Terminology and Communication Problems Associated with Lentic Carbonate Depositional Systems

Carbonate depositional systems associated with standing water (i.e., lentic bodies) in continental settings commonly occur as lakes, marshes (i.e., paludal settings), ponds, pools, and wetlands. Both modern and ancient lentic carbonate deposits serve as important high-resolution archives of environmental and climate change as well as significant hydrocarbon source rocks and reservoirs. While sedimentologic, paleontologic, pedogenic, geochemical, and other observations provide insights into the lentic carbonate depositional dynamics, accuracy and precision in interpreting the environment(s) of deposition are often lacking. Problems are commonly sourced from ambiguous terminology use and misunderstanding in making depositional and/or hydrologic interpretations. Common examples of communication problems associated with lentic carbonate depositional systems gleaned for the geological literature include: (1) ambiguous use of “lake” or “lacustrine” versus “pond” terminology; (2) misuse of “palustrine” to represent a spectrum of marginal lacustrine, wetland, and spring settings in contrast to Freytet and Plaziat (1982) and Freytet (1984); and (3) intermingling of terms such as “wetlands”, “springs”, and/or “marshes”. Previously established parameters for lentic terminology are important and the identification of bibliographic sources is critical. For example, is the term “wetland” being used in the sense of Cowardin et al. (1979), the Ramsar Convention (2000), Neuendorf et al. (2005) or another literature source? Where key sedimentologic, paleontologic, pedogenic, geochemical, and hydrologic guidance is lacking, geologists must collectively determine which criteria to use so that modern and ancient carbonate deposits representing lakes, marshes (i.e., paludal or palustrine settings), ponds, pools, and wetlands may be accurately and precisely determined; criteria should be useful and applicable in the field as well as with core acquisition and well logs.