108 THE IRON ORE DISTRICT OF EAST TEXAS. 



the courses usually pursued. These are, first, burning in the old fashioned 

 pit, in which the wood to be burned is covered by a layer of charcoal dust 

 and earth; second, burning in kiln or oven, in which the charccal is manu- 

 factured in a brick oven; and, third, burning in retorts, in which the wood 

 is carbonized in closed tubes. (For details of methods and difference of cost, 

 the reader is referred to the article by Mr. John Birkinbine,* on pages 33-37 

 of this Report.) 



CLAYS. 



The clays found in the vicinity of the town of Jefferson, Marion County, 

 belong to the Timber Belt Beds of Dr. Penrose, and are closely associated 

 with the red and white stratified sands of that series. 



On the northern side of the A. Richardson headright the clay lies close to 

 the surfaee, having as a cover about two feet of a gravelly sand containing a 

 considerable quantity of nodular concretionary iron ore and a small amount 

 of a broken and fragmentary conglomerate of siliceous pebbles, with an iron 

 oxide as the cementing matter. These siliceous pebbles are milky white in 

 color and do not exceed half an inch in the greatest diameter. The clay is 

 exposed in a small creek and around a spring issuing from the side of the 

 hill, and is not more than one hundred yards from Mr. Farrell's house, and 

 •about two hundred and fifty yards from the main line of the Texas and 

 Pacific Railway. 



The eastern end of the hill upon which this clay lies has been cut through 

 by the railway, and the section shown in the cutting gives the following: 



1. Gravelly ore, with nodules of concretionary iron ore 2 feet. 



2. Stratified red and white sands and sandy clay, in layers of from one-half to three- 



fourths of an inch, apparently lying in a horizontal condition . 6 feet. 



No. 2 is cut near the center of the cutting by a bed of ferruginous nodules, 

 dipping south at a high angle, and about one foot thick. Near the southern 

 end it is also broken by another deposit of the same sort of material and by 

 thinly laminated ore. 



The clays lie above this cutting about twenty-five feet. 



The next deposit of clay is found in the Thomas Gillespie and Stephen 

 Smith surveys, and stretches across from Black Cypress Bayou to near the 

 Big Cypress Bayou. This deposit is exposed in numerous localities around 

 Jefferson, the most extensive exposures being those on the Jefferson and Lin- 

 den road, along which it is seen cropping out in the banks of cuttings and 



*Charcoal Burning in Texas. By John Birkinbine, C. E., Secretary of the United States 

 Association of Charcoal Iron Workers. Second Annual Report of the Geological Survey 

 of Texas, page 33. 



