1895715“)! No. 'l'Hl-i liAltIBh'U-UllltUVllIlAN BEDS I
As concerns the stratigrapliir evidence of this trilohite. we see with
considerable rert y that we are in the middle or upper part at the Cambrian, although no more e, .rt determination is possihle,
Th" sinng find of a tramhrmn fossil is of extremely great interest, as it is the only one hitherto known from the Arctic Nrn'th Ameriran Archipelago. tn the coarse ’
sediments that m-rnr ronnnonly all over the Arctic regions, above the arrlnean rocks. no fossils older than from the Tienton period have so far heen disrovrrerlt
Once more reverting to Scum. "The next member In the strati- graphioal order. overlying the second of the above series of conglome- rates. is a hell of light greyish-white limestone. about 350 it, thick which cropped out midway tip the vertical fare at Cape Victoria Head".
The limestone here mentioned exhibits. in the pic.
s ln'ought ha k. a somewhat irregular appearanre. some. heng rather dark and extremely compact, nth
lighter and Inorl‘ coarsely cry 'tallino. ispecially typical are the extremer lretpient slyloI/ite formations. varying lrum quite
small to 1 dm in height. As rega Is in, . we can commonly see sections of fossil lragments. especially ol orthoeerites. from which l'arl the limestone is named orthMeme-limestone try SCH
can see some hadly pre.
In addition we
rved hryozoa stems without structure. We only see the central «anal ltttll'tttetl by more roarser crystalline ralcite,
whilst the matrix around is very liner grained, Any 'y'stematir deter-
mination is out of the question. The only remains of organism nhirh mnld supply us with any clue to the geologiual ago oi thislimestone. are those of certain small trilobites.
In spite of a very fragmentary character they : 'e of considerable in-
terest Although a study at these remains does not give us a deter- mination of the spec s. we may presume that we are dealing with the transition zones hetween litllllltl'ltlll and Ordovician. A.» tar as can
he understood we have a aligrnphiral equivalent to the zone whirh
is now considered as the val
lowest Ol‘dm'ivian, and which l't)l|ll|l the
eartl . ‘an m'.
surface in characterred by a (Ianihro-orltovi d launa. lt corresponds to the Pogonip Group in Nevada. the 'l‘remador in Eng~ land. the Ceratopyge division in Scandinavia. etc.
tn the limestone t'rnni Victut'ia llead we find two imperteut central portions at head shields, which show an evident Cambrian nhararter.
Presumably they represent Plyc/Iopuriu species. (tne head (pl. 4. [ig..'i|
