270 The American Geologist. April, 1894 
careous in composition and arenaceous in texture. Moreover, 
there is a fairly constant difference between the upper and 
lower portions of the deposit, the lower strata being coarser 
and the upper finer, while the uppermost materials are finest 
of all, particularly within the many shallow interstream basins 
circumscribed by levee-flanked bayous. Towards and beyond 
the Sabine these conditions slowly change. In the first place 
the element of northern rock flour diminishes and the calca- 
reous nodules frequently fail ; then the Red river sands di- 
minish and the materials become more tenacious; meantime 
an element of black mud, such as is carried down by the riv 
ers flowing over the Cretaceous chalks of Texas, appears and 
the deposit becomes the black tenacious clay characteristic of 
.southeastern Texas."* 
Tlie greater portion of the county is of very recent origin 
and, as already stated, mostly marsh, and the rest belongs to 
the Port Hudson clays. These clays are, however, very irreg- 
ular in their appearance and texture, and, although forming 
the prevailing substructure of the country, frequently give 
place to very extensive deposits of sand. The element of 
black mud referred to by Mr. McGee as forming the prevailing 
characteristic black tenacious clay of southeastern Texas, is 
nowhere present within the county. The presence of such 
black mud can hardly be looked for in this region, as none of 
the rivers directly involved obtain an}'' of their sediment from 
the Cretaceous areas of the state. The Neches, with its most 
important tributary, the Angelina, are both confined to the 
Tertiary areas throughout their whole length, while the Sabine 
can only be said to enter the Cretaceous in Hunt county, 
through the interposition of several small creeks forming its 
headwaters. The lime nodules, although characteristic of the 
clays, are by no means universal, but occur usually in patches, 
some of which are very extensive. On Pine Island bayou the 
Port Hudson clays are seen near the railway crossing at the 
Sabine & East Texas railway bridge, and still farther down 
the bayou at John Kerr's ferry. There they are pink and blue 
■claj^s, the blue predominating. In a deep sewer near the 
railway station in Beaumont the section shows from two to 
*"L,afayette Formation," W. J. McGee. Twelfth Annual Report, U. S. 
Geol. Survey, pp. 404-405. 
