Zirconological tracing of transition between aqueous fluid and hydrous melt in the crust: Constraints from pegmatite vein and host gneiss in the Sulu orogen

Lithos ◽  
2013 ◽  
Vol 162-163 ◽  
pp. 157-174 ◽  
Author(s):  
Wan-Cai Li ◽  
Ren-Xu Chen ◽  
Yong-Fei Zheng ◽  
Qiuli Li ◽  
Zhaochu Hu
Keyword(s):  
Aqueous Fluid ◽  
Pegmatite Vein ◽  
Hydrous Melt

scholarly journals Subduction sediment-lherzolite interaction at 2.9 GPa: effects of metasomatism and partial melting

2019 ◽  
Vol 27 (5) ◽  
pp. 503-524
Author(s):  
A. L. Perchuk ◽  
A A. Serdyuk ◽  
N. G. Zinovievа
Keyword(s):  
Subduction Zones ◽  
Central Zone ◽  
Aqueous Fluid ◽  
Piston Cylinder ◽  
Mineral Growth ◽  
Hydrous Melt ◽  
Liquid Flows ◽  
Dissolved Components ◽  
Sedimentary Layer ◽  
Upper Boundary

We present the results of analogue experiments carried out in a piston–cylinder apparatus at 750–900°C and 2.9 GPa aimed to simulate metasomatic transformation of the fertile mantle caused by fluids and melts released from the subducting sediment. A synthetic H2O- and CO2-bearing mixture that corresponds to the average subducting sediment (GLOSS, Plank, Langmuir, 1998) and mineral fractions of natural lherzolite (analogue of a mantle wedge) were used as starting materials. Experiments demonstrate that the mineral growth in capsules is controlled by ascending fluid and hydrous melt (from 850°C) flows. Migration of the liquids and dissolved components develops three horizontal zones in the sedimentary layer with different mineral parageneses that slightly changed from run to run. In the general case, however, the contents of omphacite and garnet increase towards the upper boundary of the layer. Magnesite and omphacite (± garnet ± melt ± kyanite ± phengite) are widespread in the central zone of the sedimentary layer, whereas SiO2 polymorph (± kyanite ± phengite ± biotite ± omphacite ± melt) occurs in the lower zone. Clinopyroxene disappears at the base of lherzolite layer and the initial olivine is partially replaced by orthopyroxene (± magnesite) in all experiments. In addition, talc is formed in this zone at 750°C, whereas melt appears at 850°C. In the remaining volume of the lherzolite layer, metasomatic transformations affect only grain boundaries where orthopyroxene (± melt ± carbonate) is developed. The described transformations are mainly related to a pervasive flow of liquids. Mineral growth in the narrow wall sides of the capsules is probably caused by a focused flow: omphacite grows up in the sedimentary layer, and talc or omphacite with the melt grow up in the lherzolite layer. Experiments show that metasomatism of peridotite related to a subducting sediment, unlike the metasomatism related to metabasites, does not lead to the formation of garnet-bearing paragenesis. In addition, uprising liquid flows (fluid, melt) do not remove significant amounts of carbon from the metasedimentary layer to the peridotite layer. It is assumed that either more powerful fluxes of aqueous fluid or migration of carbonate-bearing rocks in subduction melanges are necessary for more efficient transfer of crustal carbon from metasediments to a mantle in subduction zones.

In situ determination of water-saturated solidus by electrical discontinuity

2020 ◽  
Author(s):  
Xuan Guo ◽  
Huaiwei Ni
Keyword(s):  
Electrical Conductivity ◽  
Solidus Temperature ◽  
Conductivity Measurement ◽  
Aqueous Fluid ◽  
Electrical Conductivity Measurement ◽  
Rock System ◽  
Hydrous Melt ◽  
Water Saturated

<p><span>Water plays an important role in lowering melting temperature of rocks. The water-saturated solidus of rock is critical for understanding the magma generation and the dynamics of the Earth. There have been a lot of water-saturated solidi of rocks constrained by traditional quench method in literature. However, since both of the hydrous silicate melt and aqueous fluid can be quenched to glasses at high pressure, it is difficult to discriminate whether the quenched glasses were from melt or not. As a result, the water-saturated solidi of rocks from different studies may show significant discrepancy. One way to solve this problem is to detect the characteristics change of the rock system in situ, and electrical conductivity measurement is one of the good options. It is known that hydrous melt has much higher electrical conductivity than solid rock, and temperature is much more effective in enhancing melt electrical conductivity than that for aqueous fluid. Once the partial melting is triggered, the electrical conductivity of the water-saturated rock system may have remarkable increase if the hydrous melt is interconnected in the system. Accordingly, the abrupt change of electrical conductivity may mark the solidus temperature. In this study, we performed electrical conductivity measurement for the determination of water-saturated solidus of albite. We adopted albite as the starting material because its water-saturated solidus is well known, which can help to verify the accuracy our method, and its quenched products are not so controversial. The electrical conductivity measurements were carried out at four different pressures ranging from 0.35 GPa to 1.7 GPa in a 3/4″ piston cylinder apparatus with impedance spectroscopy. The obvious change of electrical conductivity was observed at solidus temperature within error, with increase of 1.8-0.18 log unit at 0.35-1.7 GPa. The results showed a stronger increase of conductivity at lower pressures, and fitted well with the water-saturated solidus of albite in literature. One defect of this method is the loss of water during experiment. The final water content in the system is about 1-2 wt%, comparing to the initial 10-15 wt% H<sub>2</sub>O. Nevertheless, the whole system is still water saturated, since water solubility in albite is fairly low. Therefore, if such a method can be improved to keep more water, it may be applied to other rocks to better constrain the water-saturated solidi in the future.</span></p><p> </p>

scholarly journals Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism

2012 ◽  
Vol 109 (46) ◽  
pp. 18695-18700 ◽  
Author(s):  
T. Kawamoto ◽  
M. Kanzaki ◽  
K. Mibe ◽  
K. N. Matsukage ◽  
S. Ono
Keyword(s):  
Subduction Zone ◽  
Aqueous Fluid ◽  
Subduction Zone Magmatism

The ecological impact of membrane-based extraction of phenolic compounds – a life cycle assessment study

2010 ◽  
Vol 62 (4) ◽  
pp. 915-919 ◽  
Author(s):  
C. Bayer ◽  
M. Follmann ◽  
T. Melin ◽  
T. Wintgens ◽  
K. Larsson ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Phenolic Compounds ◽  
Ecological Impact ◽  
Porous Membrane ◽  
Aqueous Fluid ◽  
Reactive Extraction ◽  
Molecular Weights ◽  
Process Economics ◽  
Process Implementation

Many phenolic compounds show high boiling points, low molecular weights, moderate polarities or high toxicities. Therefore, conventional wastewater treatment is limited or expensive. Recycling of the separated compounds is often not possible. But, if liquid-liquid reactive extraction is linked to a non-porous membrane, some or all of the above mentioned limitations may be overcome. The key element is a composite membrane with a dense, hydrophobic top layer which avoids the mixing of the two aqueous fluid streams. The dilute phenol stream is one of them, the other is caustic soda as stripping solvent. Since the basics of this technology have been discussed before, the scope of this study is to facilitate process implementation and integration. To this end, a life cycle assessment framework is used to identify the optimal equipment size for the treatment of wastewater that may, for example, originate from the production of polycarbonate. Limiting for this application is not the environmental performance though, but most likely process economics.

Innovative Washpipe Free Circulating ICD Delivers Reduced Well Construction Costs

2021 ◽  
Author(s):  
Zhihua Wang ◽  
Daniel Newton ◽  
Aqib Qureshi ◽  
Yoshito Uchiyama ◽  
Georgina Corona ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Drilling Fluid ◽  
Aqueous Fluid ◽  
Control Device ◽  
Lessons Learned ◽  
Innovative Technology ◽  
Well Performance ◽  
Construction Costs ◽  
Inflow Control Device ◽  
Testing Field

Abstract This Extended Reach Drilling (ERD) field re-development of a giant offshore field in the United Arab Emirates (UAE) requires in most cases extremely long laterals to reach the defined reservoir targets. However, certain areas of the field show permeability and / or pressure variations along the horizontal laterals. This heterogeneity requires an inflow control device (ICD) lower completion liner to deliver the required well performance that will adequately produce and sweep the reservoir. The ICD lower completion along with the extremely long laterals means significant time is spent switching the well from reservoir drilling fluid (RDF) non-aqueous fluid (NAF) to an aqueous completion brine. To reduce the amount of rig time spent on the displacement portion of the completion phase, an innovative technology was developed to enable the ICDs to be run in hole in a closed position and enable circulating through the end of the liner. The technology uses a dissolvable material, which is installed in the ICD to temporarily plug it. The dissolvable material is inert to the RDF NAF while the ICDs are run into hole, and then dissolves in brine after the well is displaced from RDF NAF to completion brine, changing the ICDs from closed to an open position. The ability to circulate through the end of the liner, with the support of the plugged ICDs, when the lower completion is deployed and at total depth (TD), enables switching the well from RDF NAF drilling fluid to an aqueous completion brine without the associated rig time of the original displacement method. The technique eliminates the use of a dedicated inner displacement string and allows for the displacement to be performed with the liner running string, saving 4-5 days per well. An added bonus is that the unique design allowed for this feature to be retrofitted to existing standard ICDs providing improved inventory control. In this paper the authors will demonstrate the technology and system developed to perform this operation, as well as the qualification testing, field installations, and lessons learned that were required to take this solution from concept to successful performance improvement initiative.

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