Field Notebook: IA 1951

SHELL DAKOTA 1951 doc. 463 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY LOOSE-LEAF FIELD NOTEBOOK 9-137

K.M. Waage Trip on Dakota with Ed Taylor. 1951 [6266] Iowa, Sioux City Brick & Tile Co doc. 463

6/5/51 Dr. Reeside: Excellent section showing all 5 parts of Dakota at Plainview - R.R. cut - Moffat tunnel betw. Boulder & Morrison. Mowry facies is present at very base of Grzueros on Wyo. line area. Has never seen it farther south. Graneros has two ammonite zones in Colo - or if Mowry part present should have 3. Greenhorn of Colo ≠ Greenhorn of Kansas. Type " " = upper member of Kansas Greenhorn, rest of Kan. qhn is in Graneros - starts at limey shale above siltstu? or upper ammonite zone? Thinks Leel's correlations OK and probably permissible to extend Purgatoire terminology northward. Type Greenhorn has 2 good zones in it. Suggests talking to Bass in Denver. 6/6/51 Bill Pierce: Fuels starting subsurface study of Dakota in NE Colo. this winter. Suggests paper on terminology of Dakota in NE Colo. this winter as plans are to tie subsurface in with crop. Believes oilfield terms should be extended. He and Harry Tourfelot discussed it with me and agreed good division would be Colo Spas area & Arkansas Valley for Purg - Dak. and from Castle Rock N. the Black Hills terminology. Beds cut out betw. Colo. Spas area & S. of (zssler) & this gap if extended eastward would correspond with divide betw. Platte & Arkansas drainages. Black Hills section - Newcastle (Dakota), Skull Creek (Glencourn -?partor all?) Lakota, Fusion, Fall

River (Lytle) From Quarry worker -- 2-15' Clay 2-3' Limey calkrock 20" Blue clay - Blackjack / NIX? chalk 6-1/2 Cool sth. 1o2' Gray clay 1mm Sand 3' Blue clay <- Bottom clay 0-6" Coal 4 Sand -- concretions with leaves. 8-10 Clay (Bottom clay) 'Snail,' blue clay Gray clayey sand Sandwork.

6266 Sioux City trip with Ed Taylor (June 1951 - on way to Golden. Shell Fund) Sample -2 is 11" above cool (1 below) Sioux City Brick Co. Section (1) N. of old quarry. Rough measurement Big shale bed or "Black Jack" 1 Coal + coaly sand +/- 1/2" 2 Gray silty clay grading to silvery silt + sand, plant rootlets - 1/2" thick shale, rootlets at base -- 1' 3 Siltstone- Light gray, laminated, plant frags compact + prominent bed at this outcrop. About 30", pinkish + slightly coarser -> fines in lower 6" 80" 4 Interbedded silty clay + clayey silt . . . 5' and Fe cemented layers. Siltstone finely laminated with clayey silt, reddish brown clayey light silt in upper 3 1/2 ' gray to dk gray below. Plant frags in local sandy concretions. Plant frags common in both brown & gray. 5 "Blue clay" (Spot Sample #1 taken 3' from top) This is bottom clay. A dark-gray silty clay with light gray silt pockets + laminae. Bryops rosettes on bedding. Plus crude fissility.

Section 2 - New Quarry - Sioux City Brick General - The lignite bed is 6 to 8 " and rests directly on the siltstone, thus #2 of Section 1's either cut out or gone over into silt like #3. Looks like discont. between lignite & siltstone. Above lignite is 'Blackjack' clay - a shale + silty shale about 20-25' that = Grameros. From middle+below it, of this comes the Ammonite fauna - Metengonoceras, etc in key Clay men says some ammonites also from below in bottom clay. None of ammonites found were in place. Position where found attested to by both foremen (Mr. Mathews) and worker. Both say in lower part of 'Blackjack'. Below bottom clay is another lignitic zone followed by another siltstone - sandstone. Still another clay was once mined below this - and is said to be mined now at Sergeant Bluffs.

Wednesday- Get ice at night and get tick shots. A.M. - Section Sioux City pit. See Sergeant Bluff if possible P.M. -

Section 2. from base of slubby layer down 5' Grey to slightly purple gray clay with partings of silt (white [Sample] 1 spot about 16" from top, Sample #2 channel of lower 3'.) 1" layer yellow-weathering clayey silt 4" from base. 1' Similar to above with another 1"+ parting of yellow-weathering clayey silt at base. (Sample 3) 3' Dark gray somewhat fissile shale with gyp xls on bedding, inocoramus frags and some silt partings. At top 3/4" silt 4" shale 1/2" silt descending - These 2 silts + assoc clay in Sample 4. Sample 5 = 1 1/2 feet below silt base of Sample 4; Sample 6 is to bottom of [Sample] interval from Sample 5. 1' Zone of fine sand and silt with gray silty clay partings. Zone heavily iron stained laterally has concretions or ledges. 1' Gray silty clay with silt [streaks] in abundance, some pockets pyrite + hard concretions (Fe-stone?) with gyp crack filling (Sample 7) 1' As above but somewhat siltier (Sample 8) 2 1/2 As above (Sample 9) 1' As above (Sample 10) 6" [Gradual] Sharp lith change to tough, hard silty gray clay. siltstreaks. (Sample 11).

Section 2 (Cont.) Sioux City Brick and Tile Co. 7" fine, Fe cemented to crumbly sand, with clayey conc. Fe; stained yellow to orange, some shaly streaks. (Sample 12) 6' to 8" coal - lignite (see sample not in case - thus coal changes laterally from lignitic clay to poor coal with vitrain streaks. 5 or 6" Gray clay becoming silty downward, rootlets. [Not everywhere present. 3'+ Disconf? - at least locally. Siltstone, massive, soft to hard, locally sandy. A prominent bed, bench former. Light gray with plant rootlets + vertical fracture locally. Local Fe cemented zones. 6' upper 3' hard silty gray clay with many laminize siltstone and less silty down ward. Lower 3' hard gray silty clay with fewer silt lamine. Sample 12 - lower 2' Sample 13 - middle 2' Sample 14 - upper 2' v To base of quarry floor About 3' from top local large Siltstone Caucs. - very hard but original bedding and laminize go thru. Mark base of very silty zone with silty lamine Laterally the upper 1 to 2 1/2 feet of this zone is brownish gray - it is always full of silty laminat

Section 2 Concretion key tinely cross lam siltstn Grey to green grey with black lamination, flat beds. breks along laminated silty zone sandy zone local indentation (some nearest to = ammonito conc. 1/4th. oval calc? conc. barren flat to wavy brownish siltstn - locally banded fish scales coal sltt. big hard, banded siltstone red brown. Flat oval-circular oval-conc'l few small oval similar to that above coal

Section 2 (cont. on old face right behind filings) From base of persistent layer of hard banded concretions that are 3' below base of siltstone bed in top of "bottom clay" zone. Concretion zone 4' Silty gray clay, local concretions (hard [illegible]?) Some few silty laminae but most silt in clay. Conc. zone at base, which is silty and grades laterally into silty Fe cemented str layers. 3' As above - Sample 16 upper half Sample 17 lower half 2' Lignitic clay, brown, slightly silty lower 6" silty clay to clayey silt Sample 18 3' Massive siltstone, gray-white, much Fe staining & Fe cemented stringers. Similar to siltstone under upper lignite. May be fine SS locally. 3½ to 4' Hard dense fine grained sandstone. Fe stained silty in upper foot. Pine plant fossils. Sample 19. This appears to be local channel. 1 Fine sand & silt with clay laminae 1½ Silty clay with silt laminae & pockets Sample 20, Grades laterally into silt.

Section 2 (cont.) 4-6" Fe-stained concretionary zone 2 1/2' Silty clay - 1' clayey silt at top. Fe staining. More clayey downward. All a light gray to gray. Base section - bottom of bed above not reached.

Sergents Bluff Quarry, N. well silty gray clay hard ss or siltstone (edge) clay or silty clay siltstone thin clay or silts clay - dark - coaly? siltstone local thin gray devicr than below channel-like cuts light gray locally red mottled gray silty little mottling silty gray to greenish? with red mottling.

Serquats Bluff ch. siltston dark clay Silty cl.+ siltstone int qr Hard ss

From coal 2' top, - Section 3 4' light gray weathering clay becoming darker downward. Pockets and blobs siltstone [and purplish] chiefly below upper foot+1/2. 1' Dark, locally silty clay, somewhat silty. Lower 2 inches laminated silt and clay with thin seams coal up to 1/4" [Sample 1 from upper 8" of this foot in silty clay] 6' Dark to light gray muzzy finely silty clay with many plant root lets, some dark splotches in lower higher portion. More silty toward base. [Sample 2 is spot from 2' above base of this interval]. 6' Milded gray clayey siltstone & highly silty clay, carbonaceous splotches and small ferruginous (siderite) speckles which begin foot below top + increase downward in bed. [Sample 3 is spot 2' from top] Sample #4 at base] Base( 1 1/2 feet highly silty/ferrstained but speckles die out 2' Silty clay, grading down from light gray highly silty clay to gray [muddy] silty clay. Zone of small hard Fe stained concret at base 1 to 3" diam. [Sample 5 at base] 6' Silty gray clay with ferrstained silty concret mostly small like above 4' Highly silty to sandy clay, zones fines & siltstone Big ledge heavy hard ss in locally - shown started on graphic sections ? grey clay below.

Graphic of sec 3 8" gray shale tthin ss, cnc. 12 to 14 ft. 15" friedly brown thincsl > cozl (ar slt cl) (jk sh cl) underclay, muzzy chkzt base light silt cln cans rusty weth gray soft chk ss ledg. 8' gray silty clay 2' [illegible] dk gray cl, locally coaly 8 to 12' gray silty clay to slzgy slt+ 36' upper speckled 4x24" Iocyl red+ yellow spec lower speckled green gray red spec pit floor most persistence red zone X box, plant remains dicots - czk cement weathers lazuma blved brown slabs Quarry men says below floor gray clay pyritic + some coaly streaks.

Section 2 In quarry face the sandstone appears cut out at quarry ends. It may also be that one layer of some lith as ammonites comes in in lows. (xxx) below, but this not clearly shown N S No ammonites found in place but some concretions of similar lithology occur locally 1 foot above coal at S. end face.—all cores in this zone seen in place are barren. Andy says Sweller ammonites come in ‘Blackjack’— Big ones— big as barrel head in bottom clay

Local problems. The Morrison-Dakota contact at Morrison Type Area: (Eldridge 1896) - Speaking of Morrison fm. - P.60-62 "Its upper limit is sharply defined by the Dakota sandstone ---" The most important sandstone occurs just above the Atlantosaurus clays, [="clays of the lower two thirds"-] is very persistent, and from contained saurian remains has been called the Saurian sandstone. It varies in thickness between 5 and 35 feet, and its distance below the Dakota from 10 to 125 feet, although more generally from 50 to 80 feet." "At the base [presumably of saurian ss] is generally a conglomerate, of a maximum thickness of 8 feet, in which the pebbles so closely resemble those of the Dakota that, but for a slight admixture of red jasper and the characteristic brown dots, the two layers could with difficulty be distinguished from each other. The shales overlying this sandstone are similar to those comprising the bulk of the Jura, but carry through them a number of minor sandstones and occasionally one or two strata of limestone." Eldridge on Dakota-Morrison contact, (p.63) 5745 the base of the Dakota has a distinct conglomerate very which "varies from a thin almost imperceptable layer to 30 feet in thick- ness, and is composed of well rounded, smooth, in some cases almost glazed, pebbles from the size of pea to a diameter of inch." This important as it indicates Eldridges idea on boundary - there being only one"chert pebble col in that part of section. Seeing certain that Lee, as Waldschmidt & Leroy (19 p. 1100) pointed out, confused issue by misinterpreting Eldridge (Lee 1920, p.184) when redefining the Morrison.

Lee (1920) Lee (1927) continues to cloud issue. Gives measured section of type Morrison to replace old ones but his new section is way off on measurements compared to ours. Units can be recognized, however, tho they are not sufficiently detailed for close correlation. Among interpretations given by Lee, following are in error and responsible for the confusion over type Morrison. 1. Misinterpretation of Eldridge - this apparently came about through Lee's dependence on Prof Cannon "who claimed to have first-hand information gained by association on the ground with Eldridge and other early observers in the Denver region --" (p.29) Cannon said that the two ss separated by 5' clz were what was "originally interpreted for this locality" as the 2 SS and 'five clay' of the Dakota. Cannon pointed out base of 2nd SS as "base of Dakota of Eldridge and other early observers." As there is no clz whatever here it could not possibly be what Eldridge meant (see Eldridge quote on clz base Dslt preceding page) 2. Lee - assuming that Eldridges Morrison included all 'Dakota' below czproct at Bear Creek - generalizes

that the "upper part of Morrison as first delimited, which in this paper is correlated with parts of the Dakota group of the Bellevue section, consists of soft friable sandstone and sandy shale. The lower part of these beds is similar in color to the Morrison." (Known fossils plants come from the "upper part of these beds." Lee himself may not have right base to Morrison 3. Lee confuses Szurian ss and basal Dk. cher- cql. (p. 30)

Mr. Andrew Hope 911 Witcher Ave Sioux City