Biostratigraphy and Paleoecology of Late Ordovician Conodonts from a Composite Section in the Subsurface of Saskatchewan 1
Godfrey S. Nowlan 1 and F.M Haid/
Nowlan, G.S. and Haid!, F.M. (2001): Biostrntigrnphy and paleoecology of Late Ordovician conodonts from a composite section in the subsurface of Saskatchewan; in Summary of Investigations 200 I. Volume I. Saskatchewan Geological Survey, Sask. Energy Mines. Misc. Rep. 2001 -4.1.
1. Introduction Previous work on Upper Ordovician conodont biostratigraphy in the subsurface of Saskatchewan has This paper reports on the biostratigraphy and focused on the Ordovician-Silurian boundary interval paleoecology of conodonts recovered fr om Upper (Norford et al. , 1998; Nowlan and Haid!, 1999). An Ordovician strata in fou r wells in southeastern analysis of conodonts in the Late Ordovician of Saskatchewan (Figure I). The cored intervals from Alberta has been submitted for publication (Nowlan, in these wells represent a composite section through the review) . A paper on the paleontology of the Fort Garry Yeoman, Herald, and Stony Mountain formations Member of the Red River Formation in Manitoba (Figure 2). Sixty-six samples have yielded more than (Elias et al., 1988) is the only other pub lished record of 5000 conodont elements assignable to a variety of conodonts in this interval in the Canadian part of the species. Despite the generally small size of the sam ples Williston Basin. (average 408 grams), more than 95% of the samples have produced conodonts, although many samples produce very few specimens. 2. Stratigraphy Middle to Upper Ordovician strata in the study area comprise a basal elastic unit (Winnipeg Formation) and an overlying sequence characterized by repetition of carbonate and evaporite lithologies (Yeoman, Herald, Stony Mountain, and Stonewall formations) (Figure 2).
a) Winnipeg Formation A time gap between the Winnipeg and Yeoman fonnations is generally implied, but no biostratigraphic data to support this are available from Saskatchewan. The earliest report on conodonts from the Winnipeg Formation was that of Furnish et al. ( 1936) which demonstrated its Middle Ordovician age, and that it is therefore much younger than the underlying Deadwood Formation. Later reports on conodonts from the Winnipeg Formation include those of Amsden and Miller ( 1942) in Wyoming, Carlson (1960) in North Dakota, and Oberg ( 1966) from the outcrop belt in km Manitoba. More recently, the Icebox and Roughlock members Figure J - Location m ap of wells sampled/or this stuc{r.
' Geological Survey of Canada Contribulion 1'0. 2000292. 2 Geological Survey of Canada. 3303 - 33rd Street NW. Calgary. AD T2L 2/\7.
1./ Sumnu,,-y of lm:est1gations ,!(/(} / , l'olume I evaporite strata represents three ,------i------i brining-upward cycles. The Yeoman Fonnation and the lower ~ I ~ II ~~ I STAGES I SASKATCHEWAN I Herald (Lake Alma Member) I w I w I N. America fonn the oldest cycle, and the ~-+- ~ _rnz upper Herald relates to the middle (Coronach Member) and I youngest (Redvers Unit) cycles - ·1·-~ \~Gamachian . ~::::w~~~:.~~ l···. (Kendall , 1976). New core and geophysical log data from the 1 11 1 Gunn more than 300 wells drilled into 1 1Richmondian . \ ~ t Mountain Hartaven the Red River since I 976 suggest a more complex depositional · \ \ ~ \_ _--- -- ·1-\Herald I to~~-~:~sh .] hi story than the current stratigraphic breakdown im plies (Pratt el al. , 1996; Haid! el al., I I i I ~ I Maysvillian 1-~ I Lake Alma I r- - 1997; Kreis and Kent, 2000). O However, further work is required \ ~ I :, I ~ · -- - -j~i Yeoman I to establish a detailed sequence a:: stratigraphic fram ework for nian Ordovician and Silurian strata in I ·' the Williston Basin befo re formal I~ ~ I _I E:_ stratigraphic nomenclature can be --- revised. .. anian - / ' ' , 1~ 1· ~T [ ~erm_ ? ' Yeoman Formation ldia~ 1 ci, j \__ Kirkfie I ---- Winnipeg The Yeoman Fonnation is ndian composed primarily of burrow _ .. ,,.. .., mottled fossiliferous lime ...... ' ·,. ,... . ., _,.. ·. _,,. ..._ .,,. I l i l i ~ Rock~ ·--·- ... . mudstones and wackestones which have been dolomitized to iveran varying degrees. The burrows t lackr which give a mottled appearance Ll _! :_ to the rocks are large Thalassinoides-Jike structures Figure 2 - Correlation ofSas katchewan strata with Middle and Upper Ordovician within which are small cylindrical stages. burrows (Plano/ires, Chondrites, Paleophycus, Skolilhos) (Kendall, of the Winnipeg Fonnation in South Dakota have been 1976, 1977; Pratt et al. , 1996; Canter, 1998; Kissling, shown to be Rocklandian to Kirkfieldian, and 1999; Pak et al., this volume). Other trace fossils Kirkfieldian to earliest Shennanian in age respectively include Trychophycus (Pak et al., this volume). (Sweet, 1982). However, data for North Dakota as Tabulate corals and solitary and colonial rugose corals, reported by Kessler ( 1991) may indicate that the Red cephalopods, brachiopods, bryozoans, echinoderms, River is in depositional continuity with the Winnipeg stromatoporoids, and gastropods are the most in southern North Dakota and that, therefore, the commonly observed macrofossils in core (Brindle, Roughlock in northern North Dakota may be Edenian. 1960; Kendall , 1976; Pratt et al., 1996; Haid! et al., The rocks in the upper part of the Winnipeg Formation 1997). Conodonts from this formation in Saskatchewan in the few Saskatchewan cores of the have not been reported before, although Sweet ( 1979) Yeoman/Winnipeg boundary zone examined to date has detailed them from equivalent strata in Wyoming are not suitable for acid digestion and so no samples and South Dakota. The micro-alga Gloeocapsomorpha were taken for conodont analyses. However, the prisca, of probable cyanobacterial origin (Stasiuk, qu estion of a hiatus between the Winn ipeg and 1991 ; Stasiuk et al., 1993) , is the primary component Yeoman needs to be addressed, especially in the of organic-rich kerogenites (kukersites) which are southeastern corner of Saskatchewan where Kreis preserved as thin but widespread layers in the upper (2000) has indicated the presence of the Roughlock one-third of the Yeoman. Member. Herald/Yeoman Contact b) Red River (Yeoman and Herald Formations) The contact between the Yeoman and the overlying The stratigraphic nomenclature established for Red Herald (Lake Alma Member) is difficult to pick both in River strata in southeastern Sas katchewan reflects the core and on geophysical logs. In core, strata between in terpretation that the repetition of carbonate and the burrow-mottled rocks typical of the Yeoman and
Saskatchewan Geological Survey 15 the laminated to thinly bedded dolostones which Coronach Member characterize the lower Lake Alma are variable in lithology. This thin (< l m to 8 m) transitional unit is Where fully developed (as in the 15-9-2- 14 W2 and 2- composed of variably dolomitized, poorly mottled, I I- l 0-9W2 cores), the Coronach Member comprises: irregularly bedded lime mudstones with texturally I) a basal, slightly argillaceous dolomudstone, locally variable fossiliferous, peloidal and/or coated grain with scattered quartz grains; 2) a fossiliferous, layers (Kendall, 1976; Longman and Haid!, 1996; Pratt commonly burrowed, wackestone or dolowackestone; et al., 1996, Haid! et al., 1997; Kissling, 1997; Kreis 3) slightly argillaceous lam inated dolomudstones and Kent, 2000). An 8 m thick reefal sequence in the (locally lime mudstones); and 4) the Coronach L VR et al Steelman 7-28-4-4 W2 well includes a anhydrite (Kendall, 1976). The basin-centred anhydrite stromatoporoid dolorudstone and a microbial unit is thinner and less widespread than the Lake Alma doloboundstone (Pratt et al., 1996; Haid! et al., 1997). anhydrite, extending north only to Township 11 in At the two wells of this study in which this contact is south-central Saskatchewan. cored (15-9-2-14W2 and 14-12-2J-26W2), the "transitional unit" is placed in the Yeoman Fonnation; i.e. the Herald/Yeoman contact is placed at the base of Redvers Unit the lowermost laminated dolomudstone bed. Other workers interpret the " transitional unit" as the The Redvers unit is composed of a basal argi ll aceous lowennost unit of the Lake Alma Member of the dolomudstone bed and an upper laminated Herald Formation (e.g. Kreis and Kent, 2000). dolomudstone or lime mudstone. This un it is mapped with confidence only where an argillaceous marker bed separates it from the overlying Stony Mountain Herald Formation carbonates on geophysical logs.
Conodonts have not been reported previously from this unit in Saskatchewan. However conodonts from the Stony Mountain Formation Bighorn Group in Wyoming (Stone and Furnish, 1959; Sweet, 1979) are at least partially equivalent. Ethington and Furnish ( 1960) recovered Richmondian Conodonts have also been reported from the Fort Garry conodonts from two Stony Mountain samples in the Member of the Red River Fonnation in the outcrop belt type area north of Winnipeg, Manitoba. A more of Manitoba (Elias et al. , 1988), a probable equivalent detailed assessment of conodonts from equivalent of the Herald Formation. The conodonts indicate a strata in the United States has been provided by Sweet Richmondian age, at least for the upper part of the Fort (1979). Garry Member. In all but the extreme western and northwestern parts of the study area, where it is undifferentiated, the Stony Lake Alma Member Mountain Fonnation is subdivided into (0-Y): I) the Hartaven Member of slightly argillaceous to The Lake Alma Member comprises laminated to argillaceous foss il iferous lime mudstones and bedded, commonly slightly argillaceous, wackestones; 2) th e Gunn Member of fossiliferous dolomudstones and calcareous dolomudstones. very argillaceous limestones with interbeds of variably Jnterbedded with the dolomudstones in some wells, dolomitized lime mudstones; and 3) the Gunton including the Cal-Stan Holdfast I 4-l 2-23-26W2 well Member of primarily nodular, commonly in this study, are beds of burrow-mottled and/or unfossiliferous, dolomudstones, overlain by laminated fossiliferous dolostone. In the extreme eastern part of dolomudstones and a cappin g anhydrite. Saskatchewan (Range 2W2 and eastward), beds of coated grain dolostone, which may have originated as oolitic grainstones. are interbedded with the laminated 3. Conodont Biostratigraphy and dolomudstones (Kent, 1960; Kendall, 1976; Haid! et al., 1997; Kent and Hai di, 1999; Kreis and Kent, Paleoecology 2000). The distribution of conodont species in each of the wells is discussed below. A reference for the The Lake Alma anhydrite, the upper unit of the Lake biostratigraphic subdivisions mentioned in the text is Alma Member, is composed of nodular, bedded, and shown as Figure 2. Tables I to 4 show th e numerical laminated anhydrite with interbeds of dolomudstone distribution of species in samples from the wells and (commonly anhydritic). This is the most widespread of Figures 3 to 5 show relative abundance curves for the Lower Paleozoic evaporite units. It extends from genera in each of the wells. except Imperial Pangman the basin centre in North Dakota to as far north as fo r which there is little data. Selected specimens of Township 33 , as far west as Range I OW3 and into most of the species reported in Tables I to 4 are Manitoba to the east (Kent, 1960; Kendall, 1976: illustrated in Figures 6 and 7. Norford el al., 1994; Longman and Haid!, 1996). Imperial Pangman 3- 14-8-20W2
From Imperial Pangman 3-1 4-8-20W2, fo ur samples were taken from the lowest 16 ft (4.9 rn) of the
16 Summary ofl nvestif,?a l ions 200 I, i ·otume 1
- ---·---- -·--···------····-··-· ······. that they may be part of a lineage. The faunas in this Table J - Numerical distribution ofco1101lo nt species by interval and those of a similar interval in the Oungre sample depth in feet and GSC locality number in the well (upper Yeoman-lower Heral_d) appear.to be Pangman well. transitional between the two species, or their ranges Imperial Pangman 3-14-8-20W2 overlap. Although the age of upper Yeoman to lower Yeoman Herald remains uncertain, it is at least Middle Maysvillian, as indicated by Culumbodina penna lower a, 0 N.... ("') ..... 17 Saskatchewan Geological Survey Holdfast 14 - 12- 23 - 26W2 ,- ,· . ' I&) I feet 9 .c.u•=:.~I ,__..,~~~~~~~~~ :c: 5640 Conodonts Lithology I I ~t ' I I I I -· -~ - .:_ I I c:: 1§~1 I ~~~~ Aphe/ognathus '. ~ i Anhydrite .Q o I I,'->'' ·, , ...... ro , .....- 5650 f= ..~~-=..r17-+1 13 """--=- .· I E I J:l I !~-1~-_j:0 j: - l Drepanoistodus tl' ;·1A rgillaceous dolostone 5 ~ _ ·/ ' ··-' ..1 1~ 1ffi 1 l 1~·- ~~ Burrowed argillaceous I~ ~ I 5660 10 1 : : ·/ Ou/odus )·I 1 i · · - · J lh_ ~ dolostone I ai I E I j I' :r · ' I- ~--! Panderodus .•; .'.:i I Burrowed dolostone I I<{ I 5670 1 36 c"' 5710 0 "O 21 g 0 "' 5720 ·161 ~ I 1l I . 66 5 I 5730 z I B 21 l °fil 1E 5740 0 43 , u.. c: I ro 5750 28 I t I~ 15 I 5760 I 5770 - 8 5780 ·- 5 I 5790 I 2 I J 5800 I I_ l _I 5810 /8 Summary of Investigations 2()() I. I 'olume I .,.,...~ :::: Cal-Stan Holdfast 14-12-23-26W2 ri ;::- Yeoman I Herald "'::s t:, ;;, r:; ;:, ,.._in" ,.._~ ,.._ ,.._ ...,.._ 0 ;;; ;:::- io in" ~ ;;, r:; ... 0 ;;; co ;:::- ~ ,.._ (0 (0 1/) 1/) io in" (0 Total: 5 2 5 8 9 15 28 43 21 66 161 21 36 6 9 66 11 10 5 13 19 58 617 Mass (grams): 595 535 665 378 578 314 436 624 430 393 402 521 442 41 8 650 552 496 440 608 489 501 453 10920 ._ 'O Table 2 - Numerical distribution of co11odo11t .~pecie.f by sample depth in feet and GSC locality number in the Hold/a.~, well. few specimens of the genus Oulodus indicating The next highest biostratigraphically significant form, relatively shallow conditions. Aphelognathus aff. A. divergens, occurs at l 0,028.3 ft (3056.6 m) in the upper part of the Yeoman Formation. Deepening of the basin is indicated by the appearance This form is most similar to A. divergens reported by of Plectodina at 5759. I ft (1755.4 m) and the genus is Sweet ( 1979, 1984) to be restricted to the Richmondian well represented through to the 5706 ft (I 739.2 m) Stage of the Upper Ordovician, but the M elements are level. However, clear indications of sea-level more similar to those of A. shoshonensis. a somewhat oscillations are recognized by the presence of older species. These specimens appear just a few feet shallower water biofacies represented by above mid-Maysvillian conodonts, and thus may be Aphelognathus at 5733 ft ( 1747.4 m) and 5743.6 ft transitional between Maysvillian A. shonshonensis and (1750.6 m). Abundant Oulodus mixed with Plectodina Richrnondian A. divergens and suggest a Late at 5721.4 ft (1743.9 m) may suggest an intermediate Maysvillian age. This is similar to the situation noted at water depth. An argillaceous dolostone bed at 5727 .8 ft the Holdfast well. (1745.8 m) produced the greatest abundance of Plectodina, suggesting an increase in water depth. Samples higher in the Yeornan Formation and from the Samples from adjacent beds are also abundant in lower part of the Herald Formation are conodont poor. conodonts. Specimens of Panderodus hergstroemi, a mid Maysvillian or younger species, occur at 10,019.0 ft The remainder of the section appears to represent (3053.8 m) but the interval from 9937.5 ft (3029.0 m) shallower water deposition with Aphe/ognathus and to I 0,006.55 ft (3050.0 m) is virtually barren except Oulodus dominating the fauna throughout the 5638.5 for specimens of the long-ranging Panderodus. to 5695.7 ft ( 1718.6 to 1736.0 m) interval. Abundance is low and specimens of Aphelognathus are excluded Aphelognathus re-appears at 9927.5 ft (3025.9 m), close to an evaporite unit within the Lake Alma together with a single specimen of Rhipidognathus, a Member. An extremely shallow episode is recorded by paleoecologically significant form. representing Rhipidognathus at 5640.6 ft ( 1719.3 m) within the extremely shallow conditions. Unfortunately the uppermost part of the Coronach Member of the Herald specimens of Aphe!ognathus arc not particularly well Formation. preserved and cannot be firmly identified as A. divergens which is the species expected in the Herald No indications of deep water biofacies were found in Formation based on correlation with the Fort Garry this well. Member in Manitoba. Additional collections arc required to sort out the evolution of Aphelognathus in CDR Shell FPC Oungre 15-9-2-14W2 this part of Saskatchewan. The core from CDR Shell FPC Oungre 15-9-2-14W2 A diverse fauna appears at the base of the Harthaven brackets the upper Yeoman, Herald, and lowermost Member of the Stony Mountain Formation. It includes Stony Mountain formations. Nine samples were taken the biostratigraphically diagnostic Amorphognathus from the uppermost 63 ft ( 19 .2 m) of the Yeoman ordvvicicus known from late Maysvillian to Formation. ten samples from the Herald formation Gamachian strata around the world, and abundant ( I 04 ft, 31.7 m thick) and three from the lower 13 ft specimens of Phragmodus undatus and a variety of (3.96 m) of the Stony Mountain Formation (figure 4). other taxa. Higher samples in the Stony Mountain Formation yield a markedly similar fauna. Biostratigraphy Paleoecology The distribution of conodont species is shown in Table 3. The lowest six samples (10.040.5 to 10,089.0 ft; The numerically dominant taxon throughout the 3060.3 to 3075.1 rn) yield specimens probably Yeoman and Herald fonnations is the probably pelagic, assignable to Aphelognuthus but the specimens are so simple cone conodont Panderodus. The shallow water fragmentary or the preserved apparatuses are too Oulodus-Aphelognuthus biofacies ( I 0,070.2 to incomplete for specific identification. These samples I 0,089.0 ft; 3069.4 to 3075. 1 rn) characterizes the also include specimens of Oulodus? sp. and lower part of the Yeoman Formation in the Oungre Pseudobelodina rnlgaris vulgaris, the latter supplying well. Slight deepening is indicated by the succeeding a minimum age ofmid-Edenian for the interval as at Plecrodina biofacies ( I 0,032.2 to I 0.061 .5 ft; 3057 .8 Pangman. Good specimens of Plectodina aculeatoides, to 3066.7 m) and a return to the shallower water in the a species that ranges from mid-Edenian to mid uppermost Yeoman at I 0,028.3 ft (3056.6 m) is Richmondian. were collected at I0.052.5 ft (3064.0 rn ) coincident with a change from mottled dolostone to and 10 ,061.5 ft (3066.7 m). bioclastic dolostonc. A single specimen assignable to Cu/umhodina occurs Conodonts are generally rare in the Herald Formation; at I 0,040.5 ft (3060.3 m) which suggests an age no in part, this may reflect proximity of several samples to younger than mid-Maysvillian. This places an upper anhvdrite beds. From the available evidence. the age limit on this lower part of the Yeoman at the Herald appears to have been deposited in shallow water Oungre well. inhabited mainly by pelagic forms, but also periodically by the Oulodus-Aphelognarhus biofacies. ]0 Summary uf Investigations 200/, I 'o/11111e I Oungre 15 - 9 - 2 - 14W2 feet Lithology 9910 I El a; i ~> l~~ iA rgillaceous bioclastic ~ .Q.1- limestone Ios"' .J 1:'. ro I ill~ :E 9920 1 I :-··I Bioclastic limestone I 1 ..@ , ::> I _:.::. I 9930 - - Anhydrite I ~I I · I > :-l]1 I 1l 1 Argillaceous dolosto ne ~ 9940 l1~~.J I i 1-1_ I' r,·. ··-· 1 Panderodus ,"; •·. \I Burrowed dolostone I:l .J I ,. i _ 1 I I 9950 ai 'I . .0 Plectodina lL~ ~ Bioclastic dolostone I ~I fil lI 7 / 7, 11 ·· -1 ~- 9960 b... LJ Argillaceous limestone I.c ~ Phragmadus (.) I I I ~,- I I Laminated dolostone c e 9910 j\: j Other O O I~ I U\ II <' j \ Anhydritic laminated E . I ,_ dolostone lo I 9980 K Kukersitic bed u. I Dolostone l:2 I ux Breccia ~ 9990 11 1ai l .0 I I El . 0> · 10000 I l ~ i i I~ l 10010 ! 1~ 1 ...J I I 110020 I. I I 10030 I I 110040 i 51 ii i J 1ooso '- 0 I u. 1 c I . t1l I E l 110060 o · l~ j I 10010 I I I I j 10080 I I. 1 ••• 10090 0 50 100 Figure 4 - Relative abundance of conodont genera in the Percent Oungre well. Saskatchewan Geulogic:a{ Survey 21 "-> "-> COR Shell FPC Oungre 15-9-2-14W2 Yeoman I Herald I Stony Mountain a, a, 0 ... N ;;;- ~ ~ ;:::- co 0 0 ;;;- ;:::- co a, 0 0 0 ,.._ 0 0 0 8 0 0 r- ;:::. ;::;- N ....,.._ .;- ~ s ... a, 0 ID r- r- r- r- r- r- r- r- r- ...... r- ;:::. N ll) r- ;:::. ;:::. r- r- r- r- r- r- r- r- r- r- ll) r- r- r- r- r- r- r- r- IO I() IO IO l() l() IO IO IO II) r- r- II) r- r- r- l() IO ,.._ ,.._ N N N ~ ~ IO I() N IO IO IO N IO I() ~ ~ ~ ~ ~ N N r")' "' "' ~ ~ ~ N r")' r")' ~ ~ ~ ~ ~ tl) "' ~ 8 8 8 8 8 IO 8 8 0 <"l N IO IO N <"l .... 0 II) 8 ~ IO 8 ~ ~ IO ~ ~ cri a:i ci '°0 a:i ,...: oi c.o ID ~ "I 0 I() IO '°r- "I IO 0 co r- r- co I() "I <"l N N 0 l() oi ;:::. c-i ::~ s; Table 3 - Numerical dhtributio11 ofconodo11 t specie.f by sample depth i11 feet a11d GSC locality number in the Oungre well. The recurrence of Plectodina sp. at I 0,019 .0 ft The high abundance and diversity in the Hartaven and (3053.8 m) and at 9971.7 ft (3~39.4 m) n:iay be Gunn members drop off drastically in the Gunton indicative of deeper water. A single specimen of Member. Abundance runs from an astonishing 4200 Rhipidognathus, representative of extremely shallo""'. specimens per kilogram in the Hartaven Member, to water, occurs in the upper part of the Herald Formation five specimens per kilogram in the Gunton Member. at 9927.5 ft (3025.9 m). No biostratigraphically diagnostic forms occur above 7418.5 ft (2261 .2 m) in the Gun ton Member. The fauna! change into the Stony Mountain Formation is made dramatic by the abundance of Amorphognathus a~d Phragm?dus_repres~ntative of Paleoecology deeper water biofac1es and an 1mphed maJor transgression. The yield from samples of the Coronach_M: mber is. generally too sparse to provide worthwhile mformat1on on biofacies; however, one sample (C-257723 at Imperial Hartaven 2-l 1-l0-9W2 751 3.7 ft; 2290.2 m) is within the Apehlognathus biofacies. The Redvers unit reveals a shallow Imperial Hartaven 2-1 1-10-9W2 co_ntains core fr~m the depositional episode by the dominance of specimens of Herald and Stony Mountain formations from which Aphelognathus, and the sample at 7498.5 ft (2285.S m) five samples were taken from the uppermost 47 ft (GSC loc. C-257724) includes specimens of ( 14.3 m) of the Herald Formation including the Rhipidognathus, indicating extre~ely shallow . Redvers unit and most of the Coronach Member, and conditions. The topmost sample m the Redvers yielded thirteen samples from 91 ft (27.7 m) of Stony only two specimens of l'anderodus. Mountain Formation, ranging through the Hartaven, Gunn, and Gunton members (Figure 5). Dramatic deepening of the basin during Hartaven time is indicated by the abundance of the deep water forms Phragmodus and Amorphognathus. The relative Biostratigraphy abundance of Phragmodus is reduced at the base of the Gunn Member (GSC loc. C-257729; 7467.2 ft; The distribution of conodont species in the Hartaven 2276.0 m) and specimens of the shallower water genus well is shown in Table 4. Conodonts from the Oulodus increase in abundance, although simple cones, Coronach Member and Redvers unit of the Herald especially Panderod_us, dominate _th~ faunas above this Formation are similar to those recovered from this level. Slight deepening of the basm m the upper Gunn interval in the Oungre 15-9-2-14 W2 and Holdfast I 4- Member is signified by the reappear~nce of . J2-23-26 W2 wells. They are dominated by specimens Phragmodus and l'lectodina, but their number 1s of the simple cone genera l'anderodus an~ greatly reduced. The base of th~ Gu_nton. M_ember of Drepanoistodus. The most abund~nt den_t1 c~late form the Stony Mountain Formation 1s still w1thm the is referable to Aphelognathus. This species 1s referred Oulodus biofacies, but immediately above, abundance to A. aff. A. divergens. This interval is undoubtedly and diversity completely drops off with simple cone Late Ordovician, but its precise location within the genera being the only representatives. In the seni The basal sample of the Stony Mountain Formation yields an abundant fauna that includes the 4. Discussion internationally recognized zonal fossil . The biostratigraphic data confirm an Ed:nian- . Amorphognathus ordovicicus, which ranges from m1d Maysvill ian age for the Yeoman Formation, especially Maysvillian through Richmondian and int<;> the as based on the presence of species of Cu/umhodina. Gamachian, and an enormously abundant mflux of Specimens of Parabelodina denticulata and a related Phragmodus undatus. form occur in the upper Yeoman and lower Herald formations and thereby suggest a Maysvillian age for Specimens of Oulodus rohneri Ethington and Furnish, this part of the section. The precise age of the upper an indicator of Richmondian or younger Late part of the Herald remains in doubt because of the Ordovician age, occur within the upper part of the difficulty of identifying sparse specimens of Hartaven Member of the Stony Mountain Formation Aphelognathus. However, recovery of Parabe_locl.ina (GSC Joe. C-257728, 7469.7 ft (2276.~ m). Al~o denticulata and Aphelognathus divergens, an indicator present is the first occurrence of the R1chmond1an of Richrnondian age, from the correlative Fort Garry Staufferella brevispinata Nowlan an~ Barnes. Member of the Red River Formation in Manitoba Specimens of 0. rohneri also occur m the lower part of (Elias et al., 1988) suggests that the upper Herald is the Gunton Member (GSC loc. C-257733; 7429 ft; Richrnondian, but the presence of Aphelognathus 2264.4 m). divergens cannot be confirmed. Saskatchewan Geological Survey 23 Conodonts Lithology feet --, ·17400 I • Amorphognalhus I ! . . Bioclastic limestone I 7405 I . .. I I I<>:_',-' Aphelognathus =: ~ Anhydrite I I '7410 L :· ::J t. =: ··.···,I dolostone I~ l 7415 , •.. . IDr epanoistodus j' I f.1 , IArgill aceous '-- .....1.. I I0 :i I 1420 r,: ·::-:r Burrowed dolostone I I G: -~ Oulodus ·.~ •1 .. I .I 1 1'----'C. L.. h, r-· -· I I I 1425 . r I Dolomitic limestone j Panderodus 11 I L .. . I._, I I 7430 1 /Ti 1A rgillaceous limestone i[m j j P/ectodina i-- i 7435 - LJ ,- ~ I Laminated dolostone . I / 7440 ~ Phragmodus L I . . - I Dolostone c:: I / 7445 rl:j~JJ ~ Rhipidognathus I Uli jJ 2 17450 I~ I -: )7! Other I :i :i 1.i:.\.;J I~» /<.'.> J 7455 ,-§ I / 1450 (/) I / 7465 I I I - J 7470 I I I 1 . 1475 . Q)c:: I / ~ 114ao I~ I 7485 I j _J 7490 I I~ I i ~ I 7495 I ~ J 7500 I I '7505 I i . 1-o 17510 ro I.c I wi l6 7515 II c:: I I I§ I 7520 I 1° I 1525 I I ! 7530 I I I I I 7535 I L. !7540 Figure,5 - Relativel . abundance ofc o11 oc/011t genera in the 0 Hartaven we/ . 24 Summary OJ., I nvestigati.o ns 200 I . I 'o/11me I __ .. _...... - . A-~-··- ~-J' Imperial Hartaven 2-11-10-9W2 ;,,."- ..,.!:,. Herald I Stony Mountain ::- ~ (o' ~ N M ~ ID ;::- ro 0) 0 N M ~ (o' ID ;::- N N N N N N (") - (") (') (") ro N N N ;;; (') (") (") (") ~ r-- r-- r-- r-- I'- I'- I'- I'- r-- r-- r-- r-- r-- r-- r-- r-- r-- r-- :: r-- r-- r-- r-- r-- r-- r-- r-- r-- r-- r-- I'- r-- r-- r-- r-- r-- r-- (; I!) I!) l() l() l() N'°. '°N N'° N'°. '°<';,' '°N '°N '°N N '°N N N'°. N '°N N N '°N N'° "'0 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 I,{) tO C'1 r-- lll 0 ~ !'--: N N v v 0 I'- 0 % I!) (") !'--: N tO c,; c,; ,-..: (") ~ a, ci m co '°- Total: 4 9 33 93 2 705 63 1078 78 1119 66 140 32 33 4 3 4 2 3468 Mass (grams): 300 305 300 357 350 I 499 400 415 300 265 300 596 350 345 350 409 400 449 6690 Table ,I· Numerical dis·tribution ofconot/011/ species by sample depth in feet and GSC locality number in the Hartaven well. ~"' 26 Summary of /nvestiga1ions 200 I. Volume I Figure 6 - 11/ustrlllions ofconodonts from the Upper A striking turnover in the conodont fauna occurs at the Ordovician ofSaskatchewan (specimens arranged base of the Stony Mountain Formation. alphabetically by ge11us am/ species, A to P). I to 4) Amorphognathus ordovicicus Branson and Mehl. I, Amorphognathus ordovicicus, the worldwide index for Outer lateral view, Pb element, x7/, GSC 120873; 2, outer Middle Maysvillian and younger Late Ordovician lateral view, M element, x85, GSC /20874: 3, lateral view, strata, is found together with extremely abundant Sd element, x97, GSC 120875; 4, oral view, broken Pa Phragmodus undatus. Specimens of Oulodus rohneri element, x91, GSC 120876. All .fpecimen.ffrom the lower in the lower part of the Stony Mountain Fonnation part ofthe Stony Mountain Formation in the Oungre well: confinn a Richmondian age for the unit. Conodont land 2from GSC Joe. C-257718, 3 and 4 from GSC foe. C- 257720. abundance decreases drastically in the upper part of the 5 to 15) Aphe/ognathus ,if!. A. divergens Sweet. 5, Inner Stony Mountain Fonnation and di agnostic fonns are lateral view, Sc elemenJ, x55, GSC 120877; 6, posterior absent. Previous work (Norford et al., 1998; Nowlan view, Sb element, x51, GSC 120878,· 7, posterior view, Sa and Haid!. 1999) has shown that the remainder of the element, x54, GSC 1208 79: 8, po.Herior view, Sb element, Stony Mountain and the lower part of the Stonewall are x49, GSC 120880; 9, inner lateral view, Sc element, x 76, GSC 120881; l 0, in11er lllleral view, M element, x60, GSC Richmondian and that the Ordovician-Silurian 120882; l 1, inner lateral view, M element, x 78, GSC boundary occurs within the Stonewall Formation. 120883; l 2, outer lateral view, Pb eleme/11, x31, GSC 120884; /3, lateral view, Pa element, x79, GSC 120885; 14, Conodont biofacies, expressed in tenns of relative lateral view Pa element, x59, GSC 120886; l 5, Pa element, abundance curves for genera, show marked changes in x68, GSC 120887. Specimens 6, 7, 9, l 1, /2, and 14 t1re from GSC Joe. C-257706 in the Yeoman Formation in the depositional environment from the base of the Oungre well; specimens 5, 8, I 0, and 13 are from GSC foe. Yeoman, through the Herald, and into the Stony C-257724 in the upper part ofthe Herald Formation, Mountain Formation. Yields from the basal part of the Hartt1ven well; specimen /5 1sfrom GSC foe. C-322654 in Yeoman are sparse, but the forms present ( e.g. the Hera/ti Formation, H,1/dfast well. Oulodus) are suggestive of shallow water deposition. 16 t1nd 17) /Jelodina conjluens Sweet. 16, lateral view, General deepening followed, as indicated by the compres.fiform element, x67, GSC /]()888,- 17, lt1tert1/ vh'w, grandiform element, x6l, GSC /20889. Both specimens increase in species of Plectodina throughout much of from GSC foe. C-322668 in the Yeoman Formation, the middle and upper part of the Yeoman Fonnation Hoh/fast well. (Figures 3 and 4). Within this interval. increases in the /8) Coelocerodontus trigonius Ethington. Lateral view, x75, relative abundance of Aphelognathus suggest distinct GSC I 20890, from the Stony Mountt1i11 Formation in GSC shallowing episodes. toe. C-25 7729, Hartaven well. /9) Cu/umbodina occidentalis Sweet. lateral view, x4J, GSC 120891.from the Yeoman Formation, GSC foe. C- One such shallowing episode is reflected by higher 322668, Holt/fast well. energy fabrics in the "transitional" unit at the top of the 20) Culumbodina penna Sweet. lateral view, x92, GSC Yeoman in several wells (including Oungre) (Pratt et / 2()892.from the Yeoman Formation, GSC foe. C-322668, al., 1996; Canter, 1998; Kreis and Kent, 2000), and in Holt/fast well. sub-aerially exposed surfaces in the lower portion of 21 and 22) Drepanoistodus .rnherecllis (Bram·on anti Mehl). 21, lateral view, oistodontiform r element, x84, GSC the laminated carbonate unit of the Lake Alma 120893; 22, lateral view, q element, x80, GSC 120894. Both Member (Kent and Kissling, 1998; Kreis and Kent, specimens from the basal Stony Mountain Formation in 2000). The recurrence of Plectodina within Lake Alma GSC toe. C-257718, Oungre well. laminated carbonates in the Oungre well may reflect a 23, 25, 26, a11d 31) Oulodus ulrichi (Stone and Furnish). deepening event associated with deposition of the 23, lateral view, Sc elemellt, x52, GSC 120895; 25, inner lateral view, Ph elemettt, x60, GSC I 20896; 26, inner upper portion of this laminated unit. In the Hold fast lateral view, M element, x80, GSC 120897; 31, posterior well. the presence of burrowed fossiliferous dolostone view, laterally hroke11 Pa element, x70, GSC I 20898. A II between beds of Lake Alma laminated strata also specimens from the Stony Mountain Formation, GSC foe. suggests a deepening event. The relative abundance of C-257730, Harttlve11 well. Aphelognathus in this fossiliferous unit and the 24) Oulodus rohneri Ethington anti Furnish. Posterior overlying laminated unit suggests shallower conditions view, Pa element, x85, GSC I 20899, from the Sttmy Mounlllin Formation, GSC foe. C-25 7733, Hartaven well. than in the middle part of the Yeoman. However, 27) Panderodus gibber Nowlan a11d Barnes. lateral view, palcoecological interpretation of the Lake Alma x8fJ, GSC 120900.from barn/ Stony Mountain Formation, sequence based on conodonts is limited in this well GSC foe. C-257726, 1/artaven well. because the lower laminated bed was not sampled. 28) Panderodus panderi (Stauffer). lateral view, x65, GSC Further detailed sampling in this and other cores is 12()901,from the basal Stony Mou11tain Formation, GSC foe. C-25 7726, Hartaven well. required to detennine whether or not a sequence 29) Pa11derod11s gracilis (Bra11son anti Mehl). lateral view, boundary separates lower Lake Alma laminated strata x 75, GSC 120902.from the btual Stony Mountain from overlying carbonates and basin-centred, Formation, GSC foe. C-25 7726, Hart11ven well. subaqueously deposited Lake Alma evaporites as 30) Parabelodina denticulata Sweet. Lateral view, x /00, suggested by Canter ( 1998). GSC 12090.1,from the Herald Formation, GSC loc. C- 322660, Hoh/fast well. 32 and 34) Parabelodina cf I'. df'!1ticu!ata Sweet. 32. Specimens of Rhipidognathus are present in the upper lt1tera/ view, x/3/, GSC /20904; 34, lateral view, x/20, part of the Herald Fonnation in both the Holdfast and GSC I 20905. Specimen 32 from the Herald Formation, Hartaven wells (Figures 3 and 5). This suggests an GSC foe. C-322658, Holt/fast well anti specimen 34 from extreme shallowing episode and a possible period of the Herald Formtltion, GSC foe. C-25 7708, Oungre well. emergence. Lithological evidence for sub-aerial 33) l'aroisrodus ? now/an i Zhen, Wehby anti Barnes. /1111er lateral view, oistot/ollliform element, x 13 7, GSC I 20906, exposure in this part of the stratigraphic section is from the basal Stony Moumain Formation. GSC Joe. C- reported by Kreis and Kent (2000). 257726, lltznaven well. Saskatchewan C,eofogic: al S11 rvey 27 28 Summary of ln\'estigalions 2()() I. I 'o/11me I The striking concentrati on of deep and possibly cooler from the Gunn, they are much less abundant and the water conodonts Amorphognathus and Phragmodus at proportionate decrease in number of Plectodina the base of the Stony Mountain Fonnation indicates a suggest shallowing (Figure 5). The Gunton Member of major transgression and a rise in sea level or the the Stony Mountain Formation produces few introduction of a cooler water mass. Based on evidence conodonts suitable for biofac ics analysis. from the Hartaven well, this deep water episode persists through the Hartaven Member and into the lower part of the Gunn Member. While specimens of 5. Future Work Phragmodus continue to be present in upper samples More detailed sampling combined with lithologic studies are required to facilitate sequence stratigraphic Figure 7 - Illustrations ofco nodonts from the Upper Ordo vician ofSaskatchewan (specimens arranged interpretation o f Upper Ordovician strata. The data alphabetically by genus and species, P to W). presented here are integrated with geochemical data on I to 8) Phragmodus undatus Branson am/ Mehl. I, Lateral the neodymium isotopes and samarium-neodymium view, Sc elemetll, x 77, GSC 12090 7; 2, lateral view, Sc ratios of conodont and rock samples from many of the element, x93, GSC 120908; 3, lateral view, Sd element, x75, same samples (Fanton et al., in review). The GSC I 20909; 4, inner lateral view, M element, x55, GSC combination of biostratigraphic and paleoecological 1209 JO; 5, inner lateral view, M element, x86, GSC data with these geochem ical tools provides insight into I 209JJ; 6, inner lateral view, Pb elemellf, x 74, GSC the subm ergence history of the craton in the Williston 120912; 7, outer lateral view, Pa element, x 75, GSC Basin area. Integration of these types of lithological, 120913; 8, outer lateral view, Pa element, x81, GSC geochemical, and paleontological data is planned for /2()9/4. Specimens I, 3, 4, 6, and 7 from basal Stony Mountain Formation in GSC foe. C-257718, Oungre well; correlative sections of Manitoba and Saskatchewan, specimens 2, 5, and 8 from basal Stony Mountain probabl y in the Weybum-Midale area and over the Formation in GSC foe. C-257726, Hartaven well. Ordovician-Silurian boundary interval in 9 to 13) Plectodina aculeatoides Sweet. 9, Inner lateral Saskatchewan and Manitoba. view, Sc element, x 90, GSC /2()9/ 5; 10, poMerior view, Sb element, x /07, GSC 120916; 11, inner lateral view, M element, x 95, GSC 12091 7; 12, inner lateral view, Pb element, x62, GSC 120918; I 3, lateral view, Pa element, 6. References x92, GSC 120919. All specimens from Yeoman Formation, Amsden, T. W. and Miller, A.K. ( 1942): Ordovician (.iSC loc. C-257702, Oungre well. 14 to 18 and 2 /) Plectodinajlorida Sweet. 14, Inner lateral conodonts from the Bighorn Mountains of view, Sc element, x98, GSC 120920,· I 5, posterior view, Sb Wyoming; J. Paleont., v 16, p301-306. element, x98, GSC J20921; 16, posterior view, Sc element, xi 16, GSC 12()922; 17, inner lateral view, M element, x 74, Barnes, C.R. and Fahraeus, L.E. ( 1975): Provinces, GSC /2092.i; 18, inner lateral view, Pb element, x 77, GSC communities, and th e proposed nektobenthic habit 120924; 21, lateral view, Pa element, x i 11, GSC I 20925. of Ordovician conodontophorids; Lethaia, v8, All specimens from Stony Mountain Formation in the p 133-149. Hartaven well: 14, 15, 16, 18, and 21 from GSC loc. C- 257730 and 17 from C-257729. Brindle, J.E. (1960): The faunas of the Lower 19) P/egagnathus ne/soni Ethington and Fumish. Lateral view, x98, GSC 120926,from tire Herald Formation, GSC Paleozoic carbonate rocks in the subsurface of foe. C-322654, Holdfast well. Saskatchewan; Sask. Dep. Miner. Resour., Rep. 20 and 23) Pse11dohe/odi11a? dispansa (Glenister). 20, 52 , 45p. Lateral view, broatl element, x80, GSC 12092 7; 23, lateral view, !,lender element, x69, GSC 120928. Specimen 20 from Canter K .L. (l 998): Facies, cyclostratigraphic, and basal Stony Mountain Formation, GSC foe. C-257726, secondary d iagenetic controls on reservoir Hartaven well and specimen 23 from Yeoman Formation, distribution, Ordovician Red River Formation, GSC foe. C-322665, Holtl/a,ff well. Midale Field, southern Saskatchewan; Eighth 22) Pristognathus bi~hornensis Stone and Furnish. International Williston Basin Symposium, Core Posterior view, Pa element, x70, GSC 1209 29, from Stony Mountain Formation, GSC foe. C-25773 1, Hanaven well. Workshop Volume, Regina, October 1998, 24 and 28) l'seudobe/odina vulgaris vu/garis Sweet. 24, Saskatchewan, North Dakota and Montana Geol. Inner lateral view, x64, GSC 120930; 28, lateral view, x/00, Soc., p41 -65. GSC 120931. Specimen 24 from Yeoman Formation, GSC foe. C-322665, Hold/a.~, well and specimen 28 from Carlson, C. C. ( 1960): Stratigraphy of the Winnipeg Yeoman Formation, GSC foe. C-257740, Pangman well. and Deadwood fonnations in North Dakota; N. 25 and 30) Rhipidognathus symmetricus Branson, Mehl and Dakota Geo!. Surv., Bull. 35, 149p. Bran.wn. 25, Pol·terior view, symmetrical element, x45, GSC 120932; 30, posterior view, asymmetrical element, Elias, R.J ., Nowlan G.S., and Bolton, T.E. ( 1988): x33, GSC 120933. Both specimens from upper part of Paleontology of the type section of the Fort Garry Herald Formation, GSC foe. C-257724, Hartaven well. 26, 27, and 29) Wa/liserodus amplissimus (Serpagli). 26, Member, Red River Formation (Upper Inner lateral view, S c element, x91, GSC 120934; 27, Ordovician), southern Manitoba; New Mexico foteral view, Sa element, x92, GSC 120935; 29, posterior Bureau Mines Mi ner. Resour., Mem. 44, p34 1- view, Sa element, x/00, GSC 120936. All .~pecimensfrnm 359. the lower part ofth e Stony Mountain Formation, GSC /oc. C-257728, Hartaven well. Saskatchewan Geological Survey 29 Ethington, R.L. and Furnish, W.M. (1960): Upper - -=~ - · ( 1999): Life and death roles of Red River Ordovician conodonts from southern Manitoba; J. Thalassinoides; Abstracts, Rocky Mtn. Sect., Paleont., v34, p265-274 . Amer. Assoc. Petrol. Geol. Bull. , v83, pl 184. Fanton, K. C., Holmden, C., Nowlan, G.S., and Haidl, Kreis, L.K. (2000): Geology of the Middle Ordovician F.M. (in review): 143 Nd/144Nd and Sm/Nd Winnipeg Formation in Saskatchewan. Lower stratigraphy of Late Ordovician epeiric sea Paleozoic Map Series, Sask. Energy Mines, Open carbonates; Geochim. Cosmochim. Acta. File Rep. 2000-2, Sheet 3 of 8. Furnish, W.M., Barragy, E.J., and Miller, A.K. (1936): Kreis, L.K. and Kent, D.M. (2000): Basement controls Ordovician fossils from the uppermost part of the on Red River sedimentation and hydrocarbon type section of the Deadwood Formation, South production in southeastern Saskatchewan; in Dakota; Amer. Assoc. Petrol. Geol. Bull., v20, Summary of Investigations 2000, Volume I, p 1329-1341. Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2000-4.1, p2 l-42. Haidl, F.M .. Longman, M.W., Pratt, B.R., and Bernstein, L.M. ( 1997): Variations in lithofacies in Longman, M .W. and Haid!, F.M. (1996): Cyclic Upper Ordovician Herald and Yeoman formations deposition and development of porous dolomites (Red River), North Dakota and southeastern in the Upper O rdovician Red Ri ver Fonnation, Saskatchewan; in Wood, J. and Martindale, B. Williston Basin; in Longman, M.W. and (comp.). Can. Soc. Petrol. Geol.- Soc. Econ. Sonnenfeld, M.D. (eds.), Paleozoic Systems of the Paleont. Mineral., Core Conference, Calgary, p5- Rocky Mountain Region, Rocky Mtn. Sec .• Soc. 39. Econ. Paleont. Mineral., p29-46. Kendall, A.C. ( 1976): The O rdovician carbonate Norford, B.S., Nowlan, G.S., Haid!, F.M .. and Bczys, succession (Bighorn Group) of southeastern R.K. ( 1998): The Ordovician-Silurian boundary Saskatchewan; Dep. Miner. Resour., Rep. 180, interval in Saskatchewan and Manitoba; in 185p. Christopher, J.E., Gilboy, C.F., Paterson, D.F., and Bend, S.L., (eds.), Eighth International Williston -~~~~ ( 1977): Origin of dolomite mottling in Basin Symposium. Sask. Geol. Soc., Spec. Publ. Ordovician limestones from Saskatchewan and No. 13, p27-45. Manitoba; Bull. Can. Petrol. Geol., v25, p480-504. Norford, B.S., Haid!, F.M., Bezys, R.K., Cecile, M.P .. Kent, D.M. ( 1960): The evaporites of the Upper McCabe, H.R., and Paterson, D.F. ( 1994): Middle Ordovician strata in the northern part of the Ordovician to Lower Devonian strata of the Williston Basin; Sask. Dep. Min. Resour., Rep. 46, Western Canada Sedimentary Basin; in Mossop, 46p. G.D. and Shetsen, I. (comp.), Geological Atlas of the Western Canada Sedimentary Basin; Can. Soc. Kent. D.M. and Haid!, F.M . ( 1999): Geology of Petrol. Geo I./ Alta. Rcsear. Counc., p I 09-1 27. Ordovician Winnipeg and Red River rocks, southeast Saskatchewan; Depositional Nowlan, G.S. (in review): Strati graphy and conodont environments and rese rvoir potential of Lower and biostratigraphy of Upper Ordovician strata in the Middle Paleozoic rocks in Saskatchewan. Can. subsurface of Alberta. Canada; Palaeont. Soc. Petrol. Geol., Calgary, CSPG Short Course G-4, unpubl. notes, p 1-3 7. Nowlan, G.S. and Barnes, C.R. ( 198 1): Late Ordovician conodonts from the Vaureal Kent, D.M. and Kissling, D.L. ( 1998): Covert facies of Formation, Anticosti Island, Quebec; Geo!. Surv. the Red River C Laminated Member, northern Can. , Bull. 329. p 1-49. Williston Basin; in Christopher, J.E .. Gilboy. C. F., Paterson, D.F., and Bend, S.L. (eds.), Ei ghth Nowlan, G.S. and Haidl, F.M. (1999): New conodont International Williston Basin Symposium, Sask. data from the Ordovician-Silurian boundary Geol. Soc., Spec. Publ. No. 13, p24. interval in southeastern Saskatchewan; in Summary of Investigations 1999, Volume I, Kessler, L.G. ( 1991 ): Subsidence controlled Saskatchewan Geological Survey, Sask. En ergy stratigraphic sequences and the origin of shelf sand Mines, Misc. Rep. 99-4.1, p 12-16. ridges, Winnipeg Group ( Middle Ordovician) Manitoba, Saskatchewan and North Dakota; in Oberg. R. ( 1966): Winnipeg conodonts from Manitoba; Christopher, J.E. and llaidl, F.M. (eds.). Sixth J. Paleont., v40, p130-1 37. International Williston Basin Symposium, Sask. Geol. Soc., Spec. Publ. No. 11 , pl-13. Pratt. B.R., Bernstein, L.M., Kendall. A.K .. and Haidl, F.M. ( 1996): Occurrence of recfal facies in Red Kissling, D.L. ( 1997): Rethinking the configurations of Ri ver strata (Upper Ordovician), subsurface Red River reservoirs; Fifth International Williston Saskatchewan: i11 Summarv of lnvesti!rntions Basin Horizontal Well Workshop: Sask. Energy 1996. Saskatchewan Geol~gical Survty. Sask. and Mines and North Dakota Geo!. Survey. Energy Min es. Misc. Rep. 96-4. p l47- 152. ]() Summary of lnves 1igatio11s 20()/. 1--olume I ··------Seddon, G. and Sweet, W. C. (1971 ): An ecologic model for conodonts; J. Paleont., v45, p869-880. Stasiuk, L.D ( 1991 ): Organic petrology and petroleum formation in Paleozoic rocks of northern Williston Basin, Canada; unpubl. Ph.D. thesis, Univ. Regina, 312p Stasiuk, L.D., Kybett, B.D., and Bend, S.L. (1993): Reflected light microscopy and micro-FTIR of Upper Ordovician Gloeocapsomorpha prisca alginite in relation to paleoenvironment and petroleum generation, Saskatchewan, Canada; Org. Geochem., v20, p707-719. Stone, G.L. and Furnish, W.M. ( 1959): Bighorn conodonts from Wyoming; J. Paleont., v33, p21 l- 228. Sweet, W.C. ( I 979): Late Ordovician conodonts and biostratigraphy of the western Midcontinent Province; Brigham Young University, Geology Studies, v26, p45-86. -~-~ (1982): Conodonts from the Winnipeg Formation (Middle Ordovician) of the northern Black Hills, South Dakota; J. Paleont., v56, p I 029-1049. ---=-~-=-- (1984): Graphic correlation of upper Middle and Upper Ordovician rocks, North American Midcontinent Province, U.S.A.; in Bruton, D.L. (ed.), Aspects of the Ordovician System, Palaeont. Contrib. Univ. Oslo, No. 295, p23-35. Sweet W.C. and Bergstrom, S.M. (1984): Conodont provinces and biofacies of the Late Ordovician; in Clark, D.L. (ed.) Conodont Biofacies and Provincialism, Gcol. Soc. Amer., Spec. Pap. 196, p69-87. Saskmcltewan Geological Survey 31