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The magma plumbing system throughout the entire transcrustal section of Large Igneous Provinces (LIPs) is still poorly understood. Among the most voluminous LIPs, the Central Atlantic Magmatic Province (CAMP [1], ca. 201 Ma) and the Deccan Traps (DT [2], ca. 66 Ma) coincided in time with end-Triassic and end-Cretaceous mass extinctions, respectively. Glomerocrysts containing abundant primary melt inclusions from both CAMP and DT basaltic lava flows were investigated via a multi-analytical approach (confocal Raman microspectroscopy for volatile species within bubbles, electron microprobe for major element compositions, secondary ion mass spectrometry for oxygen isotope compositions, Synchrotron X-ray microtomography and optical microscopy for microstructural analysis). The analysed glomerocrysts are dominated by augitic clinopyroxenes, and represent portions of crystal mushes. The analysed melt inclusions consist of an intermediate to felsic composition glass and CO2-bearing bubbles, and represent relics of interstitial melts and fluids entrapped during the evolution of these crystal mushes. The different volume proportions in terms of bubbles within melt inclusions indicate a heterogeneous entrapment, implying that melts were entrapped along with already exsolved fluids. The MgO-rich composition of glomerocrysts and whole rocks is in contrast with the SiO2-rich composition of melt inclusions, unveiling disequilibrium conditions of entrapment, as supported by thermodynamic modelling too. The oxygen isotope compositions of clinopyroxene in glomerocrysts indicate that they crystallized from mafic melts with normal (i.e., mantle-like) to mildly low δ18O values. However, the oxygen isotope compositions of glass in melt inclusions indicate that they entrapped distinct, intermediate to felsic melts with normal to extremely high δ18O values, which may be explained by variable degrees of crustal assimilation and partial mixing in an open system. Hence, the oxygen isotope compositions of glass in melt inclusions also suggest that the CO2 within their coexisting bubbles may be derived partly from the mantle and partly from assimilated crustal melts as well. Overall, geochemical data and microstructural observations reveal the presence of multiphase (i.e., solid + liquid + gaseous phases) crystal mushes within the magma plumbing system of both CAMP and DT, and shed light on the origin of carbon and its transfer from the mantle to Earth’s surface. [1] Marzoli et al. (1999), Science 284, 616–618.[2] Sprain et al. (2019), Science 363, 866–870.
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An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Debugging data-intensive distributed applications running in datacenters is complex and time-consuming because developers do not have practical ways of deterministically replaying failed executions. The reason why building such tools is hard is that non-determinism that may be tolerable on a single node is exacerbated in large clusters of interacting nodes, and datacenter applications produce terabytes of intermediate data exchanged by nodes, thus making full input recording infeasible. We present ADDA, a replay-debugging system for datacenters that has lower recording and storage overhead than existing systems. ADDA is based on two techniques: First, ADDA provides control plane determinism, leveraging our observation that many typical datacenter applications consist of a separate "control plane" and "data plane", and most bugs reside in the former. Second, ADDA does not record "data plane" inputs, instead it synthesizes them during replay, starting from the application's external inputs, which are typically persisted in append-only storage for reasons unrelated to debugging. We evaluate ADDA and show that it deterministically replays real-world failures in Hypertable and Memcached.
