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Abstract Talc-rich metasomatic rocks in subduction interface shear zones profoundly influence seismicity and arc magmatism, but their petrogenesis remains controversial. Magnesium isotope compositions of exhumed subduction interface rocks from the Catalina Schist (California, USA) record Mg exchange from ultramafic to crustal rocks. Preferential loss of isotopically light Mg from serpentinite produces isotopically heavy talc-rich metasomatic rocks. Addition of this isotopically light Mg to adjacent metasedimentary and metamafic rocks from the slab produces actinolite- and chlorite-rich metasomatic rocks, respectively, with convergent δ26Mg values relative to their protoliths. The addition of Ca to ultramafic- and metasedimentary-derived metasomatic rocks reflects a separate contribution from infiltrating metabasalt-derived fluids. Talc-rich rocks are formed by passive enrichment of Si in serpentinite during Mg loss to adjacent Mg sinks. These results and a global compilation of exhumed paleosubduction terranes suggest that talc is a common component of the subduction interface and often forms independent of Si metasomatism. Talc is likely prevalent along the interface from mantle wedge corner to subarc wherever ultramafic material is in contact with a Mg sink and where it could influence slow slip events, subduction interface rheology, and arc magmatism in modern subduction zones. 

ABSTRACT MotivationSNAPSHOT USA is an annual, multicontributor camera trap survey of mammals across the United States. The growing SNAPSHOT USA dataset is intended for tracking the spatial and temporal responses of mammal populations to changes in land use, land cover and climate. These data will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, as well as the impacts of species interactions on daily activity patterns. Main Types of Variables ContainedSNAPSHOT USA 2019–2023 contains 987,979 records of camera trap image sequence data and 9694 records of camera trap deployment metadata. Spatial Location and GrainData were collected across the United States of America in all 50 states, 12 ecoregions and many ecosystems. Time Period and GrainData were collected between 1st August and 29th December each year from 2019 to 2023. Major Taxa and Level of MeasurementThe dataset includes a wide range of taxa but is primarily focused on medium to large mammals. Software FormatSNAPSHOT USA 2019–2023 comprises two .csv files. The original data can be found within the SNAPSHOT USA Initiative in the Wildlife Insights platform.