The abbreviation TDS means total dissolved solids, best expressed in units of grams per liter, g/L, or milligrams per liter, mg/L. SALINITY, as used here, is synonomous with TDS. A much more formal and precise definition exists for seawater salinity, but is not required here.
The fluids which are the subject of this course are variously called: formation waters, subsurface sedimentary brines, basinal brines, oil field brines, pore waters, and connate brines. The term connate brine, as we will discuss in the next section, carries with it a specific genetic connotation. The other terms are better generic descriptors.
Many reserve the term BRINE for pore fluids having salinities in excess of 100,000 mg/L. Carpenter's (1978) classification is the best formal scheme for those who would like to use one:
I will use the term BRINE here in a much looser sense, without strict observance of the 100,000 mg/L lower limit. I have used 'brine' in the title of this short course and book to get the idea across that they deal with deep, basinal waters, not shallow, potable water systems.
The term GROUND WATER is usually reserved for shallow, fresh pore waters. The term METEORIC WATER will be used here to describe waters derived from rain or snow and having the isotopic composition of normal precipitation.
Figures & Tables
The topics covered in these notes have been selected to provide the general sedimentary geologist with an introduction to some of the key problems and a conversational familiarity with some of the basic techniques in this important area of sedimentary geology. A number of field examples are drawn from the Louisiana Gulf Coast, buy many of the general principles will be applicable to other areas and problems.