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W. H. Bradley

Publications and source records attributed to W. H. Bradley.

18 recordsLinked to original sources
USGS2003

Vertical density currents — II

Examples of vertical density currents wholly within the domain of laminar flow, one in a water solution, the other in air, have come to my attention. Both examples illustrate new ways of introducing and dispersing microscopic particles into static fluids and both demonstrate that a stable, clearly defined layer of dispersed particles forms first and that the vertical density currents originate and flow from the lower part of this layer. The new information comes from wholly unrelated lines of research, one in virology, and the other in mycology. Neither investigation was aimed at hydrodynamics yet both provide good experimental support for vertical density currents.

Limnology and Oceanography↗
USGS2003

Mud Lake, Florida: Its algae and alkaline brown water

Mud Lake (Marion County, Florida), in the Ocala National Forest, is elliptical, has an area of ca. 180 ha, and a mean depth of less than 50 cm. The water contains about 200 ppm dissolved solids, ranges from brown to nearly colorless (15 to 100 Pt units), and is always alkaline ( p H 7.7 to 10.2). Dissolved Fe, Ca, PO 4 , tannin-lignin, and the specific conductance, color, and temperature of the water were measured monthly for 1 yr, and temperature and p H were measured many other times during the 3-yr study (1966–1968). The lake is surrounded by a zone of mixed hardwood swamp flora and a floating mat of vegetation and has no submerged higher plants and only 1 or 2 m 2 of emergent plants. The lake sediment consists exclusively of minute fecal pellets produced mainly by chironomid larvae and composed solely of blue-green algae. Myxophyceae are represented by at least 10 genera and 12 species, which live exclusively on, or in, the fecal pellets; less than half show a seasonal distribution. The Chlorophyceae consist dominantly of Spirogyra triplicata with minor amounts of Sirogonium sp. and generally occur in enormous winter blooms, correlated with changing amounts of dissolved PO 4 and apparently inversely with both temperature and incident light. Bacillariophyceae are represented by 18 species and varieties, but the total population is small. Nanno-, zoo- and phytoplankton are extremely rare, probably because of the prevailing high intensity illumination and the extremely shallow water. Only the fish population is large, and this is dominated by minnows, gars, and sunfish. The midge population is remarkably small. A bacterial inhibitor probably accounts for the small population of bacteria both in the water and in the top layer of the sediment.

Florida↗
USGS1973

Oil shale formed in desert environment: Green River Formation, Wyoming

The oil shale beds of the Wilkins Peak Member of the Green River Formation differ from most of the Green River oil shale of Colorado and Utah because very few of them have varves; they have numerous mud cracks and, locally, desiccation breccias. Many have a copropelic microstructure and contain labial plates and skin fragments of chironomid larvae. Microfossils of some of these oil shale beds include such normally perishable things as first instar midge larvae, a single spiral chloroplast of a green alga, and sporangia of aquatic fungi. Taken together, these features indicate that the oil shale originated from algal ooze that formed on the bottom of very shallow, spring-fed lakes. The algae (dominantly blue-greens) were not planktonic but grew on, and in, the flocculent ooze. At intervals, perhaps tens to hundreds of years, the lake levels fell enough to expose the algal ooze to the air and partial drying. In the resulting rubbery organic gel, the most delicate microorganisms were heat-fixed and thereby preserved as “mummified” tissue.

Wyoming↗
USGS1970

Green River oil shale—concept of origin extended: An interdisciplinary problem being attacked from both ends

A much fuller understanding of the Green River oil shale and its organic chemistry will emerge when the geologists, paleontologists, organic chemists, biologists, paleolimnologists, and biogeochemists, who are now working on it, integrate their findings with those of the others. We know from the geology, paleontology, and paleolimnology that the biologic progenitors of the organic substance in the Green River oil shale could only have been microscopic algae, and other micro-organisms, that grew and accumulated in the central parts of large, shallow lakes that existed under a subtropical climate. The only nonlacustrine organic components were wind-blown, or water borne, pollens and waxy spores. These, however, made up a large and important part of the organic-rich sediment. The geology of the Green River Formation shows that as the algal and pollen-rich sediment was buried deeper and deeper, progressively more of its pore water and dissolved constituents were expressed. Static pressures may have reached as much as 210 kg cm −2 , and the ambient temperature rose, with depth, to somewhere within the range between 90° and 125° C. Beneath the ancient lakes a tectonically quiescent environment persisted for tens of millions of years after their organic sediments had been deeply buried. The organic material of the Green River oil shale can be divided into three fractions—a small bitumen fraction that is extractable with common organic solvents, a major fraction called koerogen that consists of insoluble pyrobitumens, and a somewhat smaller inert fraction that is neither soluble nor does it yield oil on pyrolysis. As all three fractions originated in the same algal, pollen-rich sediment, an explanation for their marked differences must be sought in their geochemical history or from a study of the modern analogues of their progenitors. The components of the bitumen fraction consisted of “biological markers” that were inherited from the Eocene plants and animals in which they originally formed. Diagenesis has changed these hydrogen-rich compounds, but not enough to obscure their provenance. Kerogen presumably became insoluble because its hydrogen-rich components polymerized. My speculation is that the inert fraction was derived from a polyphenolic substance produced in the original algal ooze by “non-enzymatic browning.” Only three Classes of non-marine algae need be considered as progenitors of the Green River oil shale; the Xanthophyceae, the Chlorophyceae, and the Cyanophyceae. Only the Cyanophyceae (the blue-green algae) meet the biologic and paleontologic requirements to have served as the dominant precursors of the Green River oil shale. Several other oil shales clearly were derived from the Xanthophyceae, specifically Botryococcus. The blue-green algal ooze now forming, and accumulating, in Mud Lake, Florida, has been studied biologically and chemically as a possible present-day analogue of the Green River oil shale precursor. In this small lake we have established the fact that a bacterial inhibitor is produced, which inhibits decay of the algae and thereby permits the accumulation of energy-rich organic compounds. We infer that a similar indigenous inhibitor must have acted in the Eocene lakes to permit them to become the huge energy sinks they were. Studies of the organic chemistry of living blue-green algae show that they contain appreciable percentages of fatty acids, hydrocarbons, and very large percentages of proteins. These promising, energy-rich compounds could serve as source materials for potential conversion into oil shale in the geologic future. Certain marine anaerobic bacteria convert fatty acids into aliphatic hydrocarbons. Fresh-water obligate anaerobes should be investigated to see if they also convert fatty acids into hydrocarbons. The part played by aquatic animals that live in, or on, freshwater algal ooze in synthesizing hydrocarbons has not been investigated, but deserves attention. Pollen grains, of course, must be considered an important precursor of hydrocarbons produced on pyrolysis. They contain far higher percentages of long chain hydrocarbons and alcohols than most plant materials. The major problem ahead is to account for the progressive hydrogenation and subsequent polymerization of the relatively oxygen-rich constituents of algae such as the polysaccharides, amino acids, ammo sugars, and fatty acids into the insoluble pyrobitumens that constitute, particularly, the kerogen fraction of the Green River oil shale.

Wyoming↗
USGS1969

The role of larval Chironomidae in the production of lacustrine copropel in Mud Lake, Marion County, Florida

Mud Lake is a shallow (avg 45 cm), alkaline (pH 7.7–10.2), brown‐water lake having an area of about 180 ha. A study of its organic sediment was undertaken because it appears to be a present‐day analogue of the richly organic lacustrine oozes that were the precursors of the oil shales of the Green River Formation (Eocene). The water contains about 200 ppm total dissolved solids. The soft ooze is about 1 m thick and consists of minute fecal pellets produced primarily by larvae of Chironomus ( Chironomus ) sp. Mean numbers of larvae ranged from 120 to 580 m −2 ; such a small population may reflect extensive predation by fish. The small diversity of Chironomidae at this latitude may reflect the fact that few organisms can tolerate the physical conditions produced by the shallow water. Experiments with laboratory‐reared Mud Lake midges showed that the numbers of fecal pellets produced generally increased with the concentration of algal cells available; that only when the larvae were fed blue‐green algae were the fecal pellets coherent and durable—larvae fed green algae produced pellets that disintegrated, returning the undigested algae to the food supply; and that larvae fed blue‐green algae changed from filter‐feeding to grazing on the fecal pellets when suspended algal cells became sparse. We conclude that the sediment in Mud Lake is pelletal because only blue‐green algae are available for food and that the larvae probably graze because all the blue‐greens live only on, or in, the fecal pellets. Early instars produce ovoid pellets; later instars produce longer, cylindrical pellets. The analogy between the Mud Lake pelletal ooze and the Eocene precursors of the Green River Formation oil shale is enhanced by the facts that some oil shale thin sections show minute fecal pellets and that certain beds of rich oil shale contain numerous unmineralized remains of immature chironomids.

Florida↗
USGS1965

Vertical density currents

These currents seem to carry particles downward much more rapidly than settling according to Stokes's law.

Science↗
USGS1941

Geologic structure and occurrence of gas in part of southwestern New York. Part 1, Structure and gas possibilities of the Oriskany sandstone in Steuben, Yates, and parts of the adjacent counties

The area covered by this report is in southwestern New York and includes a little more than 3,000 square miles in Steuben and Yates counties and parts of the six adjacent counties. This area has been mapped to determine the structural attitude of the exposed rocks, so as to aid those interested in prospecting for natural gas in the Oriskany sandstone of Lower Devonian age. Because of the gentle regional dip toward the southwest, the youngest beds are exposed in the southwest corner of the area, and progressively older beds crop out northeastward in successive bands that strike generally northwest. All the exposed rocks are of Upper Devonian age except those in a narrow belt at the extreme north edge of the area, where a small thickness of Middle Devonian rocks crops out. The maximum thickness of beds so exposed is nearly 4,000 feet, of which the lower part is predominantly soft dark shale and the upper part predominantly fine-grained sandstone and gray shale. All the beds are marine except a few tongues of continental deposits red shale and sandstone and gray mudstone in the youngest beds. All the beds thicken southeastward, so that there is a northwestward convergence between any two lithologic units in the series. More than 30 key horizons that are persistent and distinctive were mapped, and altitudes on these key horizons served as a basis for constructing the structure contour map. Many of the key horizons are formation or member boundaries, but others are the tops or bottoms of limestone or sandstone beds within formations. All the stratigraphic units mapped are purely lithologic. (See pi. 2.) The Tully limestone, which crops out along the northern border of the area, is an easily recognizable and therefore valuable key bed for subsurface correlations in this part of the State. Below the Tully limestone is a thick body of Middle Devonian shales of the Hamilton group which rests on another valuable key bed, the hard, cherty Onondaga limestone, also of Middle Devonian age. Below the Onondaga limestone is the Lower Devonian Oriskany sandstone, which is the gas-producing bed. Unlike the Onondaga, the Oriskany is locally thin or absent. The structure of most of the area is shown by contour lines at 25-foot intervals, but where key horizons are lacking the structure is indicated by dip symbols. Upon the regional south and southwest dip are superposed numerous gentle folds whose axes trend approximately northeastward in the greater part of the area but more nearly eastward in the eastern part. The folds generally tend to become narrower and steeper, and therefore more closely spaced, southwestward. Many of the anticlines fork southwestward, whereas the synclines. tend to fork northeastward. All the folds have a westward or southwestward plunge. Throughout the area the rocks are jointed in two dominant sets one that trends northwest and the other east or northeast. No evident relation .between these joints, which were measured only in the hard, relatively brittle beds, and the individual folds or domes was discernible. The faults are concentrated in the northeastern and southwestern parts of the area and trend either northeastward or northwestward. Some are nearly vertical normal faults; others are steep reverse faults. Subsurface data show that most of the faults increase in throw downward and also that many subsurface faults do not reach the surface. A group of faults in the northwestern part of the Greenwood quadrangle and the southwestern part of the Hornell quadrangle were active during Upper Devonian time, while the Gowanda shale and overlying beds were being deposited. At this stratigraphic horizon the beds in a zone a few hundred feet thick are highly deformed in a wide belt on both sides of the faults. Sandstone layers are thinned out into long stringers or swollen into thick masses and in places are bent acutely without fracture. Thin layers of shale, coquina, and sand have flowed together into intricately plicated zones that lack cleavage and joints. These features show that the sediments were deformed while wet and plastic and buried only a little way below the sea floor. The beds that were laid down over these disturbed zones were not involved in this deformation. Many of the sharper flexures and most of the faults are not evident in the beds several hundred feet stratigraphically higher. Accordingly, broad, gentle folds in these higher beds in parts of the area south and west of the northwest corner of the Greenwood quadrangle may conceal, at considerable depths below them, narrow folds separated by abrupt flexures or faults. Several of the larger streams and rivers occupy strike valleys, and their j courses swing to follow the changing strike of the rocks where they cross ( successive folds. But, with few exceptions, the small streams are not adjusted to the bedrock structure. Domes likely to serve as traps for natural gas are concentrated in the northeastern and southwestern parts of the area. The Wayne-Dundee gas field is in the northeastern part. All the other potentially valuable domes in this part of the area have been drilled and found valueless except one small structural feature in the southern part of the Ovid quadrangle, which, if the Oriskany is present, may trap a small quantity of gas. In the Greenwood quadrangle in the southwestern part of the area there is one gas field and four well-defined domes, all of which may be productive if the Oriskany sandstone is present. In the northwest corner of the quadrangle the dips indicate at least two domes that can be adequately defined and evaluated only by geophysical prospecting. The State Line gas field is in tbe Wellsville quadrangle. In the southeast corner of this quadrangle there are three other domes of comparable size that may also be productive if underlain by the Oriskany sandstone. At other places in the Wellsville quadrangle the dips suggest several anticlinal axes on which analogous productive domes maybe found. The structural features in this quadrangle, however, are defined by contours only in the southeastern part. In the Woodhull quadrangle a large dome east of Jasper may be productive, and the western top of the large Woodhull dome in the southwestern part of the quadrangle seems to warrant drilling, despite the absence of the Oriskany in a well on the eastern top. Two wells drilled in 1936 and 1937 a little northeast of a broad, nearly flat-topped dome in the Hornell quadrangle, a few miles east of Hornell,, struck small flows of gas, suggesting that wells drilled higher on this dome may be productive. In much of the southwestern part of the area seismograph surveys should be of great value in determining the structure at the Tully and Onondaga horizons. Without abundant subsurface control of this sort, the danger of drilling into subsurface faults can hardly be overemphasized. Three closed or nearly closed synclines in the Greenwood and Wellsville quadrangles appear to be favorable places to drill for oil in the shallow sands presumably parts of the Dunkirk sandstone.

New York↗
USGS1936

Geomorphology of the north flank of the Uinta Mountains

The Uinta Mountains, whose northern margin is almost coincident with the southern boundary of Wyoming, extend from the Wasatch Range eastward across the northern part of Utah into northwestern Colorado. They were carved out of a large, simple anticlinal fold of sedimentary rocks arched up into essentially their present attitude at the end of the Cretaceous period. The Uinta Mountain group (Uinta quartzite of previous reports) a series of brick-red to purplish-red quartzite and sandstone beds of pre-Cambrian age, aggregating more than 12,000 feet in thickness, makes up the central mass of the range. Flanking the quartzite core and sharing its anticlinal structure are beds of limestone, sandstone, and shale ranging in age from Upper or Middle Cambrian to Upper Cretaceous. These rocks, which have a total thickness of about 15,000 feet, have been eroded from the higher part of the range, so the upturned edges of the harder beds now form hogbacks ranked along the sides of the fold. In places large faults, approximating the regional strike, cut these steeply inclined beds. Gently warped Tertiary sediments, mostly of Eocene age, fill the large Green River Basin, which lies north of the range, to a depth of several thousand feet and lap up on the flanks of the mountains, from which they were chiefly derived.

Colorado, Idaho, Utah, Wyoming↗