GRAIN SIZE ANALYSIS OF SOME OLISTOSTROMES BETWEEN BALKUYUMCU AND ALCI (SW ANKARA)

Indexed In

Volume 115 / 1993

Authors:

Engin OLGUN, Teoman NORMAN

Keywords:

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Abstract:

Sedimentary features and the detailed grain size analyses of six olistostromes (debris flows) have been examined; they are located between Alcı and Balkuyumcu villages, 40 km. southwest of Ankara. Photograph-grid method and sieving methods are used for gram size distribution analyses. The distribution of clast sizes within olistostromes are shown as histograms and cumulative curves. After calculating the main gram size parameters, their relations with respect to each other are examined on distribution diagrams (scatter diagrams). So, some of the distinguishing characteristics of olistostrome clast size distributions have been established. Studies on the clast size distribution and clast roundness indicate that olistostromes are, in general, very poorly sorted, either negatively or positively skewed, mostly platykurtic. Clasts are angular to subangular. Generally, scatter plots of grain size parameters of olistostromes are distinct when compared with other sedimentary deposits.