A. M, CAMPBELL On a New or Hitherto Unrecognized Geo- logical Horizon in the Gas and Oil Redon ol Western Ontario. By H. TVf. AMI. Paper read March, /S^i^>, before the Montreal Meetings of The Canadian Mining Institute. On a New or Hitherto Unrecognised Geological Horizon in the Gas and Oil Region of West^ern Ontario, Canada. Uy IlKNKV M. Ami, M.A., I'.C.S. The forraaiion or geological horizon in (jueslion consists of a series of fine-grained calcareo-argillaceous pyriliferous shales associated wiih bands of niarine fossiliferous limestone which overlie the Portage and (lenesee shales of Western (~>niario. 'I'he shales of Kettle Point on I,ake Huron have, uj) to the present, been recognised as the highest strata in the geological scale of Pala;o/.oic sediments occurring in Western Ontario. These shales have been referred to the upper division of the Devonian system and are well develoi)ed at Kettle Point, where they crop, owing to a gentle arch or anticline occurring at that locality in the Palaeozoic series. In Ohio and New York States they were recog- nized by Prof, Orion and Dr. J. M. Clarke, whilst Dr. Johnson has identified similar shales from the drift of the Chicago boulder clays. The new geological horizon which overlies the Kettle Point shales as stated above is marine in origin. It contains a fossil fauna of not less than seven distinct species of organisms, with which I shall not deal at present as being outside the scope ot this brief note. These organisms mark a distinct period of encroachment of the old PaU\30zoic sea when marine sediments were laid down. This formation which is probably part and parcel of the true marine Chemung tormation so extensively developed across the lake in Michi- gan and again and better in New York .State across Lake Mrie, was reached by the drill at a depth of 600 feet below the surface. The superficial or Pleis'ocene dejjosits occupy but a fraction of the upper 600 feet and in them are found fragments of rock belonging to the Portage and Genesee shales underlying the hitherto unrecognised and unrecorded marine beds at this horizon in Ontario en) 2 A llitJicrlo Unrecognised Geological Horizon. The shales which under He this new forniaiion when subjected to a close examination have revealed many interesting features, foremost amongst which is the presence of numerous examples of the macrospores J'rotosalvhiia /luronensis described 1»3' Sir William Dawson in his " Report on the Erian Flora of Canada" in 1871. These macrospores from the bore hole and drillings when examined under a microscope show very marked characters. 'I'heyare thus described by Sir William Dawson (loc. cit. supra) : " Macrospores in the form of discs or globes, smooth and thick walled, the walls penetrated by minute radiating pores. Diameter about yjoths of an inch or a little more. When in situ several macrospores are contained in a thin cellular sporocarp, probably globular in form. From the upper Erian and perhaps lower carboniferous shales of Kettle Point." The Niagara and Clinton formations of the Silurian system and the Corniferous formation of the Devonian system, are the formations from which most of the gas and petroleum of Canada have l.itherto been obtained in the Province of Ontario. So far as 1 am aware, none of the oil or gas i)roducing wells of Western Ontario derive their oil or gas from the Trenton formation of the Ordovician (Lower Silurian) system. (See discussion.) That the Trenton formation of the States of Ohio and Pennsylvania is well known as a gas and oil-producing series of strata need scarcely be mentioned before this Mining Institute, and whilst in only one or two iso lated instances the Tienton formation has been reached by the drill, nevertheless we venture to hope that before long wells sunk sufficiently dee}) to reach the Trenton formation, which underlies the Devonian and Silurian strata of the Huron-l'>ie peninsula of Ontario at a depth of some 3,000 feet, (more or less, depending upon the points of depar- ture,) will reward the enterprising company which will make the ven- ture. It will be clearly seen that every few hundred feel of strata which overlie the gas- or oil-producing strata which are eagerly sought by the drillers makes considerable difference in the calculations as to the relative i)os"tion and exact geological hori/on indicated. From a very complete series of drillings recently leceived at the (ieological Survey A Hitherto Uu recognised Gcolo^^ical Hon -.on. SECTION OF VVTELl AT WALLACEBITIG OXT, C-ARACTER Of STRATA TRAVEHStD BV OniLL TH.CKNtSS OF STRATA CSOlOGlCAL FOBMATIONS' V- Bvuith r 'Jurs . c.„.c=t- o '- . • J n~r -i — I — r^? 5" 1 — I — r-^ T — r^ LiLl * Port cute luut Ofteuee ssST^;.'-' -^i I T'S- r" f ' ; : niir"^ C ^:l;^ I ij/ht coloured Utnt' i ' T I III 1 — r iturvf 7 Sanifitsnr? J lIj -rrr; JTT^ ^^3 IlLu I'll! 1 1 1 Till rrriiTTj 'I'u.'iLu. 15 feet 120 140 600 950 1000 Httfett 2. C*i< 10 Ou^lph i«20 " 1990 • ;0,t,lrui\^ites ) Ifuronensis Dawson, which connects these Devonian formations of the Chemung, Portage and Genesee. The Hamilton shales and clays and limestones were then traversed and taking the drill down to a depth of nearly 800 feet, which amount, had the fossils not been obtained, would not have been reckoned from the section in that part of Canada and led to a grievous error in our calculations. As it was, the drill traversed the above formations, then the Corn- iferous and the Oriskany (if present at all) through the lower Heider- berg and Water Lime group consistuig for the most part of fine-grained compact dolomites succeeded downward by the gypsum and salt-bearing dolomites of the Onondaga and Salina formations. The Guelph and Niagara dolomites and limestones were then traversed in the same succession or order as mentioned and the underlying Clinton shales like- // llitlurto L iirccii^^iiiicd Licologkal Horizon. wise. Anhe last hearingand from sam])les received at the Department the ■■' gray band " of the Medina — consisting of hard, dry, liuhl gray s'tndrock — was actually struck at a dei)th of 2,035 feet, and lower down to a depth of 2,100 feet the typical red mids and shales of the Medina formation were being traversed, leaving no doubt whatever as to the geological horizon reached. It would then follow from the above that — 1. The Hamilton formation of \Vestern Ontario extends over a wider area than was at one time suspected. 2. That the Portage and (leneseeor Kettle Point shales also extend south from Kettle Point to a point in Bothwell County beyond Wallace- burg. 3. That above the Kettle Point or J'rotosah'inia ( Spora/iii^iies ) shales there occurs a distinct series of marine beds containing numerous fossil organisms, including crinoidea, Crustacea, brachiopoda, not previously recognised, and forming an important cover over the under- lying Hamilton, Corniferous and older formations in the Huron-Erie peninsula. These marine beds with overlying and interstratified shales as ascertained from drillings, constitute the Chemung formation or ujiper- most member of the Devonian system in Ontario. Characteristic Fos ils from Devonian Strata in Gas ad Oil Region of Ontario. ProTOSALVINIA ISI'OKANC.ITKS) Hl'RONKUSlS, DaVSON. Magnified views of iiuurosporcs, showiiijj; pori-s, portions o( the wall jjreatlv niay^nified, the hihitii and internal j,'rannlar matter, K^'Hip with remains of sporocarp, lellular tissue of sjionjeaip hij^hly lua^mfied, also eross section of Ipper Devonian shale showing flattened niacrosp