Sedimentary facies analysis of a high-frequency,small-scale,peritidal carbonate sequence in the Lower Jurassic of the Tripolis carbonate unit (central western Crete,Greece):Long-lasting emergence and fossil laminar dolocretes horizons  

作　　者：Fotini A.Pomoni Vassilis Karakitsios 

机构地区：[1]Section of Historical Geology and Paleontology,Department of Geology and Geoenvironment,National and Kapodistrian University of Athens

出　　处：《Journal of Palaeogeography》2016年第3期241-257,共17页古地理学报（英文版）

基　　金：co-financed by the University of Athens Program KAPODISTRIAS/Special Account for Research Grants of the National and Kapodistrian University of Athens(S.A.R.G)

摘　　要：Abstract The study examines a Lower Jurassic （late Liassic） cyclic lagoonal-peritidal stratigraphic unit outcropping in central western Crete （Tripolis unit）, which corresponds to the eastern （internal） part of the mainland Gavrovo-Tripotis platform, the most significant external platform of the Hetlenides. The studied Tripolis carbonate sequence consists of meter-scale, shallowing-upward successions of restricted inner- carbonate platform facies, including cyclically repeated subtidal, intertidal and supratidal facies, that are separated by erosion surfaces （elementary cycles）. Each cycle starts with relatively open-marine facies, which are overlain by shallower, more restricted facies （tidal fiat progradation）. The lithofacies association includes dotomitic intraclastic-peloidal-bioclastic wackestones-packstones/floatstones and grainstones/rudstones dominated by a restricted shallow-marine fauna （bivalves, gastropods, ostracods and seldom benthic fora- minifers）, representing a shaUow subtidal to intertidal, moderately high-energy environment within an inner- platform setting （peritidal environment to restricted lagoon）. This lithofacies association has been intermit- tently subaeriaUy exposed and has undergone diagenetic processes in an inter- or supratidal environment, exhibiting features of vadose diagenesis and pedogenesis due to long-lasting exposure along certain horizons. The peritidat facies are capped by dolocretes controlled by root-activities （laminar dolocretes, petoi- dat-pisoid dolocretes and massive dotocretes）, marking the end of each depositional cycle, and, thus, dis- tinguishing the successive episodes of a prolonged subaerial exposure period and birth of pateosol horizons. Dotocretes consist a diagenetic facies, characterized by several vadose and pedogenic fabrics, including fenestral cavities with geopetal structures, ＂flower spar＂ to blocky sparry cement in primary pores, micritic coatings, crudely pelleted watts, atveotar-septat texture, infilts of rooAbstract The study examines a Lower Jurassic （late Liassic） cyclic lagoonal-peritidal stratigraphic unit outcropping in central western Crete （Tripolis unit）, which corresponds to the eastern （internal） part of the mainland Gavrovo-Tripotis platform, the most significant external platform of the Hetlenides. The studied Tripolis carbonate sequence consists of meter-scale, shallowing-upward successions of restricted inner- carbonate platform facies, including cyclically repeated subtidal, intertidal and supratidal facies, that are separated by erosion surfaces （elementary cycles）. Each cycle starts with relatively open-marine facies, which are overlain by shallower, more restricted facies （tidal fiat progradation）. The lithofacies association includes dotomitic intraclastic-peloidal-bioclastic wackestones-packstones/floatstones and grainstones/rudstones dominated by a restricted shallow-marine fauna （bivalves, gastropods, ostracods and seldom benthic fora- minifers）, representing a shaUow subtidal to intertidal, moderately high-energy environment within an inner- platform setting （peritidal environment to restricted lagoon）. This lithofacies association has been intermit- tently subaeriaUy exposed and has undergone diagenetic processes in an inter- or supratidal environment, exhibiting features of vadose diagenesis and pedogenesis due to long-lasting exposure along certain horizons. The peritidat facies are capped by dolocretes controlled by root-activities （laminar dolocretes, petoi- dat-pisoid dolocretes and massive dotocretes）, marking the end of each depositional cycle, and, thus, dis- tinguishing the successive episodes of a prolonged subaerial exposure period and birth of pateosol horizons. Dotocretes consist a diagenetic facies, characterized by several vadose and pedogenic fabrics, including fenestral cavities with geopetal structures, ＂flower spar＂ to blocky sparry cement in primary pores, micritic coatings, crudely pelleted watts, atveotar-septat texture, infilts of roo

关 键 词：External Heltenides Lower Jurassic Tripotis carbonate unit Peritidat environment Cyclo-thems Penesaline dolomites Dotocrete horizons ＂flower spar＂ dolomite cement 

分 类 号：P736.2[天文地球—海洋地质]