Michael F Brown

Learn More
The Fosdick migmatite–granite complex in West Antarctica records evidence for two high-temperature metamorphic events, the first during the Devonian–Carboniferous and the second during the Cretaceous. The conditions of each high-temperature metamorphic event, both of which involved melting and multiple melt-loss events, are investigated using phase(More)
Along the coast of Peninsular India, the Eastern Ghats expose a deep crustal section through a composite Proterozoic orogenic belt. To quantify the late Mesoproterozoic–early Neoproterozoic pressure (P)–temperature (T)–time (t) evolution of the Eastern Ghats Province, new SHRIMP U–Pb zircon and monazite age data from multiple localities are reported and(More)
a r t i c l e i n f o There are differences in the style of collisional orogens between the Phanerozoic and the Precambrian, most notably the appearance of blueschists and ultrahigh pressure metamorphic (UHPM) rocks in the geological record since the late Neoproterozoic, whereas these rocks are absent from older orogens. Understanding collisional orogenesis(More)
At low temperatures (<750 °C at moderate to high crustal pressures), the production of suffi cient melt to reach the melt connec-tivity transition (~7 vol%), enabling melt drainage, requires an infl ux of aqueous fl uid along structurally controlled pathways or recycling of fl uid via migration of melt and exsolution during crystallization. At higher(More)
a r t i c l e i n f o A diorite pluton and widely distributed mafic dykes occur in the Fosdick migmatite–granite complex, which is interpreted to represent middle-to-lower crustal rocks of the paleo-Pacific active continental margin of Gondwana. The mafic dykes exhibit a variety of relationships with host rocks in the field ranging from undeformed dykes(More)
a r t i c l e i n f o a b s t r a c t Keywords: Al-in-orthpyroxene thermometry P –T pseudosections sapphirine–quartz Ti-in-zircon thermometry UHT metamorphism Zr-in-rutile thermometry The limitations of conventional thermobarometry and petrogenetic grids for determining the peak P –T conditions of granulites are well known. These limitations have been(More)
Accessory minerals such as zircon and monazite are important in studies of high-grade migmatites and residual granulites, and related anatectic granites, because they may be dated using isotopic or chemical methods. Thus, these minerals have the potential to place temporal constraints on metamorphic P–T paths retrieved from migmatites and residual(More)
As a consequence of secular cooling of the Earth, there is generally no modern analog to assist in understanding the tectonic style that may have operated in the Archean. Higher mantle temperatures and higher radiogenic heat production in the Archean Earth would have impacted the thickness and composition of the crust. For this reason, well-constrained(More)
  • C Yakymchuk, M Brown, C Clark, F J Korhonen, P M Piccoli, R J M Tayl Or +3 others
  • 2015
In this study, in situ U–Pb monazite ages and Lu–Hf garnet geochronology are used to distinguish mineral parageneses developed during Devonian–Carboniferous and Cretaceous events in migmatitic paragneiss and orthogneiss from the Fosdick migmatite–granite complex in West Antarctica. SHRIMP U–Pb monazite ages define two dominant populations at 365–300 Ma(More)
  • Christopher M Kelty, Michael M J Fischer, Jason Baird Jackson, Michael F Brown
  • 2008
Presented here is a conversation among anthropologists whose research and experience have given them special insight into recent changes in the ways scholarship is produced and shared. Christopher Kelty (CK) is the author of Two Bits: The Cultural Significance of Free Software, which serves as the starting point for the discussion below. Michael M. J.(More)