Field Interpretation of Red Beds

摘要

Seven different types of red beds, with different paleogeographic interpretations, are recognized in the field: (1) shale-pebble conglomerates, with red color inherited from pre-existing red beds; (2) red clay conglomerates, with red color derived from laterites in the source area; (3) variegated red beds, developed in fluvial deposits forming under equable climates with seasonal rainfall; (4) cinnamon red beds, probably formed in shallow-water marine environments of wide areal extent; (5) brick red beds, littoral and deltaic facies of cinnamon red beds; (6) pastel red beds, a sharply defined facies of unknown origin; (7) spattered red beds, in which the red color was introduced after deposition. This classification of red beds is intended primarily for field use; it does not supplant theoretical and genetic classifications but is useful in conjunction with them.