ARTYKUŁY PRZEGLĄDOWE Jakie cechy litologiczne osadów warto kodować, a jakie nie?
Abstract
Which features of deposits should be included in a code and which not?
A b s t r a c t. Since the classical publications on lithofacies and architectural element codes (Miall, 1977, 1985), sedimentologists have made several attempts to optimize those codes. The authors present and discuss the codes of lithology and the origin of clastic rocks which have been proposed in the last thirty five years. It appears that the codes hitherto proposed are unsatisfactory because they fail to reflect several important features of deposits. It is postulated that most of Miall’s original rules should be used as a starting point but some additional rules should also be followed: (1) lithofacies symbols should not be used to describe interpretations but lithologic features only; (2) code of texture should contain two capital letters at the most; (3) structure should be described by three lower-case letters at the most; (4) genetic code should indicate depositional process or parent depositional form by capital letters; (5) coding is best applicable in practice if both the lithofacies and genetic codes are used jointly. The present authors propose a modified combination of lithofacies and lithogenetic symbols, shown to make sedimentological analyses more effective and unambigous.
A b s t r a c t. Since the classical publications on lithofacies and architectural element codes (Miall, 1977, 1985), sedimentologists have made several attempts to optimize those codes. The authors present and discuss the codes of lithology and the origin of clastic rocks which have been proposed in the last thirty five years. It appears that the codes hitherto proposed are unsatisfactory because they fail to reflect several important features of deposits. It is postulated that most of Miall’s original rules should be used as a starting point but some additional rules should also be followed: (1) lithofacies symbols should not be used to describe interpretations but lithologic features only; (2) code of texture should contain two capital letters at the most; (3) structure should be described by three lower-case letters at the most; (4) genetic code should indicate depositional process or parent depositional form by capital letters; (5) coding is best applicable in practice if both the lithofacies and genetic codes are used jointly. The present authors propose a modified combination of lithofacies and lithogenetic symbols, shown to make sedimentological analyses more effective and unambigous.