30 THE IRON ORE DISTRICT OF EAST TEXAS. 



2. NODULAR, OR G-EODE ORES. 



" These ores, though somewhat similar in chemical composition, are dis 

 tinctly different in physical character and in their mode of occurrence from 

 those already described. They are well developed in the northern part of 

 Marion County and in southern Cass County, and extend thence into Morris, 

 Camp, Upshur, and the counties lying to the west. 



"The ore is a brown hematite and occurs in a great variety of forms. It 

 very rarely shows the laminated structure of the brown laminated ores or 

 their resinous lustre. It generally occurs as nodules or geodes, or as honey- 

 combed, botryoidal, stalactitic, and mammillary masses. It is rusty brown, 

 yellow, dull red, or even black in color, and has a glossy, dull, or earthy 

 lustre. The most characteristic feature of the ore is the nodular or geode 

 form in which it occurs. Some of the beds are made up of these masses, 

 either loose in a sandy clay matrix or solidified in a bed by a ferruginous 

 cement. The ore lies horizontally at or near the tops of the hills, in the same 

 manner as the brown laminated ores to the south of the Sabine River. The 

 beds vary in thickness from less than one foot to over ten feet, the thicker 

 ones being often inter bedded with thin seams of sand. The ore-bearing beds 

 are immediately overlaid by sandy or sandy clayey strata. The sand beds are 

 in the majority, though pure clay is found at some distance below the ore. 

 The overlying sands are at times entirely eroded and the solid floor of brown 

 hematite is exposed to view. In other places it is covered by from one to 

 thirty feet or more of sand. This overlying stratum varies considerably in 

 character; sometimes the sands are loose and gray, at others more or less 

 solidified and deeply stained by iron. Sometimes they contain considerable 

 clay and show ferruginous segregations, so that a section of the bed discloses 

 lumps of hard, yellow semi-hardened sandy clay. The beds also often have 

 a mottled red, yellow, and white appearance, and contain thin seams and 

 lumps of clay. The sands are very much cross-bedded, and frequently layers 

 of hard-pan or thin ore are seen following the lines of cross-bedding. Unlike 

 the ores of Cherokee, these beds are not dependent on the thickness of the 

 immediately overlying sands. 



" Sometimes, though not so often as in Cherokee County, the ore is capped 

 by a stratum of hard ferruginous sandstone* varying from one inch to over 

 a foot in thickness, 'and occasionally similar beds are interstratified with the 

 ore. The line of separation of the top sandstone and the ore bed is sharp and 

 well defined. Though the iron ore is usually found near the tops of the hills, 

 one or more beds are often seen at a lower level, lying horizontally like the 

 upper bed, and separated from it by sands. These lower beds, unlike those 



*Frequently this sandstone is found alone and without any ore. In such cases it some- 

 times reaches a thickness of over twenty feet. (See Building Stone.) 



