KECK GEOLOGY CONSORTIUM

PROCEEDINGS OF THE TWENTY-SECOND ANNUAL KECK RESEARCH SYMPOSIUM IN GEOLOGY

April 2009 Franklin & Marshall College, Lancaster PA.

Dr. Andrew P. de Wet, Editor Keck Geology Consortium Director Franklin & Marshall College

Dr. Stan Mertzman Symposium Convenor Franklin & Marshall College

Kelly Erb Keck Consortium Administrative Assistant

Diane Kadyk Academic Department Coordinator Department of Earth & Environment Franklin & Marshall College

Keck Geology Consortium Franklin & Marshall College PO Box 3003, Lancaster PA 17604-3003 717 291-4132 keckgeology.org

ISSN # 1528-7491

The Consortium Colleges National Science Foundation KECK GEOLOGY CONSORTIUM PROCEEDINGS OF THE TWENTY-SECOND ANNUAL KECK RESEARCH SYMPOSIUM IN GEOLOGY ISSN# 1528-7491

April 2009

Andrew P. de Wet Keck Geology Consortium Stan Mertzman Editor & Keck Director Franklin & Marshall College Symposium Convenor Franklin & Marshall College PO Box 3003, Lanc. Pa, 17604 Franklin & Marshall C.

Keck Geology Consortium Member Institutions: Amherst College, Beloit College, Carleton College, Colgate University, The College of Wooster, The Colorado College Franklin & Marshall College, Macalester College, Mt Holyoke College, Oberlin College, Pomona College, Smith College, Trinity University Union College, Washington & Lee University, Wesleyan University, Whitman College, Williams College

2008-2009 PROJECTS

THE BLACK LAKE SHEAR ZONE: A POSSIBLE TERRANE BOUNDARY IN THE ADIRONDACK LOWLANDS (GRENVILLE PROVINCE, NEW YORK) Faculty: WILLIAM H. PECK, BRUCE W. SELLECK and MARTIN S. WONG: Colgate University Students: JOE CATALANO: Union College; ISIS FUKAI: Oberlin College; STEVEN HOCHMAN: Pomona College; JOSHUA T. MAURER: Mt Union College; ROBERT NOWAK: The College of Wooster; SEAN REGAN: St. Lawrence University; ASHLEY RUSSELL: University of North Dakota; ANDREW G. STOCKER: Claremont McKenna College; CELINA N. WILL: Mount Holyoke College

PALEOECOLOGY & PALEOENVIRONMENT OF EARLY TERTIARY ALASKAN FORESTS, MATANUSKA VALLEY, AL. Faculty: DAVID SUNDERLIN: Lafayette College, CHRISTOPHER J. WILLIAMS: Franklin & Marshall College Students: GARRISON LOOPE: Oberlin College; DOUGLAS MERKERT: Union College; JOHN LINDEN NEFF: Amherst College; NANCY PARKER: Lafayette College; KYLE TROSTLE: Franklin & Marshall College; BEVERLY WALKER: Colgate University

SEAFLOOR VOLCANIC AND HYDROTHERMAL PROCESSES PRESERVED IN THE ABITIBI GREENSTONE BELT OF ONTARIO AND QUEBEC, CANADA Faculty: LISA A. GILBERT, Williams College and Williams-Mystic and NEIL R. BANERJEE, U. of Western Ontario Students: LAUREN D. ANDERSON: Lehigh University; STEFANIE GUGOLZ: Beloit College; HENRY E. KERNAN: Williams College; ADRIENNE LOVE: Trinity University; LISA SMITH: Amherst College; KAREN TEKVERK: Haverford College

INTERDISCIPLINARY STUDIES IN THE CRITICAL ZONE, BOULDER CREEK CATCHMENT, FRONT RANGE, CO Faculty: DAVID P. DETHIER: Williams College and MATTHIAS LEOPOLD: Technical University of Munich Students: EVEY GANNAWAY: The U. of the South; KENNETH NELSON: Macalester College; MIGUEL RODRIGUEZ: Colgate University

GEOARCHAEOLOGY OF THE PODERE FUNGHI, MUGELLO VALLEY ARCHAEOLOGICAL PROJECT, ITALY Faculty: ROB STERNBERG: Franklin & Marshall College and SARA BON-HARPER: Monticello Department of Archaeology Students: AVERY R. COTA: Minnesota State University Moorhead; JANE DIDALEUSKY: Smith College; ROWAN HILL: Colorado College; ANNA PENDLEY: Washington and Lee University; MAIJA SIPOLA: Carleton College; STACEY SOSENKO: Franklin and Marshall College

GEOLOGY OF THE HÖH SERH RANGE, MONGOLIAN ALTAI Faculty: NICHOLAS E. BADER and ROBERT J. CARSON: Whitman College; A. BAYASGALAN: Mongolian University of Science and Technology; KURT L. FRANKEL: Georgia Institute of Technology; KARL W. WEGMANN: North Carolina State University Students: ELIZABETH BROWN: Occidental College; GIA MATZINGER, ANDREA SEYMOUR, RYAN J. LEARY, KELLY DUNDON and CHELSEA C. DURFEY: Whitman College; BRITTANY GAUDETTE: Mount Holyoke College; KATHRYN LADIG: Gustavus Adolphus College; GREG MORTKA: Lehigh U.; JODI SPRAJCAR: The College of Wooster; KRISTIN E. SWEENEY: Carleton College.

BLOCK ISLAND, RI: A MICROCOSM FOR THE STUDY OF ANTHROPOGENIC & NATURAL ENVIRONMENTAL CHANGE Faculty: JOHAN C. VAREKAMP: Wesleyan University and ELLEN THOMAS: Yale University & Wesleyan University Students: ALANA BARTOLAI: Macalester College; EMMA KRAVET and CONOR VEENEMAN: Wesleyan University; RACHEL NEURATH: Smith College; JESSICA SCHEICK: Bryn Mawr College; DAVID JAKIM: SUNY.

Funding Provided by: Keck Geology Consortium Member Institutions and NSF (NSF-REU: 0648782)

Keck Geology Consortium: Projects 2008-2009 Short Contributions – Adirondacks

THE BLACK LAKE SHEAR ZONE: A POSSIBLE TERRANE BOUNDARY IN THE ADIRONDACK LOWLANDS (GRENVILLE PROVINCE, NEW YORK) Project Faculty: WILLIAM H. PECK; BRUCE W. SELLECK; MARTIN S. WONG - Colgate University

ANISOTROPY OF MAGNETIC SUSCEPTIBLY AND TRACE ELEMENT GEOCHEMISTRY OF THE ROCKPORT GRANITE AND HYDE SCHOOL GNEISS JOE CATALANO: Union College Research Advisor: Kurt Hollocher

GARNET-FREE AMPHIBOLITES AS GEOTHERMOMETERS: TESTING HORNBLENDE GEOTHERMOMETRY IN THE ADIRONDACK LOWLANDS, NEWYORK ISIS FUKAI: Oberlin College Research Advisor: F. Zeb Page

ASSESMENT OF THE BLACK LAKE SHEAR ZONE AS A SITE OF ELZEVIRIAN SUTURE, ADIRONDACK MOUNTAINS, NEW YORK STEVEN HOCHMAN: Pomona College Research Advisor: Harold Magistrale

A CALC-SILICATE UNIT OF THE ADIRONDACK LOWLANDS: ALEXANDRIA BAY, NEW YORK JOSHUA T. MAURER: Mount Union College Research Advisor: Mark McNaught

PROTOLITH DETERMINATION OF THE HYDE SCHOOL MARGINAL GNEISSES, ADIRONDACK LOWLANDS, NY ROBERT NOWAK: The College of Wooster Research Advisor: Meagen Pollock

Sm-Nd CONSTRAINTS ON THE ANTWERP-ROSSIE GRANITOIDS AND RELATED IMPLICATIONS, ADIRONDACK LOWLANDS, NORTHERN NEW YORK SEAN REGAN: St. Lawrence University Research Advisor: Jeffrey R. Chiarenzelli

METAMORPHISM IN THE FRONTENAC TERRANE AND ADIRONDACK LOWLANDS, GRENVILLE PROVINCE, CANADA AND THE UNITED STATES ASHLEY RUSSELL: University of North Dakota Research Advisor: Dexter Perkins

GEOCHEMISTRY OF THE EDWARDSVILLE SYENITE IN THE ADIRONDACK LOWLANDS, NEW YORK: IMPLICATIONS FOR TECTONOMAGMATIC PROCESSES IN THE SOUTHERN GRENVILLE PROVINCE ANDREW G. STOCKER: Claremont McKenna College Research Advisor: Jade Star Lackey, Pomona College

CALCITE-GRAPHITE ISOTOPE THERMOMETRY NEAR THE BLACK LAKE SHEAR ZONE, ADIRONDACK LOWLANDS, NY CELINA N. WILL: Mount Holyoke College Research Advisor: Steven R. Dunn

Funding provided by: Keck Geology Consortium Member Institutions and NSF (NSF-REU: 0648782)

Keck Geology Consortium Franklin & Marshall College PO Box 3003, Lancaster Pa, 17603 Keckgeology.org 22nd Annual Keck Symposium: 2009

CALCITE-GRAPHITE ISOTOPE THERMOMETRY NEAR THE BLACK LAKE SHEAR ZONE, ADIRONDACK LOWLANDS, NY

CELINA N. WILL: Mount Holyoke College Research Advisor: Steven R. Dunn

INTRODUCTION around 0‰ and organic material has lower values of between -20‰ and -30‰. During metamorphism, ADIRONDACKS graphite and calcite exchange carbon. Graphite be- 13 comes isotopically heavier (δ C becomes less nega- The Adirondacks are part of the Grenville Province tive) and calcite becomes lighter (more negative). In of the Canadian Shield. The orogenic history of the doing so, the temperature dependent fractionation 13 Grenville Province in the Adirondack Mountains between calcite & graphite (∆cal-gr=δ Ccalcite- 13 from ca. 1200 to ca. 1000 Ma is defined by four δ Cgraphite) is reduced as equilibrium is ap- major events. Following the compressional Elze- proached. Normally, because graphite occurs in virian, the Shawinigan orogeny (1180-1170 Ma) lesser quantities than calcite, the graphite value is was a period of regional anatexis, deformation and shifted a lot and the calcite is shifted very little. migmatite production in both the Lowlands and southern Highlands. At ca. 1150, delamination of The calcite-graphite thermometer is ideal for use the overthickened Shawinigan orogen led to anor- in this study. Calcite with graphite is a common thosite-mangerite-charnockite-granite (AMCG) assemblage and because of the slow diffusion of magmatism throughout the Adirondacks. Rocks carbon in crystalline graphite, retrograde resetting were dehydrated by Shawinigan anatexis, prevent- characteristic of other thermometers is not prob- ing further partial melting in many rocks during the lematic. Empirical calibration was established by following Ottawan granulite metamorphic event (ca. previous work in the Adirondacks. However, to date 1060-1020) (Heumann et al., 2006). there has not been a successful experimental calibra- tion. Fractionations are accurate to ± 0.2 ‰, cor- The Carthage-Colton Mylonite Zone (CCMZ) is a responding to approximately ± 25ºC (Kitchen and major boundary separating the Adirondack High- Valley, 1995 and references therein). lands (part of the Central Granulite Terrane) from the northwestern Lowlands (part of the Central METHODS Metasedimentary Belt) (McLelland et al., 1996). Running parallel to the St. Lawrence River and Twenty samples from 14 locations of calcite approximately 10 km to the southeast, the Black marble with visible flakes of graphite were collected Lake Shear Zone (BLSZ) in the Lowlands may be from an area northwest of Gouverneur, New York. a terrane boundary as the suture zone which sepa- Thin sections were made for petrographic analysis. rates the Adirondack Lowlands and the Frontenac To obtain graphite, chunks of marble were dissolved terrane to the west. The purpose of this study is to in HCl and the residue was rinsed at least 4 times investigate further the significance of the BLSZ by with distilled water. Graphite was handpicked from seeing if there is a thermal gradient associated with the dried residue and loaded with CuO into pre- it through use of calcite-graphite thermometry. fired quartz tubes. Care was taken to avoid picking dull flakes with secondary overgrowths. Evacuated CALCITE-GRAPHITE THERMOMETER tubes were fused closed and combusted at 950˚C

overnight. CO2 from whole-rock calcite was ob- Marine carbonate sediments have δ13C values 60 22nd Annual Keck Symposium: 2009

tained by reacting crushed sample with phosphoric usually >85% of the whole rock, except for CNW-7,

acid at 25˚C. CO2 from both graphite and calcite CNW-8, and CNW-11, which each contain about was cryogenically purified. 45%, 60% and 67% calcite. Quartz, phlogopite, po- tassium feldspar and titanite occur in the majority of Gas samples prepared at Mount Holyoke College samples. Plagioclase and sulfides are less common were analyzed at the University of Massachusetts but are present in several samples. Diopside occurs Department of Geosciences on a Finnigan MAT in at least seven samples and tremolite is found in at Delta XL+ isotope ratio mass spectrometer with a least three. Apatite, scapolite and tourmaline oc- dual inlet system. Some samples were run at the cur as accessory minerals in a handful of analyzed University of Massachusetts using their Costech samples (Tbl. 1). Figure 1 shows a field of view from ECS140 Elemental Analyzer (for graphite) and their CNW-3, CNW-10 and CNW-18. automated gas bench (for calcite) interfaced to a Thermo Delta 5 isotope-ratio mass spectrometer In each sample, graphite flakes are usually present operating under continuous flow conditions using in both dull and lustrous varieties. For all samples, helium as a carrier gas. Duplicates and standards except CNW-7, the percentage of graphite is 2% or indicate that all data are accurate to ± 0.2 ‰ and are less. In CNW-7, nearly half the sample is graphite. reported relative to V-SMOW (for oxygen) and PDB Notably, CNW-8 from the same outcrop has nor- (for carbon). The calibration of Kitchen & Valley mal amounts of graphite but is a sample with lesser (1995) was used to obtain temperature data: amounts of calcite than average.

Δ13C(cal-gr )≈ 3.56 x 106 T-2 (K). ISOTOPIC DATA

RESULTS The δ13C range from -10.4‰ to 5.0‰ in calcite and from -15.2‰ to 1.2‰ in graphite. The Δ(cal-gr) PETROGRAPHY are between 3.2‰ and 4.8‰. For the 6 locations I sampled twice, the difference in fractionations for All analyzed samples are calcite marbles with vis- each pair was 0.30‰ or less at 4 locations (CNW-3 ible graphite. Most are coarse-grained and calcite is & 4, 25 & 26, 30 & 31, 36 & 37). The largest differ-

Table 1. Summary of isotopic data and minerals present in each analyzed sample. Minerals identification from thin section and hand sample, except where * with sample name indicates identification from hand sample only. All samples have calcite and graphite. Cal= calcite, Chl= chlorite, Di= diopside, Kfs= k-feldspar, Olv= olivine, Phl= phlogopite, Plg= plagioclase, Qtz= quartz, S= sulfide, Srp= serpentine, Tour= tourmaline, Tr= tremolite, Ttn= titanite, ?= possible but not confirmed.

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Figure 2. Calcite-graphite fractionations from this study in bold Figure 1. Photomicrographs in PPL on left and XP on right. A. with * fractionations and lighter dashed 675 ºC isotherm from CNW-3 with opaque graphites, plagioclase (Plg) and titanite Kitchen & Valley (1995). Revised 675ºC isotherm from com- (Ttn) with calcite. B. CNW-10 showing opaque graphite, high bined data in dashed bold; TW=Train Wreck. relief diopside (Di) in lower right, microcline (M) in upper left and calcite. C. Quartz on left of large diopside at center from CNW-18, with titanites larger than opaque graphites, all sur- previous data. The third location was sampled twice rounded by calcite. by Kitchen & Valley (1995), with fractionations of 3.5‰ and 4.0‰. My value at this location was ence is for the pair CNW-34 & 35 at 1.1‰. 4.5‰ (CNW-18).

Samples with fractionations above 4.0‰ tend to The majority of my data (15 samples) are located lie in the northernmost 10 km of the sampled area on the western side of Kitchen & Valley’s proposed and those in the south tend to have values of 4.0‰ 675ºC isotherm, which runs SW-NE through the and below. Samples CNW-10 and CNW-35 are northwestern Lowlands and separates a hotter exceptions to this trend. CNW-10 has an extremely western zone of 670 ± 25˚C from a cooler 640 ± high fractionation value (4.8‰) and CNW-10 has 30˚C eastern zone. Five of my samples are from the a low value (3.2‰) when compared to neighboring cooler eastern zone. Roughly half (8 of 15 western samples or those from the same location (Fig. 2). and 3 of 5 eastern) of my samples give tempera- tures in accordance with the temperature ranges DISCUSSION found by Kitchen & Valley (1995). Of the 9 samples with temperatures falling outside of these ranges, 4 Data from this study are generally consistent with samples are cooler and 5 are hotter. previous published work in the same area (Fig. 2). Four of my samples (CNW-9, CNW-18, CNW- Although the northeasterly trending isotherm is 36 and CNW-37) are from 3 locations previously consistent with the structure of the region, my new sampled by Kitchen & Valley (1995). In 2 of those data fills gaps in the southwest, which previously locations, my fractionations are within 0.2‰ of the had only 2 sampled locations. A revised 675ºC

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isotherm is generated using the data from both this study and Kitchen & Valley (1995) and shown in Figure 2 as a bold dashed line. Additional data in the southwestern region of the study area and in between areas heavily sampled by Kitchen & Valley (1995) cause the revised isotherm to curve to the west.

CONCLUSION

Temperatures from this study are generally in agree- ment with those found by Kitchen & Valley (1995). The addition of new data from previously underrep- resented portions of the study area alter the former 675ºC isotherm, which trended northeast across the northwestern Lowlands without deviation. The revised 675ºC isotherm is more complicated but continues to separate a region of hotter temperatures on the west from cooler temperatures on the east.

REFERENCES

Heumann, M.J., Bickford, M.E., Hill, B.M., McLel- land, J.M., Selleck, B.W., and Jercinovic, M.J., 2006, Timing of anatexisin metapelites from the Adirondack lowlands and southern highlands: A manifestation of the Shawinigan orogeny and subsequent anorthosite-man- gerite-charnockite-granite magmatism: Geo- logical Society of America Bulletin, v. 118, p. 1283-1298.

Kitchen, N.E., and Valley, J.W., 1995, Carbon isotope thermometry in marbles of the Adirondack Mountains, New York: Journal of Metamorphic Geology, v. 13, p. 577-594.

McLelland, J., Daly, J.S., and McLelland, J.M., 1996, The Grenville Orogenic Cycle (ca. 1350-1000 Ma): an Adirondack perspective: Tectonophys- ics, v. 265, p. 1-28.

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