GLACIAL VARVED CLAY CONCRETIONS—BASSLER 
8. Oval examples with smooth base and 
regularly lobed upper surface (pl. 6). 
9. Turban-shaped concretions with smooth 
base and concentric lobes on upper sur- 
face (pl. 7, figs. 5-11), etc. 
10. Globular forms with surface marked by 
minute nodes (pl. 7, figs. 12-17, 20-24). 
11. Watch-shaped examples with terminal 
node and concentric ornamentation on 
upper surface (pl. 8, figs. 1-10). 
12. Elongate, twisted, and bent specimens 
(pl. 8, fig. 11). 
13. Convoluted globules joined at their ex- 
tremities (pl. 8, figs. 16-20). 
14. Circular to oval concretions with flat 
base marked by growth lines and lobed 
upper surface giving artistic effects 
(pl. 9). 
The term varved clays has been ex- 
tended by geologists to include all 
seasonally deposited clays, and so in 
future studies, ocean deposits of this 
nature, those of fresh-water lakes and 
other types not connected with glacial 
action must be distinguished. Glacial 
phenomena such as moraines, till, and 
scratched boulders will always be 
found in the vicinity of glacial varved 
clays, as a check on their identification. 
The writer now believes that the study 
of concretions of all kinds and ages 
promises scientific results much out of 
proportion to what is thought and 
known of them today. 
Concretion collecting simply as a 
hobby is recommended as a source of 
outdoor exercise and good health. 
Most often the layers yielding the most 
interesting claystones crop out along 
river beds. Here a boat and pair of 
boots are excellent adjuncts to this 
particular kind of fishing, while a 
trowel helps in landing the specimens. 
The student is especially urged to 
search more ancient glacial clays, for 
example, the varved deposits of the 
Proterozoic era over a half billion 
years ago, those of the close of the 
Paleozoic 200 million years since, and 
the Mesozoic 60 million years back in 
time. 
The same great spirit or intelli- 
gence that can produce life, manifests 
itself in the inorganic world in giving 
rise to these intriguing inanimate ob- 
jects, claystone concretions. 
275 
EXPLANTION OF PLATES 
PLATE 1 
Clay Island at Ryegate, Vt. 
Views of several slopes and samples of this 
mound of glacial varved clay, 75 feet high, 
which, unless otherwise mentioned, fur- 
nished the specimens photographed for illus- 
tration of this paper. At the left, a 60° slope 
showing the laminated, concretion-bearing 
clays, with a moist, dark-colored layer near 
the top which could start a landslide. In 
the center, three edge views of varved clay 
samples showing concretions restricted to the 
light-colored (summer) layers. In each case 
a dark (winter) layer capped the concre- 
tions, but in drying it was lost except in the 
topmost specimen. To the right, view of a 
40° slope with Mr. Pringle extracting con- 
cretions mainly with his hand trowel. Foot- 
holds must be cut to ascend the slope which 
ordinarily is dry and hard, but slippery and 
dangerous after a minute or two of rain. 
PrAtTE Ee 
Photographs of a series of claystone con- 
cretions, all about 14 natural size, illustrating 
the development from simple, bulletlike 
forms (fig. 1), through two joined together 
by a narrow band (fig. 2), the band increas- 
ing in size (figs. 3-5), a flat basal side showing 
growth lines (fig. 6), and top views (figs. 7-15) 
showing the band merging with the larger 
end and the smaller extremity developing 
the usual three-noded type, this combina- 
tion usually classed as loesspiippchen. A 
double-headed form with a constricted basal 
node is shown in figure 16, while figure 17 
represents a specimen formed of dark 
material with a cover of the lighter-colored 
clay, illustrating interrupted development. 
PLATE 3 
Specimens of thin, disklike concretions, 
about 24 natural size, formed in thin layers of 
clay. Thin, smooth, flat disks (figs. 1-4) 
consisting of one or several layers which split 
apart upon frost action. No. 1 shows two 
such layers partly separated, and No. 3 the 
faint concentric lines indicating growth about 
a center. Figures 5-11, coinlike concretions 
arising from small, thin disks (figs. 5, 6) 
which are smooth on the bottom but are 
progressively ornamented by flattened con- 
fluent lobes on top as more layers are added 
(figs. 7-11). Figures 12 and 13, smooth, 
hemispherical concretions with rounded edges 
and nodes of growth added at the sides, 
formed in thicker layers of the clay. Figures 
14 and 15, thin, disklike forms merged 
together laterally, exhibiting the surface 
ornamentation (fig. 14), and a view through 
the center when split apart. Figures 16-19, 
a series of thin, platelike specimens illus- 
