Formulae 



Carbonate percentages : 



,CaC03= 0.1605 |^- 



where V = volume of CQj evolved, in ml. 



P = atmospheric pressure corrected for water 

 vapor pressure, in mm. Hg 



T = temperature in ° K 



W= sample weight in gms. 



Nitrogen percentages: 



ajuf^ - (milliequivalents HCl) (1.4) 

 sample weight 



meq HCl = (ml. HCl) (N^ci) " (ml. NaOH) (N^.^q^) 



Carbon percentages: 



i^oC: 



(Average blank value - Burette rdg.)(20)(0.138) 

 (ml. blank) (taken from standardization) 



If all reagents are exactly made then the ml. blank will 

 equal 20 and the equation will be a simple corrected 

 burette reading multiplied by 0.138. 



METHODS 



Textural analysis '■ 



Reagents : 



1. Dispersing agent - 40 to 50 gms. of 

 Calgon are dissolved in 200 ml. of 

 water and then added to 5 gallons 

 of water and mixed. A 50-ml. ali- 

 quot is drawn off by pipette and 

 dried at 100° C. The weight of 

 dispersing agent per 50 ml. is 

 noted on the storage bottle. 



Procedure : A 20- to 30-gm. sample 

 is washed with dispersing agent through 

 a screen of 0.062 mm. mesh and the 

 fine material is caught in a 1000-ml. 

 graduated cylinder. The portion coarser 

 than 0.062 mm. in diameter is dried. 

 The finer fraction is brought up to 

 1 liter with dispersing agent and agi- 

 tated. During agitation a 50-ml. aliquot 

 is drawn by pipette and dried and 

 weighed. If an appreciable amount of 

 fine-grained material is present, sub- 

 sequent aliquots are removed accord- 

 ing to a previously computed time 

 schedule from a fixed depth below the 



* Following Krumbein and Pettijohn, 1938 



suspension surface (see Krumbein and 

 Pettijohn, 1938, pp. 135-181). This 

 pipette analysis will yield the size dis- 

 tribution of the fine fraction. The 

 coarser particles are graded by seiving 

 them through a nested set of screens 

 with meshes ranging from 4 mm. to 

 0.062 mm. The intervals are taken 

 from Wentworth's classification of 

 grain sizes (1922). The sand grades 

 are carefully removed from each 

 screen, examined under a binocular 

 microscope to check for possible aggre- 

 gation, and weighed. 



After both distributions have been 

 determined the results of the separate 

 analyses are combined to yield the 

 gross size gradation in the entire 

 sample. 



The weight percentages are tabulated 

 and punched into IBM code cards. The 

 parameters of the size distributions are 

 then computed by an appropriate pro- 

 gram on the digital computer. 



After weight percentages in each size 

 grade have been computed, the totals 

 for particles of less than 0.062 mm. 

 diameter, 0.062 to 2.000 mm. diameter, 

 and greater than 2.000 mm. diameter 

 are calculated. These are the silt-clay, 

 sand, and gravel percentages respec- 

 tively. 



Carbonate content' 



Reagents: 



1. l.ON sulfuric acid - 56 ml. of con- 

 centrated sulfuric acid are added 

 to distilled water and brought up to 

 1 liter in a volumetric flask. 



Procedure : Approximately 0.300 gm. 

 of dried powdered sample is placed in 

 the sample tube of a carbonate appa- 

 ratus. The system is brought to the 

 room pressure and then closed. About 

 4 to 5 ml. of the acid are introduced 

 into the closed system via the acid 

 holder tube and a slight vacuum is 

 placed on the system by lowering the 

 mercury manometer. After the initial 

 reaction has ceased, the sample tube 

 is heated gently until the reaction is 

 complete. After the system has been 

 cooled to room temperature, the pres- 



' Following Bien. 1952 



14 



