LAVKE SUPERIOR DIVISION.
INSTRUCTIONS.
1 . Oiarl Mat lst two pages of this book will be devoted to one section. On
Iho left-hand page, place a map of as much of the section as has actually been seen.
Denote rivers, lakes, marshes, etc., by the usual topographical signs. Denote the
ledges of rock, when no structure is made out, by cross-hatching, making the cross-
hlatching cover as nearly as possible the areas occupied by the exposures. If the
ock is a massive one, but still more or less plainly bedded, use the same sign with
dip arrow and number attached, showing the direction and amount of the dip.
Denote a shaly or other very plainly bedded ledge by right parallel lines, and a ledge
Paving asecondary structure by wavy parallel lines running in the direction of the
-trike, with dip arrow and nunmber attached as before. The greatest care must be
aken to avoid confusiug slaty or schistose structure with bedding, and in all cases
,,here there is the least doubt about the true bedding direction, indicate it by a
uery. To each exposure on the face of the map attach the number of the specimen
epresenting it. In mapping the section count each of the spaces between the blue
.nes as 100 paces, and twenty of these spaces to one mile, or 2,000 paces. Usually
be southeast corner will be placed at the bottom of the page, or at the first black
ne above the bottom of the page, and at the right-hand side. If, however, for any
eason, it is desirable to show portions of an adjoining section, the southeast corner
-ay be shifted up, or the map may be turned around and the north placed at the left-
and side of the page. The ruling of the left-hand pages is also arranged so that,
desirable, a larger or a smaller scale can be used, eight inches, two inches, one
neb, or one-half inch to the mile. With the two-inch scale, the squares outlined
n black represent sections, and those in red, quarter sections and "forties," while
be space between the blue lines is 200 paces.
2. On the right-hand page place the notes descriptive of the exposures. Begin in
each case with the number of the specimen, placing the number on the left-hand
-ide of the red line, after which give in order on the right of the samo red line the
'osition of the ledges as reckoned in paces from the southeast corner of the section
and the dip and strike when observable, the latter always being expressed from the
north; for instance 4025, 250 X, 300 W., Strike, N. 780 E., Dip 50' S. Then follow
vith a full description of the ledge. When topographical maps are used for
ications this paragraph applies only ih part.
3. Collect a specimen from every ledge, or wherever there is a change of rock on
ny one ledge, taking care to get fresh material, unless for a special purjose the
eathered surface is desired. In case of trips made on foot or in canoes, for long
distances, neighboring ledges, unquestionably of one kind of rock, need not be
pecimened. The position and extent of the ledges not specimened should be
narked on the map, with notes that each is of a rock identical with specimen
o-and-so. Under the same conditions small-sized specimens, trimmed to a uniform
>ize of 2 x 2  x ( inches will be allowed, but in all other cases large-sized specimens,
rimmed to a size of 3 x 4 x1 inches, must be selected, in accordance with section 3,
bhapter IV, p. 44, Regulations of the U. S. Geological Survey. Specimens should
lot be placed together without protection in the collecting bag, as the fresh surfaces,
inportant in determining the character of rocks, are thus destroyed. They should
>e damaged by no remporary mark, but the numbers should be at once marked in
-t least two places upon the inclosing paper or cloth bags. Specimens may be
permanently marked in camp by painting the numbers upon them in white upon a
Iblack background, using Silver White and Ivory Black oil tubes for color, with
turpentine as a diluent.
4. On the last twenty-five pages of the book give, as may seem desirable, a general
-ccount of the examination of the region mapped in the previous pages, correlation
of observations, sketches, cross sections, etc.
5. Forward this note book as soon as filled as registered mail matter to C. R. Van
TieU. IS. Geologist, Madison, Wis                          ;-717