46 research outputs found
Dosage of lactate in the cerebrospinal fluid in infectious diseases of the central nervous system
Carbon-13 in groundwater from English and Norwegian crystalline rock aquifers: a tool for deducing the origin of alkalinity?
Equilibrium crystallization of massif-type anorthosite residual melts: a case study from the 1.64Â Ga Ahvenisto complex, Southeastern Finland
The Fetal Cerebral Circulation: Three Decades of Exploration by the LLU Center for Perinatal Biology
Archaean zircons in Miocene oceanic hotspot rocks establish ancient continental crust beneath Mauritius
A Precambrian microcontinent in the Indian Ocean
The Laccadive–Chagos Ridge and Southern Mascarene Plateau in the north-central and western Indian Ocean, respectively, are thought to be volcanic chains formed above the Réunion mantle plume1 over the past 65.5 million years2,3. Here we use U–Pb dating to analyse the ages of zircon xenocrysts found within young lavas on the island of Mauritius, part of the Southern Mascarene Plateau. We find that the zircons are either Palaeoproterozoic (more than 1,971 million years old) or Neoproterozoic (between 660 and 840 million years old). We propose that the zircons were assimilated from ancient fragments of continental lithosphere beneath Mauritius, and were brought to the surface by plume-related lavas. We use gravity data inversion to map crustal thickness and find that Mauritius forms part of a contiguous block of anomalously thick crust that extends in an arc northwards to the Seychelles. Using plate tectonic reconstructions, we show that Mauritius and the adjacent Mascarene Plateau may overlie a Precambrian microcontinent that we call Mauritia. On the basis of reinterpretation of marine geophysical data4, we propose that Mauritia was separated from Madagascar and fragmented into a ribbon-like configuration by a series of mid-ocean ridge jumps during the opening of the Mascarene ocean basin between 83.5 and 61 million years ago. We suggest that the plume-related magmatic deposits have since covered Mauritia and potentially other continental fragments
Metamorphic Fluids In The Deep Crust - Evidence From The Adirondacks
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62547/1/301226a0.pd