Archive

Wed 7th October @ 12 pm, Rm 312.222 Abstract When John Woodward died in 1728, in his sixtieth year, he left a will that for geology was to resonate to the present day. Not only did he leave £150 for the establishment of a professorship, still in existence today, but he also willed the University of Cambridge […]

  Wed 16th September @ 12 pm, Rm 312.222 Abstract One enduring early Earth enigma is the absence of evidence in the terrestrial record for meteorite impacts during the Hadean. Given the low likelihood of discovering an intact Hadean impact crater, the sedimentary record of detrital shocked minerals created by the erosion of such craters may offer […]

Wed 2nd September @ 12 pm, Rm 312.222 Determining an age for strata that contain ancient bones or stone tools requires the combined techniques of stratigraphy, lithologic correlation, radiometric dating (e.g. 40Ar/39Ar), and magnetic polarity zonation. By the early 1960’s, the combined application of K/Ar (a precursor to 40Ar/39Ar) and magnetostratigraphy generated the first accurate dating of […]

Wed 19th August @ 12 pm in  Rm 312.22 Abstract The strong resilience of the mineral zircon and its ability to host a wealth of isotopic information make it the best deep-time archive of Earth’s continental crust. Zircon is found in most felsic igneous rocks, can be precisely dated and can fingerprint magmatic sources; thus, it […]

Wed 5th August @ 12 pm, Rm 312.222 Titanite typically contains more non-radiogenic Pb than zircon, nonetheless it can preserve useful age information that complements geochronology from other datable phases. Titanite is more reactive than zircon and it interacts more readily with other major phases. Titanite dates frequently indicate the time of cooling below a blocking temperature […]

Wed 3rd June, 12 – 1 pm, Rm 312.222 Abstract Much of our knowledge about the driving forces of plate tectonics is derived from analyzing present-day Earth. However, reconstructing the motions of the Earth’s tectonic plates over geological timescales provides fundamental insights into the nature of geodynamic processes plate-driving forces. Plate motions during Pangea breakup are well constrained by […]

Wed 27th May, 12 – 1 pm, Rm 312.222 Abstract Komatiite-hosted nickel sulphide deposits represent very valuable ore bodies, but very difficult exploration targets, mainly due to the limited extent of their primary magmatic footprint. However, hydrothermal alteration has the potential to remobilise base metals and Platinum Group Elements (PGE), extending the detectable footprint of this ore type. Four […]

Wed 6th May, 12 – 1 pm, Rm 312.222 Abstract The ~66 Ma Cretaceous–Paleogene (KPg) boundary marks one of the most significant biological turnovers in Earth history, leaving an evolutionary imprint still visible in the modern biota. Two major geologic events, the Chicxulub bolide impact and the eruptions of the Deccan Traps continental flood basalts that cover a […]

Wed 29th April, 12 – 1 pm, Rm 312.222 Abstract The youngest (ultra-) high pressure ((U)HP) eclogites on Earth are exposed in the gneiss domes of the D’Entrecasteaux Islands of Papua New Guinea. This area is unique in that it remains in the Neogene geodynamic setting – the active Woodlark Rift – that was responsible for rapid exhumation […]

Wed 22nd April, 12 – 1 pm, Rm 312.222 Abstract A flurry of new radiometric ages confirms the synchronicity in the onset and demise of two global glaciations in the Neoproterozoic Era (1000–541 million years ago). These data strengthen support for the snowball Earth hypothesis, which posits that the entire Earth froze over for millions of years at […]