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the eastern segment of its southern part only,while the Upper Riphean occur everywhere.Their distribution conformable to large structuralelements of the plaform margin being replacedby carbonate-terrigenous rocks almost lackingstromatolites westward and southwestward in theKama-Belaya aulacogen system and by substantiallysiliciclastic succession eastward and northeastward.The distribution area of UpperRiphean stromatolitic formations includes theKaratavian stratotype region, where 12 stromatolitebeds ranging in age from ≥900 to 620 Ma areestablished. Many of the beds are traceablealong the strike far beyond the stratotype region.Representing relatively small reference units, thebeds facilitate reconstruction of distribution dynamicsof the Upper Riphean stromatolites. Distributionarea of the latter was always parallel tomarginal structures of the platform, though beingof changeable size, particularly of length. Originatedin the stratotype region eastern part, stromatolitesfirst advanced into northeastern areasnever crossing boundaries of the Upper Ripheandistribution area during the Early Karatavian. Inthe initial Late Karatavian, they occupied alongest distribution area that was sharply reducedat the end of that period. According todistribution peculiarities in space and with time,the Upper Riphean stromatolitic formations accumulatedlikely in peripheral areas of an opensea or oceanic basin adjacent to the East Europeanplatform, rather than in closed epiplatformbasins.2008040098作 为 海 进 标 志 层 的 含 红 藻 石 灰 岩 : 新 西 兰 北岛 的 化 石 和 现 代 标 本 实 例 = Rhodolith-bearinglimestones as transgressive marker beds: fossiland modern examples from North Island, NewZealand. ( 英 文 ). Nalin R D; Nelson C S; BassoD; Massari F. Sedimentology, 2008, 55(2): 249-274Rhodoliths are nodular structures composedmainly of the superimposed thalli of calcareousred algae. Because their development is controlledby an array of ecological parameters,rhodoliths are a valuable source of palaeoenvironmentalinformation. However, despite theircommon use in palaeoecological reconstructions,the stratigraphic significance of rhodolith accumulationsseldom has been addressed in detail.In a study of Cenozoic rhodolith-bearing depositsfrom the North Island of New Zealand,rhodolithic units, usually of limited lateral extent,typically occur above major unconformities atthe base of deepening upwards successions. Twotypes of transgressive rhodolith-bearing depositsmay be distinguished on the basis of texture andrhodolith internal structure: (i) type A depositsare clast-supported rhodolithic rudstones containingabundant pebbles and cobbles reworkedfrom the substrate, and are characterized byrhodoliths with a compact concentric to columnarinternal structure and a high nucleus to algalcover ratio; (ii) type B deposits are rhodolithicfloatstones with a matrix usually consisting ofbryozoan fragments, benthic foraminifera andechinoid fragments or terrigenous silty fine sand.The rhodoliths of type B units usually have aloose internal framework with irregular tobranched crusts. The two contrasting rhodolithbearingunits are interpreted as characteristicfacies of transgressive systems tract deposits,analogous to shell concentrations formed underconditions of low net sedimentation. Type Adeposits are correlated with relatively highenergysettings and/or narrow submerged palaeotopographiclows, whereas type B depositsare interpreted as forming in lower-energy settings.The association between transgression anddevelopment of rhodolithic facies is confirmedby observations of a modern rhodolith productionsite at Whangaparaoa Peninsula in NorthIsland, where algal nodules grow above aravinement surface cut during the Holocene sealevelrise, and also by a review of published fossilexamples, many of which show stratigraphicand compositional attributes analogous to thoseof the New Zealand occurrences. The reviewindicates that transgressive rhodolith accumulationsdevelop more commonly in, but are notrestricted to, non-tropical settings. It is suggestedthat a combination of factors, such as low netsedimentary input, nature of the substrate, sealevelrise and inherited physiography contributeto determine the relationship between rhodolithbearingdeposits and transgressive settings.Rhodoliths are nodular structures composedmainly of the superimposed thalli of calcareousred algae. Because their development is controlledby an array of ecological parameters,rhodoliths are a valuable source of palaeoenvironmentalinformation. However, despite theircommon use in palaeoecological reconstructions,the stratigraphic significance of rhodolith accumulationsseldom has been addressed in detail.In a study of Cenozoic rhodolith-bearing depositsfrom the North Island of New Zealand,rhodolithic units, usually of limited lateral extent,typically occur above major unconformities atthe base of deepening upwards successions. Twotypes of transgressive rhodolith-bearing depositsmay be distinguished on the basis of texture andrhodolith internal structure: (i) type A depositsare clast-supported rhodolithic rudstones containingabundant pebbles and cobbles reworkedfrom the substrate, and are characterized byrhodoliths with a compact concentric to columnarinternal structure and a high nucleus to algalcover ratio; (ii) type B deposits are rhodolithic30