The Philosophy of Conducting a Fluid Inclusion Study
To think of fluid inclusion analysis as a “black box technique” is a grave mistake. A fluid inclusion study is not something that one “just does” — it requires a more scientific methodology, first involving the formulation of specific questions along with conceivable hypotheses for possible outcomes. Such a philosophical approach is necessary because very commonly the fluid inclusion data that are required to answer a particular question may not be present in the rocks! So, a more structured approach may allow recognition of such a predicament at an early stage in a proposed fluid inclusion study, preventing the ordeal of wasting considerable effort in the collection of meaningless data.
The authors know of many horror stories in which a research supervisor has told a student, consultant, or subordinate to “do a fluid inclusion study” on some set of samples. Of course, the doleful soul taking the orders assumes it must be possible because the boss told him to do it, and feels compelled to come up with data no matter what the fluid inclusion population looks like. Time and time again, these researchers spend months conducting a fluid inclusion study on material that may not have the fluid inclusions appropriate for answering a particular set of questions. For example, if the research supervisor wanted to know the temperature and salinity from which some authigenic mineral precipitated, the subordinate would feel compelled to find primary fluid inclusions in that mineral, whether they were present or not. The subordinate would deceive
Figures & Tables
The past decade has revealed significant advantages to using fluid inclusions as a means of understanding the physical and chemical history of fluids in sedimentary basins, but it also has revealed important limitations which have required that a new approach must be employed to effectively use fluid inclusions. This book is divided into six sections: (1) what fluid inclusions are and what geologic history they are capable of recording; (2) basic phase equilibria that must be known to understand the behavior of pore fluids and fluid inclusions in nature; (3) the question of validity of using fluid inclusions as records of ancient diagenetic systems is dealt with in such a way that the questions commonly asked about the limitations of the technique are addressed; (4) hot to conduct a fluid inclusion study, a new petrographically based approach for conducting fluid inclusion research that is followed by methods that allow for the interpretation of compositions of pore fluids that existed in sedimentary rocks, and methods of geothermometry and geobarometry; (5) selected case histories that are designed specifically to give practice in evaluating fluid inclusion data from the diagenetic realm; and (6) a summary of the arsenal of analytical techniques that may be applied to fluid inclusions to develop additional constraints on fluid inclusion composition.