Record of Geology of Texas, 1887-1896. 
253 
403. Turner, Henry W. 
Volcanic Dust in Texas.* 
Science, H. S., Yol. I, pp. 453-455. April 26, 1895. 
“Gives a description by R. T. Hill of the locality [in the Llano Estacado 
region] where the material was found, and refers 'to similar volcanic mate- 
rial from Nebraska, Montana, Idaho, and California.’’ iFrom Week’s Bib- 
liog. and Index of N, A. Geol., Pal., etc.. Bull. U. S. Geol. Survey, No. 
146, p. 75. 
404. Van Hise, Cfiarles Richard. 
Principles of ISTorth American Precambrian Geology. 
IGth Annual Report of the U. S. Geol. Surv., Pt. I, pp. 571- 
843. Washington, 1895. 
(Precambrian Rocks of Texas, pp. 814-815.) 
“In Texas is a series of sedimentary rocks, named Llano by Walcott, 
which consists of alternating beds of shales, slates, sandstones, quartzites, 
limestones, ferruginous rocks, carbonaceous or graphitic schists, mica- 
schists, and chlorite-schists. There also occurs in this area granites and 
gneisses, a part of which are placed as a separate system by Comstock, 
but are regarded by Walcott as intrusive in the sedimentary rocks. 
Whether all of the granites and gneisses are intrusive or not, it is agreed 
by both that -the clastic series are cut by numerous eruptives, both basic 
and acidic, of which granite is the most prominent. Comstock also divides 
the sedimentary rocks into two series, between which he believes there is 
an unconformity. Resting upon the deeply eroded pre-Cambrian are the 
Potsdam Cambrian rocks. 
“It is clear that in Texas there is one, and possibly two, series of Algon- 
kian rocks, but whether the Archean is also represented is as yet unde- 
termined. The sedimentary rocks of the Texas area have been correlated 
by Walcott and Comstock with the Algonkian of the Grand Canyon 
region.” 
405 Vaughan, T. Wayland. 
SeetiDu of the Eocene at Old Port Caddo Landing, Harrison 
County, Texas, with Holes on a Collection of Plants from that 
Locality, by F. H. Knowlton. 
Amer. Geologist, Vol. XVI, pp. 304-309. Xov., 1895. 
In this paper two sections at Port Caddo are described. The first extends 
“from the corner of MoCathern’s field west to the landing on the south 
side of the road.” The second is “a few yards to the north of the road 
leading from the corner of McCa them’s field to the landing, in a ravine 
near Bonner’s spring.” 
“The interesting part of the above section, aside from the plants, is the 
interpretation of the phenomena seen in 3 of the firslt section and 2 
of the second. There has certainly been some erosion. Is it only a local 
unconformity, or do the sands, with the boulders, etc., at the base repre- 
sent what Mr. McGee has called the Columbian stage? After studying all 
