Titanite as a petrogenetic indicator

The trace element composition of titanite reflects the temperature, pressure and bulk‐rock composition from which it crystallized. Two geochemical discriminators are identified by applying a support vector matrix (a machine learning classifier) to a global compilation of titanite trace element data. The compilation comprises more than 7,400 analyses of igneous and metamorphic titanite from a wide range of bulk‐rock compositions. First, igneous and metamorphic titanite are differentiated on the basis of Al/Fe and ∑LREE content. Variation in Th/U aids differentiation in composite settings, such as igneous rocks overprinted by metamorphism. Second, titanite from felsic host rocks is distinguished by low Zr/Y and high Fe content. For titanite from igneous rocks, this effectively discriminates titanite from mafic and felsic rocks. Together, these geochemical discriminators may be used to characterize the crystallization setting and host‐rock of an unknown titanite, a valuable tool with applications including petrochronology and detrital provenance analysis.

[1]  M. Piochi,et al.  Machine learning applied to rock geochemistry for predictive outcomes: The Neapolitan volcanic history case , 2021, Journal of Volcanology and Geothermal Research.

[2]  S. Reddy,et al.  Deformation-enhanced recrystallization of titanite drives decoupling between U-Pb and trace elements , 2021 .

[3]  O. Laurent,et al.  Accessory mineral constraints on crustal evolution: elemental fingerprints for magma discrimination , 2020, Geochemical Perspectives Letters.

[4]  G. O’Sullivan,et al.  The trace element composition of apatite and its application to detrital provenance studies , 2020 .

[5]  F. Huang,et al.  Titanite: A potential solidus barometer for granitic magma systems , 2019, Comptes Rendus Geoscience.

[6]  C. Kirkland,et al.  Trace elements in titanite: A potential tool to constrain polygenetic growth processes and timing , 2019, Chemical Geology.

[7]  S. Reddy,et al.  Unravelling complex geologic histories using U–Pb and trace element systematics of titanite , 2019, Chemical Geology.

[8]  E. Christiansen,et al.  COMPOSITIONAL VARIATION OF FE, AL, AND F IN TITANITE (SPHENE) , 2018 .

[9]  R. Hu,et al.  Titanite major and trace element compositions as petrogenetic and metallogenic indicators of Mo ore deposits: Examples from four granite plutons in the southern Yidun arc, SW China , 2018, American Mineralogist.

[10]  C. Kirkland,et al.  Th/U ratios in metamorphic zircon , 2018 .

[11]  Kazuhiro Suzuki,et al.  AI-Fe 3 + and FOH substitutions in titanite and constraints on their PT dependence , 2018 .

[12]  Hideitsu Hino,et al.  Geochemical Discrimination and Characteristics of Magmatic Tectonic Settings: A Machine‐Learning‐Based Approach , 2017, 1712.09016.

[13]  A. Gerdes,et al.  How do granitoid magmas mix with each other? Insights from textures, trace element and Sr–Nd isotopic composition of apatite and titanite from the Matok pluton (South Africa) , 2017, Contributions to Mineralogy and Petrology.

[14]  G. Seward,et al.  Controls on Trace Element Uptake in Metamorphic Titanite: Implications for Petrochronology , 2017 .

[15]  J. Schwartz,et al.  Thermochronology of extensional orogenic collapse in the deep crust of Zealandia , 2016 .

[16]  M. Chiaradia,et al.  Primary Magmas in Continental Arcs and their Differentiated Products: Petrology of a Post-plutonic Dyke Suite in the Tertiary Adamello Batholith (Alps) , 2016 .

[17]  W. Bach,et al.  U‐Pb dating of interspersed gabbroic magmatism and hydrothermal metamorphism during lower crustal accretion, Vema lithospheric section, Mid‐Atlantic Ridge , 2015 .

[18]  G. Seward,et al.  Campaign-style titanite U–Pb dating by laser-ablation ICP: Implications for crustal flow, phase transformations and titanite closure , 2013 .

[19]  Yong‐Fei Zheng,et al.  Geochemical and U–Pb age constraints on the occurrence of polygenetic titanites in UHP metagranite in the Dabie orogen , 2012 .

[20]  P. Olin,et al.  Partitioning of rare earth and high field strength elements between titanite and phonolitic liquid , 2012 .

[21]  Martin P Smith,et al.  In situ U-Pb and trace element analysis of accessory minerals in the Kiruna District, Norrbotten, Sweden: new constraints on the timing and origin of mineralization , 2009 .

[22]  S. Klemme,et al.  Effect of melt composition on the partitioning of trace elements between titanite and silicate melt , 2003 .

[23]  M. Tiepolo,et al.  Trace-element incorporation in titanite: constraints from experimentally determined solid/liquid partition coefficients , 2002 .

[24]  R. Wintsch,et al.  U–Pb geochronology of zircon and polygenetic titanite from the Glastonbury Complex, Connecticut, USA: an integrated SEM, EMPA, TIMS, and SHRIMP study , 2002 .

[25]  D. Rubatto.  Zircon trace element geochemistry: partitioning with garnet and the link between U–Pb ages and metamorphism , 2002 .

[26]  D. Lindsley,et al.  Assemblages with titanite (CaTiOSiO4), Ca-Mg-Fe olivine and pyroxenes, Fe-Mg-Ti oxides, and quartz: Part II. Application , 2001 .

[27]  J. Schumacher,et al.  Sphene (titanite): phase relations and role as a geochronometer , 2001 .

[28]  Vladimir N. Vapnik,et al.  The Nature of Statistical Learning Theory , 2000, Statistics for Engineering and Information Science.

[29]  S. Piazolo,et al.  Stability of high-Al titanite from low-pressure calcsilicates in light of fluid and host-rock composition , 1999 .

[30]  G. Rossi,et al.  The crystal-chemistry of high-aluminium titanites , 1991 .