Fluid inclusions method

VAPOUR NUCLEATION IN METASTABLE WATER AND SOLUTIONS BY SYNTHETIC FLUID INCLUSION METHOD... 

Despite the potential problems, two recent studies provide positive results. Matthews et al. (2000) analyzed the 5D of fluid inclusions in present-day cave carbonates from Soreq cave (Israel) using the method of thermal vacuum extraction and standard techniques on cave pool water from the same cave to estimate isotopic fractionation during measurement (Aex = 5Dextracted water - 8Dcave water). After subtracting Aex from 5D... 

Schwarcz HP, Harmon RS, Thompson P, Ford DC (1976) Stable isotope studies of fluid inclusions in speleothems and their paleochmatic significance. Geochim Cosmochim Acta 40 657-665 Schwarcz HP, Rink WJ (2001) Dating methods for sediments of caves and rock shelters. Geoarchaeology 16 355-372... 

The above methods were applied to fluid inclusions from the Jabiluka, Nabarlek, Caramal, South Horn and Ranger deposits. The results are presented in Derome et al. (2003) and Derome et al. (2007) and summarized here. 

Analytical methods. IR spectroscopy is the most common method of detecting OH in minerals (Rossman, 1988, 1996), and is able to distinguish structurally incorporated OH from water in fluid inclusions, cracks, and hydrous alteration... 

Lowenstein, T. Brennan, S.T. (2001) Fluid inclusions in paleolimnological studies of chemical sediments. In Last, W.M. Smol, J.P. (Eds) Tracking Environmental Change Using Lake Sediments, Vol. 2, Physical and Chemical Methods. Dordrecht Kluwer, pp. 189-216. 

Lowenstein, T.K., Li, J., Brown, C.B. (1998) Paleotemperatures from fluid inclusions in halite method verification and a 100,000 year paleotemperature record, Death Valley, CA. Chemical Geology 150, 223-245. 

On the process side, techniques like the fluid bed method, extrusion, coacervation, the submerged nozzle process and molecular inclusion have gained importance within the last 10-15 years [1-3, 7]. 

All fluid inclusions were synthesized using an internal heating apparatus ( gas bomb ) at Edinburgh University. The runs were done with quartz matrix at 750 MPa and temperatures 530-700°C with duration from 8 to 13 days. Main part of the runs used Bodnar-Stemer method (Bodnar, Sterner, 1985) and this approach was better for measurements than overgrowing... 

Minimal values Th-Tn for different samples are between 12 and 20°C. It is mean, that nucleation of vapour phase never observed before overcooling inclusion on 10°C (or smaller) below L-V equilibrium. At average slops of water isochors as 1.5-1.6 MPa per 1°C, it corresponds to nucleation pressures from -20 to -30 MPa. Last values are very similar to cavitation pressures, estimated by other methods (see review Herbert et. al., 2006). By other words, in some fluid inclusions formation of vapour phase begin at the same pressure (rate of tension) as in capillaries, optic or other cells, but in other inclusions with same water density the cavitation take place at much higher tension (larger values of Th-Tn). 

The amount and quality of information in these studies varies greatly and only a few of the more recent papers applied a combination of several different methods to decipher the origin of saddle dolomite. We scanned published work for the following information on saddle dolomite occurrences optical mineralogy, cathodoluminescence (CL) characteristics, elemental composition, carbon, oxygen and strontium isotopic compositions, and fluid inclusion analysis. In the following sections we shall address these types of data in detail. 

Previous workers studying fluid inclusions in saddle dolomite used mainly standard microthermometric heating-cooling methods. They reported Th values and, less commonly, salinity estimates and major cation ratios. More sophisticated techniques, such as direct analysis of the major cations. 

We also suggest application of GC-FID analysis of gas, long chained alkanes and biomarkers to realize the full potential of inelusions to reservoir studies as these may represent hermetically sealed testers of palaeo-petroleum. Furthermore, only the use of fluid inclusions in combination with standard geochemical core bitumen quantification, compositional analysis and GC-FID plus GC-MS characterization, can fully realize the potential of these methods for deciphering movement of OWCs during time and determining the time for field filling. 

Lawrence Livermore National Laboratory Report UCRL-50174 sec II revision I Menez B, Simionovici A, PhiUppot P, Bohic S, Gibert F, Chukalina M (2001) X-ray fluorescence microtomography of an individual fluid inclusion using a third generation synchrotron light source. Nucl Instrum Methods Phys Res 181 749-754... 

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