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This revised account of the Devonian geology of the Operation Porcupine area is based primarily on 49 outcrop sections measured in 1962, 1970 and 1982, and incorporates new biostratigraphic data from numerous workers who have published on the area since 1968. The report area lies between latitude 65°N and the arctic coast and between longitudes 132°W and 141°W (Yukon-Alaska boundary) and embraces an area of 207 200 square kilometres. During Early and Middle Devonian time, carbonate successions were deposited on the Mackenzie Platform in the east, on the Yukon Stable Block in the west, and on two small isolated platforms, the White Mountains Platform in the north and Royal Mountain Platform in the south. During the same time interval, successions consisting largely of shale were deposited in the centrally located Richardson Trough and in the peripheral Blackstone, Selwyn, Hazen and Rapid troughs. The Lower and Middle Devonian successions on the Mackenzie Platform consist of the unnamed carbonate unit, together with the Cranswick, Hume, and Hare Indian formations. Slope deposits comprising a tongue of the Road River Formation and Mount Baird Formation (new name) are transitional between the Mackenzie Platform and Richardson Trough. On the Yukon Stable Block in the west, the carbonate succession consists of the Kutchin (new name) and Ogilvie formations and an unnamed shale unit. A succession showing a fluctuation between basinal shale and carbonate platform deposits comprises the Road River and Michelle formations in the Blackstone Trough, and the Ogilvie Formation and the unnamed shale unit on the Yukon Stable Block. Deep water sediments of the Road River Formation were deposited in the troughs. The uppermost Middle and Upper Devonian succession was characterized by a completely different sedimentary regime. Stratigraphic units comprise the Canol, Imperial, and Tuttle (new name introduced by Pugh, 1983) formations. The upper Middle Devonian Canol Formation is a dark euxinic shale that was deposited over a large part of the area and which is locally separated by an unconformity from underlying rock units. The succeeding Upper Devonian Imperial and Tuttle formations consist of fine to very coarse grained, elastic rocks. A small part of the Imperial Formation in the east is of shallow marine origin, but throughout most of the report area these two formations consist largely of flyschlike sediments and turbidites derived from an uplifted area in the north. The Tuttle Formation is uppermost and is dated by spores as latest Late Devonian and Early Carboniferous.

These rocks outcrop on the northeast flank of the Elk Point Basin near the Canadian Shield. They comprise the Middle Devonian Ashern, Elm Point, Winnipegosis and Dawson Bay formations, and the Middle and Upper Devonian Souris River Formation. The Ashern consists of argillaceous dolomite and shale unconformably overlying the Middle Silurian Interlake Group. Mottled limestone of the Elm Point where predominantly dolomitized is assigned to the Lower Winnipegosis. Carbonate banks or mounds and thin interbank dolomites are represented in the Upper Winnipegosis. A cyclic sequence, comprising shale of the Mafeking ('Second Red Beds'), biofragmental limestone of Member B, shale and argillaceous limestone of Member C, and stromatoporoidal limestone of Member D, is present in the Dawson Bay. Parts of two sedimentary cycles are represented in the Point Wilkins and Sagemace members of the Souris River. The Point Wilkins consists of basal shale ('First Red Beds'), succeeded by the Argillaceous limestone, the Micritic limestone, and the Dolomitic limestone beds; and the Sagemace consists of a basal shale succeeded by a variable sequence of limestones and dolomites. Important fossils include flesquamatia (Variatrypa) aretiea and Parapolygnathus angustieostatus - Polygnathus eurtigladius fauna (late Eifelian) in the Elm Point; Stringoeephalus and conodonts of the Lower Polygnathus vareus Subzone (early Givetian) in the Upper Winnipegosis; Rhyssochonetes aurora and conodonts of the Middle Polygnathus varcus Subzone (mid-Givetian) in the Dawson Bay; Desquamatia (Independatrypa) independensis and conodonts suggestive of the Upper Polygnathus varcus Subzone or Schmidtognathus hermanni - Polygnathus cristatus Zone (late Givetian) in the lower Point Wilkins; and Athyris vittata new subspecies, "Allanaria" allani. Eleutherokomma hamiltoni and the Pondorinellina insita conodont fauna (early Frasnian) in the upper Point Wilkins and Sagemace members. New boreholes both along and across the outcrop belt have assisted in deciphering an exceedingly complex outcrop pattern resulting from the solution of the Prairie Evaporite Formation and collapse of overlying beds onto Winnipegosis 'reefs' and 'inter-reef' carbonates. Although exploration is continuing, no hydrocarbons or base metals (lead-zinc) have been found in the Devonian rocks of Manitoba. However, these rocks are economically important sources of high-calcium limestone and road metal and contain significant reserves of potash and halite.

These preliminary descriptive studies of unclass¬ ified cutinized microfossils, occurring in sedimentary rocks of Cretaceous age of Western Canada, deal part¬ icularly with forms occurring in samples from the middle (?) portion of the Loon River shale, on the Peace River, Alberta. Two new form-genera are proposed; Sporang!toides for those forms which look like a spore-sac or sporecontainer, and Sporitoides, for those forms which look like a megaspore. On the basis of distinctive morst ze phology and^two new species of Sporitoides are proposed. Affinities of these cutinized micrcfossils are in doubt but they are probably organs of plants representing a part of their reproductive cycles. They are relatively constant in size and morphology within restricted stratigraphic horizons and geographic localities. Cutinized microfossils have been observed, also in samples of the Grand Rapids sandstone, Joli Fou shale and Pelican sandstone, from surface outcrops along the Athabaska river, Alberta; in the basal Lioydminster shale and Viking sand, Edmonton area; from the St. John formation in type area, British Columbia; more rarely in samples from the Second White Specks zone, Spirit River area, Alberta.

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