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TTU Clay Science Group

Linking Mineral Science to Geological Processes 
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Clay minerals are encountered in a variety of geological materials and, as such, represent an important line of research. Due to the environment in which they appear, that is constantly crisscrossed by man’s activity, clays are studied from different aspects of human endeavor (e.g. oil and petroleum research, environmental studies, radioactive waste storage). Clay minerals are normally present whenever water and rock meet. They are common products of weathering, and may hold a key role in the diagenetic evolution which takes place in sedimentary basins during sediment burial. Clay mineral presence in hydrocarbon reservoirs largely affects the efficiency of petroleum production, and they are important in hydrothermal and weathering ore-forming processes in particular of strategic trace elements. Our research is, therefore, focused on different geological environments, starting with the deep sedimentary basins through weathering profiles where we investigate the structure, crystalochemistry, and reaction mechanisms leading to the formation of clay minerals and related mineralizations. 

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Sedimentary basins

Clays generated by surface weathering and shallow diagenetic processes are transformed into mature clay mineral assemblages found in deep-seated sedimentary strata. In subduction zones the clay minerals breakdown releasing a hydrous component which facilitates magma generation. Once formed igneous rocks get weathered and recycled giving rise to the new clay minerals. This represents the magma-to-mud pathway of the clay cycle. Diagenetic reactions in sedimentary basins aim for higher thermodynamic stability. Since the 1970s, clay minerals have been widely studied for diagenesis and quality prediction of conventional reservoirs. Modern analytical tools enable a precise quantitative and qualitative characterization of nano-pore and mineralogy of fine grained shale creating a new era of studying clay minerals for facilitating unconventional reservoir exploration. We are presently investigating Paleozoic mudrocks from Mid-Continent Anadarko and Permian basins to find physico-chemical clues that outline the mechanisms of clay mineral evolution in deep-buried shaley strata.  

Photo by B. Šegvić (Bituminous Woodford Shale, Arbuckle Mts., Oklahoma, U.S.A.)


Weathering and trace-element mineralization

Trace elements and particularly rare earths (REE) became vital to modern technologies and lifestyles because of their ubiquitous applications that concern many aspects of life of 21st-century industrialized nations. While major REE deposits are hosted in the weathered granitic crust in our research we set focus on volcanic ash. We are working on a novel approach based on in-situ geochemical micro-analyses of glass shards and their immediate clay alteration products. Trace elements in clays are normally adsorbed onto clay minerals at broken edge sites or negatively charged siloxane surfaces. Our research looks into REE geochemical behavior and deportment through the prism of local geology (Eh, pH), water-rock interaction, trace element complexation, and clay particle morphology. The knowledge on the distribution of high-tech metals such as REE in clays developed on rare earth bearing igneous substrate may ultimately help in identifying promising areas for the future REE exploration.  

Figure from Badurina and Šegvić (2022) showing smectite neoformation on a glassy substrate. Field of view 5 μm

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Interdisciplinary research in geoarchaeology

Clay minerals were utilized in the production of archaeological pottery since the dawn of civilization. Pottery is one of the most important lines of material evidence for the archaeological enquiry of ancient societies. Once produced, ceramics are indestructible and often found in great quantities at archaeological sites. Ceramics record past cultural interaction, ranging from everyday activities such as food preparation and consumption to more sacred rituals such as religious worship and funerals. We are currently collaborating on two international projects dealing with the Prehistoric pottery production in Western Alps as well as the Hellenistic material culture of Eastern Adriatic

Figure from Carloni et al. (2021) displaying mineralogical maps of Prehistoric potshers from the Upper Rhône Valley, Switzerland

The Team

Our Team


Assistant Professor

Branimir Šegvić

M.S. University of Zagreb

Ph.D. University of Heidelberg




Ph.D. Candidate 

Giovanni Zanoni

B.S. & M.S. University of Geneva


Giovanni's Ph.D. project is focused on diagenesis of the Anadarko Basin shale (Oklahoma, U.S.A.). Using state-of-the-art techniques he aims to unveil clay mineral origin and phase transitions that had taken place in the middle Paleozoic strata during the burial of the basin. His research will ultimately help to constrain basin's thermal structure and characteristics of unconventional Anadarko reservoirs.    


Ph.D. Candidate

Hunter Green

B.S. Wayland Baptist University

M.S. Fort Hays State University


Hunter's doctoral project has a focus on the late Paleozoic shale of the Permian basin of Texas. He is studying organo-clay composites in mudrocks and their influence on clay diagenesis and thermal maturation.

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Ph.D. Student and Teaching Assistant

Emily E. Doyle

B.S. Salem State University

M.S. Texas Tech University


Emily works on an interdisciplinary project which seeks to outstands cultural traditions and interactions of pottery producing prehistoric societies dwelling in an insular context of Eastern Adriatic.


M.S. Student and Teaching Assistant

Evans Akuoko Ansah

B.S. Kwame Nkrumah University of Science and Technology


Evans works on Paleozoic clastic series affected by a large-scale siderite cementation trying to assess its impact on basin burial diagenesis. 

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M.S. Student and Teaching Assistant

Kevin Byerly

B.S. Texas Tech University


Kevin project seeks to provide answers on why multiple generations of chlorite formed in hydrothermally altered oceanic rocks feature contrasting trace-element budgets. 

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Undergraduate Researcher

Sumedh Dantale

B.S. Texas Tech University (3rd year)


Sumedh's undergraduate project looks into the texture, geochemistry and high-temperature mineralogy of late Phoenician pottery in order to reconstruct its dispersal patterns and far-flung trade routes with the West. Sumedh's research is supported by the TTU Center for transformative undergraduate experiences and was presented at the GSA2021 conference in Portland, OR.

Our Alumni


Former Undergraduate Researcher ​

Moustapha Diaby

Moustapha investigated clay mineral parageneses of the Quaternary Black Water Draw Formation of West Texas in order to assess their susceptibility to climatic changes since the last glacial period in North America. Moustapha received a recognition for the best student poster at the TTU Geoscience Research Day 2018.   


Former M.S. Student ​

Jordan Coe

Graduated in December 2019 

Jordan's master project focused on the diagenesis of the Pennsylvanian clastic reservoirs of the Anadarko Basin

in Oklahoma, USA. PDF of the thesis is avaliable here.   


Former M.S. Student

Colton Mallett

Graduated in April 2021

Colton studied paleosol profiles within the Black Water Draw Formation of Southern High Planes of Texas. The aim of the project was to investigate clay mineralogy and geochemistry of the Formation in order to add to the discussion on the Quaternary climate evolution across the Mid-Continent. PDF of the thesis is available here.  

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Former M.S. Student  

Owen Smith

Graduated in May 2022

Owen's research aimed to understand the origin and formation mechanisms of siderite cementation and concretions in Late Paleozoic siliciclastic rocks of the Anadarko Basin, OK. PDF of the thesis is available here. Owen received Texas Tech University Outstanding Thesis Award for 2022 in the category of Mathematics, Physical Sciences, and Engineering (link).


Former M.S. Student


Emily E. Doyle

Graduated in June 2022

Emily's project focused on the ceramic material culture of the Iron Age and Hellenistic communities of Eastern Adriatic. She investigated plausible raw materials readily available at the island of Hvar which were used in the ceramic pottery production by the both communities. PDF of the thesis is available here 


Former Ph.D. Student 

Luka Badurina

Graduated in May 2023

Luka's project dealt with alteration products of Neogene tuffs dispersed within the Dinaride Lake System in SE Europe. He was studying the REE behavior during tuff alteration paying particular attention to organic and inorganic controls on tuff eogenesis. PDF of the dissertation is available here. 


Selected Journal Papers

Segvic, B; Lukács, R; Mandic, O; Strauss, P; Badurina, L; Gullong, M; Harzhauser, M ‘St. Georgen halloysite tuff U-Pb zircon age, provenance, and paleoenvironmental implication for middle Miocene evolution of the southern Vienna Basin, Austria’ // Journal of the Geological Society London (2023), DOI: 10.1144/jgs2022-106


Yang, Y; Liu, Y; Segvic, B; Zhou, D; You, J; Meng, Z; Zhao, M ‘Origin, transport, and diagenesis of tuff interbeds in organic-rich lacustrine mudstone: An example from the lower part of the Middle–Late Triassic Chang7 Member, Ordos Basin (NW China)’// Applied Clay Science (2023), DOI: 10.1016/j.clay.2022.106790


Segvic, B; Slovenec, D; Badurina, LMajor and rare earth element mineral chemistry of low-grade assemblages inform dynamics of hydrothermal ocean-floor metamorphism in the Dinaridic Neotethys’// Geological Magazine (2022), DOI: 10.1017/S0016756822001030


Zanoni, G; Segvic, B; Sweet, D ‘Clay mineral diagenesis in alternating mudstone-sandstone beds from Late Paleozoic strata of the Anadarko Basin, USA’// Geological Journal (2022), DOI: 10.1002/gj.4582


Badurina, L; Segvic, B ‘Assessing trace-element mobility during alteration of rhyolite tephra from the Dinaride
Lake System using glass and clay separate LA-ICP-MS geochemistry
’// Clay Minerals - Journal of Fine Particle Science (2022
), DOI: 10.1180/clm.2022.12

Schmidt, E; Zanoni, G; Bumguardner, A; Segvic, B; Lewis, K; Abdala, D; Siebecker, M ‘Soil chemical extractions can alter potassium coordination in agricultural soils: A combined wet chemical and X-ray absorption spectroscopic approach’// Geoderma (2022), 422, DOI: 10.1016/j.geoderma.2022.115914 

Carloni, D; Segvic, B; Sartori, M; Zanoni, G; Besse, M ‘Who was buried at the Petit-Chasseur site? The contribution of archaeometric analyses of Final Neolithic and Bell Beaker domestic pottery to the understanding of the megalith-erecting society of the Upper Rhône Valley (Switzerland, 3300-2200 BC)’// Open Archaeology (2022), 8, 1064–1111, DOI: 10.1515/opar-2022-0262


Kolawolea, O; Millikan, C; Ispas, I; Schwartz, B; Kumar, M; Weber, J; Badurina L; Segvic, BInsight into the Impact of Microbial-Rock-CO2 Interactions on Containment and Storage Security of Supercritical CO2 in Carbonates’// International Journal of Greenhouse Gas Control (2022), 120, 103755, DOI:  10.1016/j.ijggc.2022.103755


Segvic, B; Zanoni, G; Bozkaya, Ö; Barnes, M; Sweet, D; Boulesteix, T; Solé, J ‘K-Ar geochronology and trace-element geochemistry of 2M1 illite from late Paleozoic shale of SW Laurentia – insights into sediment origin and drainage pathways in the Anadarko Basin, USA’// Palaeogeography, Palaeoclimatology, Palaeoecology (2021), DOI: 10.1016/j.palaeo.2021.110486

Leila, M; Lévy, D; Battani, A; Piccardi, L; Segvic, B; Badurina, L; Pasquet, G; Combaudon, V; Moretti, I ‘Origin of continuous hydrogen flux in gas manifestations at the Larderello geothermal field, central Italy’// Chemical Geology (2021), DOI: 10.1016/j.chemgeo.2021.120564


Badurina, L; Segvic, B; Mandic, O; Slovenec, Da ‘Miocene Tuffs from the Dinarides as Proxies of the Pannonian Basin Lithosphere Dynamics and Tropospheric Circulation Patterns in Central Europe’// Journal of the Geological Society (2021), DOI: 10.1144/jgs2020-262


Arbiol González, C; Layne, DL; Zanoni, G; Segvic, BGenesis and significance of phyllosilicate hydrothermal assemblages from Neo-Proterozoic epithermal Au-Ag deposits and prospects of the Avalon Zone of Newfoundland, Canada’// Applied Clay Sciences (2021), DOI: 10.1016/j.clay.2020.105960 

Carloni, D; Segvic, B; Sartori, M; Zanoni, G; Moscariello, A; Besse, M ‘Material characterization of the 3rd millennium BC pottery: insights in the megalith-erecting society of the Upper Rhône Valley (the Petit Chasseur necropolis, Switzerland)’ // Geoarchaeology (2021), 1-36, DOI: 10.1002/gea.21867


Segvic, B; Zanoni, G; Moscariello, A ‘On the Origins of Eogenetic Chlorite in Verdine Facies Sedimentary Rocks’// Marine and Petroleum Geology (2020), DOI: 10.1016/j.marpetgeo.2019.104064 

Badurina, L; Segvic, B; Mandic, O; Zanoni, GSmectitization as a trigger of bacterially mediated Mn-Fe micronodule generation in felsic glass (Livno-Tomislavgrad Paleolake, Bosnia and Herzegovina)’// Minerals (2020), 10(10), 899, DOI: 10.3390/min10100899 


Green, H; Segvic, B; Zanoni, G; Omodeo Salé, S; Adatte, T ‘Evaluation of shale source rocks and clay mineral diagenesis in the Permian Basin, USA: Inferences on basin thermal maturity and source rock potential’// Geosciences (2020), 10(10), 381, DOI: 10.3390/geosciences10100381 

Khadka, SD; Jayawickrama, PW; Senadheera, S; Segvic, BStabilization of highly expansive soils containing sulfate using metakaolin and fly ash based geopolymer modified with lime and gypsum’// Transportation Geotechnics (2020), DOI: 10.1016/j.trgeo.2020.100327

Pevehouse, KJ; Sweet, DE, Segvic, B; Barnes MA; Marshak, S; Manson, C; Zanoni, GTopography Controlled Weathering Intensity of Cambrian Paleosols, ST. Francois Mountains, SE Missouri, U.S.A.’// Journal of Sedimentary Research (2020), 90 (6): 629–650, DOI: 10.2110/jsr.2020.33

Tarokh, A; Kim, K; Zhu, X; Makhnenko, RY; Popovics, JS; Segvic, B; Sweet, DE ‘Influence of CO2 injection on the poromechanical response of Berea sandstone’// International Journal of Greenhouse Gas Control (2020), DOI: 10.1016/j.ijggc.2020.102959  

Monson, CC; Sweet, DE; Segvic, B; Zanoni, G; Balling, K; Wittmer, JM; Ganis, GR ‘The Late Ordovician (Sandbian) Glasford Structure: A marine-target impact crater connected to the ‘Ordovician meteor event‘// Meteoritics and Planetary Science (2019), DOI: 10.1111/maps.13401  


Slovenec, Da; Segvic, B; Halamic, J; Gorican, S; Zanoni, GAn ensialic volcanic arc along the northwestern edge of Paleotethys? – insights from the Mid-Triassic volcano-sedimentary succession of Ivanščica Mt. (northwestern Croatia)’// Geological Journal (2019), DOI: 10.1002/gj.3664

Leila, M; Moscariello, A; Segvic, BDepositional facies controls on the diagenesis and reservoir quality of the Messinian Qawasim and Abu Madi formations, onshore Nile Delta, Egypt’// Geological Journal (2019), 54(3), 1797-1813, DOI: 10.1002/gj.3269 

Segvic, B; Slovenec, Da; Altherr, R; Babajic, E; Ferrerio Mählmann, R; Lugovic, B ‘High-grade metamorphic soles from the Central Dinaric Ophiolite Belt and their significance for the Neotethyan evolution in the Dinarides’// Ofioliti (2019), 44(1), 1-30, DOI: 10.4454/ofioliti.v44i1.462

Slovenec, Da; Segvic, B ‘Boninitic volcanism in the NW Dinaric-Vardar ophiolite zone (Mt. Medvednica, Croatia): petrology, geochemistry and tectono-magmatic evidences for existence Middle-Late Jurassic arc-forearc system in Tethyan subduction factories’// Mineralogy and Petrology (2019), 113, 17-37, DOI: 10.1007/s00710-018-0637-0

Segvic, B; Girardclos, S; Zanoni, G; Arbiol González, C; Steimer-Herbet, T; Besse, M ‘Origin and Paleoenvironmental Significance of Fe-Mn Nodules in the Holocene Perialpine Sediments of Geneva Basin, Western Switzerland’// Applied Clay Sciences (2018), 60, 22-39, DOI: 10.1016/j.clay.2018.01.027 

Cuadros, J; Segvic, B; Dekov, V; Michalski, J; Baussà Baradaji, D ‘Electron microscopy investigation of the genetic link between Fe oxides/oxyhydroxides and nontronite in submarine hydrothermal fields’// Marine Geology (2018), 395, 247-259, DOI: 10.1016/j.margeo.2017.10.011 

Leila, M; Moscariello, A; Segvic, BGeochemical constraints on the provenance and depositional environment of the Messinian sediments, onshore Nile Delta, Egypt: Implications for the Late Miocene paleogeography of the Mediterranean’// Journal of African Earth Sciences (2018), 143, 215-241, DOI: 10.1016/j.jafrearsci.2018.03.024 

Mahrous, M*; Segvic, B; Zanoni, G; Khadka, SD; Senadheera, S; Jayawickrama, PW ‘The role of clay swelling and mineral neoformation in the stabilization of high plasticity soils treated with fly ash and metakaolin based geopolymers’// Minerals (2018), 8(4), 146, DOI:10.3390/min8040146 

Benvenuti, A*; Segvic, B; Moscariello, A ‘Tunnel valley deposits from the southern North Sea ˗ material provenance and depositional processes‘// Boreas (2018), 47 (2), 625-642, DOI: 10.1111/bor.12292 

Slovenec, Da; Segvic, B ‘The first record of ultramafic cumulates from the Mt. Kalnik ophiolite mélange in the SW part of the Zagorje-Mid-Transdanubian Zone (NW Croatia): mineralogy, petrology, geochemistry and tectono-magmatic affinity’// Geologia Croatica (2018), 71(3), 185-197, DOI: 10.4154/gc.2018.17

Stutenbecker, L*; Delunel, R; Schlunegger, F; Adrião Silva, T; Segvic, B; Girardclos, S; Bakker, M; Costa, A; Lane, S; Loizeau, J-L; Molnar, P; Akçar, N; Christl, M ’Reduced sediment supply in a fast eroding landscape? A multi-proxy sediment budget of the upper Rhône basin, Central Alps’// Sedimentary Geology (2018), 375, 105–119, DOI: 10.1016/j.sedgeo.2017.12.013 

Ragusa, J*; Kindler, P; Segvic, B; Ospina-Ostios, L. M ‘Provenance analysis of the Voirons Flysch (Gurnigel nappe, Haute-Savoie, France): Stratigraphic and paleogeographic implications‘// International Journal of Earth Sciences (2017), 106 (8), 2619-2651, DOI: 10.1007/s00531-017-1474-9 

Segvic, B; Benvenuti, A; Moscariello, A ‘Illite-smectite rich clay parageneses from Quaternary tunnel valley sediments of the Dutch Southern North Sea - mineral origin and paleoenvironment implications‘// Clays and Clay Minerals (2016), 64 (5), 488-507, DOI: 10.1346/CCMN.2016.064026. 

Zanoni, G*; Segvic, B; Moscariello, A ‘Clay mineral diagenesis in Cretaceous clastic reservoirs from west African passive margins (the South Gabon Basin) and its impact on regional geology and basin evolution history’// Applied Clay Sciences (2016), 134 (3), 186-209, DOI: 10.1016/j.clay.2016.09.032 

Segvic, B; Lugovic, B; Slovenec, Da; Meyer, H-P ‘Mineralogy, petrology and geochemistry of amphibolites from the Kalnik Mt. (Sava Unit, North Croatia): Implications for the evolution of north-westernmost part of the Dinaric-Vardar branch of Mesozoic Tethys’// Ofioliti (2016), 41 (1), 35-58, DOI: 10.4454/ofioliti.v41i1.441

Segvic, B; Ugarkovic, M; Süssenberger, A; Ferreiro Mählmann, R; Moscariello, A ‘Compositional properties and provenance of Hellenistic pottery from the necropolis of Issa with evidences on the cross-Adriatic and the Mediterranean-scale trade’// Mediterranean Archaeology & Archaeometry (2016), 16 (1), 23-52, DOI: 10.5281/zenodo.44773

Segvic, B; Kukoc, D; Dragicevic, I; Vranjkovic, A; Brcic, V; Gorican, S; Babajic, E; Hrvatovic, H; ‘New record of Middle Jurassic radiolarians from mélange of the Central Dinaridic Ophiolite Zone (CDOB) and its implications to Neotethyan dynamics in the Dinarides’// Ofioliti (2014), 39 (1), 31-41, DOI: 10.4454/ofioliti.v39i1.427

Segvic, B; Mileusnic, M; Aljinovic, D; Vranjkovic, A; Mandic, O; Pavelic, D; Dragicevic, I; Ferreiro Mählmann R ‘Magmatic Provenance and Diagenesis of Miocene Tuffs from the Dinaride Lake System (The Sinj Basin, Croatia)’// European Journal of Mineralogy (2014), 26 (1), 83-101, DOI: 10.1127/0935-1221/2013/0025-2350

Uzarowicz, Ł; Segvic, B; Michalik, M; Bylina, P ‘The effect of hydrological conditions and the pH of environment on phyllosilicate transformations in the weathering zone of pyrite-bearing schists in Wieściszowice (SW Poland)’// Clay Minerals (2012), 47, 401–417, DOI: 10.1180/claymin.2012.047.4.01

Segvic, B; Seselj, L; Slovenec, Da; Lugovic, B; Ferreiro Mählmann, R ‘Composition, Technology of Manufacture, and Circulation of Hellenistic Pottery from the Eastern Adriatic: A Case Study of Three Archaeological Sites along the Dalmatian Coast, Croatia’// Geoarchaeology (2012), 27 (1), 63-87. DOI: 10.1002/gea.21379 

Ferreiro Mählmann, R; Le Bayon, R; Bozkaya, Ö; Potel, S; Segvic, B; Nieto García, F ‘Clay mineral diagenesis/very low-grade metamorphic processes - The pioneer work of Bernhard Kübler and Martin Frey in very low-grade metamorphic terraines: Palaeo-geothermal potential of Kübler-Index – organic matter reflectance correlation’// Swiss Journal of Geosciences (2012), 105, 121-152. DOI: 10.1007/s00015-012-0115-3 

Uzarowicz, Ł; Skiba, S; Skiba, M; Segvic, BClay mineral formation in soils developed in a pyrite-bearing schists weathering zone: a case study from the abandoned pyrite mine in Wieściszowice (Lower Silesia, SW Poland)’// Clays and Clay Minerals (2011), 59 (6), 581-594. DOI: 10.1346/CCMN.2011.0590604 

Kandler, K; Schütz, L; Jäckel, S; Lieke, K; Emmel, C; Müller-Ebert, D; Ebert, M; Scheuvens, D; Schladitz, A; Segvic, B; Wiedensohler, A; Weinbruch, S ‘Ground-based off-line aerosol measurements at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: Microphysical properties and mineralogy‘// Tellus B (2011), 63 (4), 459–474. DOI: 10.1111/j.1600-0889.2011.00546.x

Lugovic, B; Segvic, B; Segvic, T ‘Mn-crust todorokite mineralization on SW backshore Cretaceous limestones from the island of Dugi Otok (Central Adriatic, Croatia)’// Acta Adriatica (2008), 49, 55-64.

Segvic, B; Lugovic, B; Tadej, N; Bermanec, V; Panjkota, L ‘Si-P impure Al-goethite mineralization on the island of Dugi Otok (Central Adriatic, Croatia)’// Geologia Croatica (2008), 61, 139-147. DOI: 10.4154/GC.2008.04

Lugovic, B; Segvic, B; Altherr, R ‘Petrology and tectonic significance of greenschists from the Medvednica Mts (Sava Unit, NW Croatia)’// Ofioliti (2006), 31, 39-50. DOI: 10.4454/ofioliti.v31i1.326





Sumedh at the GSA2021 in Portland, OR.

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