. 5 show that the mid-Jurassic Coast Range Late Jurassic subduction zone lies buried Ophiolite oceanic crust formed near the beneath California’s Great Valley and We accordingly infer that the Coast paleoequator and was transported north- thrust sheets of the Klamath Mountains; Range Ophiolite formed at a spreading ward, passing progressively through (7) the 162–164 Ma Josephine ophiolite center in an open-ocean region of pelagic Central Tethyan, Northern Tethyan, (Figs. 1 and 2), formed in the backarc carbonate sedimentation. Seafloor spread- and Southern Boreal provinces during VP region behind the Middle to Late Jurassic ing carried Coast Range Ophiolite crust to sedimentation in the Late Jurassic (Fig. 2). Rogue-Chetco arc of the Klamath region sub-CCD abyssal depths, ending pelagic Coast Range Ophiolite–VP remnants (Harper, 1984; Harper et al., 1994), and is carbonate deposition for up to ~12 m.y. at Cuesta Ridge and Llanada (also Del not related to the Coast Range Ophiolite; (Fig. 2), then into a realm of oceanic Puerto) host swarms of Upper Jurassic and (8) the diachronous Late Jurassic sub- upwelling where radiolaria flourished basaltic-diabasic, keratophyric-microdi- volcanic igneous and hydrothermal events and radiolarian ooze deposition began. oritic and quartz keratophyric–grano- took place beneath deep sea floor during This coincided approximately with entry phyric sills and dikes, and are overprinted VP sedimentation, and may represent into the distal tephra fringe of an active by hydrothermal metamorphism. The rift-tip propagation of a new, Late Jurassic volcanic arc, where airborne ash mixed widespread assumption that ophiolite oceanic rift system through the older with radiolarian remains in the water genesis (mid-Jurassic) and pyroclastic arc (mid-Jurassic) Coast Range Ophiolite column. Most parts of the mobile Coast volcanism were contemporaneous and plate (Hopson et al., 1991). Range Ophiolite plate moved through closely adjacent, and consequently that only the tephra fringe of the arc, accumu- the ophiolite formed near or within an 3. COAST RANGE OPHIOLITE AS lating radiolarian ooze and mainly fine active arc (Evarts, 1977; Evarts and PARAUTOCHTHONOUS FORE- ash (Fig. 2, VP tuff-radiolarite facies). But Schiffman, 1982; Robertson, 1989), ARC LITHOSPHERE part of the Coast Range Ophiolite plate comes from the occurrence of sills (mis- Jason B. Saleeby, Geological and Planetary approached the volcanic arc more closely, taken for ophiolite lava flows), dikes, and Sciences, 170-25, California Institute of passing first through its deep-sea tephra hydrothermal alteration within the VP Technology, Pasadena, CA 91125 fringe and then into its proximal apron of succession. This interpretation is now volcaniclastic turbidites and debris flows rendered untenable by (1) recognition The forearc generation model for the (Fig. 2; Llanada remnant). Following VP of the Coast Range Ophiolite–VP uncon- Coast Range Ophiolite is based on petro- arc sedimentation, which ended in the formity with a long depositional hiatus, chemical and stratigraphic features of the late Tithonian, latest Jurassic terrigenous (2) identification of supposed “ophiolite ophiolite, relations of coeval ophiolitic turbidites and muds from Klamath-Sierran lava flows interbedded with arc volcani- and arc rocks of the western Klamath accreted terranes advanced out over the clastics” as sills invading Upper Jurassic Mountains and Sierra Nevada, and consid- deep ocean floor. This Jurassic Coast strata and yielding Late Jurassic radiomet- eration of relations in west Pacific fringing Range Ophiolite–VP–basal Great Valley ric ages, and (3) evidence that the Late arc systems. A corollary of the forearc Group oceanic succession, uplifted when Jurassic “sill event” took place at more generation model is that at relatively short Franciscan subduction began farther out- northerly paleolatitudes than creation time scales (~5 m.y.) juvenile forearc crust board, then floored the new Cretaceous of Coast Range Ophiolite oceanic crust may find itself residing either within an forearc basin. (Fig. 2). interarc basin or within the locus of arc A mobile interpretation of Coast The lithostratigraphic columns of construction. Such changes in tectonic Range Ophiolite–VP oceanic crust also Figure 2 can be used as map tracklines setting may arise from evolving loci of stems from paleomagnetic and faunal for individual segments of moving Coast arc construction working in series with evidence of large-scale Jurassic paleolatitu- Range Ophiolite oceanic lithosphere. the production of juvenile ophiolitic crust, dinal displacement indicated by (1) paleo- The assemblage of tracklines, positioned and in the case of oblique subduction the magnetic measurements on pillow lavas geographically according to constraints tangential migration of active and inactive at three Coast Range Ophiolite remnants, imposed by the lithofacies succession, arc segments and basinal tracts into (and and (2) provinciality of radiolarian and paleolatitude–faunal province, and age out of) ephemeral juxtapositions. This molluscan faunas in VP–Great Valley of each member, show the trajectories of corollary and its possible application to Group strata that correlate roughly individual segments of an oceanic plate the Coast Range Ophiolite is demon- with paleolatitude. Paleoinclinations moving from their origin through a suc- strated by the nearby Josephine Ophiolite of remanent magnetism in Coast Range cession of sedimentary environments of the western Klamaths (Fig. 1). The Ophiolite pillow lavas at Stanley Moun- toward the consuming plate margin (Fig. Josephine Ophiolite may be broadly tain (McWilliams and Howell, 1982), 3). We conclude that (1) the Coast Range correlative with the northern Coast Range Point Sal, and Llanada (Beebe, 1986; Ophiolite is exotic to the Jurassic North Ophiolite (Saleeby, 1981, 1992), but the Pessagno et al., 1996) were acquired in the American continental-margin arc; (2) the former is easier to interpret because it is Jurassic paleoequatorial region. Lower VP trackline assemblage cannot be fitted into preserved in its emplacement configura- strata that rest on the Coast Range Ophio- a backarc, forearc, or infant-arc associa- tion with little modification. In contrast, lite remnants consistently have Central tion; (3) the Coast Range Ophiolite–VP the Coast Range Ophiolite has been Tethyan radiolarian assemblages, whereas tracklines (plate motion) must be oriented severely modified by Franciscan under- progressively higher VP strata have North- approximately north-northeast–south- thrusting and extensional attenuation ern Tethyan and then Southern Boreal radi- southwest to fit the age–paleolatitude–fau- (Jayko et al., 1987). olarian assemblages, respectively (Fig. 2; nal province constraints; (4) the tracklines The Josephine Ophiolite formed in a Pessagno et al., 1996). Molluscans indicate dextral oblique subduction of transtensional basin that initially opened (Buchias) and radiolarians of the overlying oceanic lithosphere beneath the north- along the forearc edge of the Sierran- Great Valley Group strata are Southern west-trending Jurassic arc system, (5) the Klamath Middle Jurassic arc (Saleeby, Boreal. Boundaries between Central subduction zone lay between the arc and 1982; Harper and Wright, 1984; Wyld and Tethyan, Northern Tethyan, and Southern VP tephra fringe, the trench forming a Wright, 1988; Saleeby and Harper, 1993). Boreal provinces are placed at approxi- barrier to all but airborne volcaniclastic This arc was constructed in large part over mately lat 22°N and 30°N, respectively, on materials until the trench filled and was a polygenetic basement of older ensimatic the basis of global distributions of mollus- overlapped in late Tithonian time (Fig. 2; assemblages that were previously accreted can, radiolarian, and calpionelid faunas Llanada remnant) following the main (e.g., Pessagno et al., 1987). These data pulse of the Nevadan orogeny; (6) the Ophiolite continued on p. 7

6 GSA TODAY, February 1996 the margins of the valley indicate that at least the western part of the valley is floored by the Coast Range Ophiolite, and that the eastern margin of the valley is floored by coeval mafic submarine arc strata of the western Sierra Nevada. These arc rocks and their polygenetic basement are cut by swarms of sheeted and individ- ual dikes that are the same age as the Coast Range Ophiolite and Josephine Ophiolite, and which mark the waning of Middle Jurassic arc activity in this region (Saleeby, 1982, 1992; Saleeby et al., 1989). The forearc spreading model for the Coast Range Ophiolite considers these western- most Sierran rocks to be the inner bound- ary of the Coast Range Ophiolite–Joseph- ine Ophiolite basin system. As discussed below, the Josephine and Coast Range Ophiolites appear to have migrated north- ward shortly following spreading genesis, roughly placing the Josephine Ophiolite outboard of the western Sierra Nevada and the Coast Range Ophiolite farther south during basin formation. Unlike the Josephine Ophiolite segment of the basin system, the Coast Range Ophiolite–Great Valley segment survived the Nevadan orogeny. This difference may reflect ~100 km of eastward underthrusting of Josephine Ophiolite–related rocks beneath the central Klamaths following and partly in conjunction with northward transla- tion (Saleeby and Harper, 1993); analo- gous underthrusting is not directly observed, nor imaged geophysically, for the Coast Range Ophiolite–Great Valley Figure 3. Eastern Pacific–western North America region showing key tectonic elements for part of Mid- segment. The forearc spreading model dle to latest Jurassic time (~166–143 Ma). Tracklines of Point Sal (P), Cuesta Ridge (C), Stanley Mountain thus considers the modern morphologic (S), and Llanada (L) Coast Range Ophiolite segments trace their progression by sea-floor spreading from Great Valley as a partial remnant of the a 166 Ma paleoequatorial midocean ridge spreading center through deep-sea regions of (1) sub-CCD calcareous ooze starvation, (2) volcanopelagic sedimentation, to (3) their 143 Ma positions (arrowheads) original basin. just prior to burial beneath terrigenous clastic sediments (basal Great Valley Group) from the adjacent The forearc spreading model implies Nevadan orogen. Trackline positions and direction are constrained by data combined in Figure 2: the that the Coast Range Ophiolite formed in lithostratigraphy, biostratigraphy, Coast Range Ophiolite radiometric ages and paleomagnetic latitudes, a supra–subduction-zone (SSZ) setting, as and VP faunal provinces. Location of western North America at 143 Ma from Scotese and Denham suggested by abundant geochemical data (1988), modified to paleolatitudes of May et al. (1989). Triangles mark trend of Upper Jurassic arc (Shervais and Kimbrough, 1985; Shervais, volcanics and plutons. Jurassic subduction zone in front of the arc placed at the California Great Valley magnetic-gravity high (Fig. 1), where mafic high-velocity crust dips eastward beneath the Sierra Nevada 1990). An SSZ setting is further suggested (Mooney and Weaver, 1989); projection northward and southward is schematic. VP distal tuffaceous by the presence of arc-derived pyroclastic, facies (from airborne tephra and radiolarian ooze) accumulated outboard of the Jurassic trench. VP prox- volcaniclastic, and hypabyssal material imal sandy-fragmental facies (volcaniclastic turbidites and debris flows) accumulated inboard, bounded expressed mainly in the later phases of by the trench until it filled in latest Jurassic time (see text). JO, IO, and FO schematically depict Middle the Coast Range Ophiolite igneous and to Late Jurassic back-arc basins whose oceanic crust–mantle remnants are the Josephine, Ingalls, and sedimentary succession (referenced in Fidalgo ophiolites (Harper, 1984; Miller et al., 1993). SC marks the Smartville intra-arc igneous complex (Beard and Day, 1987). model 2). These later arc components are analogous to the constructional arc prod- ucts that migrated westward to the outer fringes of the Josephine Ophiolite basin. The absence of rifted screens of older Ophiolite continued from p. 6 terranes and part of the Josephine Ophio- basement in the Coast Range Ophiolite lite basin floor. The entire system was then (as noted in model 1) may stem from the to the Cordilleran plate edge; to the south- imbricated and crosscut by plutons during limited outcrop area of the Coast Range east the arc tracks onto North American the Late Jurassic Nevadan orogeny. The Ophiolite relative to the probable original continental lithosphere, which prior to forearc spreading generation, inter-arc basin size. active-margin tectonism had been thinned basin residence, and thrust imbrication The difficulties with model 1, which by passive-margin formation. As Josephine of the Josephine Ophiolite all occurred also envisions SSZ affinity, are outlined as Ophiolite forearc spreading progressed, within ~10 m.y. follows (after Saleeby and Busby-Spera et arc magmatism to the east waned. By the Geophysical and basement core data al., 1992): (1) The implied Late Jurassic cessation of spreading, arc magmatism indicate that the Great Valley is underlain (Nevadan) collisional suture within the relocated along the outer edge of the primarily by oceanic crust (Cady, 1975; western Sierras and Klamaths cannot be Josephine Ophiolite basin, capping both Saleeby et al., 1986). These geophysical rifted screens of older Klamath (or Sierran) data as well as stratigraphic relations along Ophiolite continued on p. 8

GSA TODAY, February 1996 7 Ophiolite–Josephine Ophiolite basin system may have represented ~2000 km of the forearc (and ephemeral inter- to intra-arc) region along the Cordilleran Tuffaceous radiolarian chert within the tuff/radiolarite plate edge. Available constraints on facies of the Upper Jurassic spreading kinematics recorded within volcanopelagic succession, the Josephine Ophiolite, and locally lying unconformably on pil- within the Coast Range Ophiolite, are per- low lava (not shown) of the missive of a strong spreading component Middle Jurassic Coast Range subparallel to the plate edge, suggesting ophiolite. Point Sal Coast Range Ophiolite–VP remnant, that tangential transport was dynamically Santa Barbara, California. linked to spreading (Harper et al., 1985; Saleeby, 1992). Furthermore, regional lin- ear gravity-magnetic anomalies oriented along the axis of the Great Valley (Fig. 1) may be modeled as a fossil transform sys- tem within the basin floor. Such longitudi- nal transform(s) could have served as Ophiolite continued from p. 7 zone along which subduction nucleated. zones of terrane removal as well as ophio- The details of this mechanism encounter lite accretion and translation (Saleeby and delineated with confidence; the most difficulty for the Coast Range Ophiolite, as Busby-Spera, et al., 1992). Stratigraphic likely structures are pre-Callovian (>169 discussed in model 2. An alternative, yet differences between Josephine Ophiolite Ma) in age, as indicated not only by local fundamentally similar slab rollback mech- and Coast Range Ophiolite can be recon- crosscutting relations of plutons but also anism for the Coast Range Ophiolite is the ciled with the northward transport model. by the occurrence of a regional belt of subduction of old, cold Panthalassan Overlapping volcanic-poor turbidites are Middle Jurassic dioritic to peridotitic arc lithosphere inherited from the Pangea of Oxfordian-Kimmeridgian age above the plutons that cut across the depositional regime (Saleeby and Busby-Spera et al., Josephine Ophiolite and its fringing arc, basement of both hypothetical east- and 1992). Upper-plate extension along the and similar strata of the lowermost Great west-facing arcs. (2) The entire subduction southwest Cordilleran plate edge may be Valley Group young southward from late complex and forearc region of the postu- recorded as far back as Early Jurassic time Kimmeridgian to Tithonian age above lated east-facing arc is missing; Tethyan by earlier phases of forearc magmatism the Coast Range Ophiolite and its over- limestone-bearing melange units (Saleeby, 1992) as well as a tendency for lapping arc strata. In the western Sierra purported to represent a sandwiched much of the arc magmatism to have Nevada, similar strata locally range back subduction complex reside as depositional expressed itself by silicic ignimbrite pond- to Callovian in age. These units are inter- basement for Jurassic arc rocks and thus ing within a largely submarine graben preted as different parts of a regional represent an earlier phase of tectonic depression system (Busby-Spera, 1988). progradational submarine fan system accretion. (3) Likewise, the Middle Jurassic The single largest pulse of ignimbrite derived from northerly Middle and Late forearc and subduction complex for the ponding along the eastern Sierra Nevada Jurassic highlands and spread southward, implied west-facing system are missing; corresponds precisely in time with the for- first across the western Sierran belt and the best candidates for such rocks are cut mation of the Coast Range and Josephine then sequentially across the Josephine by copious Middle Jurassic arc plutons Ophiolites as well as the western Sierra Ophiolite and Coast Range Ophiolite as and, in the northern Sierra, are part of the dike swarms. We thus suggest that the the various segments of the basin system depositional basement of Lower and Mid- broadly extensional arc-forearc region migrated into their resting sites (Saleeby dle Jurassic arc strata. (4) Rock assemblages intensified in its extensional deformation and Busby-Spera, et al., 1992). along the Sierran crest and farther east, toward the end of the Middle Jurassic, considered to be the axial Jurassic arc, are resulting in the production of ophiolitic REFERENCES CITED dominated by silicic ignimbrites and by forearc crust in the wake of the foundering plutonic suites with scattered backarc slab. This analysis considers the dynamics Bailey, E. H., and Blake, M. C., 1974, Major chemical characteristics of Mesozoic Coast Range Ophiolite in geochemical affinities; the axis of the arc of the subducting plate to be the prime California: U.S. Geological Survey Journal of Research, more likely lay farther west, represented factor in promoting forearc spreading. v. 2, p. 637–656. in part by the regional belt of dioritic to As mentioned above, the Josephine Bailey, E. H., Irwin, W. P., and Jones, D. 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F., 1990, Sedimentology and tectonic early Mesozoic arc magmatism in the Yerington district California: Tectonics, v. 6, p. 475–488. implications of ophiolite-derived clastics overlying the Jurassic Coast Range Ophiolite, northern California: of western Nevada and its regional implications: Geo- Lagabrielle, Y., Roure, F., Coutelle, A., Maury, R. C., American Journal of Science, v. 290, p. 109–163. logical Society of America Bulletin, v. 100, p. 644–652. Joron, J-L., and Thonon, P., 1986, The Coast Range Edelman, S. H., and Sharp, W. D., 1989, Terranes, early ophiolites (northern California): Possible arc and back- Saleeby, J. B., 1981, Ocean floor accretion and faults, and pre–Late Jurassic amalgamation of western arc basin remnants; their relations to Nevada orogeny: volcanoplutonic arc evolution of the Mesozoic Sierra Sierra Nevada metamorphic belt, California: Geological Société Géologique de France, Bulletin, v. 2, p. 981–999. Nevada, California, in Ernst, W. G., ed., The geotectonic development of California: Englewood Cliffs, New Jer- Society of America Bulletin, v. 101, p. 1420–1433. Mankinen, E. A., Gromme, C. S., and Williams, K. M., sey, Prentice-Hall, p. 132–181. Edelman, S. H., Day, H. W., and Bickford, M. E., 1989, 1991, Concordant paleolatitudes from ophiolitic Implications of U-Pb zircon ages for the tectonic set- sequences in the northern California Coast Ranges, Saleeby, J. B., 1982, Polygenetic ophiolite belt of the tings of the Smartville and Slate Creek complexes, U.S.A.: Tectonophysics, v. 198, p. 1–21. California Sierra Nevada: Geochronological and tectonostratigraphic development: Journal of northern Sierra Nevada, California: Geology, v. 17, Mattinson, J. M., and Hopson, C. A., 1992, U/Pb ages of Geophysical Research, v. 87, p. 1803–1824. p. 1032–1035. the Coast Range Ophiolite: A critical reevaluation based Evarts, R. C., 1977, The geology and petrology of the on new high-precision Pb/Pb ages: American Associa- Saleeby, J. B., 1992, Petrotectonic and paleogeographic Del Puerto ophiolite, Diablo Range, central California tion of Petroleum Geologists Bulletin, v. 76, p. 425. settings of U.S. Cordilleran ophiolites, in Burchfiel, B. C., et al., The Cordilleran orogen: Conterminous Coast Ranges, in Coleman, R. G., and Irwin, W. P., eds., May, S. R., Beck, M. E., and Butler, R. F., 1989, North U.S.: Boulder, Colorado, Geological Society of America, North American ophiolites: Oregon Department of American apparent polar wander, plate motion, and Geology of North America, v. G-3, p. 653–682. Geology and Mineral Industries Bulletin 95, p. 121–139. left-oblique convergence: Late Jurassic–Early Cretaceous Evarts, R. C., and Schiffman, P., 1982, Submarine orogenic consequences: Tectonics, v. 8, p. 443–451. Saleeby, J. B., and Harper, G. D., 1993, Tectonic rela- tions between the Galice Formation and the schists of hydrothermal metamorphism of the Del Puerto ophio- McWilliams, M. O., and Howell, D. G., 1982, Exotic ter- Condrey Mountain, Klamath Mountains, northern lite, California: American Journal of Science, v. 283, ranes of western California: Nature, v. 297, p. 215–217. p. 289–340. California, in Dunne, G., and McDougall, K., eds., Menzies, M., Blanchard, D., and Xenophontos, C., Mesozoic paleogeography of the western United Gradstein, F., Agterberg, F., Ogg, J., Hardenbol, J., van 1980, Genesis of the Smartville arc-ophiolite, Sierra States—II: Pacific Section SEPM, Book 71, p. 61–80. Veen, P., Thierry, J., and Huang, Z., 1994, A Mesozoic Nevada foothills, California: American Journal of Saleeby, J. B., Harper, G. D., Snoke, A. W., and Sharp, time scale: Journal of Geophysical Research, v. 99, Science, v. 280-A, p. 329–344. p. 24,051–24,074. W. D., 1982, Time relations and structural-stratigraphic Miller, R. B., Mattinson, J. M., Funk, S. A. G., Hopson, Hagstrum, J. T., and Murchey, B. L., 1993, Deposition of C. A., and Treat, C. L., 1993, Tectonic evolution of Upper Jurassic cherts (Coast Range Ophiolite) at Stanley Mesozoic rocks in the southern and central Washington Ophiolite continued on p. 10

GSA TODAY, February 1996 9 Ophiolite continued from p. 9 WASHINGTON REPORT patterns in ophiolite accretion, west-central Klamath Mountains, California: Journal of Geophysical Bruce F. Molnia Research, v. 87, p. 3831–3848. Saleeby, J. B., Blake, M. C., and Coleman, R. G., 1984, Washington Report provides the GSA membership with a window on the activities of the Pb/U zircon ages on thrust plates of west-central federal agencies, Congress and the legislative process, and international interactions that Klamath Mountains and Coast Ranges, northern California and southern Oregon: Eos (American could impact the geoscience community. In future issues, Washington Report will present Geophysical Union Transactions), v. 65, p. 1147. summaries of agency and interagency programs, track legislation, and present insights into Saleeby, J. B., and 12 others, 1986, Continent-ocean Washington, D.C., geopolitics as they pertain to the geosciences. transect, corridor C2, Monterey Bay offshore to the Colorado Plateau: Geological Society of America Map and Chart Series TRA-C2, 2 sheets, scale 1:500,000, 87 p. text. Saleeby, J. B., Shaw, H. F., Niemeyer, S., Moores, E. M., Farewell, U.S. Bureau of Mines and Edelman, S. H., 1989, U/Pb, Sm/Nd and Rb/Sr geochronological and isotopic study of northern Sierra Nevada ophiolitic assemblages, California: Contribu- “The U.S. Department of Interior will recognize the accomplishments and tions to Mineralogy and Petrology, v. 102, p. 205–220. honor the contributions of the U.S. Bureau of Mines in a commemorative Saleeby, J. B., and seven others, 1992, Early Mesozoic tectonic evolution of the western U.S. Cordillera, in ceremony Wednesday, December 13, 1995. The ceremony will focus on the Burchfiel, B. C., et al., eds., The Cordilleran orogen: Conterminous U.S.: Boulder, Colorado, Geological research and achievements made by the 85 year old agency, slated for Society of America, Geology of North America, v. G-3, p. 107–168. closure January 8, 1996, as a result of GOP budget cuts.” Schweickert, R. A., 1976, Shallow-level plutonic —Department of Interior Media Advisory, December 11, 1995 complexes in the eastern Sierra Nevada, California, and their tectonic implications: Geological Society of America Special Paper 176, 58 p. “When I accepted the responsibilities and challenges of being the 19th Schweickert, R. A., and Cowan, D. S., 1975, Early Mesozoic tectonic evolution of the western Sierra Director of the U.S. Bureau of Mines, I did so as a scientist who believes Nevada, California: Geological Society of America Bulletin, v. 86, p. 1329–1336. that scientists should invest in scientific leadership. It is critical that the Schweickert, R. A., Bogen, N. L., Girty, G. H., Hanson, focus of our research investments be on solving problems, rather than lost in R. E., and Merguerian, C., 1984, Timing and structural expression of the Nevadan orogeny, Sierra Nevada, conflict and chaos. I have observed threats to that focus for our nation that California: Geological Society of America Bulletin, v. 95, p. 967–979. are truly staggering. We are a nation who relies on science and technology, Scotese, C. R., and Denham, C. R., 1988, User’s manual for Terra Mobilis: Plate tectonics for the Macintosh: yet we run away from science and technology leadership. First, the Office Scotese and Denham. of Technology Assessment; second, the U.S. Bureau of Mines; third, who Shervais, J. W., 1990, Island arc and ocean crust ophiolites: Contrasts in the petrology, geochemistry knows? Given the impasse in budget resolution over the past two and a and tectonic style of ophiolite assemblages in the California Coast Ranges, in Malpas, J., et al., eds., half months, we should ask, ‘How are we going to refocus our science and Ophiolites, oceanic crustal analogues: Nicosia, Cyprus Geological Survey Department, p. 507–520. technology spending so that the national interest is the common ground?’” Shervais, J. W., and Kimbrough, D. L., 1985, Geochemi- —Bureau of Mines Director Rhea L. Graham, December 13, 1995 cal evidence for the tectonic setting of the Coast Range ophiolite: A composite island-arc–oceanic crust terrane in western California: Geology, v. 13, p. 35–38. Short, P. F., and Ingersoll, R. V., 1990, Petrofacies and On December 13, 1995, the last ued programs include pollution preven- provenance of the Great Valley Group, southern workday before the start of the prolonged tion and control, environmental waste Klamath Mountains and northern Sacramento Valley, in Ingersoll, R. V., and Nilsen, T. H., eds., Sacramento shutdown of the Federal Government, remediation, minerals land assessment, Valley symposium and guidebook: Pacific Section SEPM the Department of the Interior (DOI) and minerals availability. Book 65, p. 39–52. paid tribute to the employees of the U.S. Facilities and offices that were closed Stern, R. J., and Bloomer, S. H., 1992, Subduction zone Bureau of Mines (USBM) for 85 years of are located at Spokane, Washington; Reno, infancy: Examples from the Eocene Izu-Bonin-Mariana outstanding public service and dedication Nevada; Salt Lake City, Utah; Denver, and Jurassic California arcs: Geological Society of America Bulletin, v. 104, p. 1621–1636. to improving technology and protecting Colorado; Tuscaloosa, Alabama; Rolla, Stern, T.W., Bateman, P. C., Morgan, B. A., Newell, human resources. Missouri; Minneapolis, Minnesota; and M. F., and Peck, D. L., 1981, Isotopic U-Pb ages of In October 1995, as part of the budget Washington, D.C. The 90-day time line zircon from the granitoids of the central Sierra appropriations process, the Congress expired on January 8, 1996. At the com- Nevada, California: U.S. Geological Survey Professional Paper 1185, 17 p. voted to terminate all of the USBM memoration, Secretary of the Interior programs in 90 days. It also directed that Bruce Babbitt stated, “The Bureau of Mines Suchecki, R. K., 1984, Facies history of the Upper Juras- sic–Lower Cretaceous Great Valley sequence: Response the USBM’s health and safety research has pioneered award-winning research to structural development of an outer-arc basin: Journal program activities be transferred to the and developed technologies to improve of Sedimentary Petrology, v. 54, p. 170–191. Department of Energy, that some of its the life for the country in many areas. Wakabayashi, J., 1992, Nappes, tectonics of oblique information analysis activities be trans- Their research and development helped to plate convergence, and metamorphic evolution related to 140 million years of continuous subduction, ferred to the U.S. Geological Survey, and detect and prevent fires, reduce silica and Franciscan Complex, California: Journal of Geology, that the Mineral Land Assessment in coal dust exposure, prevent mine cave-ins, v. 100, p. 19–40. Alaska be transferred to the U.S. Bureau and reengineer dangerous practices and Wyld, S. J ., and Wright, J. E., 1988, The Devils Elbow of Land Management. USBM’s helium equipment to create a safer environment. ophiolite remnant and overlying Galice Formation: program will be administered by the The Bureau has played key roles in New constraints on the Middle to Late Jurassic evolu- tion of the Klamath Mountains, California: Geological Secretary of the Interior until its proposed improving and protecting the health and Society of America Bulletin, v. 100, p. 29–44. privatization is completed by 1997. safety of mine operators.” Secretary Bab- Manuscript received July 1, 1995; revision received Septem- Almost $100 million of USBM 1995 bitt also stated, “As concerns for a cleaner ber 19, 1995; accepted September 20, 1995. ■ programs and activities were eliminated and 1200 employees separated. Discontin- Bureau of Mines continued on p. 11

10 GSA TODAY, February 1996 Bureau of Mines continued from p. 10 PUBLICATIONS NEWS FROM GSA environment grew, USBM applied its expertise to develop ways to improve mine reclamation, found ways to mitigate acid mine drainage, and remove selenium, arsenic, and lead from polluted waters. BOOK NOOK WATCH THIS COLUMN FOR NEWS ABOUT GSA PUBLICATIONS The USBM met the challenge and over- came many obstacles with professional results.” JURASSIC MAGMATISM AND TECTONICS OF THE American paleobotanists D. White, R. Thiessen, E. H. Statements by USBM Director Rhea L. NORTH AMERICAN CORDILLERA Sellards, M. K. Elias, A. C. Noé, W. A. Bell, W. C. Darrah, Graham took a more assertive tone, ques- edited by D. M. Miller and C. Busby, 1995 F. D. Reed, J. M. Schopf, C. A. Arnold, C. B. Read, L. R. tioning the decision that eliminated the The 19 papers in this book discuss diverse approaches to Wilson, and H. N. Andrews, Jr.; and amateur paleobotan- USBM. “We in the USBM have always characterize the Jurassic tectono-magmatic event, identify ists F. O. Thompson, G. Landford, Sr., and J. E. Jones. fought an uphill battle of understanding. variations in its timing and other characteristics from Other chapters deal with floral-zonation schemes, The role that mining and minerals play in region to region, and consider its ultimate origin in terms museum collections, coal-ball studies, and roof-shale our society has frequently been framed in of lithospheric processes. Crucial aspects of the Jurassic floras. The book is rich in previously unpublished extremes: extraction versus preservation. tectonic events from the Yukon to the southernmost U.S. photographs and correspondence of W. C. Darrah, are described. This is an important look into now-eroded including humorous and controversial material of Yet, the common ground is, everyday we initial subduction-driven orogeny of the Cordillera, the broad interest. all live off mining and minerals. There- precursor to later events that so strongly shaped present MWR185, 424 p., indexed, ISBN 0-8137-1185-1, $105.00 fore, it was imperative that USBM staff geology. Most papers are data-intensive first-order studies, render unbiased and professional research although some fresh synthesis studies are also present. STRATIGRAPHY AND PALEOENVIRONMENTS OF and analysis for use by our nation’s lead- SPE299, 432 p., paperback, indexed, ISBN 0-8137-2299-3, $95.00 LATE QUATERNARY VALLEY FILLS ON THE ers....” Graham continued “Always keep- SOUTHERN HIGH PLAINS ing one’s eyes on the national interests is TERRESTRIAL AND SHALLOW MARINE V. T. Holliday, 1995 Reports on a five-year study of the late-Quaternary every public servant’s responsibility and GEOLOGY OF THE BAHAMAS AND BERMUDA edited by H. A. Curran and B. White, 1995 history of ten dry valleys or “draws” on the Southern challenge. We in the USBM have a proud High Plains of Texas and New Mexico. This record is a history of responding to a need, producing The authors review the current knowledge of the Quaternary geologic history of the Bahama Archipelago key to understanding the paleoenvironmental evolution a product, and then moving forward to and Bermuda, an area with unique terranes for the study of the region, important because of the long history of the next challenge. Ironically, our suc- of carbonate rocks, sediments, and environments. The human occupation and because the High Plains is known cesses in completing what we started exposed stratigraphic sequences of the islands reveal to suffer from climatic extremes, historically. Sections are have brought us the fate we face today. much about the history of global sea-level changes during included on geomorphic characteristics and evolution, Responding to change should not make Quaternary time. The focus is an interpretation of the stratigraphy of the valley fill (the focus of the volume), an agency irrelevant. My fellow colleagues, characteristics of Bahamian and Bermudan rock units, and paleontology, paleobotany, and stable isotopes. The stratigraphy along and between draws is broadly you have used your skills well, and have their fossil faunas and floras, and the karst surface features of the islands. Information from studies of the modern synchronous and remarkably similar in lithologic and served this nation faithfully. I would pedologic characteristics, suggesting that each draw have preferred that the process of fiscal shallow marine environments are used to help understand the rock record. Up-to-date summaries of the geologic underwent a similar, sequential evolution of the reduction in government services would history are presented along with models of stratigraphic dominant depositional environments. The changing have accorded all of the USBM functions development. Other articles cover a broad spectrum of depositional environments suggest shifts in regional continuing opportunities in public service. subdisciplines, from paleontology to carbonate systems vegetation and climate, but there also were distinct I would have enjoyed seeing your ingenu- geochemistry. Chapters are case-book examples of the local variations in environmental evolution. MWR186, 142 p., indexed, ISBN 0-8137-1186-X, $54.00 ity applied to solving national problems investigation of important aspects of carbonate island into the next millennium.” geology. SPE300, 428 p., indexed, ISBN 0-8137-2300-0, $93.00 The USBM was established in the DOI DNAG PUBLICATIONS …GSA members, be on July 1, 1910, founded by the Organic sure to use your “member special list prices” on all Act of May 16, 1910. The Organic Act was HISTORICAL PERSPECTIVE OF EARLY TWENTIETH DNAG orders. See new catalog for details. supplemented over the years to make CENTURY CARBONIFEROUS PALEOBOTANY IN NORTH AMERICA USBM the world’s premier minerals and Edited by P. C. Lyons, E. D. Morey, and R. H. Wagner, 1995 fact-finding agency. USBM’s establishment Contains a wealth of information on early 20th century 1-800-472-1988 followed a series of mining disasters that Carboniferous paleobotany in North America. The 28 claimed the lives of thousands of mine chapters focus on the interactions of European and workers. In recent years, the bureau American paleobotanists and the birth of discoveries GSA PUBLICATION SALES operated as a scientific research and in Carboniferous paleobotany. Central to these inter- P.O. Box 9140, Boulder, CO 80301 actions and some of the discoveries is the research of 303-447-2020 or fax 303-447-1133 information agency designed to solve Prepayment required. Major credit cards accepted. health and safety problems that threat- W. C. Darrah, which is highlighted. Twenty-one chapters ened the lives of miners and communities are portraits of: European paleobotanists W. J. Jongmans, W. Gothan, P. Bertrand, C. R. Florin, and M. Stopes; near mining operations. Beginning before World War II and throughout the cold war, USBM was a major contributor to decisions regarding the nation’s defense easier; preventing pollution through employees of the Bureau of Mines have and military readiness. control technology; garnering research every reason to be very proud of their 85 As it approached its ultimate fate, awards; monitoring minerals by maintain- years of service to the Department of the the USBM was praised for its recent ing the official U.S. statistics; providing Interior and America. On behalf of the accomplishments in protecting workers analyses of legislation on mineral issues Administration, I want to express our by preventing fires and explosions, to federal policy makers; providing gov- appreciation for the Bureau’s distinguished developing emergency breathing devices, ernment scientific expertise where needed; service and many outstanding accom- and preventing “black lung”; restoring and for its financial stewardship. plishments. Thank you for accepting the land by taking lead out of the Secretary Babbitt concluded, “Science the challenge; your contributions are environment and constructing wetlands; and technology programs are under attack investments that will continue to pay conserving resources by making recycling by congressional Republicans. The dividends for years to come.” ■

GSA TODAY, February 1996 11 GSAF UPDATE

Robert L. Fuchs

Second Century Fund of companies, including environmental, over. Information on the membership engineering, ground-water, publishing, campaign and pledge cards have been Passes Milestone forest products, and even manufacturing sent to all members. Send in your card (a recent gift was received from Corning). today with your five-year pledge, or call The Second Century Fund for Another major component of the the Foundation if your card was lost Earth • Education • Environment passed Second Century Fund is foundations, along the way. an important milestone on the road to also with a goal of $2.5 million. Support its goal of $10 million. During December has been strong from these organizations, 1995 total contributions and pledges including the National Science Founda- Ciriacks Heads topped the $4 million mark. tion, with the result that more than 40% Growth of the fund has been achieved Rocky Mountain of this goal has been reached. Foundations through contributions from a number of generally provide financing for specific Section Drive sources. The membership campaign, which programs, such as research grants, and began in August, is generating gifts from Kenneth W. Ciriacks of Santa Fe, we can expect the continued growth of members in all of GSA’s six sections. The New Mexico, is the chair of the Rocky GSA’s SAGE (Scientific Awareness Through goal of this campaign, which is being man- Mountain Section’s Second Century Fund Geoscience Education) and IEE (Institute aged by the sections, is $1.5 million. There membership campaign; he replaces W. K. for Environmental Education) programs is a direct benefit to the sections and their Hamblin, Provo, Utah, who resigned. Ken to be accompanied by an expansion of student programs, because 20% of all unre- Ciriacks retired from Amoco in 1994 after a foundation support. stricted gifts will be added to section 31-year career in exploration and research. The backbone of the Second Century endowments at the Foundation. Members He worked both in the United States and Fund has been the major donors, GSA are being asked to consider a five-year internationally, his last position with the members who have pledged over $2 mil- pledge to the Second Century Fund, in the company being that of vice president of lion in support of the Society and its work. amount of $50 per year. technology in Amoco’s Chicago headquar- These gifts have taken a variety of forms— The Industry Support Program for ters. Ciriacks graduated from the Univer- cash, securities, artwork, trusts, insurance, Earth Science is another integral part of sity of Wisconsin with a B.S. in geology, in and Pooled Income Fund participation. the Second Century Fund, with a goal set 1958; he earned his Ph.D. from Columbia Most donations are directed toward the at $2.5 million. Nearly 30% of that goal University in 1962. He majored in paleon- GSA or Foundation endowments, and a has been reached through gifts from more tology and stratigraphy and held a number of individuals have underwritten than 20 companies. Industry has long National Science Foundation postdoctoral some of the costs of the Boulder headquar- been a strong supporter of geology and fellowship prior to beginning a career in oil ters addition. These major individual GSA’s programs. In the early 1980s, the and gas exploration. donors are continuing the history of Foundation’s Decade of North American In undertaking the Rocky Mountain personal financial commitment to the Geology campaign was successful in Section campaign, Ken Ciriacks pointed Society that began with R. A. F. Penrose, raising $3.4 million from fewer than 30 out the changes that have been occurring Jr., in 1931. His outstanding bequest exists resource companies, largely oil and gas, in geoscience in recent years, changes that today as the core of an endowment that which provided the financial base for the he has also recognized in academic, gov- has grown both internally and, in recent publication of the DNAG volumes. The ernmental, industrial, and consulting years, by significant accretion. business world is tougher today, resource areas of endeavor. In particular, there has A milestone is by no means the end companies have merged, economic been a pronounced decline in professional of the road, and there is still a distance pressures are extreme, restructurings are continuity, such as in job security, job to be traveled. The more support there is rampant. On the other side of the coin, longevity, and single career pathways. from members, the sooner the trip will be GSA now reaches a much broader universe These conditions have created both an opportunity and a need for GSA and simi- lar organizations to play a greater role in the careers of geoscientists. This expanded role will make the attainment of Second Century Fund goals extremely important SECOND CENTURY FUND to GSA and its members. EARTH ◆ EDUCATION ◆ ENVIRONMENT HELP WANTED! MEMBERSHIP GOAL The membership campaign section chairs need people to help with fund $1.5 MILLION raising during 1996. If you feel the need to communicate a bit more with your fel- SECTION GOALS low GSA members and also have the desire to give GSA some personal time and assis- CORDILLERAN NORTH-CENTRAL NORTHEASTERN tance, please consider volunteering to be a campaign worker. The work is not overly $465,000 $170,000 $265,000 time consuming: calling and writing to 10 or 15 GSA members about their contri- ROCKY MOUNTAIN SOUTH-CENTRAL SOUTHEASTERN butions to the Second Century Fund. $225,000 $165,000 $210,000 You may just expand your own personal network in the process. ■

12 GSA TODAY, February 1996 Donors to the Foundation, November 1995

Allan V. Cox Student John T. Dillon Alaska Robert G. Johnson John B. Lyons Leo F. Laporte Scholarship Award Fund Scholarship Award Fund James O. Jones* Frederick Wayne Meyer William N. Laval* Robert S. Coe Carl S. Benson Robert O. Laidlaw E. A. Noble Gretchen Luepke Matthew J. Kramer William P. Brosge* Linus R. Litsey Leigh H. Royden Ennio Marsella Harold E. Malde* Joseph L. Corones John B. Lyons* Carol A. Russell Louis C. Pakiser, Jr. Judson Mead* John S. Ferguson, Jr. Sharon Mosher* Dietmar Schumacher Arthur N. Palmer* Jacek K. Sulanowski Wendell A. Koontz Richard P. Nickelsen Robert P. Sharp Judith Totman Parrish Shirley A. Liss Richard L. Nielsen Ronald K. Sorem Mary C. Rabbitt* Antoinette Lierman Robert A. Page Occidental Oil & Gas David J. Springer Elizabeth Pretzer Rall Medlin Scholarship Sarah M. Roeske Corporation* Dale Malcolm Stickney* Michael M. B. Rochette Award Fund Alison B. Till Dorothy M. Palmer Kenzo Yagi John L. Rosenfeld* Russell A. Brant Florence Robinson Weber Lloyd C. Pray Kingsley W. Roth Frank T. Dulong Unrestricted Fund–GSAF Wayne D. R. Ranney Edward T. Ruppel Jack H. Medlin* Minority Fund Richard C. Anderson Robert Raymond, Jr.* Nathaniel McLean Sage, Jr. Terry M. Offield Brian F. Atwater Thomas F. Anderson Paul R. Shaffer Melvin C. Schroeder* John S. Ferguson, Jr. ARCO Foundation, Inc.* Biggs Excellence in Earth Laurence L. Sloss* Seymour L. Sharps Harold E. Malde* Elwood Atherton Science Education Fund F. Earl Turner David A. Stephenson* Robert A. Matthews Rachel M. Barker* Whitman Cross II Stephen J. Urbanik David P. Stewart Volker C. Vahrenkamp Somdev Bhattacharji Susan A. Green DeWitt C. Van Siclen Dale Malcolm Stickney* Robert W. Blair Penrose Conferences A. L. Washburn Stephen M. Strachan Birdsall Award Fund William C. Bradley Fund Lauren A. Wright Christopher Anne Suczek Jean M. Bahr James A. Brown, Jr. William R. Holman Neil S. Summer Shirley Dreiss Memorial Arthur P. Butler, Jr. Pierre D. Glynn Charles H. Summerson* Fund Clement G. Chase Este F. Hollyday Research Grants Fund John F. Sutter Philip C. Bennett K. W. Ciriacks* John F. Mann, Jr. John T. Andrews Curt Teichert Tim B. Byrne* Stephen E. Clabaugh Jane S. McColloch Daniel S. Barker Robert J. Twiss Michael E. Campana Philip H. Close III La Rae N. Mishler William E. Benson David Walker Alan R. Dutton H. Basil S. Cooke Stavros S. Papadopulos Frederick B. Bodholt Malcolm P. Weiss Ann I. Guhman Brian J. Cooper Robert W. Ritzi, Jr. Ellen A. Cowan John H. Whitmer Dorothy M. Palmer Edward C. De La Pena Paul R. Seaber Martin B. Farley Erhard Winkler Abraham Springer Jonathan H. Fink Cesar I. Delgado Unrestricted Fund–GSA Isaac J. Winograd Roger M. Waller Fraser E. Goff Joseph A. Dixon Daniel D. Arden, Jr. Michael B. Winter Stephen W. Wheatcraft* Jonathan H. Goodwin Mark T. Duigon David B. Bannan J. Lamar Worzel William Wilson William R. Holman George E. Ericksen James C. Brice Herbert E. Wright, Jr. Peter M. Jacobs W. G. Ernst Bruce “Biff” Reed Eugene Cameron Leland W. Younker Wayne Kemp Yehuda Eyal Scholarship Fund Richard L. Cooley Edward J. Zeller Maureen P. Leshendok Robert B. Hall John H. Fournelle Robert F. Dymek Paul W. Zimmer Thane H. McCulloh Walter D. Hall Judy Ehlen Robert Metz Frank W. Harrison Women in Science Fund Cady Award Fund William S. Fyfe Jack B. Mills Carol T. Hildreth Valerie-Ann K. Eagen Frank E. Kottlowski* John M. Garihan William G. Minarik H. Stanton Hill William G. Minarik Anita L. Grunder Carol G. and John T. Terry L. Pavlis Tanio Ito John K. Hall McGill Fund Stephen F. Personius Stephen A. Kirsch Douglas L. Inman Larry A. Jackson Donald B. Potter Charles E. Kirschner Gerald H. Johnson Peter D. Rowley* Stephen A. Kish Claude C. Albritton Lisle T. Jory Gary A. Smith Charles W. Klassette *Century Plus Roster Memorial Fund Yousif K. Kharaka Louis P. Vlangas James E. Kline (gifts of $150 or more) Arthur A. Socolow Paul A. Lindberg Ray E. Wells Doris M. Curtis Jay Zimmerman Memorial Fund Sherilyn K. Dunklau SAGE Fund M. Charles Gilbert Thomas M. Berg Elisabeth G. Newton Betty Wade Jones GSA Foundation Ross L. Kinnaman Engineering Geology 3300 Penrose Place Timothy M. Lutz P.O. Box 9140 Award Fund E. Allen Merewether Christopher C. Mathewson* Siegfried Muessig* Boulder, CO 80301 James Edward Slosson Norman K. Olson (303) 447-2020 Gretchen Louise Priscilla C. Patton* Blechschmidt Fund Elizabeth Pretzer Rall John A. Kostecki* Robert C. Rettke Enclosed is my contribution in the amount of $______for: Charles C. Rich History of Geology David A. Stephenson* Foundation Unrestricted GSA Unrestricted The ______Program. Award Fund Thomas J. Vaughn Gretchen Luepke Laureen C. Wagoner My pledge to the Second Century Fund is $______per year for ___ years. Roger M. Waller Hydrogeology Award Please add my name to the Century Plus Roster (gifts of $150 or more). Fund David L. Warburton David A. Stephenson* Second Century Fund I am interested in helping my section reach its Second Century Fund goal Institute for Jane Albritton* by working on the committee. Please ask the section campaign chair to John Eliot Allen Environmental contact me. Education Fund ARCO Foundation* Charles C. Rich Virgil E. Barnes Laureen C. Wagoner Edward Scudder Belt PLEASE PRINT Rena M. Bonem* J. Hoover Mackin Donald W. Boyd* Name ______Award Fund Keros Cartwright* H. Richard Blank, Jr. Bruce R. Clark Arthur L. Bloom Clay M. Conway Address ______Jack B. Mills Marlan W. Downey* John C. Frye Peter T. Flawn* City/State/ZIP ______Environmental Award Helen L. Foster Irving G. Grossman Fund Phone ______Leon R. Follmer Corolla K. Hoag Frank E. Kottlowski* Terry Huffington*

GSA TODAY, February 1996 13 Penrose Conference Report basin. The next day’s field trip took the participants from Calgary to Banff via the Turner Valley oil field and the Kananaskis Fault-Related Folding highway. Field trip leaders Deborah Spratt, Philip Simony, Ray Price, and Paul MacKay Conveners pointed out a startling diversity of fold- David Anastasio fault relations, from outcrops with small- Department of Earth and Environmental Sciences, Lehigh University, Bethlehem, PA 18015 scale disharmonic folds to seismic profiles Eric Erslev of the Turner Valley structure, a newly Department of Earth Resources, Colorado State University, Fort Collins, CO 80523 reinterpreted fault-bend fold in the west- Donald M. Fisher ern limb of the Alberta syncline–triangle Department of Geosciences, Penn State University, University Park, PA 16802 zone. The need for three-dimensional (3D) incremental restorations and accurate field characterizations was evident in the vigor- ous discussions prompted by the Mount The Penrose Conference on fault- individuals employed by government Kidd and Misty Range structures. related folding held in Banff, Alberta, surveys. Of the industrial representatives, The first day of talks and posters con- Canada, August 22–27, 1995, was most came from petroleum companies centrated on the geometry and kinematics organized to examine the connections interested in hydrocarbons in folded of fault-fold relations in thrust-dominated between processes of faulting and folding orogens; however, a substantial number orogens, although extensional and strike- from an interdisciplinary perspective. Field represented companies involved in earth- slip orogens were also discussed. Rick geologists, geophysicists, experimentalists, quake hazard assessment. Twelve students Groshong started the session by showing and theoreticians were brought together provided new insights and an opportunity that simplifications such as rigid-block to evaluate the geometry, kinematics, and to have an impact on research of the next displacement, single deformation mecha- dynamics of fault-related folding and to generation of geoscientists. nisms (e.g., flexural slip or oblique simple examine the match between model The conference began in Calgary with shear), self-similar geometries (which grow predictions and observations from the a lecture by Ray Price on the regional tec- in size without limb rotations), and con- field and laboratory. tonic setting of the Canadian thrust belt, a stant two-dimensional area are convenient The 82 participants came from a wide lecture that also served as an introduction for modeling but do not replicate many range of backgrounds. Eight countries to the first field trip. Regional transpres- natural structures. Contributions from sub- were represented, including large contin- sion along a restraining bend was invoked sequent speakers and poster sessions made gents from the United States (53) and to explain synchronous dextral strike slip it apparent that previous divisions in Canada (17). Professional academicians in the interior ranges, southward-increas- (33) were dominant, and there were 28 ing thrust shortening in the eastern representatives from industry and nine ranges, and subsidence in the Alberta Folding continued on p. 15

1996-97 JOI/USSAC Distinguished Lecturer Series The series: Application information: Joint Oceanographic Institutions, Inc./U.S. Science Applications will be accepted from U.S. institutions Advisory Committee (JOI/USSAC) is pleased to announce interested in hosting a talk during the Fall ‘96/Spring ‘97 the 1996-97 JOI/USSAC Distinguished Lecturer Series. academic year. The application deadline is April 5, 1996. JOI/USSAC, associated with the international Ocean To receive an application contact the JOI/USSAC Drilling Program (ODP), initiated the series as a means to Distinguished Lecturer Series, Joint Oceanographic bring the results of ODP research to students at both the Institutions, Inc., 1755 Massachusetts Avenue, NW, Suite undergraduate and graduate levels and to the earth 800, Washington, DC 20036-2102; fax: (202) 232-8203; science community in general. During the 1996-97 Internet: [email protected]. season JOI/USSAC will sponsor eighteen talks, three by each of the speakers listed below.

Distinguished lecturers: Henry Dick, Woods Hole Oceanographic Institution Michael Mottl, University of Hawaii at Manoa The formation of magmas and evolution Massive hydrothermal circulation of seawater through of the oceanic mantle mid-ocean ridge flanks: Insights from ocean drilling Andrew Fisher, University of California at Santa Cruz Suzanne O’Connell, Wesleyan University Measurements, models, and mysteries: Fluid flow and North Atlantic thermohaline circulation and climate permeability within the upper oceanic crust change: A deep sea perspective Michael Howell, University of South Carolina, Columbia Charles Paull, University of North Carolina, Chapel Hill Eastern Mediterranean sapropels: The interplay between Natural gas hydrates and ODP Leg 164: Sampling an productivity, basin hydrography, and climate ephemeral phase

14 GSA TODAY, February 1996 Folding continued from p. 14 geology showed that synchronous folding ing. These models show detachment folds and deposition can indicate rates of fold evolving into fault-propagation folds, with fault-bend, fault-propagation, and and fault processes as well as differentiate ramp spacing controlled by initial buck- detachment folds must be viewed as end- between different kinematic models. ling instabilities, which then get trans- member geometries, not as isolated enti- Seismic profiles through growth structures ported as fault-bend folds. This fold-then- ties. Basement-involved structures show were used to argue for both fixed and fault sequence is consistent with many related yet different structures, the zone migrating fold hinges. Participants from field and microstructural observations of basement faulting widening upward the petroleum industry repeatedly cau- from thin-skinned thrust belts. Both into folds in the sedimentary cover. Field tioned, however, against using nonmi- mechanical and analog modeling still and incremental strain studies showed grated seismic time sections to prove limb have difficulty, however, in replicating clear evidence for progressive limb rotation geometries, because planar reflectors flexural-slip folding, resulting in models during folding about fixed fold hinges. commonly become curved during velocity with local regions of unreasonably high Several studies emphasized the importance migrations and may have been neither penetrative strain. of mechanical stratigraphy, which can horizontal nor isochronous during This Penrose Conference allowed the cause decoupling of different stratigraphic deposition. Detailed field studies of examination of the revolution in quan- levels. In many cases, geometries alone are growth strata from the Pyrenees and Sicily titative modeling of fault-fold relations. not sufficient to determine the kinematic show complex, progressive forelimb Detailed field, subsurface, and mechanical- and dynamic framework, because the same rotation of syndeformational sediments analog modeling studies showed that geometry can be generated in several dif- on the flanks of anticlinal uplifts. Growth earlier approximations of fault-fold ferent ways. There was general agreement strata in thrust belts were also used to kinematics need revision to reflect the that more observations of microstructures confirm both the foreland progression of common occurrence of fixed fold hinges coupled with consideration of deformation deformation and the continued reactiva- and rotating fold limbs. Participants mechanisms are needed. tion of hinterland structures as predicted generally concluded that the detachment The second day of the conference by critical wedge theory. Contested exam- fold, fault-propagation fold, and fault- was spent in the field, viewing the classic ples from offshore California indicate that bend classification can be viewed both as structures of the Bow Valley. The preva- it is crucial to evaluate all sources of data. a continuum and as a time sequence in lence of footwall synclines, structures In addition, special care must be used in many thin-skinned thrust belts. In some commonly omitted from simple fault-fold applying fold-fault models developed in cases, however, such as the use of fault- kinematic models, was particularly thin-skinned thrust orogens to basement- bend folding in regional cross sections, striking. On-the-outcrop discussions about involved strike-slip orogens. The danger the choice of the kinematic model is less terminology, especially the tripartite fault- of oversubscription to any specific model important than the fact that the applica- bend fold, fault-propagation fold, and was made clear by environmental hazard tion of any area-balanced model will allow detachment fold classification, brought consultants, who wondered if some stud- regional restorations and extrapolations. out a broad range of opinions. Some ies were determining the seismic hazard Future observations of 3D fault-fold participants viewed these as descriptive of an area or the seismic hazard of a geometries, deformation mechanisms, terms based on purely geometric criteria, specific model. incremental strain histories, growth strata, whereas others advocated their use as On the final morning of the confer- and seismically active structures coupled genetic terms indicating a specific geome- ence, devoted to mechanical and analog with more rigorous numerical and analog try and kinematic sequence. A third group modeling of fault-related folding, Peter modeling will add to our understanding of took the middle ground and argued for Hudleston introduced new advances in fault-related folding. The constraints on using the terms as kinematic concepts, mechanical modeling using analytical 3D fault-fold relations are still being encompassing multiple geometries and and numerical methods. Several partici- defined, partly because the computer deformation mechanisms. The over- pants applied new finite-element and dis- technology needed for 3D balancing is whelming majority of the participants saw crete-element programs from mechanical currently unavailable to most structural no need to specify exact definitions but engineering to the modeling of fault- geologists. In his concluding remarks, Ken agreed that uncertainties in our current related folding. Simple fault-bend fold McClay looked forward to the meshing of understanding of fold and fault mecha- geometries can be replicated even though kinematic, mechanical, analog, and field- nisms make careful usage of the terms the internal deformation in the folds may based models, an infolding of data and important. not match the predictions of earlier kine- models. The participants of this Penrose The second day of talks focused on matic models. Analog models shown by Conference on fault-related folding new constraints on fold and fault mecha- John Dixon give another view of these anticipate a lot of work—and fun—as nisms from growth strata. Examples from structures, providing a time machine that they expand their models to fit the seismic reflection profiles and surface allows viewing at different stages of fold- diversity of natural structures. ■

Penrose Conference Participants

David Anastasio Harald Drewes William Jamison Shankar Mitra Philip Simony R. Ernest Anderson Bill Dunne Marc J. Kamerling Jay Namson Andy Skuce Michael Angell John F. Dunn Dave Klepacki Andrew Newson John Spang Ted Apotria Geri Eisbacher Roy Kligfield Craig Nicholson Deborah Spratt Denise Apperson Eric Erslev Charles F. Kluth Andrew Nicol Larry Standlee Normand Begin David Ferrill Thomas Kubli Carol J. Ormand Donald S. Stone Louis J. Boldt Sandy Figuers D. Frizon de Lamotte Joseph Poblet Luther M. Strayer Benjamin A. Brooks Donald M. Fisher Don Lawton Raymond A. Price John Suppe Rob Butler Mary Beth Grey Willem Langenberg Geoffrey J. Rait Aviva Sussman J. K. Campbell Richard Groshong, Jr. Nicola Litchfield Robert Ratliff Bruce Trudgill Judith S. Chester Stuart Hardy Ken R. McClay Mark Rowan Wesley K. Wallace Michelle Cooke Chris Hedlund David McConnell Sarah Saltzer John Wickham Mark Cooper Peter Hennings Mark McNaught Roy Schlische M. Scott Wilkerson Russ Cunningham Robert Hickman Donald Medwedeff Christopher Schmidt Nicholas Woodward Joachim Deramond James E. Holl Paul A. MacKay Gregor Schoenborn Tomas R. Zapata John M. Dixon Peter J. Hudleston Andrew Meigs John Shaw James Dobson Gary J. Huftile Gautam Mitra

GSA TODAY, February 1996 15 Penrose Conference Report therefore with the help of colleagues in the Universidad Nacional de San Juan that the Penrose Conference took place Octo- The Argentine Precordillera: ber 15–20, 1995, in the city of San Juan on the eastern flank of the Precordillera. A Laurentian Terrane? The 65 participants assembled from Argentina (25), the United States (23), Conveners Canada (6), Germany (6), France (2), Australia (1), Britain (1), and Chile (1). Ian Dalziel, Institute for Geophysics, University of Texas at Austin, Austin, TX 78759-8397 This cosmopolitan group represented Luis Dalla Salda, Carlos Cingolani, Centro de Investigaciones Geológicas, Universidad many disciplines as well as many coun- Nacional de La Plata, 1900 La Plata, Argentina tries: paleontology, biostratigraphy, lithostratigraphy, sedimentology and Pete Palmer, Institute for Cambrian Studies, 445 N. Cedarbrook Road, Boulder, CO 80304 sedimentary petrology, geophysics, igneous petrology and geochemistry, paleomagnetism, and structural geology and tectonics. The program consisted of The Precordillera of northwest et al., 1995), but adopted the “far-traveled one day of introductory talks, two days Argentina is composed mainly of lower terrane” model of Ramos et al., as of field trips to examine the basic stratigra- Paleozoic sedimentary strata. The range elaborated below. phy and structure of the Precordillera at has been well known for over 25 years The consequences of the collisional key localities along the San Juan and as the “San Juan” or “Mendoza” faunal hypothesis for Paleozoic paleogeography Jáchal rivers, and two days during which province (e.g., Borrello, 1971), location are far reaching indeed. If there was a the participants used their individual of the only “Pacific” fauna with olenellid continent-continent collision, Laurentia expertise to address major questions trilobites known outside of Laurentia, the was in a position relative to Gondwana concerning the Precordillera. The field ancestral North American craton that also during Ordovician time far different from trips were expertly and enthusiastically led included the northwestern British Isles its conventional one of being separated by geologists from the local Universidad with its olenellid fauna (Peach et al., from northwest Africa by 4500 km of the Nacional de San Juan and the Universidad 1907). At first considered only in paleobio- Iapetus Ocean basin—the “alternative Nacional de Córdoba, with contributions logic terms, the olenellid fauna in the paleogeographic reconstruction” vs. the from German and U.S. workers; it was a Argentine Precordillera was originally “archetypal” reconstruction of Torsvik difficult task, given the size of the group, explained by larval transfer. Comparison et al. (1995). Paleomagnetically, either is the limited time, and Andean logistics. of the Cambrian and Lower Ordovician acceptable, given the absence of paleolon- Guidebooks were prepared by Silvio Per- stratigraphy of the Precordillera with that gitudinal control and the paleolatitudinal alta, Osvaldo Bordonaro, and Matilde of the northern Appalachians, however, uncertainty inherent in even the highest Beresi (San Juan), and by Ricardo Astini, showed many similarities and led to the quality paleomagnetic data. Do the Emilio Vaccari, Fernando Cañas, Luis hypothesis by Ramos et al. (1986) and Taconic and Ocloyic “piercing points” Benedetto, Edsel Brussa, and Marcelo his colleagues that it constitutes a “far- proposed by Dalla Salda et al. (1992b) Carrera (Córdoba). traveled” exotic terrane. provide the missing relative longitudinal There is exceptional unanimity Approaching the problem from a control? Could the Precordillera of among paleontologists of varied expertise different perspective—namely, that northwestern Argentina indeed be a that diverse shallow-water faunas provide Laurentia could have been located “tectonic tracer” (Dalziel, 1993) that an excellent biogeographic signal, whereas between East and West Gondwana in Neo- positions Laurentia relative to Gondwana marginal faunas provide evidence of open proterozoic time (Moores, 1991; Dalziel, in early Paleozoic time as northwestern ocean circulation but are not so diagnostic 1991; Hoffman, 1991) and tracked around Scotland with its olenellid fauna reflects biogeographically. The shallow-water the proto-Andean margin of the South the position of North America relative to biofacies Cambrian trilobite fauna of the American part of Gondwana during the Europe prior to the early Cenozoic open- Argentine Precordillera, studied in detail Paleozoic Era (the so-called “end-run” ing of the North Atlantic Ocean basin? Is by Luis Benedetto, Emilio Vaccari, and hypothesis; Dalziel, 1991)—Dalla Salda et the Precordillera, therefore, a critical clue their colleagues at the Universidad al. (1992a) proposed that the Precordillera that Laurentia was not always a northern Nacional de Córdoba, and Osvaldo was part of a larger terrane they named continent, that it might have been Bordonaro of the Universidad Nacional Occidentalia, which was transferred from between East and West Gondwanaland in de San Juan, has Laurentian affinities Laurentia as a result of continent-conti- Neoproterozoic time, and that it might (Palmer, 1972), in many cases even to the nent collision during the Ordovician have traveled around the South American species level. This continues through the Period. They went on to propose, together margin during the Paleozoic Era as ampli- La Silla Formation (Tremadocian) and into with Dalziel, that the Taconic and Ocloyic fied by Dalziel et al. (1994)? at least the lower part of the San Juan orogenic belts of North and South Amer- The conveners decided that the best Formation (Arenigian). On the contrary, ica, respectively, were originally continu- way to approach these questions was to there is clear evidence from the presence ous, and that the Argentine Precordillera reexamine the fundamental issue of the of cool-water Hirnantian faunas that by terrane had been detached from the origin of the rocks that compose the Late Ordovician time (Ashgillian) the Ouachita embayment of North America Precordillera. The best place to do that terrane was associated with the partly where Thomas (1976) and Lowe (1985) was clearly on the spot, in Argentina. By glaciated Gondwanaland supercontinent, had suggested the presence of a now-miss- combining experts on the Laurentian the Laurentian faunal affinities having ing microcontinental block within the craton in the Precordillera with their disappeared. Ouachita embayment (Dalla Salda et al., South American colleagues, it should be Thus, the general conclusion of the 1992b). Ricardo Astini and his colleagues possible not only to decisively resolve the conference participants is that the at the Universidad Nacional de Córdoba question of whether or not the Pre- Precordillera is an exotic terrane with subsequently supported a Ouachita cordillera came from Laurentia, but also respect to South America, that it came embayment origin for the Precordillera to at least address the potential follow-up from tropical latitudes in Laurentia, and with detailed stratigraphic studies (Astini question: which part of Laurentia? It was that it was amalgamated with Gondwana-

16 GSA TODAY, February 1996 Penrose Conference Participants

Mark G. Adams Oliver Lehnert Claudia Armella Monica G. Ricardo A. Astini Lopez de Luchi Heinrich Bahlburg Werner P. Loske Christopher M. Bailey Jose Selles Martinez Bruno A. Baldis Sergios Daniel Matheos Christopher R. Barnes Camilo Montes Juan L. Benedetto Eldridge Moores Stig Bergstrom Maria Cristina Moya Osvaldo Bordonaro Francisco Nullo Edsel Brussa Allison R. (Pete) Palmer Werner Buggisch Silvio H. Peralta Fernando Cañas Brian R. Pratt Marcelo Carrera Victor A. Ramos Charles H. Carter Augusto Rapalini Carlos A. Cingolani Carlos W. Rapela John D. Cooper Richard A. Robison Tim Coughlin Sarah M. Roeske Pierre A. Cousineau Christopher Schmidt Luis Dalla Salda Frederick L. Schwab Ian W. D. Dalziel Luis Spalletti John Steven Davis George C. Stephens Patricio Figueredo Keene Swett Stanley C. Finney William A. Thomas Richard A. Fortey N. Emilio Vaccari land during Ordovician (Arenigian- “open-ocean conditions” need not mean Miguel Haller Cees R. van Staal oceanic lithosphere. Robert D. Hatcher, Jr. J. C. Vicente Ashgillian) times. Francisco Hervé George W. Viele The transition from faunas of wholly The time of “docking” of the Argen- James Hibbard Juan Fransisco Vilas Laurentian to wholly Gondwana character tine Precordillera terrane with Gondwana Suzanne M. Kay Werner Von Gosen occurs in this Arenigian-Ashgillian time appears to be constrained by the Middle Martin Keller Graciela Vujovich to Late Ordovician age of deformation Duncan Keppie S. Henry Williams interval of 20 to 30 m.y., which also Jean-Pierre Lefort Patricia Wood Dickerson marks the appearance and disappearance and metamorphism within the Fama- of certain endemic faunas unique to the tinian belt on the eastern side of the The conference was also attended by science Precordillera and by development of a journalist Tim Appenzeller, who is writing an article Argentine Precordillera terrane. The on the topic for Discover magazine. timing of the faunal “switch over” foreland basin. This is compatible with depends on the exact fauna being the faunal evidence that can be used to considered, being different for bra- argue, on the basis of knowledge of larval chiopods, conodonts, and sponges, for dispersal among recent shallow marine western North America ruled out the example. Open-ocean agnostoid trilobites arthropods and brachiopods (up to 1000 Cordillera there as a point of origin on and slope facies appeared in the western km), for the Precordillera being separated stratigraphic grounds. Although Henry Precordillera by Middle Cambrian time. from its parent Laurentian craton by up to Williams (Memorial University of There is no evidence on the Laurentian 2000–2500 km of ocean water by the time Newfoundland) and others pointed to craton of shallow-water faunal exchange it acquired its Gondwana fauna, a cratonic stratigraphic similarities between the with Gondwana, a critical point against separation near the limit indicated by northern Appalachians and the Pre- the hypothesis of mid-Ordovician craton- paleomagnetic data if proto-Appalachian cordillera, there is no evidence north to-craton collision. The distinction of Laurentia and proto-Andean South of the Ouachita embayment of a missing warm-water “Pacific” realm graptolite America were at the same longitude. As block the size of the Precordillera. Also, forms in the Precordillera and cool-water pointed out by Werner Von Gosen (Uni- there was strong support for the views “Atlantic” realm forms on the Gondwana versity of Erlangen, Germany), however, of Cees van Staal (Geological Survey of craton, however, persisted through the evidence of extension within the Argen- Canada) and Pierre Cousineau (Université Llanvirnian. tine Precordillera from mid-Ordovician du Quebec à Chicoutimi) that it would The time of detachment of the Argen- through Silurian time must be reconciled have been difficult for the Precordillera tine Precordillera from Laurentia is not with this picture. terrane to have bypassed the system of revealed by the faunas alone. As pointed On the follow-up question of the Taconic arcs in Late Cambrian and Early out by Richard Fortey (Natural History original location of the Argentine Ordovician time from the craton margin Museum, London), the terrane would Precordillera, there was nearly unanimous of the northern Appalachians. The arcs presumably have been able to “recruit” agreement with the hypotheses of Dalla were close to Laurentia on faunal and species directly from the Laurentian cra- Salda et al. (1992b) and Astini et al. (1995) paleomagnetic grounds. The participants ton as long as it remained within the that it originated in the Ouachita embay- turned repeatedly to the fact that, as paleoequatorial belt—indeed, the first ment. Critical support for this solution pointed out by Eldridge Moores (Univer- Gondwana recruits were tropical. Clearly, was recognized by all the participants in sity of California, Davis), early Paleozoic the presence of the slope facies and open- the detailed stratigraphic comparison of Iapetus became a closing Pacific-type ocean trilobite forms in Middle and Upper the Precordillera and southern Appalachi- ocean basin with heavy “traffic” of arcs Cambrian strata suggests a wide enough ans published after the scheduling of the and other terranes in both directions. southward-opening rift to the western side meeting and just before it took place Thus, backed with the elegant of the Precordillera platform (present coor- (Astini et al., 1995). The results were independent structural and stratigraphic dinates) to permit open-ocean conditions outlined for conference participants by analysis by Bill Thomas (University of by latest Middle Cambrian time. As was Ricardo Astini. Together with Martin Kentucky), who for several years has recognized by all the participants, how- Keller (University of Erlangen, Germany), recognized that a continental fragment ever, and emphasized by Ian Dalziel on who has worked in the Precordillera and was extracted from the Ouachita the basis of his experience participating in across the “southern cone” of the Lauren- drilling on the Falkland-Malvinas Plateau, tian craton from Texas and Oklahoma to the Great Basin, geologists familiar with Precordillera continued on p. 18

GSA TODAY, February 1996 17 Precordillera continued from p. 17 modified form, the tectonic tracer model ACKNOWLEDGMENTS of Dalla Salda et al. (1992b). Support for participation in the embayment (Thomas, 1976, 1991), This Penrose Conference was an un- conference was provided by the Tectonics that embayment became what might qualified success in that it resolved the Program of the National Science Founda- be referred to as a unique candidate for main question regarding a possible tion, by CONICET of Argentina, and by the original position of the Argentine Laurentian origin for the Argentine IGCP 376, a project embracing the full Precordillera terrane. Strong evidence in Precordillera terrane and went on to scope of possible Laurentia-Gondwana support of this hypothesis is provided by provide a likely answer to the subsequent interactions before the amalgamation of the geochemical evidence from metamor- question regarding from which part of Pangea. Funds for logistics and communi- phic xenoliths in Miocene plutons that Laurentia the terrane could have been cations were provided by the Institute for intrude the terrane, evidence outlined by derived. The far-reaching, yet tractable, Geophysics of the University of Texas at Suzanne Kay (Cornell University). The nature of the problem, together with its Austin, and by the Centro de Investiga- xenoliths contain 1100 Ma zircons with a interdisciplinary nature and interconti- ciones Geológicas of the Universidad common lead signature characteristic of nental scope, lent itself ideally to the Nacional de La Plata. The conveners and juvenile Grenville rocks from eastern and Penrose format. As anticipated by the participants thank Bruno Baldis and his southern North America, notably the conveners and the Penrose Conference colleagues at the Universidad Nacional de Adirondack Mountains of New York State Committee, the discussions also opened San Juan for their warm welcome in the and the Llano uplift of Texas. Although up many avenues for future research, face of this invasion of geological gringos. not totally diagnostic or unique, these notably the age of separation of the data are exactly what is expected for a Precordillera from Laurentia, the mecha- REFERENCES CITED basement block derived from the Ouachita nisms of transfer of different faunal Astini, R. A., Benedetto, J. L., and Vaccari, N. E., 1995, The early Paleozoic evolution of the Argentine embayment. This hypothetical block was groups, the source and correlation of Precordillera as a Laurentian rifted, drifted, and dubbed “Bill Thomas Land,” or volcanically derived K bentonites, the collided terrane—A geodynamic model: Geological “Guillermo Thomasia,” at the meeting! location of an Ordovician suture on the Society of America Bulletin, v. 107, p. 253–273. Everyone then agreed that the next “inboard” side of the Precordillera, and Borrello, A. V., 1971, The Cambrian of South America, critical question to be addressed is the age the relation of the Precordillera to the in Holland, D. H., ed., Cambrian of the New World: London, and New York, Wiley-Interscience, p. 385–438. of the first true oceanic lithosphere that early Paleozoic Pampean magmatic arc Dalla Salda, L. H., Cingolani, C. A., and Varela, R., developed between Laurentia and the to the east. 1992a, The Early Paleozoic orogenic belt of the Andes Argentine Precordillera platform. If true A symposium “The Origin and Evolu- in southwestern South America: Result of Laurentia- ocean floor developed in Cambrian time, tion of the Ouachita Embayment” is being Gondwana collision?: Geology, v. 20, p. 617–620. the Ouachita ocean of Thomas, then the convened as part of the South-Central Dalla Salda, L. H., Dalziel, I. W. D., Cingolani, C. A., Precordillera terrane must have traveled Section Meeting of the Geological Society and Varela, R., 1992b, Did the Taconic Appalachians continue into southern South America?: Geology, across Iapetus as an independent of America in Austin, Texas, March 11–12, v. 20, p. 1059–1062. microcontinent, as implied by Ramos 1996. With support from the Geology Dalziel, I. W. D., 1991, Pacific margins of Laurentia and et al. (1986) and illustrated by Astini et al. Foundation of the Department of East Antarctica–Australia as a conjugate rift pair: Evi- (1995). Most of the participants, given the Geological Sciences and the Institute for dence and implications for an Eocambrian superconti- nent: Geology, v. 19, p. 598–601. faunal evidence outlined above, were Geophysics of the University of Texas at inclined to this view. John Cooper Austin, several Penrose Conference partici- Dalziel, I. W. D., 1993, Tectonic tracers and the origin of the proto-Andean margin: Congreso Geológico (California State University, Fullerton) pants from Argentina, Germany, and Argentino XII, and Congreso de Exploración de referred to this as the “funeral ship” various regions of the United States will Hidrocarburos, Mendoza, Proceedings, p. 367–374. model. Under these circumstances, the present talks and take part in discussion Dalziel, I. W. D., Dalla Salda, L. H., and Gahagan, L. M., Precordillera offers only indirect control designed to inform others of up-to-the- 1994, Paleozoic Laurentia-Gondwana interaction and the origin of the Appalachian-Andean mountain sys- over the relative positions of Laurentia minute ideas concerning the Argentine- tem: Geological Society of America Bulletin, v. 106, and Gondwana early in the Paleozoic Era. Texas (“ARTEX”) connection. p. 243–252. The only evidence of ocean floor The conveners hope that, as origi- Hoffman, P. F., 1991, Did the breakout of Laurentia adjacent to the Precordillera is the nally intended, it will be possible to turn Gondwanaland inside out?: Science, v. 252, presence of pillow basalts with E-MORB organize a meeting in North America with p. 1409–1412. chemistry analyzed by Sue Kay (in Ramos a field trip, which clearly should now be Lowe, D. R., 1985, Ouachita trough; part of a Cambrian failed rift system: Geology, v. 13, p. 790–793. et al., 1986), stratigraphically interlayered around the Ouachita embayment. This is with shale containing Llandeilian- tentatively planned for the Northern Moores, E. M., 1991, Southwest U.S.–East Antarctic (SWEAT) connection: A hypothesis: Geology, v. 19, Caradocian graptolites in the Calingasta Hemisphere autumn of 1997. It will be fol- p. 425–428. Valley on the western margin of the Pre- lowed by a symposium at the Geological Palmer, A. R., 1972, Problems in Cambrian biogeogra- cordillera. An important, but undated Society of America Annual Meeting in Salt phy: International Geological Congress, 24th, Mon- ophiolite complex is also exposed between Lake City, Utah. This symposium will be treal, Proceedings, p. 310–315. the Precordillera and the Cordillera sponsored by the International Division Peach, B. N., Horne, H., Gunn, W., Clough, C. T., Frontal to the west—the as yet poorly of the Geological Society of America, and Hinxman, L. W., and Teall, J. J. H., 1907, The geological structure of the north-west Highlands of Scotland: understood Chilenia terrane of Victor may have cosponsors from one or more Geological Survey of Scotland Memoirs, 668 p. Ramos and Constantino Mpodozis of disciplinary divisions of the Society. Ramos, V. A., Jordan, T. E., Allmendinger, R. W., Chile. The ophiolite is currently under The meeting in San Juan clearly Mpodozis, M. C., Kay, S. M., Cortés, J. M., and Palma, study by Steve Davis, Eldridge Moores, demonstrated that not even ancient inner M., 1986, Paleozoic terranes of the central Argentine- and Sarah Roeske (University of Califor- biofacies of large cratons can be consid- Chilean Andes: Tectonics, v. 5, p. 855–880. nia, Davis). A Llanvirnian or older date ered in isolation. As GSA President-Elect Thomas, W. A., 1976, Evolution of Ouachita- Appalachian continental margin: Journal of Geology, would be strong evidence that the Pre- (now President) Eldridge Moores com- v. 84, p. 323–342. cordillera terrane separated from Laurentia mented as the meeting broke up, “What Thomas, W. A., 1991, The Appalachian-Ouachita rifted before it docked with Gondwana—the we have just witnessed constitutes a margin of southeastern North America: Geological funeral ship; but a younger age would strong case for a Geological Society Society of America Bulletin, v. 103, p. 415–431. leave open the possibility that the Pre- of the Americas.” Torsvik, T. H., Tait, J., Moralev, V. M., McKerrow, W. S., cordillera terrane was attached to Lauren- Sturt, B. A., and Roberts, D., 1995, Ordovician paleogeography of Siberia and adjacent continents: tia by stretched continental crust until Geological Society of London Journal, v. 152, separation in Caradocian time—in some p. 279–287. ■

18 GSA TODAY, February 1996 FIELD TRIPS WITH A DIFFERENCE … 1996 GEO ENTURES

EO OSTELS V G H For full information see January GSA Today, or see GSA’s World Wide Web site (details at the bottom of this page). Mount St. Helens and Mount Rainier Space will go quickly, so get in touch with us if you are interested. Detailed information on itineraries, registration fees, June 22–27, Packwood and Kelso, Washington and travel arrangements will be sent on request. No obligation. Questions welcomed. LEADERS Richard B. Waitt, U.S. Geological Survey, Vancouver 1-800-472-1988, ext. 134 or 303-447-2020 Donald Swanson, U.S. Geological Survey, Seattle E-mail: [email protected] Patrick Pringle, Washington Dept. of Natural Resources Fax 303-447-0648 Member Fee: $650 Nonmember Fee: $700 The Geology of the Wine Country in Geology of the Glacier Park Region Western Oregon July 20–25, August 17–22, The Big Mountain Resort, Whitefish, Montana Portland State University, Portland, Oregon SOLD OUT LEADERS LEADER Robert Thomas and Sheila Roberts, Western Montana College Scott Burns, Portland State University Member Fee: $670 Member Fee: $580 Nonmember Fee: $720 Nonmember Fee: $630

CALL FOR NOMINATIONS REMINDERS

Materials and supporting information for any of the following nominations endowment income of the GSA Foundation’s John C. Frye Memo- may be sent to GSA Executive Director, Geological Society of America, P.O. rial Fund. The 1996 award will be presented at the autumn AASG Box 9140, Boulder, CO 80301. For more detailed information about the nomi- meeting to be held during the GSA Annual Meeting in Denver. nation procedures, refer to the October 1995 issue of GSA Today, or call head- Nominations can be made by anyone, based on the following quarters at (303) 447-2020, extension 136. criteria: (1) paper must be selected from GSA or state geological sur- vey publications, (2) paper must be selected from those published DISTINGUISHED SERVICE AWARD during the preceding three full calendar years, (3) nomination must The GSA Distinguished Service Award was established by include a paragraph stating the pertinence of the paper. Council in 1988 to recognize individuals for their exceptional ser- Nominated papers must establish an environmental problem vice to the Society. GSA Members, Fellows, Associates, or, in excep- or need, provide substantive information on the basic geology or tional circumstances, GSA employees may be nominated for con- geologic process pertinent to the problem, relate the geology to the sideration. Any GSA member or employee may make a nomination problem or need, suggest solutions or provide appropriate land use for the award. Awardees will be selected by the Executive Commit- recommendations based on the geology, present the information in tee, and all selections must be ratified by the Council. Awards may a manner that is understandable and directly usable by geologists, be made annually, or less frequently, at the discretion of Council. and address the environmental need or resolve the problem. It is This award will be presented during the annual meeting of the preferred that the paper be directly applicable by informed layper- Society. Deadline for nominations for 1996 is MARCH 1, 1996. sons (e.g., planners, engineers). Deadline for nominations for 1996 is APRIL 1, 1996. JOHN C. FRYE ENVIRONMENTAL GEOLOGY AWARD In cooperation with the Association of American State Geolo- NATIONAL AWARDS gists (AASG), GSA makes an annual award for the best paper on The deadline is April 30, 1996, for submitting nominations environmental geology published either by GSA or by one of the for these four awards: William T. Pecora Award, National Medal of state geological surveys. The award is a $1000 cash prize from the Science, Vannevar Bush Award, Alan T. Waterman Award.

GSA ON THE WEB

What’s new on the GSA home page on the World Wide Web? If you haven’t yet connected to the Web, the Uniform Resource Locator (URL) is http://www.geosociety.org.

If you want to know more about the GSA Employment The Publications section has a monthly table of contents Service or about becoming a GSA Campus Representative, and abstracts of articles for the GSA Bulletin and Geology. Also in check the Membership section, which also has information on this section is a guide for authors preparing manuscripts for sub- nominating a member to fellowship and on obtaining forms for mission to GSA publications. GSA Today issues are posted here for applying to become a GSA Member or Student Associate. downloading and viewing. See the Geoscience Calendar section for a listing of meet- For Congressional Contact Information, see the Adminis- ings of general geological interest. tration section. ■

GSA TODAY, February 1996 19 SAGE REMARKS Multimedia and Geoscience Education

Alan Morris, Stuart Birnbaum, Leslie Kanat, Cambrian Systems, Incorporated

IMAGINE students. Students should be able to exploratory and self-paced and to allow work with real data, develop their own for continuous performance assessment, Seven-fifteen a.m. at Jaffee Middle hypotheses, make predictions, and test thereby allowing the student to repeat School, in rural New York State, and their hypotheses. In short, they should parts of the lesson as often as desired. Leticia, leader of Blue Team, is already think and act like scientists. By becoming Students who have developed an logged onto the computer. Michael, engaged in their own education, students understanding of a concept by defining Valerie, and Miguel, the rest of the team, develop an understanding of the methods it from their own observations will under- won’t get there for another fifteen of science and appreciate the purpose and stand it better and remember it longer minutes and Leticia wants to download results of their inquiries. than if they are simply told about it. some images before they arrive. Blue Team The GETIT™ Project will help teachers GETIT™ stresses the importance of explo- is responsible for monitoring southern gain a better understanding of scientific ration, discovery, problem solving, and Mexico, and Popocatepetl has become concepts, classrooms will become more model building wherever possible. This is seismically active. By the time the science intellectually stimulating, and students consistent with pedagogical perspectives teacher arrives, Blue Team has explored will become more emotionally involved espoused by the American Association for the eruptive history of Popocatepetl, with the curriculum and the learning the Advancement of Science (Rutherford downloaded seismic data from southern process. Our goal is to improve the quality and Ahlgren, 1990), and the National Mexico, studied infrared images of the of science education in middle schools Science Teachers Association (NSTA) region, and formulated several questions (grades 5–8) by using geoscience as the (Aldridge, 1992b). GETIT™ incorporates for the class discussion. link between the natural sciences. These databases that allow students to manipu- Move now to Florida, where a group results can be achieved by using modern late data and develop models as profes- of seventh graders are plotting hurricane technology to create a learning environ- sional scientists do. The result is a unique tracks on their computers while accessing ment in which middle school students body of work, principally a workbook, the current data from the Internet. They become actively engaged. produced by the student. have developed a model of storm behavior GETIT™ treats students as adults by and have the statistical records of previous PHILOSOPHY BEHIND GETIT™ placing them in the role of a professional hurricanes in the mid-Atlantic region. scientist. We attempt to cross boundaries They are enthusiastic about testing their It is important to gain content between disciplines by integrating hypotheses regarding landfall. knowledge through an understanding of themes—for example, the ocean-atmo- Is this happening in your local the essential nature of science. Memoriza- sphere and the core-mantle systems schools? Do you recognize this as the tion of facts is an inadequate way to learn are both manifestations of the same way the geosciences are learned where and foster appreciation of science. The fundamental process: heat transfer. We you live? To borrow from a popular ways in which we learn and teach should allow the student to make observations advertisement, “you will.” be consistent with the methods of science. and draw conclusions, rather than pre- Interactive tutoring systems use the power senting science as a mere list of facts; THE FUTURE IS UPON US of the computer to its best advantage, this approach helps develop critical permitting students to explore aspects of The Geological Society of America thinking and exposes the true nature science that are otherwise unattainable, (GSA), in conjunction with Cambrian of science (Tobias, 1993). observe the effects of manipulating Systems, Inc. (CSI), is developing the variables, and use visual imagery (pho- Geoscience Education Through Intelligent FEATURES OF GETIT™ tographs, video clips, and graphs), and Tutors (GETIT™) Project, which is sup- sound. This, in turn, allows students to GETIT™ employs the methods of sci- ported by a National Science Foundation modify their ideas as they explore topics ence and is consistent with the pedagogi- (NSF)–Instructional Materials Develop- more fully. cal style proposed by NSTA (Aldridge, ment grant. The purpose of GETIT™ is Our experience is in accord with the 1992b), which asks: “What do we mean? to make the above classroom situations findings of the National Research Council How do we know? Why do we believe?” a reality. ([NRC] 1993): it is impractical and unde- Our pedagogical approach offers multiple sirable to overburden students with facts entries into the lessons. We are designing THE GETIT™ PROJECT (“Imagination is more important than a challenge-based scenario (a problem- In too many classrooms, students are knowledge”—Einstein). GETIT™ allows solving game) in order to engage students given a book and a box of rocks and fos- students to assimilate information regard- who may otherwise be uninterested in sils, and are required to memorize names ing natural processes using the methods learning science, a discovery-inquiry for which they have no context to create of science and their senses to develop approach that relies upon the teacher for understanding. Teachers, faced with the theories that explain their observations. assignments, and a more structured entry task of managing their classrooms, often Learning requires critical thinking using that teaches and explains distinct and have difficulty maintaining a high level various modes of inquiry. The techniques explicit areas before moving toward the of proficiency in their content area. Few and skills used in all scientific endeavors abstract. For example, lesson sequences teachers are trained as scientists, and (observation, classification, measurement, may be centered around solving a specific many find it challenging to convey interpretation, inference, communication, earth science problem. In this approach, some scientific concepts accurately. control of variables, development of mod- students are provided with the necessary What is required is content and els and theories, the creation of hypothe- tools, data, and suggestions to analyze context development for the teacher, and ses, and prediction skills [Aldridge, 1992a]) active involvement and excitement for the are incorporated. GETIT™ is designed to be Multimedia continued on p. 21

20 GSA TODAY, February 1996 GONDWANA MASTER BASIN OF PENINSULAR INDIA BETWEEN TETHYS AND THE INTERIOR OF THE GONDWANALAND PROVINCE OF PANGEA by J. J. Veevers and R. C. Tewari, 1995 The Gondwana master basin grew during Permian and Triassic time on Precambrian basement between the Tethyan margin and interior rebound. Coal measures accumulated in valleys between growing faults. The Triassic succession lacked coal, except for coaly shale deposited in valleys renewed by Late Triassic Pangean rifting. Deposition ended during an Early Jurassic phase of intense transpression that dismembered the lobate master basin into individual structural basins. The basin lay 1000 km inboard of the passive, locally volcanic, margin of Tethyan Gondwanaland in a 10,000-km-wide radial drainage system that focused on an upland in conjugate East Antarctica. The basin evolved through interplay of the Gondwanan climate and biota with the Pangean tectonics of latest Carboniferous initial subsidence, Late Triassic rifting of an anisotropic basement, Early Jurassic internal dismemberment, and Late Jurassic and Early Cretaceous breakup. MWR187, 80 p., hardbound, indexed, ISBN 0-8137-1187-8, $42.00

research in Late Paleozoic and Early VOLUMES OF RELATED INTEREST Mesozoic paleoclimate modeling, geological calibration of climate models, Permian-Triassic Pangean Basins and Foldbelts along the tectonics studies, sedimentary facies and Panthalassan Margin of Gondwanaland events, extinction, and other studies related to the geological environment during the edited by J. J. Veevers and C. McA. Powell, 1994 accretion, zenith, and breakup of the supercontinent, Pangea. Chapters focus on the tectonic The 12,500 km margin of Gondwanaland from Argentina to eastern evolution of Pangea, the paleoclimate and sedimentary consequences on Earth’s environments, Australia subsided during synchronous stages of Pangean extension and tectonic and orographic effects on paleoclimate, Permian and Triassic extinction events, isotope diachronous Panthalassan subduction that formed a foreland basin (Du stratigraphy of sedimentary rocks, evidence of Permian polar cooling, Permo-Triassic reefs, and Toit’s “Gondwanide foredeep”) by craton-ward thrusting of a foldbelt/ Carboniferous sequence stratigraphy during accretion. Workshop recommendations are magmatic arc (“Samfrau Orogenic Zone”). After reconstructing included. SPE288, 304 p., paperback, indexed, ISBN 0-8137-2288-8, $72.50 Permian-Triassic Gondwanaland, authors writing on South America, South Africa, Antarctica, and Australia profusely illustrate the relevant The Cimmeride Orogenic System and the Tectonics of Eurasia geology of each sector in maps and time-space diagrams underpinned by robust biostratigraphic by A. M. Celâl S¸engör, 1984 and radiometric dating. The work is then drawn together in a The author’s interest in Tethyan problems goes back more than a decade, when he saw a gap in stratigraphic-tectonic synthesis, which features the specifically the regional tectonic literature of Eurasia. What was lacking, he felt, was a synthetic overview of Gondwanan glaciogene and coal facies, the Early and Middle Triassic the early history of the Alpine-Himalayan mountain ranges and its expected implications for coal gap, and the interplay of Pangean and Panthalassan tectonics. the “Tethyan paradox,” first brought into focus by Alan Smith. This work includes a history of MWR184, 372p., hardbound, ISBN 0-8137-1184-3, $100.00 the Tethys concept, a regional review, and an orogenic history of the Cimmerides. SPE195, 92 p., paperback, 1 pocket-plate, indexed, ISBN 0-8137-2195-4, $3.00 Pangea: Paleoclimate, Tectonics, and Sedimentation During Accretion, Zenith, and Breakup of a Supercontinent edited by George D. Klein, 1994 1-800-472-1988 • FAX303-447-1133 Summarizes presentations at the Global Sedimentary Geology Program GSA Publication Sales • P.O. Box 9140 workshop in 1992. Presents a summary of state-of-the-art current Boulder, CO 80301 • 303-447-2020

Multimedia continued from p. 20 • student monitoring module built into [email protected]). The GETIT™ GETIT™. Project will be completed early in 1998. and construct solutions. Students will use real databases representing natural WHO’S WHO AND WHAT’S WHEN THE FUTURE IS NOW phenomena. The results of student investi- GSA received the NSF grant in Astronauts have no prior experience gations will depend upon the data they September 1995, and subcontracted with with space flight; however, they are select. Students may reach various conclu- CSI to develop the GETIT™ Project. CSI is trained and prepared for missions by sions, but they should be able to produce a small business, based in San Antonio, means of computer simulations that defensible arguments for their ideas, and Texas, devoted to developing interactive provide them with realistic problems to they will be able to find patterns that have educational software. It is managed by respond to. The purpose of GETIT™ is meaning in application to future inquiry. three geologists who are active in college- to provide students with real data and Exercises such as these encourage coopera- level teaching, scientific research, and data analysis tools so they can teach tive learning and engage students and K–12 teacher enhancement projects, and themselves how to become scientists. teachers in a quest for understanding. who publish in peer-reviewed journals. GETIT™ applications are intellectually GETIT™ will be developed by CSI with the REFERENCES CITED challenging, promote the use of advanced assistance of a design team of middle- technology in the classroom, and have a Aldridge, B. G., 1992a, Scope, sequence, and coordina- school science and math teachers. tion of secondary school science, Volume I, The content comfortable and simple user interface. Middle-school teachers nationwide core: A guide for curriculum designers: Washington, D.C., National Science Teachers Association, 152 p. will be involved at numerous levels of Benefits to Students project development serving as test teams. Aldridge, B. G., 1992b, Scope, sequence, and coordina- • more freedom for students—self-paced tion of secondary school science, (Volume II), Relevant We will form a national pilot test team • students produce their own workbook research: Washington, D.C., National Science Teachers and a national field test team; these teams Association, 270 p. • students evaluate their own progress via will help ensure that the user interface and National Research Council, 1993, National science performance assessments. content are appropriate for the cognitive education standards: An enhanced sampler: Washing- ton D.C., National Research Council, 60 p. level of middle-school students, the Benefits to Teachers intended target audience. If you are Rutherford, F. J. and Ahlgren, A., 1990, Science for all • an interactive, flexible learning tool Americans: New York, Oxford University Press, 246 p. a middle-school teacher, or know a • customized teaching units—teachers Tobias, S., 1993, What makes science hard? A Karplus middle-school teacher who would like can customize their own lessons lecture: Journal of Science Education and Technology, to participate in the GETIT™ Project, v. 2, p. 297–304. ■ • resource guide for teachers please contact Ed Geary at GSA (E-mail:

GSA TODAY, February 1996 21 ENVIRONMENT MATTERS geological phenomena, but also to the rela- tion between those phenomena and the behavioral patterns of human beings. Geology as a Social Science Geology is a social science. The perspective of the geoscientist is Daniel Sarewitz, Program Manager, Institute for Environmental Education informed by an appreciation of geologic time, an understanding of geologic rates of change—of the normality of change Progress is a difficult concept to At first glance, the range of responses itself—but the audience for our work is measure, but if anthropological studies was fairly predictable: supply and quality thinking about tomorrow’s paycheck, next of stone-age cultures are to be trusted, of water, both on and below the surface, month’s vacation, next year’s election. modern society has only in the past was a dominant issue; clean-up and stor- Reconciling these perspectives is difficult. century achieved average standards of age of various types of hazardous waste Why don’t people just LISTEN to us? Here living equivalent to those of our big- was also a prime concern. The threat of is another theme of the questionnaires— game–hunting forebears 20,000 years ago. natural hazards was mentioned several an undercurrent of frustration about In his book Cannibals and Kings, anthro- times; energy resource problems, in people’s unwillingness to act on geologic pologist Marvin Harris portrays Paleolithic contrast, appeared on only two question- information: “In the case of the barrier hunting cultures as enjoying “relatively naires. More surprising, to me at least, was beach the problems and solutions have high standards of comfort and security … the frequency with which the term “land been known and documented for over with rich furs for rugs and beds, as well as use,” or “land-use planning” appeared in 30 years.… Despite this all ‘solutions’ are plenty of dried animal dung or fat-laden connection with other issues. Some political and do not solve the problem.” bones for the hearth, [providing] a quality respondents mentioned land use in the In the case of mining, the “fear of envi- of shelter superior in many respects to context of hazards, such as flooding, ronmental damage outweighs the facts, contemporary inner-city apartments.… earthquakes, and coastal erosion; others and mitigation through application of Vast herds of mammoth, horses, deer, discussed it in the context of water supply, geologically sound principles is simply reindeer, and bison [were exploited for of toxic waste clean-up in inner-city areas, not given any weight.” In the case of solid food] systematically and efficiently. More- and of waste-disposal siting. A few made waste disposal, “oftentimes good geologic over, the skeletal remains of the hunters the connection between land use and pop- data is available, but the decision makers themselves bear witness to the fact that ulation growth—in the mega-cities of the do not have the necessary background to they were unusually well nourished.” And developing world, and also in the Ameri- understand the implications.” comparison with hunter-collector cultures in Africa today suggests that the average stone-age workday may have lasted about three hours. Wages were minimal, but benefits were generous. Scientific data may fail to dictate solutions that are compatible with The final pulse of Pleistocene the way that the human world operates, or to speak to very real glaciation marked the end of this period of plenty. Since then, tension between political, economic, ethical, and esthetic dilemmas. human cultural aspirations and Earth’s environment has been a perennial theme of societal evolution, as humanity has depended on continual technological can southwest, where urban expansion GEOLOGY AND DEMOCRACY innovation to leverage Earth’s resources creates mounting pressure on water Of course, the reasons why society into the products necessary for the suste- resources. On my third foray through the fails to act on scientific data may be nance and comfort of an ever-growing pile of questionnaires, technical distinc- diverse and complex. Scientific illiteracy population. tions between the various responses began and political expediency are commonly to fade in significance, and “land-use” cited; on the other hand, scientific data VOX POPULI seemed to emerge on virtually every page. may fail to dictate solutions that are From complaints about the “NIMBY” When I asked the members of the compatible with the way that the human mentality that can obstruct efforts to dis- Geology and Environment Public world operates, or to speak to very real pose of hazardous wastes or develop natu- Outreach Program (GEPOP)—IEE’s volun- political, economic, ethical, and esthetic ral resources, to discussions of the damag- teer outreach network—for their technical dilemmas. Some Nevadans may legiti- ing effects of engineered structures on assessment of geoenvironmental priorities, mately feel that one nuclear facility in fragile ecosystems, the unifying theme I was not thinking in grandiose terms. I their state is enough, in which case no was that of a society confronted by was simply interested in getting a sense amount of data demonstrating the safety increasingly difficult and controversial of the range of environmental issues that of the Yucca Mountain high-level nuclear- choices about conflicting land-use goals were currently of interest and concern to waste repository will convince them and philosophies. the geoscience community. More than otherwise. Some Americans look at the 225 “Issue Assessment Questionnaires” Alaska National Wildlife Refuge and see a GEOLOGY AND DEMOGRAPHY were mailed out, and I received about major oil reserve that offers economic and 75 responses. The questionnaire asked: In other words, the social value of geopolitical benefits to the nation; others “What are the one or two most important geology increasingly derives from the envi- see a pristine wilderness whose intrinsic environmental problems and/or contro- ronmental tensions created by the resource value outweighs that of any oil potential. versies facing people in your region today and land-use needs of an expanding popu- Science cannot reconcile such differing that would be more successfully resolved lation. Quality of life for the eight or ten perspectives; scientific “answers” to through greater involvement of geoscien- billion people who will inhabit the planet environmental problems will always be tists and increased use of existing geosci- by the end of the coming century will integrated into a cultural context. entific knowledge?” Views on national depend on how well these unavoidable and global geoenvironmental concerns tensions are managed. Thus, our scientific were also solicited. agenda is inextricably bound not just to Social Science continued on p. 23

22 GSA TODAY, February 1996 Social Science continued from p. 22 CALENDAR If scientists seek to influence environ- mental decision making simply by May supplying data and other information to Only new or changed information is being May 21–24, Mineral Resources of the policy makers and the public, they will published in GSA Today . A complete listing Commonwealth of Independent States, St. Petersburg, Russia. Information: Organizing probably wind up disappointed and can be found in the Geoscience Calendar Committee, Mineral Resources Meeting, P.O. disillusioned. On the other hand, by section on the Internet: http://www. becoming involved in the decision-mak- Box 215, 199004, St. Petersburg, Russia, phone geosociety.org. 7-812-355-7952, 164-7711, fax 7-812-213-5926, ing process, by understanding the kinds 112-2348, E-mail: [email protected]. of information that are both needed and usable in a real-world context, by engag- June June 12–19, Geological Institute of Roma- ing in dialogue—rather than monologue— 1996 Penrose Conferences nia 90th Anniversary Meeting, Bucharest, with stakeholders in environmental issues, Romania. Information: G. Udubasa, IGR—90th April scientists may find that they can have a Anniversary, Str. Caresebes No. 1, RO-78344 April 17–22, Tectonic Evolution of the Gulf Buchuresti 32, Romania, phone 40-1-665-6720, tangible impact on the design and imple- of California and its Margins, Loreto, Baja fax 40-1-312-8440, E-mail: [email protected]. mentation of practical solutions. This is California Sur, Mexico. Information: Paul J. where geoscientists can be particularly Umhoefer, Department of Geology, Box 4099, September effective, because, unlike many other Northern Arizona University, Flagstaff, AZ September 3–7, 13th Annual International scientific disciplines, geological insight is 86011, (520) 523-6464, fax 520-523-9220, Pittsburgh Coal Conference, Pittsburgh, E-mail: [email protected]. Pennsylvania. Information: Adrian DiNardo, predominantly synthetic and interpreta- Pittsburgh Coal Conference Office, University October tional, rather than reductionist. That is, of Pittsburgh, 1140 Benedum Hall, Pittsburgh, October 8–14, Exhumation Processes: Nor- while most of the natural sciences use PA 15261, (412) 624-7440, fax 412-624-1480, mal Faulting, Ductile Flow, and Erosion, E-mail: [email protected]. the laboratory to isolate particular Island of Crete. Information: Uwe Ring, Institut phenomena from their broader natural für Geowissenschaften, Universität Mainz September 22–27, Third USA/CIS Joint context, geology seeks to understand the Becherweg 21, D-55099 Mainz, Germany, 011- Conference on Environmental Hydrology context itself. The intellectual tools and 49-6131-392164, fax 011-49-6131-394769, and Hydrogeology, Water: Sustaining a Criti- processes regularly used by geoscientists E-mail: [email protected]. cal Resource, Tashkent, Uzbekistan. Information: are thus ideally suited for understanding American Institute of Hydrology, 3416 Univer- sity Ave. S.E., Minneapolis, MN 55414-328, and confronting complex real-world (612) 378-0169, E-mail: [email protected]. problems. The question, then, is how 1996 Meetings to get involved. November April November 9–10, Aspects of Triassic-Jurassic April 15–18, Applied Geoscience, Warwick Rift Basin Geoscience, Dinosaur State Park, PART OF THE SOLUTION University. Coventry, UK. Information: Confer- Rocky Hill, Connecticut. Information: Peter ence Office, Geological Society, Burlington LeTourneau, Lamont-Doherty Earth Observa- That’s where IEE comes in. IEE’s House, Piccadilly, London W1V 0JU, UK, phone tory, P.O. Box 1000, Palisades, NY 10964-8000, general mission is to increase the effective 44-171-434-9944, fax 44-171-439-8975. (914) 359-2900, fax 914-365-8154, E- contributions of the geosciences to the mail: [email protected]. April 28–May 1, 11th Himalaya-Karakoram- resolution of environmental problems. Tibet Workshop, Flagstaff, Arizona. Informa- Ongoing activities include: raising aware- tion: Allison M. Macfarlane, Dept. of Geography Send notices of meetings of general interest, ness within GSA of the potential role of & Earth Systems Science, George Mason Univer- in format above, to Editor, GSA Today, P.O. Box geoscientists in environmental problem- sity, Fairfax, VA 22030-4444, (703) 993-1207, 9140, Boulder, CO 80301, E-mail: editing@ solving, through forums, symposia, and fax 703-993-1216, E-mail: [email protected]. geosociety.org. theme sessions at GSA meetings; conduct- ing media workshops that teach geoscien- tists to communicate more effectively with the public through the mass media; and identifying productive activities for GEPOP network volunteers in support of IEE’s mission. A new program—The Roy Shlemon Mentors in Applied Geology— SEG Offers Research Grants will sponsor workshops in applied environmental geoscience for senior The Society of Economic Geologists will offer six research grants for 1996. undergraduate and graduate students, beginning at several of this spring’s GSA Five $1000 grants from the McKinstry Fund are for field or laboratory studies by gradu- section meetings. Future initiatives will ate students, faculty, or geologists on study leave from their employment. Projects must focus on technical workshops, public be beneficial to the science of economic geology and especially to work in field situa- roundtables and forums, and other tions. The application deadline is March 31, 1996. mechanisms designed to foster productive dialogue among scientists One $2000 grant from the Hickok-Radford Fund is intended to support research projects and stakeholders in environmental issues. that emphasize geologic field studies related to minerals exploration. Projects in Alaska, The GEPOP network will be a princi- British Columbia, or other regions north of latitude 60ºN are preferred, but projects in pal technical resource for future IEE challenging terrain in other parts of the world will be considered. Applicants should be activities. For more information on studying geology at the undergraduate or graduate level, or have completed a degree GEPOP, or to become a member of the in geology or a related earth science within the past two years. The application dead- network, write to me at the Institute for lines is February 28, 1996. Environmental Education, P.O. Box 9140, Boulder, CO, 80301, call (303) 447-2020, Submit applications to Special Grants Committee, Society of Economic Geologists or E-mail [email protected]. ■ Foundation, 5803 South Rapp St., Littleton, CO 80120.

GSA TODAY, February 1996 23 Final Announcement trations are RECEIVED by the preregistra- tion deadline of March 8, 1996. All registrations received after this date will ROCKY MOUNTAIN SECTION, GSA be held for on-site processing and charged 48th Annual Meeting the on-site rates. Rapid City, South Dakota CANCELLATIONS, CHANGES, April 18–19, 1996 ★ AND REFUNDS All requests for registration additions, changes, and cancellations must be made he Rocky Mountain Section of the Geological Society of America will meet in writing and received by March 15, jointly with the Rocky Mountain Section of the Paleontological Society of America 1996. GSA will refund or credit preregistra- T and the Southwest Section of the National Association of Geology Teachers at the tion fees for cancellations received in writ- Rapid City Civic Center. The host for the meeting is the Department of Geology and ing by March 15, 1996. NO REFUNDS OR Geological Engineering, South Dakota School of Mines and Technology. CREDITS WILL BE MADE ON CANCELLA- TION NOTICES RECEIVED AFTER THIS DATE. Refunds will be mailed from GSA SETTING because of participation limits. Use the after the meeting. Fees paid by credit card preregistration form provided in this Rapid City, population of 68,000 in will be credited according to the card announcement. and around the city, is the gateway to number on the preregistration form. Badges must be worn for access the Black Hills. The city is located on There will be NO refunds for on-site to ALL activities, 6 p.m. April 17 through Mesozoic rocks that dip gently eastward registration and ticket sales. 5 p.m. April 19. off the Black Hills, a Laramide uplift. Registration discounts are given to Excellent exposures of Mesozoic and Pale- ON-SITE both GSA and Associated Societies mem- ozoic rocks are within a few miles of Rapid REGISTRATION SCHEDULE: bers listed on the registration form. Please City. Precambrian metamorphic and indicate your affiliation(s) to register using Wednesday, April 17 igneous rocks are exposed in the central the member rates. 4:30 p.m. to 8:00 p.m. Black Hills. These rocks contain world- Full payment MUST acccompany Thursday, April 18 famous pegmatites near Mount Rushmore. registration. Unpaid purchase orders are 7:30 a.m. to 4:30 p.m. The northern Black Hills area contains NOT accepted as valid registration. Charge Friday, April 19 numerous Tertiary igneous intrusive cards are accepted as indicated on the pre- 7:30 a.m. to 11:30 a.m. centers, including beautifully exposed registration form. If using a charge card, examples of laccoliths. Four major gold Preregistration by mail will be han- please recheck the card number given. mines, including the Homestake mine, dled by the Geological Society of America Errors will delay your registration. The con- are currently operating. Meetings Department, P.O. Box 9140, firmation card will be your receipt for all The climate during April is typically Boulder, CO 80301-9140. For lower regis- payments. No other receipt will be sent. unpredictable, ranging from warm tration fees and to assist the local commit- Register one professional or student temperatures in the 60’s to near freezing. tee in planning, please preregister. On-site per form. Copy the form for your records. Precipitation is normally as rain, although registration will be held beginning at Guest registration is required for a snowstorm is likely sometime in April. 4:30 p.m. on Wednesday, April 17, 1996, those attending guest activities, technical in the Upper East Concourse of the Rapid sessions, or the exhibit hall. Guest regis- REGISTRATION City Civic Center. trants MUST be accompanied by either GSA is committed to making every PREREGISTRATION DEADLINE: a registered professional or student. A event at the 1996 Rocky Mountain Section March 8, 1996 (no exceptions). guest is defined as a nongeologist spouse Meeting accessible to all people interested or friend of a professional or student If you preregister, you will not have to in attending. If you have special require- registrant. wait in long registration lines to pick up ments, such as an interpreter or wheel- Students and K–12 teachers must badges in the registration area, because chair accessibility, please indicate this on show a CURRENT ID in order to obtain they will be mailed within two weeks prior the registration form, or call Perry Rahn, these rates. Students or teachers not to the meeting. Save yourself time and (605) 394-2464. If possible please let us having a current ID when registering will money—preregister today! There is savings know by March 8, 1996. be required to pay the professional fee. in fees if you register before the preregis- Because the badges are mailed in tration deadline. Advance registration is TRAVEL advance, it is imperative that ALL preregis- suggested for many of the special activities Air service to Rapid City Regional Airport is provided by United Express, REGISTRATION FEES Northwest, and Delta airlines. Car rental agencies operating at the airport are Avis, Advance (by 3/8/96) On-site Budget, Hertz, National, Sears, and Thrifty. Full Meeting One Day Full Meeting One Day Off-airport car rentals include Alamo, Dollar, Economy, Enterprise, Rent-A- Professional—Member $55 $35 $70 $50 Wreck, and Practical. Rapid City Regional Professional—Nonmember $70 $50 $85 $65 Airport is about 10 miles from Rapid City. Student––Member $15 $10 $20 $15 Many hotels provide courtesy bus service from the airport to their hotel. Also, an Student––Nonmember $20 $15 $25 $20 inexpensive airport shuttle service to K–12 Professional $15 N/A $20 N/A Rapid City is available for all flights; Guest/Spouse $10 N/A $10 N/A check at counter in the baggage claim Field Trip Only $15 $15 area. Because there are numerous hotels within easy walking distance of the Civic

24 GSA TODAY, February 1996 Center, there is no shuttle bus service between hotels and the Civic Center. See the index map of central Rapid City.

ACCOMMODATIONS Blocks of rooms have been reserved at special convention rates for GSA meeting attendees at three Rapid City hotels (all within easy walking distance from the con- vention center): Hotel Alex Johnson (4 blocks from Civic Center), 523 6th St., $39 single or double occupancy, 1-800- 888-2539; The Inn at Rapid City (4 blocks from Civic Center), 445 Mt. Rush- more Rd., $55 single or double occupancy, 1-800-456-3750; and Holiday Inn Rush- more Plaza (adjacent to Civic Center), 505 North 5th St., $62, $72, $82 single occupancy or $70, $80, $90 double occu- pancy, 1-800-777-1023. A tax of 8% is added to all rates. To make reservations, telephone the hotel directly and indicate that you are attending the 1996 GSA meet- ing. Please make your reservations early, because the special rates are on a space- available basis only. After March 17, 1996, these rates may no longer be in effect. In addition to these hotels, there are about 60 motels, hotels, and bed and breakfast lodg- ings in the Rapid City area. To inquire about them or about other travel informa- tion, call the Rapid City Area Hospitality RAPID CITY AREA Association, 1-800-487-3223.

FIELD TRIPS trips (see individual descriptions) and will 3. Hydrogeology of the Central also be available for sale at the meeting. Black Hills. Wednesday, April 17, 1996. Both premeeting and postmeeting General Black Hills geology, recharging field trips are planned. All field trips will Premeeting streams, springs in Precambrian and Paleo- begin in the parking lot (south side) by 1. Tertiary Tectonism in the North- zoic rocks, and a brief look at hydrogeol- the main entrance to the Holiday Inn ern Great Plains. 2–3 days, April 15–17, ogy of abandoned mines. Includes a two- Rushmore Plaza (next to the Civic Center), 1996. Shallow folds and faults in the Little hour hike along Boxelder Creek. Perry 505 North 5th St. For details, contact the Badlands, North Dakota, and the spectacu- Rahn, Dept. of Geology and Geological respective field trip leaders. General ques- lar slump-type structures of the northern Engineering, South Dakota School of tions should be addressed to Jack Redden, Slim Buttes (South Dakota), where the Mines and Technology, 501 E. St. Joseph Field Trip Coordinator, Dept. of Geology displaced White River Group is overlain St., Rapid City, SD 57701, (605) 394-2464, and Geological Engineering, South Dakota angularly by the Arikaree. On the third fax 605-394-6703; Tim Hayes. Cost: $55 School of Mines and Technology, 501 E. day we would examine faults and clastic (includes transportation, coffee and St. Joseph St., Rapid City, SD 57701, (605) dikes in Badlands National Park. Allan doughnuts, guidebook). Limit: 24. 394-5113, fax 605-394-6703. Ashworth, Dept. of Geosciences, North 4. Major Unconformities of the Preregistration for all trips is required. Dakota State University, Fargo, ND 58105, Black Hills. Wednesday, April 17, 1996. Participants will be accepted on a first- (701) 231-7919, fax 701-231-7149; George Well-exposed Middle Proterozoic, Precam- come, first-served basis through GSA Shurr, Dept. of Earth Sciences, St. Cloud brian-Cambrian, Ordovician–Upper Devo- headquarters. Complete the form provided State University, St. Cloud, MN 56301, nian, Mississippian-Pennsylvanian, and with this announcement. Participants pre- (612) 255-2009, fax 612-255-4262; and Tertiary unconformities in the northern registering for a field trip only must pay a Rachel C. Benton and Edward G. Murphy. and east-central Black Hills. Jack Redden, $15 nonregistrant fee in addition to the Cost: $155 (includes 2 nights accommoda- Dept. of Geology and Geological Engineer- charge for the field trip. Preregistration tion, 2 lunches, guidebook). Limit: 26. ing, South Dakota School of Mines and deadline is March 8, 1996. 2. Paleogene Stratigraphy and Sedi- Technology, 501 E. St. Joseph St., Rapid The cancellation deadline is March mentation. Wednesday, April 17, 1996. City, SD 57701, (605) 394-5113, fax 605- 15, 1996. All cancellations must be in writ- Classic sections in Badlands National Park, 394-6703; Mark Fahrenbach. Cost: $55 ing; no refunds will be given for cancella- with additional emphasis on structural (includes transportation, lunch, tion notice received after this date. If GSA features (this trip is the same as the third guidebook). Limit: 26. must cancel a trip, that cancellation will day of trip #1). Rachel Benton, Badlands 5. Reclamation at Northern Black be announced by March 22, 1996. Full National Park, P.O. Box 6, Interior, SD Hills Gold Mines. Wednesday, April 17, refunds will be issued after the meeting. 57750, (605) 433-5361, fax 605-433-5404, 1996. Reclamation activities that include Field trip guidebooks containing road Internet: [email protected]; Dennis mitigation of acid-generating sulfide waste logs for most of the field trips as well as Terry and Kimberlee Stevens. Cost: $60 rock at LAC Mineral’s Richmond Hill gold technical papers on Black Hills geology (includes transportation, lunch, guide- will be provided with most of the field book). Limit: 26. Rocky Mountan continued on p. 26

GSA TODAY, February 1996 25 Rocky Mountan continued from p. 25 (includes transportation, 2 lunches, 1 ated metamorphic events in the Black night double-occupancy motel room, Hills and southern Trans-Hudson orogen. mine. Also concurrent and final reclama- guidebook; $115 for single-occupancy Jack Redden and Ed Duke, Dept. of Geol- tion activities at the active Wharf accommodation). Limit: 26. ogy and Geological Engineering, South Resources gold mine. Tom Durkin, Office 10. Lower Paleozoic Stratigraphy Dakota School of Mines and Technology, of Minerals and Mining, S.D. Dept. of of the Black Hills. Saturday, April 20, 501 E. St. Joseph St., Rapid City, SD 57701, Environment and Natural Resources, Joe 1996. Outcrops of Cambrian through (605) 394-5113, fax 605-394-6703. Foss Building, 523 E. Capitol Ave., Pierre, Permian rocks in the northern Black Hills 2. Applications of Geographic Infor- SD 57501-3181, (605) 773-4201. Cost: $52 (South Dakota and Wyoming), especially mation Systems and Computers in (includes transportation, lunch, guide- Cambrian and Devonian rocks of the Geology. Maribeth Price, Dept. of Geol- book). Limit: 28. Lead-Deadwood area, and Pennsylvanian ogy and Geological Engineering, South rocks of the Sand Creek area (Wyoming). Dakota School of Mines and Technology, Postmeeting James Fox, Dept. of Geology and Geologi- 501 E. St. Joseph St., Rapid City, SD 57701, 6. Homestake Iron-Formation– cal Engineering, South Dakota School of (605) 394-2492, fax 605-394-6703, Inter- Hosted Gold Deposit—Underground Mines and Technology, 501 E. St. Joseph net: [email protected]. Tour. Friday, April 19, 1996 (evening tour, St., Rapid City, SD 57701, (605) 394-2468, 3. Late Cretaceous Marine Paleontol- departing Holiday Inn Rushmore Plaza at fax 605-394-6703; Mark Fahrenbach and ogy and Biostratigraphy. 2:45 p.m.). Underground tour of a gold John Rezac. Cost: $55 (includes trans- Interdisciplinary approaches to Late Creta- mine that has operated since 1876, and portation, lunch, guidebook). Limit: 26. ceous marine successions in the Rocky which is developed to the 8000 foot level 11. Tertiary Igneous Systems and Mountain and Great Plains provinces, in an Early Proterozoic, structurally Related Au-Ag Mineralization of the with emphasis on integration and correla- complex iron-formation host. Moderate Northern Black Hills. Saturday and tion of various biostratigraphic scales with physical condition required. Chief Mine Sunday, April 20 and 21, 1996. Petrologic, fossil vertebrate ranges. James Martin and Geologist, Homestake Mining Company, structural, and gold-ore relations, and the Gorden L. Bell, Jr., Museum of Geology, 630 E. Summit St., Lead, SD 57754-1700, character of dikes, stocks, sills, and lacco- South Dakota School of Mines and (605) 584-4841. Cost: $42 (includes liths, illustrated in natural and open-pit Technology, 501 E. St. Joseph St., Rapid transportation and handouts). Limit: 15. mine exposures of the Laramide igneous City, SD 57701, (605) 394-2427, fax 605- 7. Geologic Hazards of the Black province. Mine visits include Gilt Edge 394-6703, Internet: jmartin@msmailgw. Hills. Saturday, April 20, 1996. Land- gold mine, Homestake open cut, and sdsmt.edu. slides, swelling soils, flood plains, and Annie Creek–Foley Ridge gold mine. James 4. Tertiary Alkalic Igneous Rocks of gypsum solution features in the areas of Kirchner, Dept. of Geography-Geology, the Northern Rockies. Silica-saturated Rapid City, Lead, and Spearfish. Perry Campus Box 4400, Illinois State Univer- and silica-deficient alkali-rich rocks, lam- Rahn, Dept. of Geology and Geological sity, Normal, IL 61790, (309) 438-8922, fax prophyres, and carbonatites. James Kirch- Engineering, South Dakota School of 309-438-5310. Internet: [email protected]; ner, Dept. of Geography-Geology, Campus Mines and Technology, 501 E. St. Joseph Alvis Lisenbee and Colin Paterson. Cost: Box 4400, Illinois State University, Nor- St., Rapid City, SD 57701, (605) 394-2464, $135 (includes transportation, 2 lunches, mal, IL 61790, (309) 438-8922, fax 309- fax 605-394-6703; Arden Davis. Cost: $60 1 dinner, double-occupancy motel room 438-5310, Internet: [email protected]. (includes transportation, coffee and for 1 night, guidebook; $155 for single- 5. Hydrology of Karst Aquifers. doughnuts, guidebook). Limit: 24. occupancy accommodation. Limit: 24. Permeability and chemistry of karst 8. Late Cretaceous Marine Stratigra- aquifers, with special emphasis on the phy and Paleontology of the South- TECHNICAL SESSIONS AND Madison Limestone of the Rocky Moun- ern Black Hills. Saturday and Sunday, SYMPOSIA tain region. Perry Rahn and Arden Davis, April 20 and 21, 1996. Key sections and Dept. of Geology and Geological Engineer- General sessions will include fossil localities representing the entire ing, South Dakota School of Mines and structural geology and tectonics, economic sequence of Upper Cretaceous marine Technology, 501 E. St. Joseph St., Rapid geology, igneous and metamorphic rocks. James Martin, Dept. of Geology and City, SD 57701, (605) 394-2461, fax 605- petrology, stratigraphy and sedimentation, Geological Engineering, South Dakota 394-6703. paleontology, hydrogeology, engineering School of Mines and Technology, 501 E. 6. Contaminant Hydrogeology of the geology, geomorphology, geophysics, and St. Joseph St., Rapid City, SD 57701, (605) Northern Rocky Mountain Region. general geology. Technical sessions will 394-2427, fax 605-394-6703; Gorden Bell. Abandoned mines, defense base cleanups, allow 15 minutes for presentation and Cost: $130 (includes transportation, 2 leaking underground storage tanks, EPA 5 minutes for questions and discussion. lunches, double-occupancy motel room Superfund sites, and related issues. Cath- Session chairs and speakers are asked to for 1 night, guidebook; $150 for single leen Webb, Dept. of Chemistry and Chem- adhere stringently to these time limits. occupancy accommodation). Limit: 26. ical Engineering, South Dakota School of The following symposia will include 9. Tectonic and Plutonic Develop- Mines and Technology, 501 E. St. Joseph both invited papers and selected volun- ment and Associated Metamor- St., Rapid City, SD 57701, (605) 394-1239, teered papers. General questions should phism-Metasomatism in the South- fax 605-394-1232, Internet: cwebb@silver. be addressed to Alvis Lisenbee, Dept. of ern Black Hills. Saturday and Sunday, sdsmt.edu; Tim Hayes, U.S. Geological Sur- Geology and Geological Engineering, April 20 and 21, 1996. Key structural, vey, 1608 Mountain View Rd., Rapid City, South Dakota School of Mines and Tech- metamorphic, and igneous outcrops SD 57702, (605) 394-1780, ext. 215, fax nology, 501 E. St. Joseph St., Rapid City, (including Mount Rushmore and the Etta 605-394-5373. SD 57701, (605)394-2463, fax 605-394- pegmatite mine) illustrating the complex 7. Northern Great Plains and Rocky 6703. Abstracts limited to 250 words and Proterozoic history and metamorphism Mountain Cenozoic Depositional submitted camera ready on official 1996 and metasomatism associated with the Systems, Stratigraphy, and Paleon- GSA abstract forms were required to be 1.7 Ga S-type Harney Peak granite. Jack tology. Recent developments in Great sent by Friday, January 5, 1996, to conven- Redden, Dept. of Geology and Geological Plains and Rocky Mountain Cenozoic ers of the symposia or to Alvis Lisenbee. Engineering, South Dakota School of deposition, stratigraphy, and paleontol- 1. Precambrian Geology of the Mines and Technology, 501 E. St. Joseph ogy. Rachel Benton, Badlands National North-Central United States. Develop- St., Rapid City, SD 57701, (605) 394-5113, Park, P.O. Box 6, Interior, SD 57750, (605) ment of Proterozoic igneous and associ- fax 605-394-6703; Edward Duke. Cost: $95

26 GSA TODAY, February 1996 433-5361, fax 605-433-5404, Internet: 1:100,000 scale map of the central Black further information and booth reserva- [email protected]. Hills, a 1:250,000 scale 1° × 2° quadrangles tion, contact Lynn Hedges or Foster 8. Metallogeny of Gold in the North- of South Dakota, and the new 1:500,000 Sawyer, S.D. Department of Environment ern Rockies. Recent advances in under- scale South Dakota State Geological Map. and Natural Resources, 2050 W. Main standing of gold metallogenesis, including New AVIRIS remote-sensing data will also St., Suite 1, Rapid City, SD 57702, greenstone–iron-formation–hosted be displayed. Inquiries regarding posters (605) 394-2229. deposits and alkalic igneous-associated should be directed to Lynn Hedges, S.D. deposits. Colin Paterson, Dept. of Geology Department of Environment and Natural STUDENT PRESENTATIONS and Geological Engineering, South Dakota Resources, 2050 W. Main St., Suite 1, The Museum of Geology at the South School of Mines and Technology, 501 E. Rapid City, SD 57702, (605) 394-2229. Dakota School of Mines and Technology St. Joseph St., Rapid City, SD 57701, (605) will provide a $50 award for the best paper 394-5114, fax 605-394-6703, Internet: FIELD TRIP–WORKSHOP FOR K–12 by an undergraduate, and $25 for the [email protected]. EARTH SCIENCE EDUCATORS second best paper. 9. Perspectives on the Western Inte- A one-day field trip–workshop will be The Paleontological Society will rior Cretaceous Seaway. The center of offered, titled An Illustration of Basic Prin- sponsor an award for the best student the seaway, where perspectives from both ciples of Geology Using Outcrops in the paper in paleontology. A nonstudent can the eastern and western margins illustrate Black Hills as a Natural Laboratory. Atten- be coauthor, but the student must be how interpretations of depositional envi- dance will be limited to 40 persons, and both the presenter and senior (primary) ronments and paleotectonics are influ- is specifically intended for K–12 educators, author. To be eligible, the speaker must be enced by the geographic location of the and those involved in educational currently enrolled in a graduate or under- data sets. Richard Hammond, S.D. Geolog- management and processes in earth graduate program or have completed such ical Survey, University Science Center, science disciplines. The cost of meeting a program no more than one month prior Vermillion, SD 57069; Karen Porter, Mon- registration, bus travel (for the field trip), to the meeting. The award will be a tana Bureau of Mines, Montana College lunch, and course materials is $60. Depar- one-year subscription to Paleobiology. of Mineral Science and Technology, Butte, ture will be at 8:00 a.m. Wednesday, MT 59701. Abstracts to George Shurr, April 17, 1996, from the parking lot by STUDENT ACTIVITIES Dept. of Earth Sciences, St. Cloud State the main entrance of the Holiday Inn University, St. Cloud, MN 56301, (612) A special activity for stu- Rushmore Plaza on 5th Street. Travel will 255-2009, fax 612-255-4262. dents, especially those interested in envi- be by bus, returning to the departure 10. Geoscience Education in Native ronmental and engineering geology, The point by 5:00 p.m. For more information American Communities. Discussions Roy Shlemon Mentors in Applied Geology, or to sign up, contact Rick Baker (K–12 of the unique cultural interactions, peda- will be sponsored by GSA’s Institute for chair) at (605) 342-4105. The workshop gogical approaches, and practical experi- Environmental Education. Rick Baker, sign-up deadline is March 8, 1996, and ences of those who teach earth sciences to engineering geologist from FMG, Inc., the course fee is due by April 5, 1996. predominantly Native American popula- will present a workshop on practical Any notice of cancellation will be made tions in K–12 schools, tribal colleges, affili- aspects of engineering geology, including by March 22, 1996. ated universities, or collaborative outreach management of geotechnical projects, If they request it, K–12 teachers may programs. Steven Semken, Navajo Dry- communication, and ethics. This presenta- receive 1 credit of Geology 490, Special lands Environments Laboratory, Navajo tion will take place on Thursday, April 18, Topics in Geology, through the South Community College, P.O. Box 580, at the Civic Center. A complimentary Dakota School of Mines and Technology. Shiprock, Navajo Nation, NM 87420-0580, luncheon is included as part of the Those wishing to receive course credit (505) 368-5291, fax 505-368-4993. workshop program. Following the must register through the Registrar’s Office lectures there will be an opportunity for at SDSM&T by April 5, 1996. Tuition and PROJECTION EQUIPMENT one-on-one discussion with Rick Baker. fees are approximately $86 for South Undergraduate or graduate students All slides must be 2" × 2" and fit stan- Dakota residents and nonresidents. who wish to attend this function should dard 35 mm carousel trays. Two projectors The Registrar’s Office can be reached write a one-page letter by March 1, 1996, and two screens will be available for oral at (605) 394-2414; each person must to Perry H. Rahn, Dept. of Geology and sessions. Authors are strongly encouraged make his or her own arrangements in Geological Engineering, South Dakota to bring their own preloaded carousels. this regard. School of Mines and Technology, Rapid The organizing committee will not be Attendees may apply for a block grant City, SD 57701. The letter should docu- responsible if a carousel is unavailable for from the Geological Society of America to ment why the student would benefit from your talk. A limited number of carousels assist in expenses for attendance. The this experience. Twenty applicants will be will be available in the speaker-ready room grant application should list your name, selected and notified by March 15, 1996. (Civic Center room 102). address, educational involvement and interest, and a detailed accounting of STUDENT TRAVEL SUPPORT POSTER SESSIONS your expense request. Send applications to Rick Baker, c/o Dept. of Geology and The Rocky Mountain Section has Poster sessions will be located adja- Geological Engineering, SDSM&T, 501 E. funds available to support student associ- cent to the exhibit and registration area. St. Joseph St., Rapid City, SD 57701-3995. ates of the Geological Society of America If you wish to present a poster, indicate The grant request must be received by who plan to attend the meeting. your preference on your abstract form. March 8, 1996, and notification of accep- Preference for support will be given to Presenters will each be provided with tance will be made by March 22, 1996. presenters of papers and posters and to two 8’ wide x 4’ high boards (white); group applications. Students are strongly posters are to be attached by thumbtacks. EXHIBITS encouraged to apply for these grants. Presenters should provide their own sup- Send a letter of application which identi- plies for pinning the posters. Exhibits are planned for the registra- fies all student travelers in the group, GSA There will be a special poster session tion–poster session area. The cost per Student Associate member numbers, and a on Geologic Maps of the Black Hills and booth is $50 per 12' x 10' space. Addi- South Dakota, displaying 7.5' quadrangle tional adjacent booths may be purchased maps of the northern Black Hills, a for $50 each to expand display space. For Rocky Mountan continued on p. 28

GSA TODAY, February 1996 27 Rocky Mountan continued from p. 27 SPECIAL EVENTS people are interested, transportation may be arranged for a visit to the site on Thurs- A welcoming reception with cash summary of costs to Rocky Mountain Sec- day evening, April 18, leaving the Civic bar and free hors d’oeuvres will be held at tion Secretary Ken Kolm, Dept. of Geology Center at 6:00 p.m. Cost: $10. Please indi- the Rapid City Civic Center (Rushmore H and Geological Engineering, Colorado cate your interest on the registration form. and adjacent Upper Concourse) on School of Mines, Golden, CO 80401, (303) The annual business-luncheon Wednesday, April 17, 1996, beginning at 273-3932, fax 303-273-3858, Internet: meeting of the GSA Rocky Mountain 6:30 p.m. One free drink ticket will be [email protected]. If you are pre- Section will be held at 12 noon on Fri- provided with the registration materials. senting a paper or poster, please include a day, April 19, 1996, in Room 101 at the The annual business-luncheon meet- copy of your notification of acceptance. Civic Center. ing of the Rocky Mountain Section Applications must be received by Ken of the Paleontological Society will Kolm by Friday, March 15, 1996. GUEST PROGRAM be held on Thursday, April 18, 1996, at The Rocky Mountain Section, GSA, 12 noon in Room 101 at the Civic Center. Mount Rushmore and Custer State will award full or partial field-trip registra- The National Association of Park are well-known attractions in the tion for two students on each field trip. Geoscience Teachers will be holding a Rapid City and Black Hills area, and there To receive free registration, the students breakfast on Friday, April 19, 1996, from are many scenic drives in the Black Hills must write letters that describe why 7:00 a.m. to 830 a.m. Cost: $6.50. Infor- and Badlands. The Civic Center is conve- participation in the field trip will enhance mation to be announced at a later date. niently located near the downtown area, their research or education. Letters may The GSA Rocky Mountain Sec- which features galleries, shops, hotels, and also address financial need and minority tion Education Committee meeting other attractions. The depot for the Rapid status. Letters must be sent to Perry will be held on Thursday, April 18, 1996, Ride bus system is a two-minute walk Rahn, Dept. of Geology and Geological from 5:00 p.m. to 6:00 p.m. in the Civic from the Civic Center; routes include the Engineering, South Dakota School of Center. Rushmore Mall and other parts of Rapid Mines and Technology, 501 E. St. Joseph Larry Agenbroad has offered to guide City. The Museum of Geology at the South St., Rapid City, SD 57701, (605) 394-2464, registrants and registered guests on a tour Dakota School of Mines and Technology fax 605-394-6703. Letters must be received of the Mammoth Site in Hot Springs, has outstanding exhibits and research by March 15, 1996. about 1 hour south of Rapid City. If enough collections and is a major tourist attrac- tion. A guidebook for a walking tour of downtown Rapid City will be available for purchase. Organized activities will depend on the number of preregistered guests.

DETAILED INFORMATION More detailed information will be provided in the Rocky Mountain Section DEEP DISCOUNTS Abstracts with Programs. To order Abstracts with Programs, fill out and mail in the form on p. 34. Address questions and suggestions to Colin Paterson, GSA Meeting Chair, Dept. of Geology and FOR GSA MEMBERS Geological Engineering, South Dakota School of Mines and Technology, 501 E. GSA MEMBERS NOW GET St. Joseph St., Rapid City, SD 57701, (605) 394-5114, fax 605-394-6703, Internet: EXTRA DISCOUNTS ON ALL [email protected]. ■ DNAG PUBLICATIONS … FOR A TOTAL 35% OFF! Members use the “GSA MEMBERS SPECIAL LIST PRICE” (printed in Visit the red) rather than regular list prices, in the GSA publications catalog. Then, as always, deduct your 20% member discount. GSA Bookstore Order as many copies as you want at this special price. Offer GSA Bookstore good only while limited supplies last. Membership verification AT ALL THE required. 1996 GSA Publication Sales SECTION MEETINGS P.O. Box 9140, Boulder, CO 80301 303-447-2020; 1-800-472-1988; fax 303-447-1133 SEE THE DNAG DISPLAY AT THE GSA BOOKSTORE AT ALL 1996 MEETINGS MEMBERS: IF YOU DON’T HAVE A CATALOG, YOU MAY DEDUCT 35% FROM THE REGULAR LIST PRICES

28 GSA TODAY, February 1996 ✃ Amount $______TOTAL FEES TOTAL Full Meeting One Day Single Occupancy...... (109) $ 150 $ ______Double Occupancy $ ...... April 20Ð21...(113) 135 $ $Single Occupancy...... (114) 155 ______$ ______Single Occupancy ...... (111) $Single Occupancy ...... (111) 115 $ ______Mineralization of Northern Black Hills of Southern Black Hills Double Occupancy $ ...... April 20Ð21...(108) 130 $ ______Metamorphism-Metasomatism in Southern Black Hills Double Occupancy $ ...... April 20Ð21...(110) 95 $ ______Member fee applies to any current Professional OR Student of GSA or Associated Societies listed at left. Discount does not apply to guest registrants. REGISTRATION FEES REGISTRATION Professional Member* ...... $55 (01) Professional Nonmember ...... (03) $70Student Member* ...... (05) $15 (02)Student Nonmember $35 ...... (07) $20 Professional...... KÐ12 (04) (42) $50 $15Guest or Spouse (06) ...... (09) $10 $ $10 ______Only FeeField Trip ...... (08) (98) $15 $15 $* ______$ ______$SPECIAL EVENTS ______1. Paleontological Society Business Luncheon...... April 18 ...... ( $ 61) 2. to Mammoth Site, Hot Springs...... April 18 Tour 8 ...... ( $ 62) $ ______$ 103. ______NAGT Breakfast ...... April 19 $ ...... ( $ ______63) $6.50 ______4. $ $ GSA Rocky Mountain Section Business Luncheon...... April 19 ...... ( ______64) $ 8WORKSHOP $ ______Science Educators...... April for KÐ12 Field Trip 17 ...... ( 50) $ 60FIELD TRIPS $ ______in Northern Great Plains Tectonism 1. Tertiary ...... April 15Ð17 $155 ...(101) $ 2. ______Paleogene Stratigraphy and Sedimentation...... April 17 $ ...... (102) 603. Hydrogeology of Central Black Hills...... April 17 $ ...... (103) $ 55 ______4. Major Unconformities of Black Hills...... April 17 $ ...... (104) 55 $ ______5. Reclamation at Northern Black Hills Gold Mines...... April 17 $ ...... (105) $ 52 ______6. Homestake Iron-FormationÐHosted Gold Deposit ...... April 19 $ ...... (106) $ ______427. Geologic Hazards of the Black Hills ...... April 20...... (107) $ $ 60 ______Late Cretaceous Marine Stratigraphy and Paleontology 8. $ ______and Plutonic Development Associated Tectonic 9. Lower Paleozoic Stratigraphy of Black Hills...... April $ 10. 20...... (112) 55 Igneous Systems and Related Au-Ag Tertiary $ 11. ______I ⁄ fax Expires DR CR Home Phone Business Phone FOR OFFICE USE I GSA Rocky Mountain Section ( ______) ______-______( ______) ______-______( ______) ______-______A ______CK#______V ______M ______Bal. A/R 1233 ______Ref. A/P 2006 ______Refund ck# ______ORM F Employer/University Affiliation March 8 March 15 March Mailing Address (use two lines if necessary) Name as it should appear on your guest’s badge City State Name as it should appear on your badge (last name first) City State or Country City State or Country ZIP Code Country (if other than USA)

Please print clearly ¥ BADGE YOUR THIS AREA IS FOR I I I I

GUEST INFORMATION ¥ Please print clearly ¥ badge This area is for I I I I I I I I I I I I I I I II I I will need services to accommodate a disability: Yes Please indicate if you or your guest I I I I I I I I I I II I REREGISTRATION Cancellation Deadline: Check American Express VISA MasterCard I I I I I I I I I I I I I I I II I II I Preregistration Deadline: Preregistration MAIL TO: SECTION MEETING, MOUNTAIN GSA ROCKY 9140, BOULDER, CO 80301 BOX P.O. to: funds payable Remit in U.S. Mountain Section Meeting GSA Rocky 1996 P 8, 1996Preregistration Deadline: March South Dakota • April 18–19, 1996 Rapid City, Circle member affiliation (to qualify for registration discount): (A) GSA (B) PS (C) NAGT (All preregistrations must be prepaid. Purchase Orders not accepted.) Payment by (check one): I Card Number I Signature

GSA TODAY, February 1996 29 Final Announcement STUDENT PAPERS AND TRAVEL ASSISTANCE NORTH-CENTRAL SECTION, GSA The North-Central Section of GSA will award $75 for each of the eight papers 30th Annual Meeting judged best whose principal author and Ames, Iowa presenter is a graduate or undergraduate ★ student. Abstracts of papers submitted for May 2–3, 1996 consideration for these awards should be so indicated on the abstract form. In addi- tion, awards for travel assistance of up to he Department of Geological and Atmospheric Sciences at Iowa State University $200 may be made to student members at Ames will host the 30th Annual Meeting of the North-Central Section of the and associates. The assistance will be T Geological Society of America. The meeting will be held on campus in the Sche- offered on a first-come, first-served basis, man Center for Continuing Education. Scientific sessions will begin at 8:00 a.m. on with priority given to students presenting Thursday, May 2, and will end at 5:00 p.m. Friday, May 3. Societies that will meet in con- oral or poster papers, if funds are limiting. junction with the North-Central Section of GSA include the North-Central Section of the Students must be currently enrolled in an Paleontological Society, the Great Lakes Section of SEPM, and the Central Section of the academic department and certify their National Association of Geoscience Teachers. Additional information can be found on student membership. Applications for the World Wide Web at URL http://www.public.iastate.edu/~geat/ncgsa/intro.html. travel assistance awards may be obtained by writing to the General Chair, Carl F. Vondra, Department of Geological & REGISTRATION GSA is committed to making every Atmospheric Sciences, 253 Science I, Iowa event at the 1996 North-Central Section Preregistration Deadline: State University, Ames, IA 50011-3212 or Meeting accessible to all people interested March 29, 1996 by calling (515) 294-4477. Applications for in attending. If you have special require- travel assistance must be received no later Preregistration by mail will be han- ments, such as an interpreter or wheel- than February 16, 1996. dled by the Geological Society of America chair accessibility, please indicate this Meetings Department, P.O. Box 9140, on the registration form, or call Carl F. SPECIAL EVENTS Boulder, CO 80301-9140. Full payment Vondra at (515) 294-4477. If possible, MUST accompany registration (purchase please let us know by March 29, 1996. All special events will be held in the orders are NOT accepted). Charge cards are Cancellations, Changes, and Scheman Building. A welcoming recep- accepted as indicated on the preregistra- Refunds. All requests for registration tion will be held on Wednesday, May 1, tion form. Your confirmation letter from additions, changes, and cancellations 1996. The annual banquet will be held GSA will be your receipt; no other receipt must be made in writing and received by Thursday, May 2, preceded by a social will be sent. Register one professional or April 5, 1996. Faxes will be accepted. hour beginning at 6:00 p.m. and followed student per form. Copy the form for your Advance registrations will be refunded for by a short business meeting. Cost for the records. Preregistration forms received all such cancellations. NO REFUNDS WILL banquet is $20. Please indicate which after the March 29 deadline will be BE MADE ON CANCELLATION NOTICES entree you prefer, on the preregistration charged at the on-site rate. RECEIVED AFTER APRIL 5, 1996. Refunds form. A special address titled “Employ- Early registration is strongly recom- for fees paid by credit card will be credited ment and Education in the Geosciences, mended for all field trips and many of according to the card number on the 1996–2006” will be given by Gordon P. the special activities because of participant preregistration form. NO refunds will Eaton, Director of the U.S. Geological limits. be given for on-site registration and Survey, following the banquet in Benton Badges must be worn for access to ticket sales. Auditorium. The lecture will be open to ALL activities. Guest registration is all registrants. required to attend guest activities. To ON-SITE The GSA North-Central Section obtain the guest rate, all guests must be REGISTRATION SCHEDULE Management Board will hold its busi- accompanied by a registered professional ness meeting with breakfast on May 2, Registration will be held on the or a registered student. Current student ID 1996, at 7:00 a.m. A breakfast for the second floor of the Scheman Continuing is required to obtain student rates. Stu- North-Central GSA Campus Repre- Education Building, dents not carrying a current student ID sentatives will be on Friday, May 3, at Wednesday, May 1, 4:30 p.m. to 8:00 p.m. when they arrive to pick up registration 7:00 a.m. Thursday, May 2, 7:30 a.m. to 4:30 p.m. materials will be required to pay the The North-Central Section of the Friday, May 3, 7:30 a.m. to 12:00 noon. professional fee. Paleontological Society will hold a luncheon on Thursday, May 2, at 12:00 noon. The National Association of Geology Teachers will hold a luncheon REGISTRATION FEES on Friday, May 3, at 12:00 noon. Cost for each luncheon is $10. The American Advance (by March 29) On-site Women in Geoscience will hold a Full Meeting One Day Full Meeting One Day breakfast on Friday, May 3, at 7:00 a.m. Cost for this breakfast is $3.00. Professional—Member $60 $35 $70 $40 Professional—Nonmember $65 $40 $75 $45 SPOUSE AND GUEST ACTIVITIES Student––Member $20 $15 $25 $20 1. Campus Walking Tour. A free Student––Nonmember $25 $20 $30 $25 guided tour of the Iowa State Campus K–12 Professional $15 N/A $20 N/A will be available. Because this is a walk- ing tour and requires good weather, Guest/Spouse $10 N/A $15 N/A we will set time and date at the begin-

30 GSA TODAY, February 1996 AMES, IOWA

ning of the meeting. Please watch for eyes of 27 professional artists from the ments. Reservations should be made announcements. midwest. no later than April 1, 1996, to guaran- Iowa State University is situated on a Living History Farms is an outdoor tee the rates given. Be sure to indicate that beautiful 1770-acre campus. Founded in museum that takes you through the his- you are participating in the North-Central 1858, it has a mixture of modern and his- tory of farming in the Midwest from pre- Section of the Geological Society of Amer- torical buildings, including the recently historic, Native American times through ica to receive the special meeting rate. renovated Carrie Chapman Catt Hall. the 21st century. Some easy walking will 1. Memorial Union—ISU Campus at The 1 to 1-1/2 hour tour will end with a be required on this tour. In case of bad Lincolnway and Morrill Road, Ames, visit to the Iowa College Salon, a show weather we will visit an indoor museum IA 50011, (515) 292-1111, $40–$50. of prize-winning artwork of students instead. 2. Holiday Inn/Gateway Conference from Iowa colleges and universities, at The tour will leave Ames on Friday, Center—U.S. Highway 30 at Elwood the Brunnier Gallery. May 3, at 10:00 a.m., and return around Drive, Ames, IA 50010, (515) 292-8600, 2. Pella. The town of Pella is a little piece 6:00 p.m. Cost: $25 per person, (800)-HOLIDAY, $64–$76. of Holland in the American midwest. The including transportation (van) and all 3. Budgetel Inn—Hwy 30 and Elwood picturesque 150-year-old town is especially admissions, excluding lunch. Minimum: Drive, Ames, IA 50010, (515) 296-2500, famous for its annual tulip festival, which 5 participants. $44.95–$50.95. celebrates its 60th year in 1996. Most of 4. Bridges of Madison County and 4. Silver Saddle Motel—U.S. Hwy 30 the several hundred thousand tulips John Wayne Birthplace. Yes, there and South Duff Ave., Ames, IA 50010, should be in bloom during our visit. We really is a Madison County, Iowa, with (515) 232-8363, $45. will have a guided tour through the town, covered bridges, and the historic little 5. Comfort Inn—1605 S. Dayton, Ames, visit the historical village, and see the town of Winterset. We will visit the town, IA 50010, (515) 232-0689, $54.95. restored Scholte House, mansion of the the covered bridges from both the book 6. Heartland Inn—Junction of I-35 town’s founder, with its beautiful gardens. and the movie version of Bridges of Madi- and U.S. Hwy 30, Ames, IA 50010, This is an all-day tour, leaving son County, and “Francesca’s Home,” now (515) 233-6060, (800) 334-3277, $35. Thursday, May 2, at 9:00 a.m., and a museum. Winterset also happens to be returning around 4:45 p.m. Cost: $35 the birthplace of John Wayne, whose MEALS per person, including transportation house we will be visiting as well. Lunch will be available in the (van), guide, and admissions. Lunch is The tour is tentatively set for Friday, Scheman Center on both Thursday not included; you will have time to May 3, leaving Ames at 9:00 a.m., and and Friday for $7.00. Tickets must be sample one of the original Dutch eating returning around 4:00 p.m. Cost: $35 per purchased in advance to take advantage establishments on your own. Minimum: person, including transportation and all of this service (see registration form). 5 participants. admissions, excluding lunch. Minimum: A wide variety of restaurants in Ames, 3. Des Moines: Iowa State Historical 5 participants. ranging from fast food to formal dining, Museum and Living History Farms. also offer meal service. A list will be This day trip to Des Moines will visit the ACCOMMODATIONS provided in the registration materials. Iowa State Historical Building and Living A total of more than 400 rooms has History Farms. The State Historical Build- been reserved at several local motels for ing will be hosting the unique exhibit, meeting participants. Please note that Land of the Fragile Giants, an artistic participants are responsible for interpretation of the extraordinary land- making their own lodging arrange- scape of the Iowa Loess Hills through the North-Central continued on p. 32

GSA TODAY, February 1996 31 North-Central continued from p. 31 omy, Iowa State University, Ames, IA Falls, WI 54022, (715) 425-3345, fax 715- 50011-1010, (515) 294-2414, fax 515- 425-3785; Sam Huffman, Dept. of Plant TRANSPORTATION 294-3517, E-mail: [email protected]; and Earth Science, University of Wiscon- Gerry Miller, Dept. of Agronomy, Iowa sin, River Falls, WI 54022, (715) 425-3345, Iowa State University is near I-35 and State University, Ames, IA 50011-1010, fax 715-425-3785, E-mail: samuel.huffman@ U.S. Hwy 30. Major commercial airlines (515) 294-1923, fax 515-294-3517, E-mail: uwfr.edu; Robert D. Shuster, Dept. of serve Des Moines International Airport, [email protected]; Carolyn Olson, USDA, Geography and Geology, 260 Durham located approximately 45 miles from Lincoln, NE, 68508-3866, (402) 437-5423, Science Center, University of Nebraska— campus. Ames Municipal Airport is an all- fax 402-437-5336, E-mail: agro202@ Omaha, Omaha, NE 68182-0199, (402) weather airport designed to accommodate unlvm.unl.edu. (Invited papers only; 554-2457, fax 402-554-3518, E-mail: general aviation, including small contributed papers on this topic will be [email protected]. corporate jets. Bus service directly into put together in a special poster session.) 11. Geomicrobiology: From Basic Ames is provided by both Greyhound 4. Subduction Zone Magmatism. Science to Implications for Bioreme- and Jefferson bus lines. James Walker, Dept. of Geology, Northern diation. Blythe Hoyle, Dept. of Geologi- The Scheman Center for Continuing Illinois University, Dekalb, IL 60115-1943, cal and Atmospheric Sciences, Iowa State Education has 100 parking spaces immedi- (815) 753-7936, fax 815-753-1945, E-mail: University, Ames, IA 50011-3212, (515) ately adjacent to the building. An addi- [email protected]; Shanaka L. de Silva, 294-6583, fax 515-294-6049, E-mail: tional 900 spaces are available in the Dept. of Geography and Geology, Indiana [email protected]; Pedro Alvarez, Dept. surrounding Iowa State Center complex. State University, Terre Haute, IN 47809, of Civil and Environmental Engineering, There is no charge for parking in any of (812) 237-2269, fax 812-237-8029, E-mail: University of Iowa, Iowa City, IA 52242, these locations. [email protected]. (319) 335-5065, E-mail: pedroalvarez@ Shuttle service from the hotels to 5. Mesozoic Paleoenvironments of uiowa.edu. the Scheman Center for Continuing Edu- North America (Joint with Great Lakes 12. Recent Studies of Precambrian cation begins at 6:45 a.m. and ends at 10 SEPM). Greg Ludvigson, Geological Survey Geology in the Mid-continent. Ray- p.m. on May 2 and 5:30 p.m. on May 3. Bureau, Iowa DNR, Iowa City, IA 52242- mond R. Anderson, Geological Survey Schedule information will be posted in 1319, (319) 335-1761, fax 319-335-2754, Bureau, Iowa DNR, Iowa City, IA 52242- the hotels during the meeting. E-mail: [email protected]; 1319, (319) 335-1575, fax 319-335-2754, Brian J. Witzke, Dept. of Geology, Univer- E-mail: [email protected]. TECHNICAL PROGRAM sity of Iowa, Iowa City, IA 52242-1319, edu; Kenneth E. Windom, Dept. of Geo- Questions regarding the technical (319) 335-1761, fax 319-335-2754, E-mail: logical and Atmospheric Sciences, Iowa program should be addressed to [email protected]; Carl F. Vondra, State University, Ames, IA 50011-3212, Kenneth E. Windom, Dept. of Geological Dept. of Geological and Atmospheric (515) 294-2430, fax 515-294-6049, E-mail: and Atmospheric Sciences, 253 Science I, Sciences, Iowa State University, Ames, [email protected]. Iowa State University, Ames, IA 50011- IA 50011-3212, (515) 294-4477, fax 515- 13. Long-term Effect of Mass Extinc- 3212, phone (515) 294-2430, fax 515- 294-6049, E-mail: [email protected]. tion. Patricia E. Kelley, Dept. of Geology 294-6049, E-mail: [email protected]. 6. Edge-wise Conglomerates (Joint and Geological Engineering, University of with Great Lakes SEPM). Roger Bain, Dept. North Dakota, Grand Forks, ND 58202, SYMPOSIA of Geology, University of Akron, Akron, (701) 777-2380, fax 701-777-4449, E-mail: OH 44325-4101, (216) 972-7659, fax [email protected]; The following symposia have been 216-972-6990, E-mail: [email protected]. Joanne Kluessendorf, Dept. of Geology, organized. Authors are encouraged to con- 7. Earth Science Educators and University of Illinois, Urbana, IL 61801, tact the individual symposium organizers National Standards. Tim Cooney, Dept. (217) 367-5916, fax 217-244-4996. for information. of Earth Sciences, University of Northern 14. The Geology of Early Hominids. 1. Applications of Hydrogeology Iowa, Cedar Falls, IA 50614, (319) James L. Aronson, Dept. of Geological Sci- in Agricultural Water Quality 273-2918, fax 319-273-7124, E-mail: ences, Case Western Reserve University, Studies. Sponsored by the Institute for [email protected]; Frederick P. 10900 Euclid Ave., A.W. Smith #112, Environmental Education. William W. DeLuca, Dept. of Geological and Atmo- Cleveland, OH 44106-7216; Carl F. Von- Simpkins, Dept. of Geological and Atmo- spheric Sciences, Iowa State University, dra, Dept. of Geological and Atmospheric spheric Sciences, Iowa State University, Ames, IA 50010-3212, (515) 294-7254, Sciences, Iowa State University, Ames, IA Ames, IA 50011-3212, (515) 294-7814, fax fax 515-294-6049, E-mail: fpdeluca@ 50011, (515) 294-4477, fax 515-294-6049, 515-294-6049, E-mail: [email protected]; iastate.edu. E-mail: [email protected]. George R. Hallberg, University of Iowa 8. Historical Perspectives on Mid- 15. The Des Moines Lobe: Sediment, Hygienic Laboratory, 102 Oakdale Cam- continent Geology (Cosponsored by Landforms, and Modeling. Carrie pus, University of Iowa, Iowa City, IA Central Section of NAGT). Wayne I. Patterson, Minnesota Geological Survey, 52242-5002, (319) 335-4500, fax 319- Anderson, Dept. of Earth Sciences, Univer- (612) 627-4815, fax 612-627-4778, E-mail: 335-4600, E-mail: [email protected]. sity of Northern Iowa, Cedar Falls, IA [email protected]; Mark 2. Groundwater Consultants’ Sympo- 50614, (319) 273-2759, fax 319-273-7124, Johnson, Gustavus Adolphus College, sium: Role of Geology in the Charac- E-mail: [email protected]. St. Peter, Minnesota, (507) 933-7442, terization and Remediation of Con- (Invited papers only; contributed papers fax 507-933-7042, E-mail: [email protected]. taminated Sites (Joint with Great Lakes on this topic will be put together in a SEPM). Roger Bruner, Foth and Van Dyke special poster session.) WORKSHOPS Inc., 10340 Viking Drive, Suite 100, Eden 9. Geology and General Education Prairie, MN 55344, (612) 942-0396, fax 1. AutoCAD for Geologists. A two-day (Cosponsored by NAGT). Robert Corbett, 612-942-0865, E-mail: [email protected]; workshop to be held Saturday and Sunday Dept. of Geography-Geology, Illinois State Doug Connell, Barr Engineering, Min- following the meeting. This course will University, Normal, IL 61790-4400, (309) neapolis, MN, E-mail: [email protected]. provide an introduction to AutoCAD, with 438-7649, fax 309-438-5310, E-mail: 3. Robert V. Ruhe Symposium: emphasis on those features of most utility [email protected]. Historical Perspectives of Research to geologists. It is expected that sufficient 10. Undergraduate Research Results. in Soil Science and Quaternary grounding can be provided so that partici- Robert W. Baker, Dept. of Plant and Earth Geology. Tom Fenton, Dept. of Agron- pants can go on to master AutoCAD on Science, University of Wisconsin, River

32 GSA TODAY, February 1996 their own. The training sessions will Poster sessions will include all topics include several geologically useful Auto- listed on the GSA abstract form. In addi- CAD add-in programs, such as for per- tion, two thematic poster sessions will forming contouring. Care will be taken be held. Visit the to select only those programs that are Poster Session 1: Recent Research in freeware or modestly priced. Approval is Soil Science and Quaternary Geology being sought for participants to receive in the Midcontinent. This session will continuing education credit through the be for contributed presentations and is GSA Bookstore Continuing Education Program at Iowa meant to complement the Ruhe Sympo- State University. The course will be offered sium (#3, above). Presenters interested in AT ALL THE by Carl E. Jacobson, Dept. of Geological further information should contact one and Atmospheric Sciences, Iowa State of the organizers of that symposium. 1996 University, Ames, IA 50011-3212, (515) Poster Session 2: Special Poster Session 1996 294-4480, fax 515-294-6049, E-mail: on Undergraduate Research. The SECTION MEETINGS [email protected]. Fee: $50 for Council on Undergraduate Research and S M professionals, $30 for students; includes the NAGT will be sponsoring a special two box lunches. Limit: 20. poster session highlighting undergraduate 2. Roy Shleman Mentors research. These papers are to be written in Applied Geology Program: and presented by undergraduate students Workshop for Students. Sponsored on their research. Coauthored papers for by the GSA Institute for Environmental which the student is senior author will Education. Dean Lewis and other person- also be considered. The session will form nel from ATC Environmental, Inc. will a separate poster session or be part of present a workshop for upper-level under- another poster session, depending on the graduate and graduate students covering response. Undergraduate students who is variable, so winter parkas, rain gear, and processes involved in an environmental have been involved in research are boots are all recommended. All field trips site assessment. Case studies will be used strongly urged to submit abstracts on their will begin and end at the north entrance to illustrate environmental geological research projects, activities, techniques, to the Scheman Center for Continuing issues, with emphasis on investigations and/or preliminary results for this session. Education. Full refunds will be issued for of underground storage tanks containing Additional information can be obtained trips canceled due to logistical reasons. petroleum products. A demonstration of by contacting Samuel F. Huffman, Dept. Questions about the field trips may be an environmental drilling and monitoring of Plant & Earth Sciences, University addressed to Field Trip Coordinator well installation is planned. There is no of Wisconsin, River Falls, WI 54022, William W. Simpkins, Dept. of Geological charge to students for this short course; (715) 425-3345, fax 715-425-3785; and Atmospheric Sciences, Iowa State however, space is limited to two students E-mail: [email protected]; or University, Ames, IA 50011, (515) per participating college or university. Robert D. Shuster, Dept. of Geography & 294-7814, fax 515-294-6049, E-mail: (A waiting list will be maintained of other Geology, University of Nebraska—Omaha; bsimp@iastate. edu. students interested, in case additional Omaha, NE 68182, (402) 554-2457, spaces are available.) Preregistration is fax 402-554-3518; E-mail: bshuster@cwis. Premeeting required. For additional information, unomaha.edu. 1. Mid-Cretaceous Fluvial Deposits contact R. Dean Lewis, ATC Environmen- of the Eastern Margin, Western Inte- tal, Inc., ISU Research Park, 2625 North ABSTRACTS rior Basin: Nishnabotna Member, Loop Dr., Ste. 2150, Ames, IA 50010, (515) Dakota Formation. Brian J. Witzke and Abstracts must be submitted camera- 296-6850, fax 515-296-6851. Greg A. Ludvigson, Iowa Department of ready on official GSA abstract forms in Natural Resources–Geological Survey accordance with instructions on the PROJECTION EQUIPMENT Bureau, Trowbridge Hall, University forms. Abstract forms are available from: of Iowa, Iowa City, IA 52242, (319) Two standard 35 mm carousel projec- Abstracts Coordinator, Geological Society 335-1575, fax 319-335-2754, E-mail: tors for 2|| x 2|| slides and one overhead of America, P.O. Box 9140, Boulder, CO [email protected], or projector for transparencies will be pro- 80301-9140; (303) 447-2020, E-mail: [email protected]. vided in each meeting room. Please bring [email protected], or from Ken- This field trip will examine coarse-grained your own loaded carousel tray(s) identified neth E. Windom, North-Central Program clastic units deposited by westward-flow- with speaker’s name, session, and speaker Coordinator, Dept. of Geological and ing river systems that drained the cratonic number to your session room before the Atmospheric Sciences, Iowa State Univer- margin of the Cretaceous Western Interior start of the session. A speaker-ready room sity, Ames, IA 50011-3212, (515) 294-2430, basin. Recent research suggests that the equipped with projectors will be available E-mail: [email protected]. Forms are late Albian deposits intertongue westward for review and practice. also available from GSA campus represen- with marginal marine facies of the Skull tatives at most colleges and universities Creek–Kiowa marine cycle. One day, POSTER SESSIONS and from symposium organizers. May 1. Lunch and snacks provided. Students and professionals are Cost: $50. Limit: 30. FIELD TRIPS encouraged to take advantage of this 2. Greenfield Quadrangle—Revisited. effective means of presentation. Please Premeeting, during meeting, and Gerald A. Miller and Thomas E. Fenton, indicate Poster Session on the GSA postmeeting field trips are planned. Pre- Dept. of Agronomy, Iowa State University, abstract form. Each poster booth will registration for field trips is recommended Ames, IA 50011, (515) 294-1923 (Miller), contain a 4' high × 8' wide board because participants will be accepted on a or (515) 294-2414 (Fenton), fax 515-294- arranged at table height. Poster sessions first-come, first-served basis. Field trip par- 3163, E-mail: [email protected], or tefen- will be located in the area near exhibits ticipants must also register for at least one [email protected]. This field trip will travel and will be available for viewing for day of the meeting. All trips are technical to southern Iowa to review the soil geo- one-half day. in nature and may be physically demand- ing for participants. Weather in early May North-Central continued on p. 34

GSA TODAY, February 1996 33 North-Central continued from p. 33 Iowa State University, Ames, IA 50011. major facies of the Jurassic-age Fort Dodge Since 1990, research in the Walnut Creek Formation: the underlying basal clastic morphic relations investigated during the watershed—one of three U.S. Department unit, the laminated gypsum bed, and the early 1950s by Robert V. Ruhe. Classic soil of Agriculture Management System Evalu- overlying clastic units known informally landscapes and soil profiles will be exam- ation Areas (MSEA) in Iowa—has focused as the Soldier Creek beds. We will discuss ined. One day, May 1. Lunch and snacks on the impact of current and future farm- the origin of the gypsum and associated provided. Cost: $55. Limit: 90. ing practices on ground- and surface-water sediments. We will end the trip with a quality. The field trip will examine the visit to the U.S. Gypsum wallboard During Meeting hydrogeological aspects of this study, (sheetrock) plant, where we will discuss 3. Hydrogeology and Water including the glacial and alluvial stratig- the economic value of gypsum to the Fort Quality of the Walnut Creek raphy, ground-water flow in till and allu- Dodge area. One day, May 4. Lunch and Watershed. Sponsored by the Institute vium, ground-water–surface-water inter- snacks provided. Cost: $50. Limit: 25. for Environmental Education. William W. action, and the fate and transport of 5. Hogs, Bogs, and Logs: Quater- Simpkins, Dept. of Geological and Atmo- agrichemicals in the watershed. One-half nary Deposits and Environmen- spheric Sciences, Iowa State University, day, May 3, afternoon. Snack provided. tal Geology of the Des Moines Lobe. Ames, IA 50011, (515) 294-7814, fax 515- Cost: $40. No limit. Sponsored by the Institute for Environ- 294-6049, E-mail: [email protected]; mental Education. E. Art Bettis III, Debra J. Michael R. Burkart, USDA-ARS, National Postmeeting Quade, Carol A. Thompson, Robert D. Soil Tilth Laboratory, Ames, IA 50011, 4. Jurassic Gypsum Deposits near Libra, Iowa Department of Natural (515) 294-5809, fax 515-294-8125, E-mail: Fort Dodge, Iowa. Robert D. Cody, Resources–Geological Survey Bureau, [email protected]; James M. Eidem, Dept. of Geological and Atmospheric Trowbridge Hall, University of Iowa, Iowa Beth L. Johnson, Martin F. Helmke, Sciences, Iowa State University, Ames, IA City, IA 52242, (319) 335-1575; fax 319- Hyejeung H. Seo, Heyo Van Iten, Mikael S. 50011, (515) 294-1714, fax 515-294-6049, 335-2754, E-mail: abettis@gsbth-po. Brown, and Sarah R. Vlachos, Dept. of E-mail: [email protected]. This field trip igsb.uiowa.edu; Timothy J. Kemmis, Rust Geological and Atmospheric Sciences, will visit locales that illustrate the three Environmental and Infrastructure, She- boygan, Wisconsin, (414) 451-2657, fax 414-458-0550; Thomas E. Fenton, Dept. of Agronomy, Iowa State University, Ames, IA 50011, (515) 294-2414, fax 515-294-3163, E-mail: [email protected]; Angela ORDER FORM—1996 GSA Abstracts with Programs Rieck-Hinz, Agricultural Extension Pro- For advance-copy purchases of GSA Abstracts with Programs, use this form and submit by the gram, Iowa State University, Ames, IA deadline listed for each section (deadlines vary). Prepayment is required. Members, check your 50011, (515) 294-0577, fax 515-294-9985, records to make sure that you have not previously purchased any of these publications on either E-mail: [email protected]. This field trip your dues statement or through Publication Sales. No refunds for duplicate orders. The Abstracts will examine the Quaternary sedimentary with Programs books will be mailed about three weeks prior to the meeting. and landform assemblages of the Des Meeting Deadline Price Quantity Amount Moines lobe in north-central Iowa that were formed by an active surge advance Southeastern 1/3/96 $12 — $ — and subsequent glacial stagnation. We will Northeastern 1/8/96 $12 — $ — visit subglacial and supraglacial deposits in South-Central 1/11/96 $12 — $ — outcrop and will view landforms consist- Cordilleran 2/15/96 $12 $ ing of linked depressions, circular disinte- Rocky Mountain 2/19/96 $12 $ gration features (ice-walled lakes), proxi- mal outwash terraces, and fens. We will North-Central 2/29/96 $12 $ discuss the development of large-scale hog Annual Meeting (Denver) 8/15/96 $24 $ confinement operations, the spreading of Total $ manure from these facilities near agricul- tural drainage wells, and the results of SHIP TO: Check here if GSA Member. (Member # ______) hydrogeological investigations at earthen Name ______manure storage facilities. Two days, May 4 and 5; 1 breakfast, 2 lunches, 4 snacks, Address ______1 dinner at the Lakeside Laboratory; City______State ____ ZIP ______Daytime Phone ______overnight lodging. Cost: $115. Limit: 40. METHOD OF PAYMENT: EXHIBITS CHECK or MONEY ORDER (payable in U.S. funds on U.S. bank) Exhibits of educational and commer- Credit Card (Please print information) cial organizations will be on display in the MC VISA AmEx Diners (circle one) Exp. Date ______Scheman Building in proximity to the symposia, technical, and poster sessions. Card No. ______Exhibit space must be reserved by Febru- Signature of Cardholder ______ary 23, 1996. For further information, con- tact Scott Thieben, Dept. of Geological TO PLACE YOUR ORDER BY MAIL: and Atmospheric Sciences, 253 Science I, Send this form to GSA Publication Sales, P.O. Box 9140, Boulder, CO 80301-9140 Iowa State University, Ames, IA 50011- TO ORDER BY PHONE OR FAX using a major credit card 3212, (515) 294-9686, fax 515-294-6049, ■ fax (24 hour line): 303-447-1133; or phone (303) 447-2020 or 1-800-472-1988 (8:00 a.m. to 4:30 p.m. MT) E-mail: [email protected]. ON-SITE PURCHASES may be made in the registration area. Supplies are limited. Due to prohibitive postal costs and delays in overseas mailings, this offer for the advance copies is for U.S., Canada, and Mexico only.

34 GSA TODAY, February 1996 ✃ Amount $______(20) FREE $ ______TOTAL FEES TOTAL (02) $ 35 $ ______May 2 $ 35 ...... (21) May 3 ...... (22) $ 25 $ ______May 3 ...... (23) $ 35 $ ______$ ______Professional $Student (150) 50 $ ______$ (151) 30 $ ______(05) $ 20(07) $ 25(42) $ 15 (06)(09) $ $ 10 15 (08) $ 20 $ ______$ ______$ ______$ ______(03) $ 65 (04) $ 40 $ ______Full Meeting One Day ...... B ...... TBA ...... (01) $ 60 $ ...... (01) ...... Stuffed Pork Loin...... (63)Stuffed $ 20 LasagnaVegetarian ...... (64) $ 20 $ ______$ ______Member fee applies to any current Professional OR Student of GSA or Associated Societies listed at left. Discount does not apply to guest registrants. AutoCAD Workshop ...... May 4Ð5 Student Nonmember Professional KÐ12 Guest or Spouse * Student Member* Professional Nonmember REGISTRATION FEES REGISTRATION Professional Member* GUEST EVENTS 1. Tour Campus Walking 2. Pella 3. Des Moines 4. Madison County SPECIAL EVENTS 1. GSA N-C Section Management Board Breakfast ...... May 2 ...... (60) FREE $2. Paleontological Society Luncheon ...... May 2 ______$ ...... (61) 103. Lunch at Scheman...... May 2 ...... (62) $ $ ______74. Annual Banquet...... May 2 $ ______5. GSA Campus Representatives Breakfast ...... May 3 ...... (65) FREE $6. Geoscientists Breakfast...... May Assoc. for American Women 3 ______...... (66) $ 37. Central Section NAGT Luncheon...... May 3 ...... (67) $ 10 $ ______8. Lunch at Scheman...... May 3 $ ...... (68) $ 7 ______WORKSHOP $ ______Roy Shlemon Mentors in Applied Geology Program...... May 4 ...... (50) FREE $ ______FIELD TRIPS 1. Mid-Cretaceous Fluvial Deposits ...... May 1 $ ...... (101) 50 2. $ Greenfield Quadrangle ______...... May 1 $ ...... (102) 55 Creek...... May 3 $ Quality—Walnut $ 403. Hydrogeology and Water ...... (103) ______$ ______4. Jurassic-age Gypsum Deposits ...... May 4 $ 50 ...... (104) $ ______5. Hogs, Bogs, and Logs ...... May 4Ð5 $ 115 ...... (105) $ ______COURSE CONTINUING EDUCATION Mount St. Helens, April 19Ð20 I ⁄ fax Expires DR CR Home Phone Business Phone FOR OFFICE USE I GSA North-Central Section ( ______) ______-______( ______) ______-______( ______) ______-______A ______CK#______V ______M ______Bal. A/R 1233 ______Ref. A/P 2006 ______Refund ck# ______ORM F Employer/University Affiliation Mailing Address (use two lines if necessary) March 29 March Name as it should appear on your guest’s badge City State April 5 Name as it should appear on your badge (last name first) City State or Country City State or Country ZIP Code Country (if other than USA)

Please print clearly ¥ BADGE YOUR THIS AREA IS FOR I I I I

GUEST INFORMATION ¥ Please print clearly ¥ badge This area is for I I I I I I I I I I I I I I I II I I will need services to accommodate a disability: Yes Please indicate if you or your guest I I I I I I I I I I II I REREGISTRATION Check American Express VISA MasterCard I I I I I I I I I I I I I I I II I II I P 29, 1996Preregistration Deadline: March Ames, Iowa • May 2–3, 1996 Circle member affiliation (to qualify for registration discount): (A) GSA (B) PS (C) SEPM (D) NAGT Deadline: Preregistration Cancellation Deadline: MAIL TO: SECTION MEETING, GSA NORTH-CENTRAL 9140, BOULDER, CO 80301 BOX P.O. to: funds payable Remit in U.S. GSA North-Central Section Meeting 1996 (All preregistrations must be prepaid. Purchase Orders not accepted.) Payment by (check one): I Card Number I Signature

GSA TODAY, February 1996 35 Statistics

TECHNICAL PROGRAM Abstracts submitted...... 2360 Abstracts presented ...... 2260 Abstracts rejected or withdrawn . . . 100 Percentage of abstracts accepted ...... 98% Poster presentations (including theme posters) . . . . 524 Oral presentations...... 1736 Oral presentations, discipline sessions...... 915 Oral presentations, theme sessions ...... 512 Oral presentations, symposia ...... 309 Highest number of concurrent oral sessions ...... 16

REGISTRATION Professional ...... 2863 Student ...... 1420 Exhibitor ...... 488 Guest ...... 344 Total attendance ...... 5115

SHORT COURSES Number of GSA-sponsored courses...... 10 Participants ...... 290

FIELD TRIPS Number of trips...... 11 Participants ...... 262

EXHIBITS Number of booths...... 211 Number of exhibiting companies ...... 152

EMPLOYMENT SERVICE Applicants ...... 336 Employers ...... 26 Interviews ...... 329 Positions available...... 49

36 GSA TODAY, February 1996 GSA TODAY, February 1996 37 GSA ANNUAL MEETINGS

1996 Denver, Colorado • October 28–31 Colorado Convention Center, Marriott City Center General Chairs: Gregory S. Holden and Kenneth E. Kolm, Colorado School of Mines Technical Program Chairs: John D. Humphrey and John E. Warme, Colorado School of Mines, Dept. of Geology & Geological Engineering, Golden, CO 80401, (303) 273-3819, fax 303-273-3859 E-mail: [email protected] Field Trip Chairs: Charles L. Pillmore, (303) 236-1240 and Ren A. Thompson, (303) 236-0929 U.S. Geological Survey, MS 913, P.O. Box 25046, Denver Federal Center, Denver, CO 80225

1997 Salt Lake City, Utah • October 20–23 Salt Palace Convention Center, Little America General Chair: M. Lee Allison, Utah Geological Survey Technical Program Chair: John Bartley, University of Utah Call for Field Trip Proposals: We are interested in proposals for single-day and multi-day field trips beginning or For general informa- ending in Salt Lake City, and dealing with all aspects of the geosciences. Please contact the field trip chairs listed below. tion on any meeting Paul Link Bart Kowallis call the Department of Geology Department of Geology GSA Meetings Idaho State University Brigham Young University Pocatello, ID 83209-8072 Provo, UT 84602-4646 Department (208) 236-3365 (801) 378-3918 1-800-472-1988 or fax 208-236-4414 fax 801-378-2265 (303) 447-2020, E-mail: [email protected] E-mail: [email protected] ext. 133 Field trip guides will be published jointly by Brigham Young University Geology Studies and the Utah Geological E-mail: meetings@ Survey. Review drafts of field guides will be due March 15, 1997. geosociety.org

GSA SECTION MEETINGS — 1996 Student Travel Grants SOUTH-CENTRAL SECTION, March 11–12, 1996. University of Texas, Austin, Texas. The GSA Foundation will award matching Information: Mark Cloos, Department of Geological Sciences, University of Texas, Austin, TX grants up to a total of $3500 each to the six 78712, (512) 471-4170, fax 512-471-9425, E-mail: [email protected]. GSA Sections. The money, when combined with equal funds from the Sections, will be SOUTHEASTERN SECTION, March 14–15, 1996. Ramada Plaza Hotel, Jackson, Mississippi. Information: Darrel Schmitz, Department of Geosciences, P.O. Box 5448, Mississippi State used to assist GSA Student Associates travel- University, Mississippi State, MS 39762, (601) 325-2904; or Charles Swann, Mississippi ing to the 1996 GSA Annual Meeting in Mineral Resources Institute, 220 Old Chemistry Bldg., University, MS 38677, (601) 232-7320, Denver in October and to the 1996 Section E-mail: [email protected]. meetings. Contact your Section Secretary for application procedures. NORTHEASTERN SECTION, March 21–23, 1996. Hyatt Regency, Buffalo, New York. Information: Parker E. Caulkin, Department of Geology, SUNY at Buffalo, 876 NSM, Buffalo, Cordilleran ...... Bruce A. Blackerby NY 14260, (716) 645-6800, ext. 3985, fax 716-645-3999, or preferably by E-mail: glgparkr@ (209) 278-2955 ubvms.cc.buffalo.edu. Preregistration Deadline: February 26, 1996. Rocky Mountain ..... Kenneth E. Kolm ROCKY MOUNTAIN SECTION, April 18–19, 1996. Rapid City Civic Center, Rapid City, (303) 273-3932 South Dakota. Information: Colin Paterson, Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East St. Joseph St., Rapid City, North-Central ...... George R. Hallberg SD 57701-3995, (605) 394-5414, E-mail: [email protected]. Preregistration Deadline: (319) 335-4500 March 8, 1996.

CORDILLERAN SECTION, April 22–24, 1996. Red Lion Hotel at Lloyd Center, Portland, South-Central ...... Rena M. Bonem Oregon. Information: Michael Cummings, Department of Geology, Portland State University, (817) 755-2361 P.O. Box 751, Portland, OR 97207-0751, (503) 725-3022. E-mail: [email protected]. Preregistration deadline: March 15, 1996. Northeastern ...... Kenneth N. Weaver (410) 554-5532 NORTH-CENTRAL SECTION, May 2–3, 1996. Iowa State University, Ames, Iowa. Submit completed abstracts to: Kenneth E. Windom, Department of Geological and Atmospheric Southeastern ...... Harold H. Stowell Sciences, Iowa State University, 253 Science I Building, Ames, IA 50011-3210, (515) 294-2430, E-mail: [email protected]. Preregistration Deadline: March 29, 1996. (205) 348-5098

38 GSA TODAY, February 1996 CLASSIFIED ADVERTISING

Published on the 1st of the month of issue. Ads (or can- ates and post-doctoral fellows, and 22 faculty with an broader themes. The award aims to encourage student cellations) must reach the GSA Advertising office one exceptional record of funded research and interdisci- participation on board ODP's drillship, JOIDES Resolution. month prior. Contact Advertising Department (303) plinary collaboration in both research and teaching. With April 15, 1996 is the shipboard fellowship application 447-2020, 1-800-472-1988, fax 303-447-1133, or this appointment, we seek to augment our current atmo- deadline for the following legs: Leg 170 Costa Rica, Leg E-mail:[email protected]. Please include com- sphere of excitement in research and teaching that 171 Barbados LWD - Blake Nose, Leg 172 NW Atlantic plete address, phone number, and E-mail address with all focuses on interactive Earth dynamics. Our Web site, Sediment Drifts, Leg 173 Iberia, Leg 174 New Jersey Mar- correspondence. http://www.geo.umn.edu, provides additional information gin, and Leg 175 Benguela Current. about the School of Earth Sciences and the Department of Per line Staffing for these legs will begin during the next few Geology and Geophysics. Per Line for each months. Students interested in participating as shipboard Applicants should submit a resume with a statement of for addt'l month scientists must apply to the ODP Manager of Science research and teaching interests, official graduate tran- Classification 1st month (same ad) Operations in College Station, TX. A shipboard scientist scripts, and arrange to have at least three letters of refer- application form and leg descriptions are included in the Situations Wanted $1.75 $1.40 ence sent to: Professor V. Rama Murthy, Chair, Faculty JOI/USSAC Ocean Drilling Fellowship application packet. Positions Open $6.50 $5.50 Search Committee, Department of Geology and Geo- For more information and to receive an application packet, Consultants $6.50 $5.50 physics, 310 Pillsbury Drive, S.E., University of Min- contact: Andrea Johnson, JOI/USSAC Ocean Drilling Fel- Services & Supplies $6.50 $5.50 nesota, Minneapolis, Minnesota 55455, USA. The dead- lowship Program, Joint Oceanographic Institutions, Inc., Opportunities for Students line for receipt of the application and supporting material is 1755 Massachusetts Ave., NW, Suite 800, Washington, DC first 25 lines $0.00 $2.35 February 29, 1996. The successful candidate is expected 20036-2102 (telephone: (202) 232-3900, ext. 213; Inter- additional lines $1.35 $2.35 to assume the postion September 1996. net: [email protected]). Code number: $2.75 extra The University of Minnesota is committed to the policy that all persons shall have equal access to its programs, Interdisciplinary Graduate Study in Hydrology. The Agencies and organizations may submit purchase order or facilities, and employment without regard to race, color, Cincinnati Earth System Science group announces the payment with copy. Individuals must send prepayment religion, national origin, sex, age, marital status, disability, availability of graduate traineeships from the National Sci- with copy. To estimate cost, count 54 characters per line, public assistance status, veteran status, or sexual orientation. ence Foundation for research and education leading to a including all punctuation and blank spaces. Actual cost Ph.D. degree. We seek highly motivated and creative indi- may differ if you use capitals, centered copy, or special GEOLOGY-OCEANOGRAPHY INSTRUCTOR viduals with a strong interest in understanding, character- characters. MiraCosta Community College District, located in North izing, and modeling the occurrence, distribution, transport, San Diego (CA) County, is recruiting for a full-time, and quality of water in the natural environment from an To answer coded ads, use this address: Code # ----, tenure-track Geology-Oceanography Instructor, beginning earth system science perspective. GSA Advertising Dept., P.O. Box 9140, Boulder, CO August 1996 (subject to available funding). A Master's Five NSF graduate research traineeships will be 80301-9140. All coded mail will be forwarded within degree or the equivalent is required. To request an appli- awarded during the 1996-97 academic year. The total 24 hours of arrival at GSA Today office. cation form and job announcement: leave your name, amount of each traineeship award is $33,964 per year that address, and title of the position on the Job Line Tape includes a monthly stipend, full-tuition, cost-of-education (619) 757-2121, ext. 8071; or reply by e-mail on the Inter- allowance, and a three-month sabbatical at a national lab- Positions Open net to: [email protected] (Website: http://www. oratory. Applicants must have a bachelors or masters miracosta.cc.ca.us). The closing date is March 8, 1996. degree in one of the hydrology interfacing disciplines NEWTON HORACE WINCHELL SCHOOL MiraCosta College is an equal employment opportunity including, but not limited to, atmospheric sciences, biol- OF EARTH SCIENCES and affirmative action employer and seeks to enhance its ogy, engineering, geography, geology, mathematics, and University of Minnesota, Minneapolis, MN 55455 USA staff diversity by specifically inviting and encouraging physics. Students will have the option to earn a Ph.D. in Applications are invited for a tenure-track assistant profes- qualified minorities and women to apply. MiraCosta Col- their primary discipline, in environmental science, or in sor position in the Department of Geology and Geo- lege, Attn: Human Resources, One Barnard Drive, Ocean- interdisciplinary hydrologic science. Although the NSF physics from individuals with a demonstrated ability to side, CA 92056. program is limited to U.S. Citizens and permanent resi- apply chemical and physical principles to the integrated dents, other funding opportunities are available for inter- study of the solid Earth. Candidates must be capable of national students. For more information and to request an establishing a vigorous research program and exhibit a Services & Supplies application package, please contact: Dr. Shafiqul Islam, breadth in research interests that complements our The Cincinnati Earth System Science Program, P.O. Box 210071, University of Cincinnati, Cincinnati, OH 45221- strengths in Earth Structure and Tectonics, Geodynamics, LEATHER FIELD CASES. Free brochure, SHERER 0071; E-mail: [email protected]. For more pro- Geofluids, Sedimentary Basin Analysis, Mineral/Rock CUSTOM SADDLES, INC., P.O. Box 385, Dept. GN, gram information, including participating faculty and study Physics, Rock Magnetism, Aqueous and Isotope Geo- Franktown, CO 80116. chemistry, Limnogeology, or Earth System studies. We areas, please see http://www.cee.uc.edu on the WWW. emphasize opportunities for collaboration and interaction with ongoing research programs in the School of Earth Traveling Fellowship: Interdisciplinary Research Train- Sciences and the availability of state-of-the-art instrumen- Opportunities for Students ing Group (RTG) in ecology, geology, archeology, geogra- tation and computational facilities for geoscience phy, and soils. Graduate students are invited to Minnesota research. JOI/USSAC Ocean Drilling Fellowships. JOI/U.S. Sci- for up to 3 months to enhance training in “Paleorecords of The succssful candidate will be expected to teach at all ence Advisory Committee is seeking doctoral candidates Global Change.” Stipend (provided for citizens, nationals, levels through advanced graduate classes, as well as par- of unusual promise and ability who are enrolled in U.S. or permanent residents of the U.S.), travel and living ticipate in teaching Petrology in our innovative curriculum, institutions to conduct research compatible with that of the allowance, and tuition. Application deadline April 1 (for and supervise graduate-student research. Applicants must Ocean Drilling Program. Both one-year and two-year fel- travel July 1 Ð December 31) and October 1 (for travel have an earned doctorate degree and must demonstrate a lowships are available. The award is $20,000 per year to January 1 Ð June 30). For application contact RTG, Uni- clear promise of creative scientific achievement, leader- be used for stipend, tuition, benefits, research costs and versity of Minnesota, Ecology, Evolution and Behavior, ship and teaching ability in the geosciences. incidental travel, if any. Applicants are encouraged to pro- 1987 Upper Buford Circle, St. Paul, MN 55108. Phone: The Department of Geology and Geophysics com- pose innovative and imaginative projects. Research may (612) 624-4238; FAX: 612/624-6777. An Equal Opportu- prises about 60 graduate students, 28 research associ- be directed toward the objectives of a specific leg or to nity Educator and Employer.

Final Announcement Additions Attending the 1996 Northeastern Section Meeting?

On Friday, March 22, the Northeastern Section is hosting a of Buffalo Office of Conferences and Special Events, (716) Reception and Light Supper at the Buffalo Museum of 645-2018; be sure to indicate you are with the GSA Northeast- Science from 6:00 to 9:30 p.m. During this event the museum’s ern meeting. Please preregister using the form found on page exhibit areas will be open, including items of special paleonto- 255 of the December 1995 issue of GSA Today. Cost: $15. logical interest—dinosaurs, Green River fossils, eurypterids, systematic arrays of minerals—and more. The special traveling Sigma Gamma Epsilon Luncheon exhibit “Our Weakening Web” explores all aspects of biological Friday, March 22, 12:00 noon to 1:15 p.m. This lunch will extinction, past and present. feature a presentation on the use of new technology and real This special event includes round-trip bus transportation data sets in teaching the earth sciences—CD-ROMS and more. between the Hyatt Regency and the museum as well as an Ital- We will demonstrate AGI’s Portrait USA. Cost: $15; preregistra- ian buffet with salad, main course, dessert, and coffee or tea. A tion is required (use the preregistration form in the December cash bar will be open. For more information call the University 1995 issue of GSA Today).

GSA TODAY, February 1996 39 GSA JOURNALS ON COMPACT DISC A CD-ROM publication of the Geological Society of America. Published since 1992, each annual CD contains a full year of articles from GSA Bulletin, Geology, and GSA Today, plus the current year’s GSA Data Repository and a Retrospec- tive Electronic Index to GSA’s journal articles published since 1972. You can search the full text of articles, or view, print, or export from them. View- able, printable graphical images of all pages are included and all photo- graphs are provided in high- EXAMINE THESE NEW resolution, linked to the text. Now published twice RELEASES FROM GSA annually, with new Acrobat technology that permits you TODAY! to print complete pages with photos in place (since 1995, except color photos). JURASSIC characteristics of Bahamian and Bermudan rocks units, their fossil The viewable, printable MAGMATISM AND faunas and floras, and the karst surface features of the islands. Data Repository, and any TECTONICS OF THE Information from studies of the modern shallow marine inserts, are available as NORTH AMERICAN environments are used to help understand the rock record. Up-to- scanned images, without CORDILLERA date summaries of the geologic history are presented along with searchable text. edited by D. M. Miller and models of stratigraphic development. Other articles cover a broad C. Busby, 1995 spectrum of subdisciplines, from paleontology to carbonate systems GSA Journals on CD is avail- There is a growing realization geochemistry. Chapters are case-book examples of the investigation able for DOS, MS Windows that in about mid-Jurassic time, of important aspects of carbonate island geology. (1995/96 editions only), both magmatism and SPE300, 428 p., indexed, ISBN 0-8137-2300-0, $93.00 and Macintosh as follows: tectonism were widely initiated ■ JCD001. 2-year, 2-CD in the western North American STRATIGRAPHY AND PALEOENVIRONMENTS introductory package continental crust, earlier OF LATE QUATERNARY VALLEY FILLS ON THE (1992 & 1993), 6,000+ subduction-driven magmatism and tectonics being localized near SOUTHERN HIGH PLAINS pgs. Net price: GSA Mem- the plate margin. The 19 papers in this book discuss diverse V. T. Holliday, 1995 bers $99, all others $125. approaches to characterize the Jurassic tectono-magmatic event, Reports on a five-year study of the late-Quaternary history of ten ■ JCD004. 1-year, 1-CD identify variations in its timing and other characteristics from region dry valleys or “draws” on the Southern High Plains of Texas and (1994), 3,000+ pgs. Net to region, and consider its ultimate origin in terms of lithospheric New Mexico. This record is a price: GSA Members $99, processes. Crucial aspects of the Jurassic tectonic events from the key to understanding the all others $125. Yukon to southernmost United States are described. The lead paper paleoenvironmental evolution ■ JCD005. 1-year, 2-CDs presents a broad synthesis of Cordilleran subduction cycles, and is of the region, important be- (1995), 3,000+ pgs. Net followed by papers arranged in three groups, from north to south: cause of the long history of price: GSA Members $89, Canadian Cordillera; U.S. Great Basin; and southwestern U.S. desert human occupation and all others $125. regions. Within each group, papers are arranged from magmatic arc because of the climatic ■ JCD006. 1-year, 2-CDs eastward to craton. This is an important look into now-eroded initial extremes of the High Plains. (1996), 3,000+ pgs. subduction-driven orogeny of the Cordillera, the precursor to later Sections are included on Jan–Jun in July 1996; events that so strongly shaped present geology. Most papers are geomorphic characteristics Jan–Dec in February and evolution, stratigraphy of 1997. Net price: data-intensive first-order studies, although some fresh synthesis GSA Members $89, studies are also present. the valley fill (the focus of the all others $125. SPE299, 432 p., indexed, volume), and paleontology, ISBN 0-8137-2299-3, $95.00 paleobotany, and stable UNSURE? Write or call isotopes. The stratigraphy along and between draws is broadly GSA Production Manager TERRESTRIAL AND synchronous and remarkably similar in lithologic and pedologic to learn more, or E-mail to: SHALLOW MARINE characteristics, suggesting that each draw underwent a similar, [email protected]. GEOLOGY OF THE sequential evolution of the dominant depositional environments. A limited supply of demon- BAHAMAS AND The changing depositional environments suggest shifts in regional strations may be available. BERMUDA vegetation and climate, but there also were distinct local variations edited by H. A. Curran and in environmental evolution. 800-472-1988 B. White, 1995 MWR186, 142 p., indexed, ISBN 0-8137-1186-X, $54.00 The authors review the current Volumes are 8-1/ x 11". Price includes shipping & handling. 303-447-2020 knowledge of the Quaternary 2 fax 303-447-1133 geologic history of the Bahama Archipelago and Bermuda, an area Indicate DOS, MS Windows, or with unique terranes for the study of carbonate rocks, sediments, Macintosh platform when ordering. and environments. The exposed stratigraphic sequences of the 1-800-472-1988 FAX303-447-1133 islands reveal much about the history of global sea-level changes JOIN THE DIGITAL GSA PUBLICATION SALES ✦ P.O. BOX 9140 REVOLUTION WITH GSA! during Quaternary time. The focus is an interpretation of the BOULDER, CO 80301 ✦ 303-447-2020