T-A-IBIjE "VII. 209 
Showing Range in Silica of Lamprophyres and their Equivalent Surface Rocks. 
Lamprophyres. 
Volcanic Rocks. 
Si0 2 
Rock. 
Si0 2 
Rock. 
40.95 
39.29 
... Nephelinite 
41.43 
Minette 
40.26 
Leucite-basalt 
41.63 
41.01 
.Hornblende-basalt 
41.94 
42.21 
. Nephelinite 
42.07 
Minette 
42.30 
.. Nephelinite 
42.77 
42.68 
.Hornblende-basalt 
44.94 
Minette 
42 69 
. Nephelinite 
45.14 
42.92 
Leucite-basalt 
45 93 
Minette 
42.92 
46.00 
43.90 
. Nephelinite 
46.17 
44.04 
.Basalt 
47.56 
Minette 
44.14 
47.64 
.... Kersantite 
44 35 
Leucite-basalt 
47.73 
Minette 
44.62 
Leucite-basalt 
47.88 
Minette 
44.80 
47.99 
Minette 
45.04 
. Nephelinite 
48.43 
Syenite 
46.41 
Leucitophyre 
48.57 
Minette 
46.97 
. Nephelinite 
49.01 
Minette 
47.16 
Leucitophyre 
49.16 
47.17 
Leucitophyre 
49 50 
47.44 
.Basalt 
49.52 
47.64 
.Basalt 
49.82 
47 78 
Leucitophyre 
50.80 
48.17 
Leucitophyre 
51.15 
Minette 
48.21 
51.64 
Minette 
48.27 
. Nephelinite 
51 94 
48.28 
Nephelinite 
52.32 
Minette 
48.54 
Leucitophyre 
52.61 
48.68 
Leucitophyre 
52.68 
49.15 
Leucitophyre 
53.16 
50 75 
."Rfl.sa.lt 
53^26 
50.99 
.Hornblende-ande- 
53.40 
site 
53.42 
Minette 
51.12 
..Basalt 
54.25 
51.41 
Trachyte 
54.80 
51.51 
. Mica-melaphvre 
54.94 
52.37 
.Basalt 
55.06 
52.42 
.Augite-andesite 
55.76 
Minette 
52.58 
56.37 
Minette 
52.69 
.Mica-melaphyre 
56.80 
Minette 
53.17 
57.05 
Minette 
53.22 
.Mica-melaphyre 
57.30 
Minette 
53.33 
Trachyte 
57.37 
Minette 
53.50 
58.25 
Syenite 
53.75 
58.34 
Minette 
53.81 
.Basalt 
60 02 
Minette 
54.10 
61.12 
Minette 
54.39 
..Basalt 
62.00 
54.80 
. Bfl.sa.lt 
63.61 
54 82 
.... Mela.phyre 
67.28 
Minette 
55.00 
55 08 
Trachyte 
55.35 
57.04 
57.48 
.. Mica-basalt 
58.30 
59 21 
.Porphyrite 
