-- 
‘BD 
Ville Pommereul ( Boring ). 
fe im: 
Brick Earth and Gravel ... ne aks 6 9 
Tertiary Sands... San a Seo.) 4810 
White Chalk et Be 34 a 300 0 
Chalk Marl ay BS as 3. 544 6 
Tourtia ... Se aa mae cs B eee 
Greensands Ss oe ade eo So LO 
Coal Measures at 1,036 5 
Boring at Calais. 
fe. “in: 
Sands and Gravel ... =! = 2EF 1804.0 
Tertiary Strata... as Roe seep e Gling (0 
Chalk and Chalk Marl a sos es 162) a0 
Upper Greensand } ete “ 3.0 
Gault? ... Pets cn see uiWZE RO 
Carboniferous Strata a saz eo LOGE TO 
1,138 0 
Although so many formations are absent within and immediately 
around the coal basins of France and Belgium, many of them are 
found to exist in the adjoining country at no great distance. In 
a paper contributed by the Rev. J. T.. Blake .to the Geological 
Society in 1881 on the Jurassic of the Paris basin, he shows that 
most of the subdivisions of the Oolite from the Portland beds to 
the Oxford Clay are there represented, and the lower divisions 
‘of the Secondary rocks are met with in various parts of the 
Continent. 
In comparing the conditions within the coalfield of France and 
Belgium with what prevail outside that area, we are reminded of 
a similar comparison drawn by Mr. Charles Moore in this 
neighbourhood in his able paper on ‘Abnormal Secondary 
Deposits,” in which he shewed that many of those formations 
were either absent or only thinly represented in the Somersetshire 
‘coal basin. The inference to be drawn in’ both instances is the 
