Donald E. Hattin

Widespread, Synchronously Deposited, Burrow-Mottled Limestone Beds in Greenhorn Limestone (Upper Cretaceous) of Kansas and Southeastern Colorado

In central Kansas the Hartland Shale and Jetmore Chalk Members of the Greenhorn Limestone contain 16 burrow-mottled, ledge-forming, chalky limestone beds that can be traced across the entire outcrop. The same beds are recognized in equivalent strata of the Bridge Creek Limestone Member of westernmost Kansas, and all but one or two can be recognized in a Bridge Creek exposure in southwestern Pueblo County, Colorado. For a distance of nearly 450 mi some of these beds lie on, below, or close to equally persistent bentonite seams. The parallelism of bentonite seams and adjacent or nearly adjacent beds of limestone, and the uniform relative spacing of all the limestone beds prove that some of the latter are time parallel and suggest most convincingly that each of these widespr ad beds is time parallel. In contrast to intervening beds of laminated shaly chalk, the limestone beds lack internal stratification because of activity of a highly mobile infauna. The shaly chalk beds contain higher percentages of terrigenous detritus, organic carbon, and pyrite than the limestone beds, and are interpreted as reflecting greater rates of terrigenous detrital influx and an interstitial reducing environment that was inimical to development of a burrowing infauna. Smaller organic carbon and pyrite content of the limestones is believed to reflect a lower clay content of original sediments, and at least a partly oxidizing interstitial environment, as suggested by the high degree of bioturbation. Despite substrate differences, the aqueous environment directly above the sediment-water interface did not change significantly as sediment type alternated from detritus-rich to detritus-poor, because the shelly epifauna is essentially the same in adjacent be s of shaly chalk and chalky limestone. The widespread, apparently time-parallel limestone beds are believed to be the result of regionally manifested changes in volume of terrigenous detrital influx, coming principally from the west, that were superimposed on a more or less continuous accumulation of carbonate sediments. The noncrushed condition of macrofossils and fecal pellets suggests that limestone beds suffered early lithification; this process was probably influenced by initially greater purity of limestone-forming muds, slower sedimentation, and interstitial circulation resulting from bioturbation.

Petrology and Origin of Fecal Pellets in Upper Cretaceous Strata of Kansas and Saskatchewan

ABSTRACT Carbonate deposits of the Greenhorn Limestone, Fairport Member of the Carlile Shale, and Niobrara Chalk of Kansas are characteristically speckled by nearly white, ellipsoidal calcareous pellets having an average diameter near 0.12 min. Similar pellets occur in two widespread calcareous units, the first and second speckled shales, of the western Canadian plains. The two speckled Canadian units are approximately correlative with chalk-bearing intervals of the Kansas section. In both areas the pellets are of similar size, shape, color and texture and are known to be rich in coccoliths. Scanning electron micrography of these pellets, and of rock matrix adjacent to the pellets demonstrates (1) that pellets from the two areas are identical in being composed largely of coccoliths or coccolit debris and (2) that most non-pelletoid matrixes are composed predominantly of material not derived from coccolithophorids. Concentration in the pellets, of whole and broken coccoliths, as well as size of the pellets suggest origin as fecal matter of small, herbivorous, planktonic organisms that fed selectively on coccolithophorids. Copepods are known to feed selectively and are known also to feed on coccolithophorids. Furthermore, some living copepods produce pellets of similar size and shape to those in the Cretaceous strata. Alternatively, the pellets could have been produced by pelagic tunicates which are known to produce ellipsoidal pellets and to feed upon coccolithophorids. Further elaboration of trophic structure in the Late Cretaceous Western Interior sea requires search for ske etal remains of the pellet-producing organisms.

Petrology of Smoky Hill Member, Niobrara Chalk (Upper Cretaceous), in Type Area, Western Kansas

The Smoky Hill Member of the Niobrara Chalk is composed primarily of olive-gray, well-laminated to nonlaminated impure chalk, which is mostly foraminiferal pelmicrite with packstone or wackestone texture. The rock is characterized by well-stratified grain fabric. Ubiquitous constituents include coccolith-rich fecal pellets, mostly well-preserved tests of planktonic forams, wisps and silt-sized grains of black organic matter, fish bones and scales, and minute framboids of pyrite or its oxidized equivalent. Inorganic detritus is common in all samples, but only sparse grains of angular quartz silt are detected commonly in thin sections. Scattered through the member are thick to very thin beds of lighter colored, bioturbated (probably microbioturbated), and granular chalk. These are mostly foraminiferal and pelletal micritic wackestones, which lack well-stratified grain fabric; in thin sections, fecal pellets are less obvious than in well-stratified chalks, organic matter is much less common, and pyrite framboids are less common in the matrix. Diagenetic features of Smoky Hill stratified chalks include compactional deformation of fecal pellets, forams, burrow structures, and macroinvertebrate remains; dissolution of aragonitic skeletal material; incipient microstylolites; sparry calcite cement in foram chambers; interstitial calcite cement, and secondary calcite overgrowths on coccoliths, especially in the matrix. Bioturbated and granular beds are less well compacted than the stratified chalks and have greater amounts of secondary calcite as interstitial cement and overgrowths on coccoliths. In these chalks lithification was initiated earlier than in the stratified chalks. Bioturbation of these and related Kansas chalk deposits produced textures similar to those ascribed by others to deep-burial diagenesis and extensive sol tion transfer. Thin-section and scanning-electron-microscope (SEM) data suggest that most reduction of original porosity to the present average of 38% was accomplished by gravitational compaction. The remainder of porosity reduction resulted from the limited addition of secondary calcite, which was derived mainly from dissolution of abundant aragonitic skeletal remains and in small part from pressure solution. The Smoky Hill chalk is a pelagic, deeper water outer shelf deposit, which was laid down mostly as a soft, perhaps mostly soupy, coccolith-rich ooze on a nearly flat sea floor under conditions of normal or nearly normal salinity and generally poor bottom-water circulation. At irregularly spaced intervals, deposition of purer ooze furnished substrates suitable for a burrowing endobenthos, which bioturbated sediments and helped to initiate earlier lithification than in nonbioturbated deposits.

Paleoecology of scalpellomorph cirripeds in the Fairport Member, Carlile Shale (middle Turonian), of central Kansas

Scalpellomorphs were a major component of the benthic marine fauna that flourished during deposition of pelagic and hemipelagic muds that today comprise chalky and marly sediments of the Fairport Member, Carlile Shale, in Kansas. Primary inhabitants of oozy Fairport sediments were inoceramic bivalves, among which recumbent, meter-sized Inoceramus cuvieri furnished stable platforms upon which most epizoic macroinvertebrates depended for survival

Use of Rhythmic Bedding Patterns for Locating Structural Features, Niobrara Formation, United States Western Interior

Milankovitch-type bedding cycles are well developed in the Upper Cretaceous Fort Hays Limestone Member, Niobrara Formation. These time-equivalent cycles can be correlated across much of Colorado, Kansas, and northeastern New Mexico by combining subsurface and outcrop data. Documentation of thickness variations within the regionally persistent Fort Hays bedding sequence furnishes a basis for fine-scale analysis of Late Cretaceous crustal movements within the eastern ramp region of the Western Interior foreland basin. Regional thickness changes in groups of shale-limestone couplets were correlated and mapped in outcrop and in the subsurface to locate structural elements that influenced Fort Hays deposition. In the Denver-Julesburg basin of Colorado and western Kansas, up to 6.1 m (20 ft) of thinning of the section occurs dominantly along northeastwardly trending belts formed during Late Cretaceous reactivation of the Transcontinental arch. Mapping of these small-scale thickness changes in the Fort Hays demonstrates that Cretaceous reactivation of the Transcontinental arch was not restricted to the northern part of the Denver-Julesburg basin. Additional structures may occur as far south as the Colorado-New Mexico border. A northwestwardly thinning trend is also apparent and may have resulted from increased compaction and diagenesis, reduction of sediment input during transgression, or from uplift in the vicinity of the Colorado Front Range.

Holocene Cementation of Carbonate Sediments in the Florida Keys

ABSTRACT Previously undescribed examples of Holocene cementation of carbonate sediment have been discovered at two localities in the Florida Keys. Slabs of weakly cemented carbonate sand were discovered on a continuously submerged portion of White Bank, 3.1 km SE of the Mosquito Bank tower. The cement comprises furry coatings of acicular crystals interpreted as aragonite on basis of morphology, results of staining tests, and high-strontium, low-magnesium content. This is a normal form of submarine cement. Near the southeasternmost corner of Bahia Honda Key carbonate rock ledges crop out discontinuously along a 46 m foreshore stretch of sandy beach. Rock texture is like that of adjacent unconsolidated beach sands. Grains range from fine sand to free gravel, commonly in alternating layers within a single exposure, and most of the rock is laminated. The rock dips seaward, at approximately the same angle as the beach surface, but is apparently a form of cay rock. The rock is weakly cemented by rhombic crystals that by electron probe microanalysis were determined to have low strontium and relatively low magnesium content. This suggests that the cement is low-magnesium calcite. Similarly cemented carbonate sand occurs as much as one meter below the backshore surface, and at depths of 16 to 25 cm in a freshwater marsh lying inland from the beach. The relatively low magnesium content of the calcite and the salinity of water in contact with the rock suggest that cementation occurred in the zone of fresh water-sea water mixing.

Regional Stratigraphy of Limestone Marker Beds in Bridge Creek Member, Greenhorn Limestone (Upper Cretaceous), Western Interior United States: ABSTRACT

Time-parallel limestone beds of the well-known Kansas section have been traced westward in an attempt to determine their total geographic extent, their origin, and their utility in precise regional correlation. The entire sequence of marker beds extends from Canon City, Colorado, to Springer, New Mexico. Certain groups of these markers are traceable southward to White Oaks, New Mexico, northward to the Black Hills, and westward to the northern San Juan basin. The most widespread limestone beds were deposited across areas no smaller than 388,000 sq km (150,000 sq mi). Individual beds are identified positively by position in sequence, relation to adjacent bentonite seams, lithology, and fossils. Each bed is thoroughly bioturbated, and the thickness, fossil content, and fiel characteristics are remarkably uniform for great distances. Dominant mineralogy is calcite; quartz and pyrite are the only consistent accessory minerals. The limestones are micritic to microsparitic wackestones and, uncommonly, packstones. Principal allochems are planktonic forams, inoceramid bivalve fragments and prisms, calcispheres, and oyster fragments. Fecal pellets are scarce west of the Rocky Mountain front but common in Great Plains sections. Limestone bed contacts are mostly gradational with adjacent shaly strata, and evidence for hardgrounds is lacking. Limestone beds of the Bridge Creek Member reflect offshore shelf deposition during the late Cenomanian-early Turonian transgressional maximum of the Western Interior sea. Relative proportions of pelagic versus benthonic allochems confirm that limestone beds represent slow deposition caused by reduced detrital influx. Deposition occurred on a nearly planar surface, with local highs marked by areas of condensed sequences. End_of_Article - Last_Page 464------------

Memoriam — Dr. Donald E. Hattin (1928–2016)

Don was born in 1928 in Cohasset, Massachusetts, the son of Edward Hattin and Una W. Hattin. He began his college studies in 1946 at the University of Massachusetts, where he soon discovered his love for geology. He graduated there with a BS degree in 1950. In the fall of that year he and his bride, Marjorie Elizabeth Macy, headed west to Lawrence, Kansas, where he studied stratigraphy and paleontology at the University of Kansas, earning a master’s degree and PhD in 1954 under the tutelage of Raymond C. Moore.

Volumetric histogram for field study of carbonate sediments

ABSTRACT The volumetric histogram is a teaching aid which permits field evaluation of sediment size distribution. Wet sediment fractions are taken from a standard sieve series and placed in graduated cylinders that are mounted in a row on a wooden base assembly. The resulting histogram can be used at the sample station for visual estimation of statistical parameters.