UA Geosciences Newsletter, Volume 4, Number 1 (Fall 1998)

Item Type Newsletter

Authors University of Arizona Department of Geosciences

Publisher Department of Geosciences, University of Arizona (Tucson, AZ)

Rights Copyright © Arizona Board of Regents. The University of Arizona.

Download date 29/09/2021 07:00:49

Link to Item http://hdl.handle.net/10150/295172 THE UNIVERSITY OF ARIZONA®

The Department of Geosciences Fall 1998 Volume 4, Number l Letter from the Chair JOAQUIN RUIZ s you'll see from the contents of this We profile Newsletter, our efforts at integrating two of our former cutting edge teaching and researchstudents, Tina continue. We highlight the Center of Mineral Wells (BS '94) and Resources and the Nyanza Project as two Joydeep Haldar large -scale operations that effectively integrate (MS'97) who these activities. The Center for Mineral visited us as part of Resources is a multi -disciplinary entity, co- their company's directed by Mark Barton and Eric Force recruiting teams (USGS), with the goal of furthering our this fall. We had an understanding of the processes that form excellent recruiting mineral deposits. The Center is a Dept. of season with Geosciences -USGS cooperative effort and Amoco, Arco, BP, makes for a very dynamic group. Strong Chevron, EXXON connections with the Center to the mineral and Mobil and Peter Coney and Joaquin Ruiz solemnly prepare for Commencement. industry are beneficial to the educational recruiters were unanimous in praising the high INSIDE mission of the organization. caliber of our students. The Department is deeply The Nyanza Project, directed by Andy appreciative of the generous financial support Colloquium Series Schedule "2 Cohen, is an NSF -funded multi -disciplinary provided by these companies. operation involving students in the study of As you know, the only thing constant in News Around the Department 3 East African lakes. The Project grew out of our Department is change and this year has been combined efforts to maintain the viability of no exception. We welcomed 24 extraordinary Center for Mineral Resources 4 East African lakes and takes students to Lake graduate students who will undoubtedly further Paleoclimate, Magmas and Tanganyika where limnological, biological, enhance the reputation of our graduate ecological, and other studies are performed program. We are in the final stages of a search Hydrothermal Systems 6 for a geomorphologist and will probably begin by a host of scientists. Alumni News 8 Jay Quade describeshisrecent another search in the spring for a colleague paleoclimatology research in the Atacama in a currently unspecified field. Randy '98 Field Camp 10 Desert with Julio Betancourt (MS '83, PhD '90) Richardson has been appointed Assistant Vice Peter Coney Retires .. 11 and students Jason Rech and Claudio Latorre President for Undergraduate Affairs, and (MS '96). although this is great for Randy we miss our Nyanza Project: Phase One 12 Of course, we haven't forgotten our more daily interactions with him. Unwelcome classical teaching efforts, such as Field Camp, farewells also come with change, such as the Climate Change in the Atacama which is now mostly taught in Utah. Pete retirement of Peter Coney. Students will miss Desert 13 DeCelles, the new Director of Field Camp, his classes and we will miss his insight. describes some of the activities that went on this That's all for now. As we approach the Nuclear Explosion Epicenter 14 holidays,I take this opportunity to wish you summer. We are strongly committed to our Field Spring '98 Degrees 15 Camp and Clem Chase, Sue Beck, Pete DeCelles all a happy holiday season and a prosperous and Judy Parrish have done a phenomenal job New Year. Please keep in touch -we're always Earth Week at Mineral Museum 15 in keeping it a vibrant course. happy to hear from all of you. UA Geosciences Río Mayo Plants NEWSLETTER Fall 1998 Published Gen "During the fall the air moves in sporadic Rio MAYO PLANTS gusts, which seem to have no other direction The Tropical De4icJuc)us Forest & Faxvircz* c} :orlJawc1; Geosciences Advisory Board Artidttlad4414 than that of the colored autumnal leaves they PAWL I. MARTIN, LMT.pYRTMAK, N.tXA rlselrY:rc, MfiL:6NR7N# T/tOktüs & VAN 60'00611, k ROSSO. Steven R. May (Chair), EXXON disturb and carry downward from the trees. Steven R. Bohlen, USGS They suddenly startle the great infinity of Hugo T. Dummett, BHP Minerals forest silence into a local multitudinous rustle of descending leaves, of flapping paper -like Frederick T. Graybeal, ASARCO copal bark, of rubbing branches, only to drop Kerry F. Inman, BP as suddenly back again into Charles F. Kluth, Chevron a pervasive silence." Robert W. Krantz, ARCO Alaska -Howard Scott Gentry, Río Mayo Plants J. David Lowell, Consultant David K. Rea, University of Michigan Gentry's Rio Mayo Plants: The Tropical Deciduous Forest and Environs of Northwest David Stephenson, D/H Stephenson, Inc. Mexico. 1998. Revised and edited by Paul S. Martin, David Yetman, Mark Fishbein, Phil Jenkins, Thomas William H. Wilkinson, Phelps -Dodge R. Van Deveder and Rebecca K. Wilson. University of Arizona Press, Tucson; 558 pages ($75.00). Draining the barranca country of This expanded, revised publication The UA Geosciences Newsletter is southwestern Sonora and western Chihuahua, represents the field work of over 100 published twice a year by the the Rio Mayo originates in the fir forests of individuals - faculty, students and friends of Department of Geosciences the Sierra Madre Occidental at 9000 feet and PO Box 210077 this and other universities of the region, The University of Arizona plunges over an 800 -foot waterfall at including the Universidad de Sonora. Included Tucson, AZ 85721 -0077 Basaseachic to find its way to the mangrove are some 100 species of tropical trees, many tidal flats of the Gulf of California. In the 1930s, profiledinGentry's enchanting and Boleyn E. Baylor, editor naturalist Howard Scott Gentry began to explore scientifically accurate prose. For those who 520- 621 -6004 the Rio Mayo region -lands still inhabited by have a taste for exploring the tropics in wild bbaylor @geo.arizona.edu indigenous people speaking their own tongue: country it is not necessary to fly to Belem or Tarahumare, Warahio, Mayo, and Yaqui. Gentry Borneo or Brazil. Dry tropical habitats and Geosciences Home Page absorbed local botanical knowledge (the best pine -oak forest, along with a variety of well - http: / /www.geo.arizona.edu way to meet the people in the Sierra is with a known mines or mineralized outrops for the specimen in hand and the query "Por favor, economic geologist, are a day's drive south como se llama este tipo de planta ? "). of Tucson. CORRECTIONS GEOSCIENCES FALL '98 COLLOQUIUM SERIES We would like to acknowledge the SEPTEMBER generous donation of BHP Copper to Terry Wallace (UA)The May 1998 Indian and Pakistani Nuclear Tests: Seismology and the CTBT GeoDaze '97 and apologize for omitting Kelin Whipple (MIT)Dynamics of Bedrock Channel Erosion them from the list of donors. Julia Cole (U of Colorado)The Changing Pulse of Pacific Variability & It's Impact on U.S. Drought OCTOBER Claus Siebe (UNAM)Late Pleistocene and Holocene Plinian Eruptions at Popocatepetl Volcano Paul Jensen (MS '98) received the AGS Tom Sharp (ASU)High -Pressure Minerals in Shocked Meteorites Harold Courtright Scholarship for $1000 in December 1997 for his work in the Suzanne Baldwin (UA)The Aegean Metamorphic Core Complexes Sierrita Mountains. John Chesley (UA)The 1870s/1880s Record of Himalayan Paleorivers Louise Kellog (UC- Davis)Geodynamic Models to Try to Reconcile Geochemistry, Seismology, and Geodynamics of the Earth's Mantle NOVEMBER The concluding sentence of Copper Maya Elrick (UNM)Recognizing Millennial -scale Paleoclimate Fluctuations in Paleozoic Deep - Metallogenesis in Chile by Joaquin Ruiz water Carbonates (Spring '98 issue) was omitted: Barbara Tewksbury (Hamilton College) How to Do a Better Job Designing a Course "Interestingly, and not suprisingly, the Bob Hecky (National Water Research Institute of Canada)The Changing Surface of Africa: Are mantos have more of their Os derived Land Use Practices a Threat to the Biodiversity of the African Great Lakes? from the crust and are therefore more DECEMBER radiogenic. This may be very useful in Jon Spencer (Arizona) Geological Survey)Geologic Continuous Casting as a Newly Recognized exploration since one sample may yield Geologic Process and Significance for Extensional Tectonics information on the type of target." CHECK OUR WEB PAGE (WWW.GEO.ARIZONA.EDU) FOR SPRING '99 COLLOQUIUM LISTINGS page2 The University of Arizona /Geosciences Newsletter Fall 1998 Basin and Range Province. Peaks of up to 15,000' elevation occur along the TAM, and News peaks over 16,000' are present in the EWM. The aim of this project is to address a fundamental question regarding the tectonic Around the relationship between East and West Antarctica: does the Cenozoic rift flank of the West Antarctic rift system (the TAM) extend along Department the EWM of West Antarctica, or does the Cenozoic rift flank continue along the trend of the TAM? The answer to this question has Randy Richardson implications for the tectonic evolution of the West Antarctic rift system, the uplift history Named Assistant and uplift mechanism of the TAM, and the relationship of East to West Antarctica. Fission Vice President for track and 40Ar /39Ar thermochronology will be used to determine the timing and relative Undergrad Education amounts of Mesozoic versus Cenozoic thermal and denudation events in the TAM. These results will be compared to those from the EWM. The field party will be flown from McMurdo Station on Ross Island to the Thiel Mountains, a flight of almost 5 hours in a ski - equipped C -130. Once there the group will use snowmobiles and sledges to move around as well as ski -equipped Twin Otter aircraft to reach locations inaccessible by snowmobiles. Delores Robinson Wins GSA Award Delores Robinson (shown here climbing "Steve's Arete" at Windy Point on Mt. Lemmon) has received one of two GSA Division Student Research Awards for 1998 for her proposal "Investigating the origin of the Chainpur Thrust through structural and This summer Randy Richardson was petrogenetic examinations, western Nepal appointed Assistant Vice President for Himalaya." This award recognizes the most Undergraduate Education. Randy began meritorious proposals to the GSA Committee teaching General Education courses (Physical on Research Grants in structural geology and Geology and Oceanography) inthe tectonics. "D" is a second -year Ph.D. student department and will now be responsible for working with Peter DeCelles. the University's new General Education Program. The Gen Ed program took effect this fall semester and presents a major challenge Antarctic Expedition and opportunity for undergraduate education at the University of Arizona. to Track the West Randy, while now housed primarily in the Administration Building, continues to teach in Antarctic Rift Flank the department. This semester he teaches a new General Education course (Physical The Transantarctic Mountains (TAM) are a Cenozoic rift flank uplift that define the edge Science: a Geological Perspective) to almost Photo courtesy of P.K. Weis, Tucson Citizen. 200 students. Randy's research support is now of the East Antarctica craton. In December primarily in the area of science education 1998 and January 1999 Paul Fitzgerald Happy Birthday to where he is active in teacher preparation, (Associate Research- Scientist) and Suzanne especially at the university /college level. Baldwin (Associate Professor) will lead a Our Favorite Fossil! geologic expedition to the Thiel Mountains and Ohio Range in the TAM and to selected On August 22, 1998, the family of Dr. nunataksinthe Ellsworth -Whitmore Paul S. Martin, Professor Emeritus, held a Mountains crustal block (EWM) of Westsurprise party in honor of his 70th birthday. Antarctica. In contrast to the geology of East About 90 family members, colleagues and Antarctica, West Antarctica is composed of a other friends helped him celebrate at the number of microplates, separated by areas of Desert Laboratory on Tumamoc Hill. The extended crust, including the West Antarctic theme, "Dancing Elephants," commemorated rift system which is about the size of the entire Paul's longtime interest in megafauna.

The University of Arizona /Geosciences Newsletter Fall 1998 page 3 The Center for Mineral Resources by Mark Barton In spite of the breadth of academic Over 50 people from five questions and societal relevance, programs in continents enrolled in economic geology are disappearing across the three offerings of a well - US and other developed countries. The Center received short course on forMineral Resources (CMR)isan the interpretation of interdisciplinary program in which geologists leached cappingin of widely differing backgrounds, ranging from porphyry copper deposits undergraduate and graduate students taught by Spence Titley through postdoctoral scholars, faculty, USGS and Steve Enders.Eric professionals, and individuals from the private Force and Andrew Grosz sector, come together to interact. The Center of the USGS will lead a was born three years ago, growing from short course on titanium discussions going back at least two decades depositsin January that highlighted the need to build on 1999. Several opportunities for interaction between the workshops, such as the University, industry, and the USGS. We seek two on Fe- oxide- to catalyze educational, research and service copper -gold systems, activities in scientific and societal issues related contributed to ongoing to mineral resources. The well -known strength research projects, with of the Department in studies of mineralparticipants from the deposits, geochemistry, tectonics, and related Department, the USGS fields acts as a solid foundation for Center and mining companies. projects toward these goals. An October1998 Roughing it in Guanajuato, Mexico on a Mexico Consortium field trip The Center deals with many exciting workshop looked at in 1995. scientific and societal issues involving the distribution of natural resources in the solid deposit collections in the earth, their utilization by society, and the Department. Through implications of their use for other human this initiative we hope to activities. Because ore -forming systems span add materials to the the globe, lithospheric settings, and geologic collection and use them time, their impact and study is by nature for CD and Web -based interdisciplinary, integrating the geosciences documentation and and bridging them with other fields of science. instruction. Throughout Center projects span the globe, ranging from the US, irreplaceable economic analysis to basic geochemistry to collections have been science applied to exploration, operational discarded; many others and environmental issues. Center projects are are threatened. We are relevant beyond the realm of research journals lookingat waysof because mineral resource issues directly affect preserving selected our health and economic well- being. In materials.For example, Arizona, for example, copper production we will acquire (when Spence Titley instructing others on the wonders of leached capping alone generates nearly ten billion dollars in funding and space are in (or, for those more pedogenically inclined, the expanded soil horizon economic activity; and nationally, mineral place) Waldemar on a porphyry copper deposit) at one of several recent CMR short production has a direct economic impact of Lindgren's collection from courses on the subject. about one -half trillion dollars. districts around Europe, Current CMR activities fall into several broad coordinating global GIS -based research on Asia and the Americas, many of which have been categories: (1) education, (2) monograph and mineral deposits and geology with a new inaccessible since the early 20th century. The goal map series, and (3) basic research. international minerals assessment program is to ensure its preservation in an institution, such within the USGS. as the UA, with a strong mineral resources EDUCATIONAL ACTIVITIES: We are presently exploring options for a program. Other collections and donations will SHORT COURSES, WORKSHOPS, non -traditional graduate degree program in be preserved to the extent that we can generate LECTURE SERIES, COLLECTIONS mineral resources. The intent is to serve the needs adequate long -term support.Efficient One of the principal missions of the of full -time employed professionals in private organization of these collections will also make Center is to educate geologists in academia, industry or government who want to obtain them useful tools for future research on old industry, and the USGS. Toward this goal, additional training but cannot readily districts and broader comparative studies. the CMR organizes a lecture series that brings accommodate the residency requirements of MONOGRAPH AND MAP SERIES in 5 -10 speakers from outside and local traditional programs. The key to this initiative organizations each semester to speak to the will be to identify adequate faculty resources to The Center produces a monograph and University and local geology community. run the program without short- changing other map series, initiated by Eric Force, the series The CMR also organizes a series of needs. editor and Center co- director, with the goal workshops and short courses attended by Another initiative underway aims to curate, of publishing high -quality monograph -length geologists from both industry and academia. add to, and better utilize the exceptional mineral works on topics relevant to mineral deposits. page 4 The University of Arizona /Geosciences Newsletter Fall 1998 Initially, the opportunity came about to capture high -quality manuscripts orphaned by the USGS reorganization. The project expanded to include Eric Force Leads Short Course publication of full color maps and digital products such as GIS databases. on Titanium -Mineral Resources Eric contributed the first monograph on the geology and mineral deposits of the Santa Catalina Mountains and nearby areas (p. 7). More monographs are in the works, including a comprehensive study of the geology and mineral deposits of the Battle Mountain gold- mining region of Nevada by Ted Theodore and others of the USGS. Three new full color quadrangle geologic maps accompany the 400+ pages of text and figures in the Battle Mountain Monograph. Another exciting monograph by David Richards (PhD '95) documents the terranes and Phanerozoic development of the Andes and will be accompanied by color plates and a digital compilation. Manuscripts in preparation include a collection of papers on the mineralogy, geology, Heavy mineral enrichments (black) of the Sanostee deposit, and economics of rare earth element deposits, northwestern New Mexico. High -grade enrichments of ilmenite and one on the geological and metallogenic and zircon record successive beach profiles in prograding Gallup development of Mexico. A multi -layer GIS map Sandstone (Cretaceous). of the geology and other features of the US- Mexico border region will be completed in 1999. Monographs and full -color plates are Eric Force, retiring as USGS coordinator for the Center for Mineral Resources, is generated and printed in Tucson with distribution going out by leading a Center short -course titled "Titanium -Mineral Resources of through the Center (520- 626 -4962 or the US -New Perspectives." The course is scheduled for Jan. 7 -8, 1999, and coincides cmr @geo.arizona.edu) or the University of with the release of new work on titanium -mineral resources of the western U.S. Arizona Press. We are actively soliciting high - quality monograph -length products and large Eric has been the USGS titanium -mineral specialist since 1972 and has worked format maps with broad relevance to the geology on all kinds of titanium -mineral deposits from beach -sand heavy- mineral deposits to and utilization of mineral resources. rutile- bearing eclogites. (Titanium studies are a great vehicle to become conversant

RESEARCH: BASIC TO APPLIED, with a range of crustal depths.) GEOCHEMISTRY TO ECONOMICS Perhaps the largest single component of the short course addresses heavy -

Research associated with the Center ranges mineral resources in Cretaceous shoreline placer deposits that formed along the from fundamental studies of earth materials to shores of the Western Interior Seaway (see photo). In comparison to more applied science of more immediate use to the conventional Quaternary deposits, they provide an unusual opportunity to look at mineral industry. Fields range from geochemistry heavy- mineral concentration in beach systems in stratigraphic and paleogeographic to tectonics to economics. Support for these contexts. Eric's work with Bob Butler on the economic mineralogy of these deposits activities comes from diverse sources both private and federal. Most projects are student -focused should raise a few jaded eyebrows. whether part of graduate degrees or undergraduate research. to topics focused on the weathering environment papers in technical journals, and a series of maps Basic work in geochemistry includes and sedimentary basins. Most of these projects showing the mineral deposits, geology, structural development of the Re -Os isotope system and link to efforts in regional and global geology, and magmatic evolution, and geochemistry of its application of dating and isotopic systematics mineral economics, and basic geochemistry. Mexico and the border region. New initiatives to a wide variety of problems. New results were The Mexico Consortium exemplifies one of build on this model to use multi -disciplinary described by Joaquin Ruiz (CopperMetallogenesis our "combined projects ".This program, a strengths of the Department for examination of in Chile from Re -Os Isotopes) in the Spring '98 collaborative effort now in its sixth year, is many kinds of geologic environments. issue of the newsletter. We are also examining supported by mining companies and the USGS. the compositions of ancient geothermal fluids To date, it has supported almost 30 graduate OUTSIDE INVOLVEMENT from a wide variety of settings in western North and undergraduate students' work in the America.Differences in these fluids not only tectonics, geochemistry, and mineral deposits of In addition to federal and UA support, reflect associated mineralization (if present), but Mexico and the US- Mexico border region.In more than ten mining companies have also give an important clue to the surface aggregate, over 15 MS and PhD theses, most supported individual and cooperative projects environment from which they were derived (see field- oriented, received direct support. The handled through the Center. The USGS has article on paleoclimate, magmatism and Consortium has funded numerous field trips and committed base support level; we hope to hydrothermal systems). other excursions as part of these activities. generate comparable private support. We Field -based projects investigate diverse Consortium products include a new, digitally - welcome input to and involvement in the topics ranging from studies of fluid flow and gold based syntheses of the geology and mineral Center. For information contact Mark Barton, mineralization in regional metamorphic and deposits of Mexico and digital maps of the border Director, or Meg Watt, Admin. Asst., at extensional regimes to studies of ore deposits region with the US. The Mexico Consortium is cmr @geo.arizona.edu or 520- 626 -4962. associated with magmatism (porphyry Cu to entering its final year and will culminate in Information is periodically updated on our epithermal to Fe- oxide(- Cu -Au) mineralization) production of a Center monograph, multiple website (www.geo.arizona.edu /cmr).

The University of Arizona /Geosciences Newsletter Fall 1998 page 5 Paleoclimate, Magmas and Hydrothermal Systems:

Percentage evaporates The Example of Iron -Oxide -Copper -Gold Mineralization of modern sediments by Mark Barton 0 5 10 15 20 25

6 Igneous rocks are widely used to interpret generated from distinctive high -salinity surface Brines are widespread in ancient tectonic environments because their or near surface, non -magmatic brines. the modern world and the characteristics reflect the compositions and The implications of these hypotheses ancient, here illustrated by physical conditions of their sources in the differ. Both magmatic hypotheses imply a our seismologists as they correlation with particular types of corrode their field vehicles /R.leer crust and mantle. Likewise, sedimentary in Bolivia. Widespread rocks reflect the surface environmentthe magmatism and tectonic environments. In ancient brines should tectonic and climatic settings in which they contrast the non -magmatic fluid hypothesis leave a distinctive geologic predicts a correlation with saline surface or 90 I I I I I I form. The corollary to these the way signature. (Photo by 400800 1200 1600 2000 2400 magmatic systems can reflect surficial ground waters, thus a common direct link George Zandt.) conditions has received relatively littleto the climate. Volume rock (km3) systematic attention. Ongoing projects byComparison of the 001 o ,00 ,.000 Mark Barton, several students and postdocsgeologic settings and are looking at ancient hydrothermal systems paleogeographic Cantle., Cu Contents ofFe- oPorphyry as recorders of surface fluids and as a means distribution \ 10 000 to understand a broad group of enigmaticoxide(- Cu- Au -REE) Fe -oxide iron -oxide -rich, copper- and gold- bearing systems supports mineral deposits. geochemical inferences Q Interaction of fresh and marine waters that these deposits Q o with the upper part of the crust is wellform by circulation of U

,00 known. In the vicinity of magmas,non -magmatic brines 0.o, Fe concentrated @ -10°0? mboldt circulation of these fluids has a profound(see Jurassic paleo- Cu concetrated @ ??°á mass of Cu mobiiizad by geographic map). Pb & Zn not trapped? lhe hydrothermal systems effect on the composition of the upper crust Cortez and can mineral deposits in An ongoing 000 loa 10 favorable areas. On the other hand, the cooperative project Mass rock (tonnes) involvement of surface -derived brines in funded by NSF and igneous -related hydrothermal systems is miningcompanies Aqueous fluids move enormous quantities of materials in the continental poorly known; yet such fluids arebuilds on our earlier and oceanic crust - both major and trace elements. This diagram, from widespread today and were probablywork to investigate current research by David Johnson and Mark Barton, indicates that the widespread through much of geologic time system -scale geological amount of metals moved in briny terrestrial hydrothermal systems compares (see photo). Generation and circulation of relationships, the with the amounts contained in some of the world's largest ore deposits. brines during Cenozoic extension in thesources of fluids and This is compatible with formation of many Fe- oxide -rich ore deposits in Southwest led to regionally extensivemetals, and the ancient geothermal systems that formed in arid environments. alkaline alteration and detachment -related mechanisms that mineralization. Whether circulated byconcentrate metals in economically igneous heat or other mechanisms, saline significant amounts. The lack of adequate fluids readily exchange sodium, potassium geological and geochemical knowledge of and other elements with the rocks through these enormous hydrothermal systems has which they pass and they can move large hampered effective mineral assessment and quantities of iron and other metals (see the understanding of baseline geochemical grade- tonnage diagram). data in many parts of the world including Fe- oxide(- Cu- Au -REE) -rich large areas of the United States. hydrothermal systems have been of A broader implication of these results economic importance for centuries, and is that these saline hydrothermal systems controversial in their origin for nearly as long may provide direct evidence for ancient arid (see photo).Recent work, stimulated by climates. This could be important where an the discovery in the 1970s of the giantindependent record, for instance from Many of the iron deposits of the eastern US and Olympic Dam deposit in Australia, has sedimentary rocks, is not preserved (see Europe probably represent ancient hydrothermal focused on three possible origins: (1) these photo). For example, distinctive sodium -rich systems that owe their distinctive characteristics to deposits are fundamentally magmatic, and potassium -rich, oxidized rocks occur in an arid paleoclimate. The Cornwall, Pennsylvania formed by an immiscible oxide -rich melt many parts of the geologic record, notably deposits were mined from 1742 to 1974 and were that separated from geochemically in high -grade metamorphic terrains. Likely among the first strategic mineral deposits in the distinctive magmas; (2) the deposits are metamorphosed analogs, and thus evidence US, producing cannon for the Revolutionary Navy hydrothermal, formed from magmatic - for ancient arid environments, exist in rocks as well as products for civilian use. Geologic and sourced brines and can be considered as going back to Archean. geochemical evidence shows that these systems broadly analogous to porphyry copper formed as the result of basaltic magmatism in deposits; and (3) the deposits are alkaline rift basins during initial opening of the hydrothermal driven by magmatic heat, but central Atlantic ocean. page 6 The University of Arizona /Geosciences Newsletter Fall 1998 Igneous Rocks Qfelsic(- intermediate) Geology and Mineral intermediate( -mafic) Associated Metals Resources of the Santa Cu ± Au present (Fe -oxide dominant) Cu ± Au significant Catalina Mountains, (Fe -oxide dominant) Cu ± Au significant (Fe -oxide subordinant) Southeastern Arizona A Cross -Sectional Approach ERIC R. FORCE with sections by D. M. UNRUH and R. J. KAMILLI

155 Ma This monograph is the most comprehensive treatment plate available of the geology of the Santa Catalina Mountains positions Scotese and Denham (1988) north of Tucson, expanding greatly on classic older descriptions of the southern Catalinas. The study treats the entire range with a cross -sectional emphasis to clarify relations among the mylonitic core -complex aspects to the south, passing northward through voluminous Tertiary District Size & Age

>10 9 >10 '

The distribution of iron - oxide -rich hydrothermal segment of the range is described. deposits and regionally extensive alkaline The book includes a full color 1:48,000 geologic map alteration through time matches well with independent indicators of saline- fluids, most of an 11 x 48 km transect through the range, oriented to commonly formed in a contemporaneous arid permit reconstruction of the jigsaw puzzle produced by setting. This diagram shows the correspondence Tertiary crustal stretching. Three other detailed maps and of most large Mesozoic Fe -oxide districts and the low- to mid- latitude arid zones. (From Barton descriptions of key localities make the monograph a and Johnson, 1996, Geology, p. 259) self -guided tour through the geologic history of the range.

ERIC FORCE, a geologist with the U.S. Geological Survey since 1970, walked thousands of miles in the Catalinas from 1989 to 1995, collecting information for this monograph. He is also the author of Geology of Titanium -Mineral Deposits.

Geology and Mineral Resources of the Distributed by the Santa Catalina Forming spectacular outcrops in the Colorado Center for Mineral Mountains, Plateau, the ancient dunes and other sedimentary Resources features of that area are familiar indicators of an Southeastern and climate in the early and middle Mesozoic. Less Arizona Monographs in Mineral well known is how this record translates to the arc A Cross -Sectional Approach Resource Science, No. 1 rocks of the Cordillera's western margin, a region many times larger. This sheeted dike complex Eric R. Force 135 pp., 121 illus. belongs to the Middle Jurassic Humboldt complex with. eaiore by 8 1/2 X 11 Daniel M. Unruh and Roben J. Kamilli of western Nevada. These back -arc basaltic rocks Price: $38.00 plus S & H have been transformed to scapolite (Na -Cl -rich (plus tax, if applicable) framework silicate) and have had much of their tincrat R'soul, St.inïi.. metals and other components leached by coeval Center foe Mineral Resources:11. n, AZ evaporitic fluids. Such compositional changes are surprisingly widespread, yet little appreciated in the geologic record.

The University of Arizona /Geosciences Newsletter Fall 1998 page 7 ALUMNI NEWS 1940s 1980s JEN BONINI (MS '94) writes that she and Scott married in June 1997 at the Princeton ROBERT H. HIGGS (BS) retired as Director MARTHA CODER (BS '81) writes that she Geology Field Camp near Red Lodge, of the Geophysics Department of the Naval had some wonderful experiences in the field Montana and then went trekking in Nepal Oceanographic Office in July 1987. He's in the San Juan Mountains of Alaska, but over the summer. Scott is getting his PhD currently living in Sevierville, Tennessee. with the drop in the price of gold she found at the UA in Renewable Natural Resources. it difficult to find employment as a geologist. Jen is teaching science and building an 1960s Martha recalls seeing a classified ad in The academic and extracurricular program at St. Denver Post in the mid -80s saying, Gregory College Prep School here in Tucson. PAUL W. ANDREWS (BS '61) has retired to "Geologists need not apply "! Making aShe's integrating nature themes and the tall pines of Payson, Arizona after a 26- career change, she then worked as anexperiential education into the life of the year career with Motorola. engineer with AT&T /Lucent Technologies school. Jen writes that it's been fantastic fun andhasrecently started with Sun and the first year of the program has been Microsystems as a Senior Telecommunications wonderfully successful. She's got her fingers 1970s Analyst in Colorado. Her responsibilities crossed for year #2. include regional planning and deployment of JEFFREY W. BRYANT (MS '78) has just voice and video services. Martha's region JOHN BUGGENHAGEN (BS '92) writes that returned to the States after almost eight includes South America and so she especially after leaving the UA he completed his MS years in Saudi Arabia. He has a new job in enjoyed the Spring '98 Newsletter profiling at the University of Wyoming in 1992. He downtown Houston with CMS NOMECO the department's research on thatthen worked for Landmark Graphics, working West African prospects and properties. Jeff has two daughters, continent. designing and configuring exploration computer systems around the world. John Stephanie (nine) and Madeline (six). He and DAVID HUSTON (MS '84) went on tois currently working towards his PhD in his wife Mary Ann (Leon) (UA '76 BA receive his PhD from the University ofGeophysics on the Seismic Stratigraphy of Education) have been married for 22 years. Tasmania in 1990. He's now working as a Unconventional Petroleum Reservoirs where Senior Scientist with the Australian RON CORBETT (MS '72) took early much of his research involves processing Geological Surveyandliving in and interpreting modern 3D seismic data. retirement from Cyprus Climax Metals Co. Jerrabomberra, Australia. He's currently working on data from the at Miami, Arizona in March 1998 and is now BighornBasin, Wyoming and the doing consulting mineralogy from his new SARA L. RATHBURN (MS '89) is working Norwegian North Sea. After graduation home in Fruita, Colorado. He is also on a PhD at Colorado State University. Sara John will be moving to Anchorage where associated with the geology program at and husband Jim Finley now have two kids, he will be working for ARCO Alaska in their Mesa State College, Grand Junction in an ages two and four. exploration department. John has been adjunct faculty capacity. married three years to a native Wyoming 1990s girl and they have a 15 -month old son, Dylan Tanner. John returns to Arizona every year to backpack in the Grand Canyon - the Newsletter makes him wish he was back in Tucson!

DAVID COBLENTZ (PhD '94) has moved to Eugene, Oregon where he has a postdoc/ adjunct teaching position in the Dept. of Geological Sciences at the University of Oregon. He writes that fellow alum KAREN (BAROVICH) HATCH (PhD '91) is now at the University of Adelaide in Australia

Ron Corbett hiking in Colorado National ERIN (BARGER) CUNNINGHAM (MS '96) Monument in the summer of '98. has returned to work in Seattle with Pacific Groundwater Group after working with an EBERHARD A. SCHMIDT (MS '67, PhD '71) engineering consulting firm in Cambridge, is working in Spokane, Washington as a Massachusetts for about eight months. consulting geologist. He writes that he enjoys the Newsletter, especially the DANIELLE KANE (BS '97) is working as a research papers and their variety of subjects. staff geologist for American Geotechnical in San Diego.

Jen Bonini with husband Scott and trekking buddy Mike in Gorak Shep (closest town to Basecamp 1 of Everest). page 8 The University of Arizona /Geosciences Newsletter Fall 1998 ALUMNI NEWS BARBRA (SCHUESSLER) MAHER (MS '94) and C. JOHN MAHER (BS '94) sent us a Alumni Tina Wells and Joydeep picture of their beautiful new daughter, Ashlyn Julia (pictured below), who was born in November 1997. Barbra is working on a Haldar Visit Department with PhD at Colorado School of Mines and John is working for Western Geophysical. Industry Recruiting Teams

Tina Wells (BS '94) and Joydeep Haldar (MS '97) are two of our recent alums joining their industry recruiting teams this fall. Tina accompanied Kerry Inman (MS '82) of BP and Joydeep accompanied Chuck Siebels and Linda Kinslow of Amoco.

TINA WELLS (BS '94) Since I graduated from the University of

Arizona in December 1994, I have been continuing my journey north and west. I spent two years in Boulder, Colorado, attending the University of Colorado, where I obtained my MSc in Geological Sciences. My thesis work examined the fluvial architecture of avulsion deposits in the Fort Union Formation of Wyoming. After my first year of studies at CU, I was an intern for BP Exploration in Anchorage, Alaska. The two months I spent living in Anchorage and working as an intern for BP convinced me that working full time for an oil company would be challenging but fun. During my second year of studies at CU, Ashlyn Julia Maher, born November 17, 1997. BP made me a full time job offer to begin in CATHY (KIK) MOORE (MS '93) works in 1997. I completed my graduate studies in May Tucson at the Arizona Geological Survey as 1997, and began working for BP in the Earth Science Information Center (ESIC) Anchorage in July 1997. I am proud to say Coordinator. This job used to be a USGS that I survived my first winter in Alaska, and position but due to downsizing the Stateeven though I'm considerably paler now Tina Wells with Peter Kresan. Tina presented an picked up the ESIC. Her primary job is to sell than I was when I lived in Tucson, I think I overview of employment opportunities with the topographic maps of various scales and USGS have acclimated quite well! oil industry to the SESS club. thematic maps and publications. She also performs geological and aerial surveys, JOYDEEP HALDAR (MS '97) answers geologic and geographic questions posed by the public, and interfaces with other I worked for Amoco as a summer intern ESICs nationwide. Kik is also Lapidary for three months on a project in Venezuela, Instructor for Tucson Parks and Recreationwhere I found myself applying my training at where she teaches rock cutting and polishing Arizona to make million dollar decisions on and takes her classes on rock hunting drilling wells (scary isn't it ?), but the expeditions. Kik says she still plays ice hockey excitement of it sucked me into the "dark side" and soccer but would rather do things with of joining the oil industry. It also gave me an her two girls, Alex (9) and Kitty (7). They get opportunity to evaluate "life and science in out as much as possible- camping, hiking, the industry". Following my internship I was and rock hunting. They're also spending time hired full time by Amoco as an exploration with their wonderful new dog George, a three - geologist prospecting in the deep water Gulf year -old Black Lab mix. "Dogs don't get anyof Mexico. My third big milestone was finally better than this fellow," says Kik. tying the knot to my beautiful fiancee back in India, who had been waiting for me for five Joydeep Haldar and advisor Peter DeCelles. long years (the last two we had met only twice!). We returned to Houston in February reminded us of home -Calcutta (with ten after a huge wedding that was attended by times less pollution). But it really has some In Memory of 800 people including Carmi Garzione (current cool things to do if you are into theatre, music, PhD) and Damian Hodkinson (MS '98). We concerts and restaurants. It was great to be AL REID (MS '66, PhD '68) passed away on went to London and France for our back in Tucson as a member of Amoco's May 29, 1998. He is survived by his wife SUE honeymoon! Houston was a challenge to recruiting team -made me realize just how REID (MS '66, PhD '68). begin with but soon it grew on us because it much I miss school and you folks.

The University of Arizona /Geosciences Newsletter Fall 1998 page 9 '98 UA FIELD CAMP HELD IN UTAH, COLORADO, AND NEVADA

The view of Castle Valley, near Moab Utah, from our base camp on the northwest flank of the LaSal Mountains (photo by Susan Beck). The great Field Camp experiment was completed during the summer of 1998, when UA Geologic Field School was held entirely in Utah, Colorado, and Nevada. A group of 36 students accompanied instructors Clem Chase, Judy Parrish, Susan Beck, and Peter DeCelles, with graduate students Nadine McQuarrie and Delores Robinson, across the southern Colorado Plateau to a basecamp on the north flank of the LaSal Mountains, east of Moab, Utah. Mapping exercises included salt -cored anticlines, normal faults, and a large Laramide monocline. The geological engineering and geophysics students departed for Tucson midway through the five -week course, and the geology majors continued their trek into central Utah, where they mapped Sevier thrust belt structures in the Canyon Range and Pavant Range. Inclement weather (including an overnight snowstorm that pancaked some tents!) plagued the Canyon Range segment of the course, but the students persevered under real -world conditions and managed to Group photo during the second half of field camp with snow covered Mt. Nebo in the background. produce good maps and interpretations of the complex geologic history of central Utah. The weather improved as the group headed west across the Sevier desert basin into the northern Snake Range in eastern Nevada, where ductile extensional detachment faulting became the focus of mapping efforts. The now traditional climb of Wheeler Peak in the Snake Range was accomplished by many of the students, in spite of an unusually heavy spring snowpack. Although we now know that field camp can be successfully run as a "road show," we also know how important it is to have quality equipment and camping facilities. With (L) Students warming up around the campfire after a wet day of a solid geological framework in place, we can mapping in the Canyon Range, central Utah. (M) Pete DeCelles- focus more on logistics next summer. the boss. (R) Graduate Teaching Assistant Nadine McQuarrie at -Peter DeCelles our camp in the Canyon Range, central Utah. page 10 The University of Arizona /Geosciences Newsletter Fall 1998 Peter Coney Retires

budding geologists. (Among the him with extreme serenity. He received his BA luminaries that Peter taught at from Colby College, MS from the University Middlebury is our own Andy of Maine and then proceeded to study at the Cohen.) George Davis tells the Ecole National Superierre de Petrole in Paris. story of how, when he gave a He returned to the U.S., where he obtained speech at Middlebury and his PhD from New Mexico with an epic mentioned Peter Coney, the entire dissertation on the Cordillera Huayhuash in audience broke out into applause. Peru, where he was accompanied by his wife This saysitall.Peterleft Darlene. Before enrolling at New Mexico, Middlebury more than 15 years however, Peter and Darlene lived in Zion ago as an Associate Professor. He National Park, where Peter was a ranger. Here is now a bit of a cult figure there - he created his most famous publication, the Peter has the power to do that. cross section showing the relationship In 1975, Peter came to our between Bryce, Zion and the Grand Canyon. Department where he joined You've all seen his cross section if you've visited George Davis and Bob Butler in any of these Parks. Most of you, however, forming a powerful group in probably didn't know that Peter was the tectonics. Bill Dickinson later author of that publication since the first edition joined this group and what had published by the Park Service omitted Peter's to be one of the most powerful name. tectonic programs in the world When Peter arrived in our Department, was created. he quickly added to his scientific stature with One of the big attractions papers with George Davis and Tekla Harms when Iapplied to the UA was on metamorphic core complexes, with Steve Peter Coney. I had just finished my Reynolds on variable dipping subduction PhD research on the evolution of zones in western North America, with Berg, fluorine -rich rhyoliltes of the Sierra Jones and Silberling on tectonostratigraphic Madre Occidental in Mexico and terranes, with Dickinson on the origin of the was trying to determine the Gulf of Mexico, and with Chuck Kluth on the Peter Coney on Vancouver Island during the trans- Canadian- composition of the basement so ancestral Rocky Mountains. You can envision Cordillera field trip in April, 1998 -a fantastic field trip led that I could model the evolution what his citation index must be like. Peter's

by Peter and Jim Monger for the Orogenic Systems class of the volcanic rocks. I started courses are just as famous as his articles. His (photo by Susan Beck). reading some of the work Peter courses on orogenic systems were always filled had done on the suspect terranes by wide -eyed undergraduate students and Deter Coney retired. Unthinkable, isn't it? of Mexico and I found myself becoming more awed graduate students. Well, the story goes that when Vince Kelley, interested in the tectonics than in the igneous In addition to his strong research and Peter's PhD advisor at the University of New petrology. My early work here consisted of teaching record, Peter makes his own Mexico, asked a young Peter Coney what he many studies that moved along in a fruitful furniture, paints, plays the guitar and the wanted to do, Peter's response was "to fashion because of Peter's enthusiasm. Ah, I banjo, enjoys model trains and builds ship understand the Cordillera from Alaska to the will miss him. replicas that are bigger than my car. How he tip of South America." I guess Peter has done I'm not sure how much to write of Peter's has time to do all this is beyond me. that, so it's time for something else! past since I don't want to be on the receiving I'll finish by saying that if Peter played Peter began his career in Middlebury end of one of Peter's famous long, enigmatic the sitar instead of the guitar, he would easily College in Vermont, where he built a modern looks. Let me just say that he was born in qualify as a guru. and flexible curriculum that served many Maine, where his parents must have endowed - Joaquin Ruiz

of his students' ideas, gently helped focus our work is balanced by love and respect for his A Student's Tribute thinking, always allowing us the freedom to family, and for the exploration of his creativity explore and think about problems in newoff the geologic playing field. On our most ways. Reflecting on my experience as an RA recent visit, we spent half our time together

for Peter, I realize that he had exposed me talking about geology and business and the early on to She power of working on a team other half talking about landscape painting! towards an integrated solution -who would How does he stay so calm? I think its

have thought ?! Indeed, working for Peter, I because he has his priorities straight -one of always felt like a valued member of the team - the few people I know who really does seem he provided that respect, encouragement and to be able to balance the elements in his life. gentle "coaching" that enthusiastic, but naive Thanks Peter for enriching my life; I know that the generations of students you gently guided Kerry Inman students need to excel. Peter's version of a geoscientist as a all thank you too. I look forward to many more For me, Peter Coney embodies a great broad, lateral thinker has greatly influenced great conversations with you. me but it is as a whole person that Peter is the educator and an extraordinary role model. As -Kerry Inman (MS '82) an educator, he encouraged the development most positive role model. His passion for his

The University of Arizona /Geosciences Newsletter Fall 1998 page 11 Phase One of the Nyanza Project by Andrew Cohen

"You mean that's it? No more forms to Decade of East African Lakes (IDEAL), a expenses covered and receive a small stipend fill out or signatures required ?" "No. You are scientific consortium dedicated to promoting for participating. In addition to the American free to go sir."I looked at my watch. It was research on the African Great Lakes. As a participants, 12 African students are selected 4:55 p.m., five minutes before the customs member of the IDEAL's steering committee, I and funded by the United Nations' Global inspections office at the Dar es Salaam airport have always been interested in the linkages Environmental Facility project for Lake was going to close, and I was supposed to between research and research training, and Tanganyika, called the Lake Tanganyika leave the next day on a 36 hour bus and train Biodiversity Project (LTBP). ride to our field station in Kigoma. Finally, the These students also were last of our field research equipment had recruited from ahighly cleared customs and I could breathe a sigh of competitive applicant pool relief and head to the hotel bar for a cold Safari and came to us from the four Lager. countries surrounding Lake So ended Phase One of the Nyanza Tanganyika: Tanzania, Project, a six -week undergraduate research Burundi, Congo and Zambia. training program that I run for the Dept. of Not surprisingly, we had Geosciences and NSF focused around tropical some outstanding students lake studies. Phase one: get about one ton of participatingthisyear. equipment to Kigoma, Tanzania, on the shores Students spent the first three of Lake Tanganyika, without serious mishap, weeks in intensive lab, lecture so that the students have field gear and computers. With the invaluable assistance of Nick Mathieu in Tucson and Simone Alin, Dave Dettman and Catherine O'Reilly in Tanzania we managed to get our shipping container, miscellaneous air freight and our "sort of new" Land Cruiser out to the field.

Top: Ginger Edatukkaran (Boston University), one of the Nyanza Project's undergraduates, working in the lab. Lower L: Andy Cohen in review sessions with Nyanza students. Lower R: Geology field trip to examine riff -margin border fault environments and sedimentology.

Where is the field you ask? On the eastern when IDEAL geared up to develop a research and field exercises, learning the fundamentals shore of Lake Tanganyika, the largest (34,000 training program, I volunteered to take charge of tropical lake science from a team of four square km), deepest (1470 m) and oldest of the proposal. faculty mentors, myself (paleolimnology), (about 10 Ma) of the African rift lakes. My lab Eventually we obtained funding for this Chris Scholz (Univ. of Miami, reflection seismic group has been working on a variety of five -year program from two sources. The U.S. stratigraphy and tectonics), Ellinor Michel limnogeological and biological problems at National Science Foundation provides funds (Univ. of Amsterdam, evolutionary biology that lake for the past 12 years, so it was natural for 11 American undergraduates, plus one and ecology) and Pierre Denis Plisnier (Royal when the opportunity came about to develop high school science teacher, to attend each Museum for Central Africa, Belgium, this training program on tropical lakes that year. Participants are selected following a very limnology). Our approach is explicitly we would hold it there. competitive national search (last year we had interdisciplinary. Although students come The Nyanza Project developed to fulfill almost 200 applicants for the 12 spaces). the training objectives of the International Those chosen get their travel paid, all of their (Cont'd on p. 14)

page 12 The University of Arizona /Geosciences Newsletter Fall 1998 Climate Change in the AtacamaDesert by Jay Quade

This summer, Julio Betancourt and I, and channels now buried by shifting sands. A years for this period), when the region was PhD students Jason Rech and Claudio Latorre, particularly powerful record of climate change significantly wetter than today. This event is journeyed to the heart of the Atacama Desert might be evidence of exactly when and where much in evidence at places like Tuina Cave, of northern Chile to study geologic records there was rain and runoff, as well as plant where we spent several days. of climate change in the driest region of the cover, in the Absolute Desert of the Atacama. The bottom layers of the cave are sterile world. Our efforts to reconstruct the Our mission to reconstruct vegetation wind -blown dust and rock. Sooty black vegetation and hydrologic history of the and hydrology in the Atacama was assisted smudges mixed with thousands of fragments Atacama are being funded by National by the incredible mummification that occurs of bone denote the arrival of man and the Geographic and the InterAmerican Institute. in this hyperarid environment. Plant remains, many meals he made of the local llamas. textiles and even human burials Mixed with and overlying the human (a local museum displays one occupation levels are thick masses of fossil under the label "Miss Chile ") can grass, so thick that at first they looked like bales persevere for millennia in the of hay (see photos). Today, these grasses grow open, and even longer under hundreds of meters higher in elevation, on shelter in rocky environments. the edge of the Andean Altiplano, where it is Around Calama and San Pedro de colder and wetter. The area around the cave Atacama, these rockytoday, devoid of all but a few desperate - environments are characterized by looking shrubs, makes Death Valley look lush. In fact, we spent much of this trip in pursuit of fossil plant material from the caves. Julio has obtained a suite of It's an exciting time for Quaternary carbon -14 dates on studies in South America. Paleoclimatic a fewofthe research has accelerated, in part due to deposits, and most mounting interest inEl Niño and its cluster between conspicuous impacts on key environmental about 12,000 and and socioeconomic phenomena. These 8000 carbon -14 include flooding on the Peruvian Coast, years ago. The drought and biomass burning in the Amazon fossils invariably Basin, and glacier and lake level fluctuations includedplants throughout the Andes. Questions about the nowfound in deep history of the Bolivian High, a monsoonal wetter, higher system similar to the Indian and Mexican elevation settings. monsoons, have also fueled a flurry of recent Ignimbrite cliffs and boulders form rock shelters along the edge (2400- So by Atacaman studies in the central Andes. Today, the 3200 m elevation) of the Atacama's Absolute Desert. Middens made by standards, Atacama lies at the downstream end of this vizcachas (a chinchillid that looks like a rabbit with a long tail) and leaf- conditions were monsoonal flow across the Amazon Basin, eared mice (about the size of deer mice in the southwestern U.S.) provide good when man where it barely spills over the Andes. an excellent record of former expansion of vegetation into what is now first entered the During our outing in July, in the dead of Absolute Desert. The vizcacha midden in the photo (top left) looks like a region midway into the austral winter, the word "desert" took on bale of hay; the grasses preserved in this 10, 000 -yr old midden do not this "wet" phase. a new meaning for us. Actually, a better occur today at this elevation. This expansion of grasses and other plants to But the good times description for the lower parts of the Atacama barren elevations of the Atacama Desert between 12,000 and 8000 yrs ended with virtually ago coincides with the Tauca Phase, a prominent wet episode on the Bolivian is "Absolute Desert", to distinguish it from the c o m p l e t e kind of lush tropical desert of our Sonoran and Chilean Altiplano, which is poorly understood paleoclimatically. abandonment of Desert here. A closer cousin of the Atacama the lower areas of would be the surface of Mars, devoid not only Neogene tuffs and ignimbrites intercalated the Atacama between about 8000 and 3200 of plants, animals or insects of any kind, butwith fluvial sediments. The ignimbrites form carbon -14yearsago. The Chilean also of evidence of recent running water. It cliffs, some of which have wasted down to archaeologists aptly call this period "El Silencio never rains in Calama (2450 m elevation, boulder fields. The cliffs and boulder fields are Archeologico". Looking at the Atacama now, 100,000 inhabitants), the bustling mining ideal habitats for rodents, some of which it is hard to imagine that it was actually once town where we rented vehicles, bought produce plant -rich deposits akin to packrat drier than today, but the evidence clearly groceries and eventually celebrated our middens in our own southwestern deserts. points to expansion of the Absolute Desert success. Evidence of major climate switches in the during that time. So far, Julio and Claudio have Like Mars, there is plenty of evidence that region has been known to Chilean found no fossil plants from caves in the lower things haven't always been the same in at least archaeologists for some time. For example, Atacama that date to that period. some portions of the Atacama. At elevations paleoindians appear suddenly in the region The last 3500 years have been highly below where it rains today (2700 m or almost about 10,500 carbon -14 years ago (carbon- eventful both archaeologically and climatically. 9000 ft), there are hillslopes carved by 14 years are about 10% shorter than calendar (Cont'd on p. 14)

The University of Arizona /Geosciences Newsletter Fall 1998 page 13 64° 48' 64° 54' 65° 00' UA Seismologists Pinpoint Pakistani Nuclear Explosion

28° 54' Epicenter In May 1998 India and then Pakistan detonated nuclear explosions, breaking a worldwide moratorium that had lasted nearly two years. As part of the Department of Geosciences research program in seismology supporting the technical aspects of the Comprehensive Test Ban Treaty (CTBT), the Indian and Pakistani explosions were extensively investigated using "open ", or freely 28° 48 available seismic and imagery data. This figure shows high resolution topography in the area of the Pakistan explosion on May 28. The preliminary locations determined automatically by the USGS and the UN prototype International Monitoring System (REB) as well as our relocation (JHD) of the epicenter are shown. The large mountain is part of the Ros Koh range. The (figure by Terry Wallace and inset in the lower right hand corner is a photo obtained Todd Bredbeck) from Pakistan showing the Pakistani nuclear scientists shortly before the detonation. The mountain in the background is viewed looking to the NNW.

Nyanza Project cont'd The first year of the Nyanza Project was a high on the walls of the quebradas, we noticed greatsuccess.Thankstotheable patches of green, muddy sediment and hard, from all of the above fields to the Nyanzahousekeeping of the Lake Tanganyika Beach yellow travertine. Our first instinct was that Project, we want them to leave with an Hotel, our students stomachs were well cared these were the remains of irrigation ditches built understanding of the interconnectionsfor (one incident of salty ice cream by natives, which are common in some parts of between their original research interests and notwithstanding). Our lab and computer the valleys. On closer examination we realized other related fields. What came out of thisfacilities (based at the Tanzania Fisheries these deposits were natural and represented disciplinary melange was often surprising and Research Institute's Kigoma field station) were remnants of spring and creek deposits that once always gratifying. a bit overloaded with almost 30 people, but filled many of the quebradas. After finishing the first three weeks ofwe've gotten supplemental funding from NSF In effect, the spring deposits are old directed projects and class /lab activities, theto partly alleviate that next year. Several bathtub rings that mark episodes when the students began their independent research lakeside encounters with the endemic water water table stood much higher in all the valleys projects. Some of these were thought out wellcobra of Lake Tanganyika (none close up) of the region. At this writing, we still do not in advance, whereas others developed overdidn't seem to deter our students from going have any dates on these strange deposits, but the course of the first few weeks of the Project. in the water, and most seemed downright not for lack of datable organic remains. Some projects were individual efforts, whereas disappointed that they never saw a hippo or Beautifully preserved plant parts abound, others involved teams of students, usuallycrocodile (this latter lack of sighting made including thick tap roots of mesquite that once working closely with their faculty mentor.yours truly VERY happy), though we did shaded the water courses. We placed bets on Projects ran the gamut of student interests, manage to get a day trip in to Jane Goodall's the expected ages of these deposits, and all the everything from studies of organic material world- famous Gombe Stream National Park guesses fell between 12,000 and 8000 carbon - content of sediments, to studies of the diatom for some chimpanzee watching on the shores 14 years ago, the last time the region was much floras on rocky shorelines, to fish censusingof Lake Tanganyika. Our biggest mishap was wetter than today. This semester, if you see Jason (Tanganyika is justifiably famous among probably the day that I almost drove our Land Rech staring into glass beakers in room 376, he ichthyologists and aquarists for its 200+Cruiser into a 10 foot deep ditch, but that's a is in search of the biggest and best charcoal species of brightly colored fish, most of which story for another day. fragments for radiocarbon dating. So stay tuned. are found nowhere else on Earth, as well as its Personally, I have had few more productive typical 60 -foot underwater visibility). Atacama Desert cont'd or enjoyable field seasons than our July stay in A large team of limnology students Chile. Many bad Peruvian and Clinton jokes, and worked on understanding temporal More rainfall began to fall during this period, hours of fireside brainstorming about the patchiness in nutrients in the water column, which nourished springs and streams that geologicalstory unfoldingbeforeus both spatially and through the course of the flowed far down into the bleak interior of the compensated for the long, Martian -cold windy and dry season when we were there. desert. These stream courses have been the evenings. I actuallyfelta bit wistful as I unpacked This work hasdirectrelevance forfocus of intensive agriculture and village my bags back in the States and was greeted by understanding the lake's fishery, since the building, which in many ways reminded us of clouds of Atacaman dust and the scent of burnt nutrient availability determines where fish food the ruins of the Anasazi here in the Southwest. saltbush in all my field gear. But there is little (i.e., algae) is likely to grow most quickly. Other Some of these stream courses, or time for regrets, as we and Camille Holmgren, a students worked on a study related to some quebradas, are cut deeply into the huge new graduate student in Geosciences, plan to of my research group's ongoing activities, ignimbrite sheets on the flanks of the Andean return next summer and push our explorations looking at impacts of watershed deforestation massif. The quebradas contained some real of the Atacama north toward Peru. and increased sedimentation on the lake'sgeological surprises that were to occupy our ecology. attention toward the end of the trip. Plastered page 14 The University of Arizona /Geosciences Newsletter Fall 1998 Spring '98 Degrees Awarded

BACHELOR OF SCIENCE Shari Ann ChristoffersonChristopher J. EckhartRichard Shelton Law Jeffrey Bruce NorbergStephanie Danielle RossElizabeth Ann Yurasko

MASTER OF SCIENCE and DOCTOR OF PHILOSOPHY

Kurt N. Constenius (PhD) Extensional Andrew M. Freed (PhD) Visoelastic solutions tectonics of the Cordilleran foreland fold to tectonic problems of extinct spreading and thrust belt and the Jurassic - centers,earthquake triggering,and Cretaceous Great Valley forearc basin. subduction zone dynamics. 189p. Randall 270p. Roy Johnson. Richardson.

Brian S. Currie (PhD) Jurassic- Cretaceous Elizabeth J. Miksa (PhD) A model for assigning evolution of the central Cordilleran temper provenance to archaeological foreland -basin system. 239p. Peter ceramics with case studies from the American DeCelles. Southwest. 324p. Jeffrey Dean.

Thomas E. Dilley (PhD) Late quaternary Lois J. Roe (PhD) Advances in the isotopic loess stratigraphy, soils, and analysis of biogenic phosphates and their environments of the Shaw Creek flats utility in ecophysiological studies of aquatic paleoindian sites, Tanana Valley, Alaska. vertebrates. 1 58p. Jay Quade. 296p. Vance Haynes. Mineral Museum Celebrates Earth Science Week The Department of Geosciences kicked off Earth Science Week with a mineral extraganza. The Society of Earth Science Students (SESS) a club of undergraduates interested in geology, teamed up with the UA Mineral Museum to provide an educational experience for the children of Tucson. SESS has developed an internationally renowned mineral education program for the annual Tucson Gem and Mineral Show, and they previewed their "Jr. Education Tables" outside of the Mineral Musuem on Sunday, Oct. 11. The SESS tables had exhibits on mineral properities, mineral identification, geologic maps, and free mineral samples. They also had a treasure hunt which was filled with clues that could only be answered by studying the (Top -R) Department Head Joaquin exhibits in the Mineral Museum. Successful Ruiz and son Peter take part in the completion of the treasure hunt was rewarded Mineral Museum's Earth Week with a choice mineral specimen, and probably festivities. (Above) SESS exhibit tables will lead to some future geologists enrolled at attracted 300 kids. (Right) The the UA! Approximately 300 youngsters visited interior of the Mineral Museum, now the tables, and more than 600 people visited located in the lower level of the the Mineral Museum. Flandrau Planetarium.

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