Descriptive, interpretive, and quantitative study of the coarse clastics of the Middle Ordovician Tellico Formation in the vicinity of South Holston Dam, Tennessee

Coarse clastics of the Middle Ordovician Tellico Formation in the vicinity of South Holston Dam in northeast Tennessee are described by distinct sets of attributes which are thought to reflect the action of three transport mechanisms: fluid turbulence, grain dispersive pressure, and debris flow. Normal distribution grading, clast-supported fabric, erosive features, Bouma (l962) divisions, and relatively good sorting reflect fluid turbulence. Inverse grading and imbrication suggest the action of grain dispersive pressure. Chaotic, matrix-supported beds indicate debris flow. Coarse-fraction and distribution grading are distinguished on the basis of their standardized cumulative densities by the Kolmogorov-Smirnov Statistic. Distribution grading is studied by a one way analysis of variance. Vertical variation is shown to be significant but not adequately characterized by a linear model. Departures from linearity are related to competency-availability constraints.

The coarse clastics are divided into five lithotypes following Walker (1978): classical turbidites, massive sandstones, pebbly sandstones, clast-supported conglomerates, and matrix-supported beds. Each lithotype is characterized as to its descriptive features and possible transport mechanism. . Certain distinct patterns of regular change, both within beds and between beds, are suggested by upward transition probability matrices.

Associational and sequential regularities in lithotypes and their properties provide evidence for distinct environments of deposition. Broadly, the six outcrops studied are best explained as deposits of a submarine fan. Markov analysis and smoothing procedures are used to study the sequential regularities in the rocks. Transitions in conglomerates and turbidites provide information on the environmental constraints that induced regularity in their probability matrices.

Factor analysis is used to objectively specify the common factors explaining variation in properties (R-mode) and beds (Q-mode). An iterative R-mode factor analysis disclosed five factors: a turbulence factor, a scale or parameter factor, a bed geometry factor, a timecompetency factor, and a clast concentration factor. These factors explain property variance in the coarse clastic beds studied. Q-mode analysis uncovered one important factor that defines a seriation of the beds from proximal to distal environments. This seriation in turn can be used to stochastically ordinate the properties of the coarse clastic beds.

Kolmogorov (1951) analysis is used to investigate the interaction of accumulative and erosive processes in turbidite sedimentation. By extending shale thickness distributions into the negative region left of the ordinate, an approximation (p) to the stable probability value of shale accumulative events is achieved. A model of shale deposition is proposed for a stationary, independent time series. The convolution integral of the thickness distributions of pelagic and turbiditic shale in such a series yields a near normal, though erosion-truncated, density distribution. It is this distribution that is used to calculate Kolmogorov's coefficient and ratio. Autocorrelation coefficients, thickness ratios, and amalgamations provide some empirical evidence in favor of the theory. Compaction and phenomenological limitations suggest important qualifications to the values of the ratio and coefficient.