J. D. Dana—Taconic Rocks and Stratigraphy. 399 
mg uplift—the source of foliation or slaty cleavage; if to any 
pressure, it is to vertical, like that of the gravitating mass, or 
that pressure to which a shaly structure is attributed. 
3. Stratigraphy of the region.—The question in this region of 
upturned, flexed and crystalline rocks, is, as in Part I— 
Which is normally the upper stratum, the limestone, or the 
schist? Are the schist ridges usually synclinals or anticlinals ? 
The fact that in the southern part of the Appalachians—the 
Alleghany Mountains—the rzdges are usually synclinals shows 
that the view as to their being synchinals in the Taconic region, 
if it be sustained, is not exceptional. 
a. Characters of the flecures.—The flexures over the area have 
usually the north-by-east direction or strike characterizing the 
main Taconic range. They generally, and probably always, 
have the axis inclined instead of horizontal—sometimes to the 
northward and as often’ to the southward, the two kinds being 
necessarily accompaniments in a complex system of warping 
(as not badly illustrated in the sleeve of a coat at the elbow- 
bend inside). The inclination is sometimes indicated by the 
form of the ground-plan of the schist ridges—that is by its 
widening from one end to the other. An example is seen on 
the map, west of the village of Great Barrington: the area nar- 
rows southward; and it necessarily follows that the axis of the 
flexure inclines to the southward if it is an anticlinal and to 
the northward, if a synclinal. ‘Two similar areas occur in the 
town of West Stockbridge, those of Maple Hill and Tom Ball 
(the latter extendiny into the town of 
_Great Barrington); others in Lee and 
Pittsfield. | 
The dips, moreover, often indicate the 
precise kind of flexure. At the narrow 
end, they are usually eastward on both 
the east and west sides, as in a careened 
trough, as in the annexed (fig. 4); but 
at the other, while eastward on the west 
side, they are often westward on the east 
side, indicating a tray lke synclieal (fig. 1) 
—the whole fold being, therefore, an in- 
clined tray-like synclinal with the nar- 
rower end of the synclinal, or that where 
the effects of pressure were greatest, ca- 
reened or overthrust. The succession of 
figures 1, 2, 3, 4, represent sections of a 
mountain ridge having a broad tray-like 
synclinal structure (1) at one end and a 
careened synclinal (4) at the other, with two of the interme- 
diate conditions in 2 and 3; and if the series of figures is 
viewed upside down, they then serve to illustrate the corre- 
