Recent Submissions

  • How Farms Make Money

    Parlee, Caroline; Silvern, Steven (2020-05-04)
    One of the challenges confronting Massachusetts is how to feed its population with local resources. It takes a lot of food to feed these people and a lot of this food is coming from out of state. This means that the state's food supply requires fossil fuels for transport and this contributes to the state's carbon footprint and climate change. Numerous studies have recommended that food should be eaten and produced in the same area to increase sustainability and resilience and reduce its environmental impacts. So, the question is how to promote local agriculture? To do this we need to turn to Massachusetts farmers and see what they are actually doing to survive in a global agricultural marketplace. Lots of farmers are struggling to compete with grocery store chains despite their superior product. If these farms fail then the state is left with less local food and communities suffer for it. Here lies the question: what are Massachusetts farmers doing to make money and how can they improve on their existing business practices? In this study we examine the business practices of farmers through statistics, personal stories and interviews to see what is working and what is not in an effort to promote the sustainability and resilience of Massachusetts farmers
  • Kodiak Island, Alaska and the 1989 Exxon Valdez Oil Spill

    Van Hazinga, Cora; Ratner, Keith (2020-05-04)
    Tanker ships have transported Alaskan crude oil through Prince William Sound since 1975. In March of 1989, the Exxon Valdez ran aground on the Bligh Reef, spilling 10.8 million gallons of crude oil into the Prince William Sound (Figure 1). The timing of the spill, remote location, thousands of miles of rugged and wild shoreline, and the abundance of wildlife in the region combined to make it an environmental disaster. Approximately 1,300 miles of Alaskan shoreline was impacted, and effects are still being felt today.
  • Active Learning Pedagogies to Design a New Advanced Genetics Course: Using Students' Feedback to Create a Tailored STEM Class for SSU

    Tarantino, Marina; Brown, Jason; Laranjo, Laura; Laranjo, Laura; Brown, Jason (2020-05-04)
    The STEM field is constantly evolving where graduate schools, medical schools, and the science job market are becoming more competitive. It is important for the students of Salem State University (SSU) that their curriculum is consistently being adapted to fit these new needs. A large percentage of the SSU biology community aims to enter the medical field, biotechnology field, or go on to pursue post graduate education. These are paths that require students to have an advanced level of knowledge pertaining to genetics and this is an area Salem State is starting to fall behind in compared to options offered at various local universities. We currently only offer two introductory genetics courses, this requires students to learn everything they will need to know about genetics for their future careers in one semester. If we were to offer an advance genetics course students would graduate with advance knowledge in this field and have a better chance getting into post graduate schools or landing job opportunities. Using the feedback of students in the SSU science community we have found a way to both fill this new need and satisfy their interest and concerns via a new Advanced Genetics of Disease course.
  • The Influence of Non-Steroidal Anti-Inflammatory Drugs on Quasi-Palindrome Driven Template-Switch Mutagenesis in Escherichia coli

    Smith, Savannah; Laranjo, Laura (2020-05-04)
    Quasi-palindrome regions are characterized by almost perfect inverted repeats of DNA bases which can form secondary structures known as hairpins1. These structures are found in nature and have been found to interfere with important cellular events such as replication and transcription regulation. Harpins are known to block DNA replication. Once DNA replication is blocked by these DNA structures, the DNA replication fork needs to find a solution to continue to replicate the DNA. At some frequency, DNA polymerase (responsible for replicating the DNA) can use alternative DNA strands as template to make more DNA2,5. One alternative method is called “Template-switching” and it results in a mutation that creates a perfect palindrome from a quasi-palindromic sequence3,4. This class of mutation has been associated with multiple human diseases, including osteogenesis imperfecta and cancer. FDA approved non-steroidal anti-inflammatory drugs are commonly used to treat many different types of human ailments6. Although we know different mechanisms of how these drugs work, we have yet to understand how they interfere with DNA polymerase during DNA replication at QP regions. Using a library of 300 FDA-approved drugs, we aim to assess the propensity of QP mutations after exposure of chemicals - known to block or stall DNA polymerase. Using a QP mutation reporter in E. coli, we are screening hundreds of drugs for their ability to promote QP mutations3,4. Elucidating the consequences of these drugs in template-switching QP mutations is essential in providing full understanding of the potential side effects for the current FDA-approved drugs.
  • Detailed Records Of IRD Input From Central North Atlantic Sediment Core VM28-89 During The Last Glacial Cycle (Marine Isotope Stages 4-2)

    Surette, Adam; Cullen, James L. (2020-05-04)
    High resolution records from North Atlantic deep-sea sediment have been instrumental in documenting millennial-scale climate variations during the last glacial cycle (Marine Isotope Stages (MIS) 4 to 1) including variations of Ice-Rafted Detritus (IRD) concentrations related to massive iceberg discharges from glacial continental ice sheets. We have sampled core VM28-89, located within the Ruddiman IRD Belt in the central North Atlantic at 1 cm intervals and produced detailed records of %IRD ((number of lithic grains >150μm / (number of lithic grains >150μm + number of Planktic foraminifers >150μm)) x 100); lithic grains, >150μm per gram of sediment (lithics/gram); planktic foraminifers, >150μm per gram of sediment (forams/gram), and % coarse fraction for the top 1.20 m. The %IRD reveals two relatively long intervals of >90% IRD and very low forams/gram between 42-71 cm and 91-113 cm separated by intervals of very low (10-25%) IRD and higher forams/gram. Lithics/gram exhibits much higher frequency fluctuations during these same intervals reaching upwards of 6,000 lithics/gram in the upper long interval and up to 12,000 lithics/gram in the deeper long interval. Unlike IRD records from farther to the northeast (ODP Site 980 for example), %IRD and lithics/gram show a distinct lack of correlation at higher values. This decoupling is likely due to the effects of significant changes in the input foraminifer shells in the high %IRD intervals. Our records bear a remarkable resemblance to those from a well-dated core to the west, V23-14 (Hemming & Hajdas, 2003), particularly in %IRD. Tentative correlations of our results to the V23-14 chronostratigraphic framework suggests that our two intervals of very high %IRD correspond to Heinrich Events H2 and H4. The two peaks in %IRD in V23-14 identified as Heinrich Events H1 and H3 are more difficult to identify using our IRD results from VM28-89.
  • Anti-Cancer Drugs Effect on Quasi-palindrome Mutations in Escherichia coli

    Perkins, Sydney; Dwyer, Joseph; Patten, Madison; Laranjo, Laura; Laranjo, Laura (2020-05-04)
    Cancer is one of the world's largest health problems in today’s age. The Global Burden of Disease estimates that 10 million people died as a result of cancer per year (IHME). Although there are many treatments for different types of cancer, many of the drugs used are known to have severe side effects. These known consequences include hair loss, nausea, and, unfortunately, an increase in DNA mutation, which can trigger other classes of diseases. One class of mutations that have been studied and linked to a form of cancer is Quasi-palindrome template switch mutations. Quasi-palindromes are nearly perfect inverted repeats of nucleotides able to form DNA secondary structures. These Hairpins are an example of a secondary DNA structure made by DNA repeats and are known to block the DNA replication fork (VOINEAGU et al. 2008). Once DNA replication is blocked by these secondary DNA structures, the DNA replication fork needs to find a solution to continue the replication process. At some frequency, DNA polymerase (responsible for replicating the DNA) can use alternative DNA strands as templates to make more DNA. One alternative method is called “Template-switching”, and it results in a mutation that creates a perfect palindrome from a quasi-palindromic sequence. Previous work has linked anti-cancer drugs such as 5-azacytidine to an increase of QP mutations (Laranjo 2018). Therefore, I am interested in analyzing other anti-cancer drugs and their potential to cause QP mutations. Using an FDA approved drug library, with over 300 different drugs, we will select anti-cancer drugs to screen for QP mutators. We have constructed a QP reporter in E. coli that is specific for QP mutations (Laranjo 2017). To understand the effect of anti-cancer drugs during DNA replication is critical to give us an understanding of potential side effects for patients undergoing chemotherapy.
  • A Study In Contrasts

    Kysilovsky, Cassandra; Sprenkle, Amy B. (2020-05-04)
    Genome annotation work of an Actinobacteriophage presented at the 2019 SEA-PHAGES symposium. GenBank Accession Numbers awarded late in 2019 have been included after peer review of the annotation.
  • Nasa L'space Mission Concept Academy

    Lorenzo, Anaily; Crow, Kathi (2020-05-04)
    NASA L'Space Mission Concept Academy is a virtual academy in which we had to complete a 12-week team mission concept. Our mission objective was to design a small mission concept that characterized the polar water ice on Earth's moon. Our mission had to fit within the mission concept constraints (mass, volume, and budget). Our spacecraft design and scientific payload had to reflect what can be afforded within these constraints. To complete this mission concept, our team relied heavily on math, engineering, geology, and chemistry.
  • The Future Of Geography In The Massachusetts Curriculum Framework

    Mazares-Monga, Michelle C.; Silvern, Steven; Silvern, Steven (2020-05-04)
    The National Assessment of Education Progress evaluated eighth grade students on their geographic literacy in 2014 and in 2018, and found a decrease in average scores. One reason is that Geography has historically not been taught as a separate subject in most K-12 public schools. Certain states are updating their frameworks to be more inclusive of a diverse array of subjects. In Massachusetts, Geography is addressed under the History and Social Science Frameworks. Unfortunately, the teaching of Geography is given short shrift under these frameworks. The overarching goal of this project is to assess the status of Geographical education in the Massachusetts K-12 system. This study examines the degree to which Geography is being taught in public school districts across the Commonwealth of Massachusetts and offers an assessment of where and how it is being taught; exploring what training state geography educators receive, and what professional development is needed to help support their endeavors. Additionally, why has geographical education lagged in this “liberal” state? Why have efforts to expand geographical education not been successful to date? Therefore, this project studies efforts to expand the requirements for the teaching of Geography in the state’s social studies frameworks; identifying efforts by geographical education advocates (Massachusetts Geographical Alliance, National Geographic, AAG, and Mass. State University Geography Professors) to lobby state political representatives and state public education administrators to pass legislation expanding and mandating geographical education across the state. Finally, this research will determine if geographic literacy among Massachusetts K-12 public school students will significantly increase.
  • Tiny Earth @ SSU 2020

    Angelli, Madison; Cervone, Frankie; Ludwig, Sawyer; Sprenkle, Amy B.; Sprenkle, Amy B.; Sprenkle, Amy B. (2020-05-04)
    Tiny Earth, Studentsourcing Antibiotic Discovery is an undergraduate research experience for students in the Biology department taking BIO 304, Microbiology & Its Applications. This is the result of work in the program during AY19/20.
  • Application Of XRF To The Correlation Of Colonial Bricks To A Local Clay Deposit In Southwestern New Hampshire

    Doyle, Emily; Allen, Douglas; Hanson, Lindley; Hanson, Lindley (2020-05-04)
    Handmade, colonial bricks are eroding from a stream bank along the Cold River, South Acworth, NH. Bricks were regularly made close to local sources. There are two potential sources: glacial lake clays from the Cold River Valley and glacial lake clays further downstream in the Connecticut River Valley. The predicted source is a varved clay deposit 100m upstream. A sample of this clay deposit was collected along with two bricks for trace element analysis using XRF spectroscopy. Determination of the mineralogy was attempted using a petrographic microscope. However, minerals in the clay-fired matrix were too fine-grained to be identified. Observed components in the brick include lithic clasts that are likely pebbles or sand grains. Literature suggests that quartz, feldspar, and mica should be contained in the matrix. XRF spectroscopy analysis indicates the majority of heavy metals increased from the clay to the brick. Elemental ratios between these metals, such as zirconium and titanium, are the same in the clay and bricks. Firing conditions should result in total dehydration and decarbonation of the clay, increasing elemental concentrations in the bricks. Therefore, dehydration and decarbonation reactions can be used to estimate the mass concentration increases expected during firing. Typical dehydration and decarbonation reactions should result in an 11%-28% increase in elemental concentrations in bricks. However, not all elemental concentrations measured in the Cold River bricks fell into this predicted range. This can be explained through heterogeneity in the source clay, which would be expected if from a varved clay or till, or if the source is one of the other deposits along the Cold River. To help answer this question, the Cold River clay was sampled and tested using XRF spectroscopy again. Clay from another popular brick source, Glacial Lake Hitchcock, was also tested and analyzed for elemental ratios. Results indicated that the Pleistocene varved clay along the Cold River is the source material, as most elemental ratios between the brick and Glacial Lake Hitchcock did not match.
  • Records Of The Late Glacial Influx Of Ice-Rafted Detritus On The Orphan Knoll, Northwest Atlantic Ocean

    Guglielmi, Alisha L.; Cullen, James L.; Lott, Annette; McManus, Jerry; Cullen, James L. (2020-05-04)
    The top 110 centimeters of IRD records for GVY002 reveal 5 distinct peaks in IRD input, each between 4000-6500 lithics/gram. Three of these peaks coincide with three peaks in the Ca/Sr ratios in the upper meter indicative of dolomite rich IRD from the Canadian margin. The IRD record and Ca/Sr ratio record generated in this study, when compared to the previously generated similar records in GVY001, reveals a similar pattern but over a much longer downcore sediment interval (over the upper 4.5 meters in GVY001 versus the upper 1.8 meters in GVY002). This is due to the higher sedimentation rate in GVY001. Hendry, et al. (2019) tentatively correlated the shallowest peaks in Ca/Sr ratios with Heinrich Events H0 - H4 by correlating the Ca/Sr ratio records in GVY001 to the δ18O record of N. pachyderma (s.). An IRD peak in GVY001 corresponds to each of the Heinrich Events identified in Hendry, et al. (2019). Subsequent comparison of GVY002 IRD records with those of GVY001 suggest that Heinrich Events H0, H1, and H2 can be identified over the first meter. Both GVY002 and GVY001 display two additional IRD peaks of at least 4000 lithics/gram between H1 and H2 during intervals of very low Ca/Sr ratios.
  • Survey of European Green Crabs and Asian Shore Crabs in Salem Sound

    Morey, Connor P.; Mulligan, Chris J.; Young, Alan M.; Young, Alan M.; Young, Alan M. (2020-05-04)
    The European green crab (Carcinus maenas) has been the dominant crab species in New England rocky intertidal zones since the late 1800’s, but since around 2000 they have begun to be outcompeted by a new invasive species, the Asian shore crab (Hemigrapsus sanguineus). Rocky intertidal zones at Chandler Hovey Park in Marblehead, MA and Pavilion Beach in Ipswich, MA were surveyed for both species monthly at low tide from June 2019 through March 2020. Asian shore crabs made up 94% of all crabs surveyed compared to European green crabs (6%). Also, at both sites, the average carapace width of European green crabs was found to be larger than that of the Asian shore crabs collected. From this survey, it appears that Asian shore crabs are outcompeting European green crabs at these locations.
  • Using the Extrusive Volcanic Features of Mt. Marsabit, Kenya to Identify Regional Tectonic Stress

    Van Hazinga, Cora; Muirhead, James; Mana, Sara; Mana, Sara (2020-05-04)
    Extrusive volcanic features like vents, craters, and cones can produce alignments and other linear structures that indicate the orientations of feeder dikes and regional tectonic stresses. These dikes form parallel to the maximum compressional stress (σ1) and perpendicular to minimum compressive stress (σ3), and/or exploit preexisting planes of weakness. Volcanic constructs fed by these magmatic intrusions are therefore indicators of tectonic stress directions and subsurface structural fabrics, which can be deduced through detailed mapping and assessment of the spacing, shapes, and linear arrays of these volcanic features. Mt Marsabit (2.32°N, 37.97°E) is a massive 6,300 km2 off-axis volcano located in Northern Kenya on the eastern shoulder of the Kenyan Rift, 170 km east from the center of the East African Rift System (EARS). Initial construction began in the Miocene, with the peak of volcanic activity occurring in the Pliocene. A multitude of maar craters, scoria cones, and tuff cones developed in the Quaternary, primarily along the northern and eastern slopes. These extrusive volcanic features were mapped in the late eighties but have not been revisited using modern technology. Here we present findings from our analyses of the morphologies and alignments of 242 of extrusive volcanic features found on Marsabit. We then interpret the subsurface feeder system to off-axis volcanism in this sector of the EARS. Methodologies modified from Paulsen and Wilson (2010) and Muirhead et al. (2015) are used to map volcanic craters and cones using Google Earth. The orientations, shapes, and positions of volcanic features observed over the 8,000 km2 region indicate the presence of NE-SW orientated feeder dikes, which trend oblique to the general N-S trends observed in nearby sectors of the EARS such as faults found immediately south of Lake Turkana and the Elgeyo escarpment of the Kenyan rift. The strong NE-SW orientation of volcanic lineaments on Marsabit suggests that either a local NW-SE extension direction or a NE-SW orientated crustal fabric controls the geometry of the underlying plumbing system to this off-axis volcano. From this data we have created a series of rose diagrams to indicate the possible angles and locations of subsurface dikes, illustrating the regional tectonic stress field in Marsabit. We then compare these rose diagrams to other features found in the EARS.
  • Investigation Of The Volcanics Rocks On Marblehead Neck Through Petrographic, Geochemical, And Field Analyses

    Wright, Rebecca; Hanson, Lindley; Toraman, Erkan; Hanson, Lindley (2020-05-04)
    Marblehead Neck is a rocky island within the Dedham-Milford zone in northeastern Massachusetts and is separated by the younger Late Silurian Salem Gabbro-Diorite on the adjacent mainland of Marblehead by a fault of unknown motion. Although shown on the 1983 bedrock map of MA, to be underlain by the Late Proterozoic Dedham Granodiorite and Lynn Volcanics, attempts to date and definitively correlate these rocks have been unsuccessful. This study focuses on confirming the identity of the volcanics and correlating to local lithologies(Middlesex Fells Complex, Lynn-Mattapan Volcanic Complex, Newbury Volcanics, and extrusives of the Cape Ann Granite) through field mapping, petrographic analysis, and a review of previous geochemical analyses. During field mapping, eight lithologies were identified; metasedimentary rocks, granodiorite, alkali “pink” granite, subvolcanic dacite, pyroclastic volcanics (lapilli tuffs, ignimbrites, flow-banded vitrophyres, and red vitrophyres), lahars, epiclastic carapace, and diabase and basalt intrusions. Contact relations of the lithologies are asfollows: inclusion of metasedimentary rocks within granodiorite; diffusive contact of alkali “pink” granite and granodiorite; granodiorite as an intrusive contact with the dacite (chill margin); inclusions of the lapilli tuff of the pyroclastic volcanic rocks contained within the granodiorite; and epiclastic overlaying the ignimbrites. All the lithologies are transected by NW-SE diabase and basalt dikes. Evidence for a tilting event is preserved in steeply dipping fiamme within the ignimbrites. The granodiorite is interpreted as the Dedham Granite based on modalcomposition, character, and inclusion of the metasedimentary rocks (now interpreted as Westboro Formation). Based on expected relationships between the Dedham the older Middlesex Fells and younger Lynn Volcanics more investigation is warranted for the subvolcanic dacite rocks. The pink alkali granite intrudes the granodiorite and a cold contact is visible further inland. Petrographic analysis reveals Westboro Quartzite clasts within the epiclastic rocks, supporting an Edicarian age. The contact between the Dedham and the volcanics excludes boththe Newbury Volcanics and the Cape Ann Plutonic Complex from consideration of the volcanics relation. Considering Thompson et al. (2007) determined Ediacaran age of 595.8 ± 1.2 Ma for the Lynn Volcanics, an unconformity of approximately 10 Ma excludes the Lynn from being related to the Dedham Granite. Therefore, the volcanics present on Marblehead Neck must belong to Middlesex Fells. This relationship is shown to be inconsistent with field relationships observed at Marblehead Neck and field relations in general north of Boston. Geochemical data of the flow-banded vitrophyres found at Marblehead Neck Lighthouse are similar to a flow-banded rhyolite from the Mattapan Volcanic Complex collected in Milton, MA. Marblehead Neck could be considered a fault block offset of the Melrose subblock (Goldsmith, 1999), or the Marblehead Harbor Fault could be a steeply dipping reverse fault that brought Ediacaran basement rocks to juxtapose against Silurian Salem Gabbro Diorite. The steeply dipping fiamme in the ignimbrites suggest a titling event of the entire section. The lithologies present on Marblehead Neck may offer further insight where exposures around Boston have not. Perhaps the Lynn Volcanics have multiple magmatic events that span a longer time frame then previously suggested. Further study and geochronology efforts of the subvolcanic and volcanic rocks and their relation to the Dedham Granite is essential to fully understand the geologic history of New England.
  • The Effect of Plyometric Training on Collegiate Dancer's Jumping Abilities

    Kelsen, Victoria; D'Amico, Anthony (2020-05-04)
    Introduction: The purpose of this study was to examine whether Plyometric training effects dancers’ vertical jump heights and broad jumps, compared to standard jump training activities normally done by dancers. Methods: The six-week study included 14 collegiate leveled dancers, 9 of them (21.3±2.6 years old) completed the plyometric training program while 5 of them (21.5±2.2 years old) completed the dance training program. Each group met twice a week and participated in pretesting and post-testing. Three tests were used to assess the effects of training and included the squat jump, countermovement jump, and broad jump. The first three weeks of training were a series of beginner jumps (80 touches per session) and then the last three weeks progressed to intermediate leveled jumps (100 touches per session). Data was assessed for normality with the Kolmogorov-Smirnov Test, and normally distributed data was assessed using the two-tailed T-test. Non-normally distributed data was assessed with a Mann-Whitney U test and the alpha level used was .05. Results: Improvements in the squat jump were significantly higher in the plyometric group (2.3 inches ± 2.2) compared to the dance group (0.8 inches ± 1.7) (p<.05). Improvements in the broad jump were significantly higher in the plyometric group (10.1inches ± 7.2) compared to the dance group (1.8 inches ± 3.8) (p <.05). No significant differences between groups were found in the countermovement jump (p>.05). Discussion: According to the findings plyometric training increased dancer's jump heights in both the squat jump and broad jump. This suggests that dancers could incorporate a plyometric training program to improve their jumping ability.
  • The Influence of Light Therapy on Recovery from Exercise-Induced Muscle Damage

    Smith, Brian; D'Amico, Anthony (2020-05-04)
    Introduction: Engaging in physical activity and exercise can result in muscle damage and soreness. When muscles lengthen under tension during eccentric contraction, which can happen during daily physical activities, it can cause exercise-induced muscle damage (EIMD). When you repeat those movements at a high intensity, intracellular muscle damage can occur leading to a 24 to 48-hour delay in the onset of muscle soreness (DOMS) (Choi, 2014). There have been products invented to enhance the recovery of DOMS created by EIMD. Light therapy (LT), in this case, is a non-invasive clinical technique commonly used to treat muscular injuries. The purpose of this study is to examine the effectiveness of LT on EIMD compared to a placebo group (PL) during an eight-day trial. Methods: Participants were divided into two groups (LT & PL) not knowing which group they were in (single-blind experiment) and were tested on their range of motion (ROM) on their hip flexion and abduction, their perception of muscle soreness (GLMS scale), vertical jump, and agility (T-test). To induce muscle damage, participants ran 40 15-meter sprints with a 5-meter deceleration zone, thereafter, commenced the LT treatment on the fourth day on. LT was applied to the quadriceps, hamstring and calf muscles on both legs. We hypothesized LT following EIMD would neither influence perceptions of muscle soreness, flexibility, vertical jumping ability, nor agility, compared to a placebo treatment group. Discussion/Conclusion: A significant difference (p < .05) was found between the two groups in the measurement of calf soreness. The LT group reported lower calf soreness level throughout the week. No other significant differences were found between groups. This data lends itself to the theory that light therapy is more beneficial for treating soreness in Type I muscle fibers.
  • The Neural Encoding of Arabic Root Patterns : A Behavioral Pilot Study

    Nagle, Lindsay; Gow, David (2020-05-04)
    Words in Semitic languages, like Arabic and Hebrew, are created by combining roots and word patterns. In some cases, a word may be composed of a root that repeats a consonant. This consonant repetition is a part of a process called reduplication. Reduplication results in Semitic languages having a morphological root structure, in which some words have a root that repeats the second consonant. The behavioral pilot study I am doing is interested in this reduplication pattern, and if Arabic speakers generalize the root patterns onto words they know, and ones they do not. In a study done by Berent (2002), she had found Hebrew speakers rejected nonwords with unattested repetition patterns, or nonwords with roots that repeated the first consonant, at a faster rate than they rejected nonwords with an attested repetition pattern, or nonwords that had roots that repeated the second consonant. After replicating her experiment with Arabic speakers in a pilot study, we plan to test Arabic speakers in a scanner to assess the representation of reduplication patterns in the brain. Through neural decoding and effective connectivity analyses of brain imaging data, we hope to determine if reduplication is a rule-driven process (grammar) or an associative process involved in mapping speech to stored wordform representations.
  • Testing for Magmatic CO2 Degassing Above the North Appalachian Anomaly

    Gaffney, Arianna; Mana, Sara; Muirhead, James; Fischer, Tobias; Mana, Sara (2020-05-04)
    The Northern Appalachian Anomaly is a thermal anomaly inferred from shear wave velocities beneath New England and interpreted as a mantle plume. Possible evidence of magmatism is investigated here by analyzing soil CO2 flux emissions in areas surrounding regional springs in New York, Massachusetts, New Hampshire and Vermont. To test the presence of magmatism at depth, we measured the flux of diffusely degassing soil CO2 using an EGM-5 portable CO2 gas analyzer. We hypothesize that magmatic CO2, if present, will produce a CO2 degassing signature distinguishable from a shallow biogenic CO2 source. Samples were taken in areas with springs because the water traveling from within the Earth’s crust, and sometimes deeper, exploits the easiest pathway to reach the surface. We expect that CO2 would exploit similar paths. Data obtained thus far are unable to confidently confirm a second-high flux population that would support a possible magmatic component. The CO2 fluxes in this area are quite high (mean CO2 flux of 26 g m-2 d-1), and similar to magmatic fluxes observed in regions of moderate magmatic CO2 degassing (e.g., Natron Basin, Tanzania), which makes it hard for the two possible components to be distinguished. To address the question of whether our method is truly capable of distinguishing low concentrations of two distinct components, we generate a number of synthetic datasets representing biogenic and magmatic CO2 flux components based on data obtained in this study and compare it to data from regions of magmatic CO2 elsewhere (Natron Basin, Tanzania, and Mammoth Mountain, USA) to investigate the potential range of magmatic fluxes that could be discriminated from these high background values. The two magmatic components selected have different signatures: data from Lake Natron display moderate fluxes, mean CO2 flux of 30 g m-2 d-1 (Muirhead et al., 2019) and are treated here as a weak magmatic component; while the CO2 fluxes from Mammoth Mountain are considerably higher, mean CO2 flux of 1,991 g m-2 d-1 (Cardellini et al., 2003) and are treated as an example of a strong magmatic component. The relative proportions of the biogenic and magmatic populations modelled are 50:50, 60:40, 70:30, 80:20, 90:10, and 95:5. These data show that when investigating areas of high biogenic CO2 fluxes, if the magmatic signal is strong, or weak, the magmatic CO2 flux population is discernible even if such a population represents a small proportion of the overall dataset (e.g., 5%). Ultimately, isotopic analyses must be conducted to confidently distinguish between magmatic and biogenic CO2 signatures.
  • Modal, Textural Analysis and Geochemical Signature of Intrusive Igneous Rocks in a Mingling Environment at Salem Willows, MA

    Mato, Klementina; Mana, Sara; Mana, Sara (2020-05-04)
    This study focuses on the variation of mode, texture and geochemical signature of heterogeneous igneous intrusive rocks found at the contact between felsic and mafic melts intruded within the West Avalon terrane at Salem Willows, Massachusetts. Here, the mafic unit is generally interpreted as the Salem Gabbro-Diorite (~424 Ma) while the felsic unit is commonly assigned to the Beverly Syenite (~425 Ma). A felsic sample and two mafic samples were selected to represent extreme examples of the various composition and texture observed along the outcrop. The samples were analyzed with a petrographic microscope and for whole rock geochemistry. Grain size distributions were determined as averages of the long and short axis of randomly selected grains. The modes were used to assign rock names based on the QAPF igneous classification. Additionally, we conducted radiogenic isotope (Pb-Nd-Sr-Hf), major and trace element analyses on the same set of samples. The mode, texture and geochemical signature in the rocks analyzed show changes at a centimeter scale. Sample 19-WL-1f, classified as a porphyritic tonalite, contains elongated plagioclase phenocrysts dispersed in a matrix of hornblende, biotite and minor amounts of quartz and pyroxene. The euhedral plagioclase phenocrysts exhibit a variety of disequilibrium textures which include a combination of complex zoning patterns and resorption. Sample 19-WL-2c collected only a few centimeters away, is quite different. This rock has been classified as a pyroxene-hornblende gabbro composed of plagioclase, amphibole, biotite, clinopyroxene and minor amounts of olivine. This sample exhibits a poikilitic phaneritic texture with abundant anhedral grains. Sample 19-WL-2b is enriched in alkali feldspar and plagioclase with minor amounts of quartz, biotite and amphibole. This is a syenite with an equigranular granoblastic texture. The boundary between the mafic and felsic unit shows interfingering and lobate contacts where the felsic unit is present all-around mafic enclaves. These relationships suggest the formation of these rocks is best explained by a process of magma mingling presumably occurring due to synchronous emplacement of felsic and mafic magmas, which is consistent with their similarity in age of these magmatic suites.