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Low‐temperature thermochronology of francolite: Insights into timing of Dead Sea Transform motion
Author(s) -
Kohn Barry,
Weissbrod Tuvia,
Chung Ling,
Farley Ken,
Bodorkos Simon
Publication year - 2019
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/ter.12387
Subject(s) - geology , thermochronology , fluorapatite , apatite , fission track dating , siliciclastic , geochemistry , authigenic , sedimentary rock , paleontology , mineralogy , zircon , sedimentary depositional environment , structural basin
Abstract Cambrian siliciclastic sequences along the Dead Sea Transform ( DST ) margin in southern Israel and southern Jordan host both detrital fluorapatite [D‐apatite] and U‐rich authigenic carbonate‐fluorapatite (francolite) [A‐apatite]. D‐apatite and underlying Neoproterozoic basement apatite yield fission‐track ( FT ) data reflecting Palaeozoic–Mesozoic sedimentary cycles and epeirogenic events, and dispersed (U–Th–Sm)/He ( AH e) ages. A‐apatite, which may partially or completely replace D‐apatite, yields an early Miocene FT age suggesting formation by fracturing, hydrothermal fluid ascent and intra‐strata recrystallisation, linked to early DST motion. The DST , separating the African and Arabian plates, records ~105 km of sinistral strike‐slip displacement, but became more transtensional post‐5 Ma. Helium diffusion measurements on A‐apatite are consistent with thermally activated volume diffusion, indicating Tc ~52 to 56 ± 10°C (cooling rate 10°C/Ma). A‐apatite AH e data record Pliocene cooling (~35 to 40°C) during the transtensional phase of movement. This suggests that timing of important milestones in DST motion can be discerned using A‐apatite low‐temperature thermochronology data alone.