Note 30 — APPENDIX.
Reading edition
Section I.
The section of the bank at the mouth of the Bear Lake River is as follows, beginning with the lowest bed:—
81Gravel, with thin layers of sand rising from the water's edge in a perpendicular cliff, to the height of30feet
Lignite (70 to 80 and 84)1
83Potter's clay of a bluish gray colour, alternating with layers of sand40
A sloping uneven brow, covered with soil, extends to the summit of the bank20
91
Lydian stone is the most abundant, and whitish quartz the least so of the pebbles mentioned in the text as entering into the composition of the gravel.
82A little farther up the Mackenzie, this bed of gravel passes into sand, which, in some spots, has sufficient coherence to merit for it the name of sandstone. During a great part even of the summer season, all the beds of sand are frozen into a hard sandstone; but a piece having been broken off and put into the pocket, speedily thawed into sand.
83Specimens of the clay, which I have denominated potter's clay, taken from near the beds of lignite, have a colour intermediate between yellowish-gray and clove-brown, a dull earthy fracture, and a slightly greasy feel. It is not gritty under the knife, and acquires a slightly shining smooth surface, adheres slightly to the tongue, and, when moistened with water, assumes a darker colour, and becomes plastic.
Section II.
About five miles above Bear Lake River, the cliff consists of Slaty sandstone evidently composed of the same materials with the friable kinds described in the text, but having tenacity enough to form a building stone. It incloses some
seams of lignite10feet
Lignite14½
Clay and Sand50
Irregular slope from top of cliff to summit of bank90
154½
Section III.
A little farther up the river than the preceding:—
85Pipe-clay on a level with the water1foot
86Lignite1
90Potter's clay14feet
87Pipe-clay1foot
89Lignite1
91Potter's clay10feet
Lignite1foot
Sandstone8feet
Lignite2½
Potter's clay10
94Friable sandstone and clay20
Sandstone a little more durable12
Sloping Summit40
121½
The pipe-clay, when taken newly from the bed, is soft and plastic, has little grittiness, and when chewed for a little time, a somewhat unctuous but not unpleasant taste. When dried in the air it acquires the hardness of chalk, adheres to the tongue, and has the appearance of the whiter kinds of English pipe-clay, but is more meagre.
Section IV.
A little above the preceding:—
A precipitous bank of gravel12feet
Lignite and clay, the beds concealed by debris40
Friable sandstone30
Height of the cliff82
Section V.
Ten miles above Bear Lake River, at the junction of a small torrent with the Mackenzie, there is a cliff about forty feet high, in which the strata have a dip of sixty degrees to the southward.
98Bed, No. 1 Porcelain clay2yards
992 Potter's clay slightly bituminous
100, 1012½
3 Thin-slaty lignite, with two seams of clay-iron stone, an inch thick
104
1054 Pipe clay, (nine inches)¼
1065 Porcelain clay3
6 Bituminous clay3
1077 Lignite, with a conchoidal fracture2
8 Pipe clay¼
1109 Porcelain clay3
10 Bituminous clay3
11 Lignite, earthy paste, enclosing fibrous fragments2
12 Porcelain earth9
13 Bituminous clay
14 Porcelain earth
31yards
The three last beds it is probable, once inclosed seams of coal which have been consumed, but the quantity of debris prevented this from being ascertained satisfactorily during the hurried visit I paid to them.
108Over these inclined beds there is a shelving and crumbling cliff of sand and clay covered by a sloping bank of vegetable earth. A layer of peat at the summit has a thin slaty structure, and presents altogether, except in colour and lustre, a striking resemblance to the shaly lignite, forming bed No. 3 in the preceding Section.
104, 98. The substance composing beds Nos. 1 and 5, which I have denominated Porcelain clay, has a fine, granular texture, and the appearance of some varieties of chalk. It adheres slightly to the tongue, yields readily to the nail, is meagre, and soils the fingers slightly. There are many specks of coaly matter disseminated through it, and some minute scales of mica, and perhaps of quartz. When moistened with water, it becomes more friable, and is not plastic. It does not effervesce with acids.
Bed No. 9 is the same mineral that forms beds 1 and 5; but it has a grayer colour from the greater quantity of coaly particles, and its structure is slightly slaty.
The bituminous clay of bed No. 6, has a thick-slaty structure, a grayish-black colour, and a shining resinous streak. It is sectile, but does not yield to the nail. Pieces of lignite occur imbedded in it, and it is traversed by fibrous ramifications of carbonaceous matter.
Specimens 115, 116, 117, 118, 119, are of substances altered by contact with beds of burning coal.