Definition
Molar-tooth structure is a synsedimentary, combined deformation and early diagenetic feature occurring in calcareous strata of mainly Precambrian age. It consists of arrays of closely spaced, sharply defined, upright veins , and subordinate horizontal sheets and spheroids composed of calcite microspar . Veins are vertically to obliquely oriented, discontinuous, typically strongly squashed or crumpled, and often brecciated.
Geological age
Molar-tooth structure (MTS) was first named in 1885 from its appearance on limestone bedding planes in the Mesoproterozoic Purcell Supergroup (= Belt Supergroup in USA.) along the border between southwestern Canada and adjacent northwestern Montana. Almost all occurrences are in Mesoproterozoic to late Neoproterozoic (Ediacaran) strata, representing a 1 billion-year time span from about 1,600 to 600 Ma, but there are several examples noted from the Paleoproterozoic and one from the Neoarchean (James et al., 1998; Pratt, 1998b; Shields, 2002;...
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Bibliography
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Pratt, B.R. (2011). Molar-tooth Structure. In: Reitner, J., Thiel, V. (eds) Encyclopedia of Geobiology. Encyclopedia of Earth Sciences Series. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-9212-1_150
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DOI: https://doi.org/10.1007/978-1-4020-9212-1_150
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