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Proceedings of the Koyal Society of Edinburgh. [Sess. 
(2) The occurrence of transition groups in which both the petroliferous 
and the carbonaceous phases are in evidence. 
(3) The fact that in such cases the petroliferous phase is always 
associated with more argillaceous and less pervious strata than the carbon- 
aceous phase. 
(4) The fact that when a petroliferous series is thoroughly exposed to 
weathering, the argillaceous and less pervious beds retain petroleum im- 
pregnations long after porous sandstones and limestones are deprived of all 
traces of petroleum. 
(5) The fact that oil can be naturally filtered by migration through 
very slightly pervious strata, the filtration taking the form of the removal 
to a greater or less extent of the heavier and less volatile hydrocarbons, 
especially the unsaturated hydrocarbons. 
(6) The nature of the process of inspissation. 
(7) The occurrence of intrusive manjaks or “ native bitumens ” in argil- 
laceous rocks overlying rich and porous oil-rocks. 
(c) From New Brunswick. 
We have now considered some of the characteristics of oil-shale fields 
and of oil-fields, and have noted certain minor points of resemblance 
brought out by a study of field relations. It remains now to bring into 
line and connect the various items of evidence by the study of an area 
where oil-field and shale-field conditions approach each other very closely. 
For this purpose no better field could be selected than New Brunswick. 
The oil-shales of New Brunswick have been known for many years, and 
have been examined by many competent geologists, but have not as yet 
been mined extensively. They belong to the Devonian formation, which 
lies upon an irregular surface of pre-Cambrian rocks in this region. It is, 
however, to one particular locality that attention is called, i.e. the Albert 
Mine, Albert County, whence albertite takes its name. 
At this place there is an anticline of shales about 1000 yards long, 
rising from beneath an unconformable capping of arenaceous strata. The 
anticline is complicated by sharp minor folding, and the structure is very 
similar to that described in a Barbados manjak-field above. Almost but 
not quite along the crest of the anticline a very highly inclined vein of 
albertite was worked for many years for a distance of some 2800 feet along 
the strike, and to a depth of 1300 feet, while exploratory workings have 
been carried to a depth of a further 200 feet, and have found the vein 
breaking up into a network of fine stringers among shales, and finally 
reaching sandstone beds, where traces of semi-liquid bitumen were 
