Evolution of the Southwest Australian Rifted Continental Margin During Breakup of East Gondwana: Results from IODP Expedition 369

International Ocean Discovery Program Expedition 369 drilled four sites on the southwestern Australian continental margin, in the deep water Mentelle Basin (MB) and on the neighboring Naturaliste Plateau (NP). The drillsites are located on continental crust that continued rifting after seafloor spreading began further north on the Perth Abyssal Plain (PAP) between magnetochrons M11r and M11n (133‐132 Ma), ending when spreading began west of the NP between chrons M5n and M3n (126‐124 Ma). Drilling recovered the first in‐situ samples of basalt flows overlying the breakup unconformity on the NP, establishing a magnetostratigraphically constrained eruption age of >131‐133 Ma and confirming a minimal late Valanginian age for the breakup unconformity (coeval with the onset of PAP seafloor spreading). Petrogenetic modeling indicates the basalts were generated by 25% melting at 1.5 GPa and a potential temperature of 1380‐1410 °C, consistent with proximity of the Kerguelen plume during breakup. Benthic foraminiferal fossils indicate that the NP remained at upper bathyal or shallower depths during the last 6 Myr of rifting and for 3‐5 Myr after breakup between India and Australia. The limited subsidence is attributed to heat from the nearby Kerguelen plume and PAP spreading ridge. The margin subsided to middle bathyal depths by Albian time and to lower bathyal (NP) or greater (MB) depths by late Paleogene time. Periods of rapid sedimentation accompanied a westward jump of the PAP spreading ridge (108 Ma), rifting on the southern margin (100‐84 Ma), and opening of the southern seaway between Australia and Antarctica (60‐47 Ma)

The provenance of Borneo's enigmatic alluvial diamonds:A case study from Cempaka, SE Kalimantan

Gem-quality diamonds have been found in several alluvial deposits across central and southern Borneo. Borneo has been a known source of diamonds for centuries, but the location of their primary igneous source remains enigmatic. Many geological models have been proposed to explain their distribution, including: the diamonds were derived from a local diatreme; they were brought to the surface through ophiolite obduction or exhumation of UHP metamorphic rocks; they were transported long distances southward via major Asian river systems; or, they were transported from the Australian continent before Borneo was rifted from its northwestern margin in the Late Jurassic. To assess these models, we conducted a study of the provenance of heavy minerals from Kalimantan's Cempaka alluvial diamond deposit. This involved collecting U–Pb isotopic data, fission track and trace element geochemistry of zircon as well as major element geochemical data of spinels and morphological descriptions of zircon and diamond. The results indicate that the Cempaka diamonds were likely derived from at least two sources, one which was relatively local and/or involved little reworking, and the other more distal which records several periods of reworking. The distal diamond source is interpreted to be diamond-bearing pipes that intruded the basement of a block that: (1) rifted from northwest Australia (East Java or SW Borneo) and the diamonds were recycled into its sedimentary cover, or: (2) were emplaced elsewhere (e.g. NW Australia) and transported to a block (e.g. East Java or SW Borneo). Both of these scenarios require the diamonds to be transported with the block when it rifted from NW Australia in the Late Jurassic. The local source could be diamondiferous diatremes associated with eroded Miocene high-K alkaline intrusions north of the Barito Basin, which would indicate that the lithosphere beneath SW Borneo is thick (~ 150 km or greater). The ‘local’ diamonds could also be associated with ophiolitic rocks that are exposed in the nearby Meratus Mountains

Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

Potential health and economic impacts of dexamethasone treatment for patients with COVID-19

Acknowledgements We thank all members of the COVID-19 International Modelling Consortium and their collaborative partners. This work was supported by the COVID-19 Research Response Fund, managed by the Medical Sciences Division, University of Oxford. L.J.W. is supported by the Li Ka Shing Foundation. R.A. acknowledges funding from the Bill and Melinda Gates Foundation (OPP1193472).Peer reviewedPublisher PD

Expedition 369 methods

This chapter documents the procedures and methods used in the shipboard laboratories during International Ocean Discovery Program (IODP) Expedition 369. This introductory section in particular provides a rationale for the site locations and an overview of IODP depth conventions, curatorial procedures, and general core handling/analyses during Expedition 369. Subsequent sections describe specific laboratory procedures and instruments in more detail. This information only applies to shipboard work described in the Proceedings volume; methods used in shore-based analyses of Expedition 369 samples and/or data will be described in various scientific contributions in the open peer-reviewed literature and the Expedition Research Results chapters of this Proceedingsvolume