Most natural diamonds are formed in Earth's lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth's mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.
View Article and Find Full Text PDFDeep carbon and nitrogen cycles played a critical role in the evolution of the Earth. Here we report on successful studying of speciation in C-O-H-N systems with low nitrogen contents at 6.3 GPa and 1100 to 1400 °C.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2013
Subduction tectonics imposes an important role in the evolution of the interior of the Earth and its global carbon cycle; however, the mechanism of the mantle-slab interaction remains unclear. Here, we demonstrate the results of high-pressure redox-gradient experiments on the interactions between Mg-Ca-carbonate and metallic iron, modeling the processes at the mantle-slab boundary; thereby, we present mechanisms of diamond formation both ahead of and behind the redox front. It is determined that, at oxidized conditions, a low-temperature Ca-rich carbonate melt is generated.
View Article and Find Full Text PDFPurpose: We assessed the impact of prostate size on operative difficulty as measured by estimated blood loss, operating room time and positive surgical margins. In addition, we assessed the impact on biochemical recurrence and the functional outcomes of potency and continence at 1 year after radical prostatectomy as well as postoperative bladder neck contracture.
Materials And Methods: From 1998 to 2007, 3,067 men underwent radical prostatectomy by 1 of 5 dedicated prostate surgeons with no neoadjuvant or adjuvant therapy.
Analysis of data on micro- and nano-inclusions in mantle-derived and metamorphic diamonds shows that, to a first approximation, diamond-forming medium can be considered as a specific ultrapotassic, carbonate/chloride/silicate/water fluid. In the present work, the processes and mechanisms of diamond crystallization were experimentally studied at 7.5 GPa, within the temperature range of 1,400-1,800 degrees C, with different compositions of melts and fluids in the KCl/K(2)CO(3)/H(2)O/C system.
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