Abstract
Apatite has recently gained considerable attention as a mineral with many uses within the Earth and planetary sciences. Apatite chemistry has recently given new insight into a wide range of geological processes and tools, for example, magmatism, metasomatism, planetary geochemistry, and geochronology. We expand the utility of apatite here by presenting a novel way to fingerprint magma chemistry and petrogenesis using apatite inclusions within robust titanite and zircon. We present trace element data from apatite mineral inclusions shielded within magmatic zircon and titanite. Importantly, apatite inclusion and host titanite chemistries detailed in this study allow estimation of the whole-rock Sr and SiO2. We show how these data can be used to assess the degree of fractionation of the host magma and to calculate key trace element abundances and ratios. We demonstrate that the inclusions can be linked to discrete periods in the crystallization history of the host phases, thus providing insight into petrogenesis. The results highlight that apatite compositions might discriminate modern granitoids (younger than 2.5 Ga) from Archean–Proterozoic transitional granitoid compositions (sanukitoid signatures). Development of such a petrological tool has important potential for interpretation of provenance and a better understanding of the secular evolution of the continental crust, including that of early Earth.
Highlights
Detrital zircons have revolutionized how we study the evolution of the continental crust, through in situ analysis of U-Pb, Hf, and O isotopes (e.g., Kemp et al, 2009)
Apatite is ubiquitous in magmatic rocks and is able to incorporate more than half of the periodic table, including rare earth elements (REEs) and other important trace elements
The demonstration here, that strontium content in apatite (Srap) and Srttn allow estimation of Srwr, lends optimism that estimates with these minerals might be more successful
Summary
Detrital zircons have revolutionized how we study the evolution of the continental crust, through in situ analysis of U-Pb, Hf, and O isotopes (e.g., Kemp et al, 2009). The robust nature of detrital zircon in sediments means that we can access global records of the continental crust through most of Earth’s history with confidence that the data are meaningful and relate to the parental magmas from which the zircons crystallized While these data can provide excellent constraints on the longer scale differentiation of the crust and mantle, plus intracrustal reworking of previously formed crust (e.g., Kemp et al, 2009; Collins et al, 2011), they have not proved promising at giving insights into magma petrogenesis (Hoskin and Ireland, 2000; Coogan and Hinton, 2006; Bruand et al, 2014). Both minerals (titanite and apatite) plot on the single correlation in Figure 1B, confirming that these accessory minerals preserve the original whole-rock Sr signature even after the whole rock has undergone alteration
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
