ISSN 0869 5938, Stratigraphy and Geological Correlation, 2012, Vol. 20, No. 2, pp. 211–229. © Pleiades Publishing, Ltd., 2012. Original Russian Text © M.A. Rogov, D.B. Gulyaev, D.N. Kiselev, 2012, published in Stratigrafiya. Geologicheskaya Korrelyatsiya, 2012, Vol. 20, No. 2, pp. 101–121.
Biohorizons as Infrazonal Biostratigraphic Units: An Attempt to Refine the Jurassic Stratigraphy Based on Ammonites M. A. Rogova, D. B. Gulyaevb, and D. N. Kiselevc aGeological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, Moscow, 119017 Russia e mail: [email protected] bScientific–Industrial Center “Nedra”, ul. Svobody 8/38, Yaroslavl, 150000 Russia e mail: [email protected] cYaroslavl Ushinskii State Pedagogical University, ul. Respublikanskaya 108, Yaroslavl, 150000 Russia e mail: [email protected] Received February 8, 2011; in final form, June 7, 2011
Abstract—The biohorizons (faunal horizons) as infrazonal units are the smallest correlatable biostratigraphic units. Their main features are: (1) potential indivisibility based on taxonomic differentiation of guide fossils; (2) determinancy of both lower and upper boundaries in the geological section; (3) identification by a single index species/subspecies. First such units were defined at the end of the 19th century and since the 1980s have been widely used in biostratigraphic investigations of Jurassic and, later, Cretaceous systems. The biohorizons are characterized by phylogenetic or immigrational paleobiological nature and geologically they are con nected with depositional and postdepositional transformation (and, consequently, structure) of the sedimen tary succession. Based on parallel sequences of phylogenetic and separate immigrational biohorizons, they are integrated into different zonal scales and an integrated regional scale. The problems related to the lack of universal criteria for defining and using biohorizons are discussed. The basic nomenclature rules, which are aimed at regulation of the use of these units in practical stratigraphic investigations, are suggested for their recognition and description.
Keywords: infrazonal biostratigraphy, biohorizons, faunal horizons, ammonites.
As the middle system of the middle (Mesozoic) group of fossiliferous rocks, the Jurassic is as good a sample as any that could be chosen to find out what light can be thrown on geological prob lems by the study of a single system all over the world (Arkell, 1956, p. 3). DOI: 10.1134/S0869593812010066
INTRODUCTION 1 taceous systems. Similar to many other innovations Despite the 150 year long development history of in stratigraphy, paleobiology, and paleogeography, the the zonal method in stratigraphy, its basic theoretical infrazonal biostratigraphic units were first proposed by principles concerning biostratigraphic zones were for the experts engaged in study of the Jurassic System and mulated only in the second half of the 20th century. At are now most widely used in the Jurassic stratigraphy. the end of the 19th century, it became clear that Until recently, the biohorizons (in the sense consid smaller (infrazonal) biostratigraphic units may also be ered in this work) are defined by stratigraphers only for useful for subdivision and correlation of sedimentary 1 sections. Some researchers (Page, 1995; and others) use in this sense the term “intra subzonal” units. Nevertheless, inasmuch as the sub zones represent stratigraphic units of the zonal rank (similar to Now, these smallest infrazonal biostratigraphic subgenera, which are taxa of the generic rank), the use of the less units (biohorizons, faunal horizons) are widely used in cumbersome adjective “infrazonal” seems a better choice for biostratigraphic investigations of the Jurassic and Cre biohorizons.
211 212 ROGOV et al. Kosmoceras Biohorizons medea Catasigaloceras Catasigaloceras Catasigaloceras enodatum aeeta Sigaloceras micans Gulyaev et al.2002) Kepplerites galilaeii (after Kiselev, 2001; enodatum Catasigaloceras pagei Sigaloceras calloiense enodatum planicerclus Jason Medea Henrici Proniae Galilaeii Keppleri Kamptus Lamberti Phaeinum Curtilobus Enodatum Terebratus Obductum Calloviense Gowerianus Grossouvrei “Spinosum” Jason Athleta Herveyi Koenigi
Lamberti
Calloviense Coronatum oe ideUpper Middle Lower Bajocian Toarcian Aalenian Callovian Tithonian Bathonian Oxfordian Hettangian
Sinemurian
Pliensbachian Kimmeridgian
Upper Middle Lower Triassic Jurassic Cretaceous
Cenozoic Paleozoic Mesozoic Erathems and systems and stages Series Substages, zone, and subzones Fig. 1. The growth of resolution of stratigraphic scales depending on the lower rank of stratigraphic units. the Mesozoic based mainly on ammonites, although it possible to increase the biostratigraphic resolution the number of fossil groups used for defining such several times (Fig. 1) and the accuracy of correlation stratigraphic units as well as for widening the strati between biostratigraphic scales (Fig. 2). graphic range of their application is gradually increas At the same time, the use of infrazonal biostrati ing. The application of the infrazonal approach made graphic units is frequently ambiguous and even slightly
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 213
Boreal Atlantic realm East Mediterranean–Caucasian Realm European province Submediterranean province (European Russia) (mainly central and southern France, Portugal) (Fig. 7) (after Biostratigraphie …, 1997) Biochoremas Biohorizons Subzone (tints show biohorizons of Biohorizons Subzone Zone Zone different subprovinces) Substage Substage Collotia collotiformis “Spinosum” K. kuklikum Collotiformis Orionoides piveteaui F. funiferus K. rowlstonense Sublunuloceras trezeense Proniae F. patruus Trezeense K. proniae Pseudopeltoceras leckenbyi
“F. sp. nov.” Upper (pars) “Pseudopeltoceras” Upper (pars) Phaeinum K. phaeinum Rota F. allae Rehmannia rota K. grossouvrei Choffatia waageni Grossouvrei Leuthardti K. posterior Erymnoceras leuthardti
K. crassum Erymnoceras baylei Coronatum Athleta Obductum L. stenolobum Baylei K. obductum Flabellisphinctes villanyensis
CallovianL. praestenolobum Stage
K. jason jason Rehmannia richei Middle
Middle Jason Tyranniformis K. jason sedgwickii Rehmannia blyensis Chanasia turgida Jason Coronatum Athleta K. medea magnum R. milaschevici Stuebeli Medea milaschevici K. medea medea Chanasia bannensis C. enodatum aeeta ? R. milaschevici C. enodatum Hecticoceras posterius Enodatum khudyaevi enodatum Patina C. enodatum (pars) . i A. difficilis Collotia pamprouxensis R in planicerclus fk ef Lower (pars) Gracilis (pars) Anceps
Lower (pars) Calloviense h tc P. cracoviensis C. pagei Hecticoceras boginense
Fig. 2. Correlation of biohorizons in regional (provincial) stratigraphic scales for the Middle Callovian in different paleobiogeo graphic realms. Here and in Figs. 3–7, names of conditional (preliminary) biohorizons are given in quotes. The dark and light gray colors indicate sequences of biohorizons based on cardioceratids and perisphinctids, respectively. chaotic. In this work, we consider critically the devel zonal units, for example, the Ammonites calloviensis opment history of the infrazonal biostratigraphy, ana and A. bullatus horizons in the A. macrocephalus Zone lyze the main features and nature of biohorizons, (Oppel, 1856–1858, p. 2009). Slightly later, Waagen assess their correlation potential, and formulate prin (1869), who established the first phylogenetic lineage ciples of their recognition and application. In addi of Bathonian and Callovian ammonites, formulated a tion, we propose a code of rules, which should concept of evolutionary mutations (quantitative mor decrease, if not eliminate, ambiguity inherent now in phological transformations) through time and the infrazonal biostratigraphy. described the zone as an interval corresponding to the existence period of a single mutation. This concept was further developed by Neumayr (1878, p. 40), who A DEVELOPMENT HISTORY OF INFRAZONAL noted that the Oppel’s zones of the Jurassic System BIOSTRATIGRAPHY chronologically correspond to the average existence In his famous work dedicated to the Jurassic Sys period of a single mutation among most widespread tem of England, France, and southwestern Germany, marine animals primarily such as cephalopods. Oppel (1856–1858), who formulated the basics of the Already at that time, the inconsistency between the zonal stratigraphy, described the zone as a horizon, historical continuity of zonal scales and their resolu which is characterized by the same fossil assemblage tion became clear for many researchers of the Jurassic even in remote areas of its development. He empha System. The zones that became generally accepted at sized that the accuracy in defining zones depends on that time could be divided into smaller units. Thus, the number of well described species (especially guide two different approaches to the zonal stratigraphy taxa), in addition to other factors. In the same work, existed at the end of the 19th century. The zones were this author defined the so called horizons as intra accepted either as smallest biostratigraphic units or as
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 214 ROGOV et al. some stable stratigraphic “framework,” which implied the Bathonian–Callovian boundary interval of Scot the possibility of defining smaller stratigraphic units. land (Buckman, 1920), he subsequently increased The further development of views on detailed their number to eleven based on materials on Dorset stratigraphy is primarily connected with S. Buckman and Yorkshire defining five ammonite horizons in the and his undeservedly forgotten concept of a hemera. same stratigraphic interval (Buckman, 1927). The latter was in fact understood as a geochronologi Unfortunately, Buckman discredited his method cal equivalent of the biohorizon. The last researcher by constructing subsequently incorrect hemerae defined it as a “chronological indicator” of the small sequences based on fossils from other people’s collec est stratigraphic interval corresponding to the acme of tions and hypothetical interpretations. The reputation single or several species (Buckman, 1893, 1902). of this method most suffered significantly from criti When studying limestones from the Inferior Oolite cism by Arkell, who was the recognized expert in the Group in the Dorset and South Somerset (England), Jurassic ammonite stratigraphy. This researcher Buckman (1893) was able to compile an unusually believed that small units such as hemerae cannot be detailed sequence of faunal assemblages based on traced through any spacious regions and are absolutely thorough bed by bed sampling of ammonites and cor inappropriate for correlation, which means that their relation of their host sections. The matter was compli defining made no sense (Arkell, 1933, 1956). Time has cated by the fact that the Lower Oolite rocks are proved this outstanding scientist wrong. strongly condensed and none of their sections is strati As was noted, after Arkell’s criticism of the Buck graphically complete. Practically every bed with man’s method, zonal units were most frequently con ammonites is separated from its neighboring counter sidered not from positions of maximal resolution in parts by distinct or cryptic hiatuses. In order to over understanding by W. Waagen, M. Neumayr, and come this difficulty, Buckman first established the S. Buckman, but from the standpoint of their correla bed by bed sequence of ammonite assemblages in tion potential and preservation of the nomenclature each section. Then, this researcher correlated identi stability (continuity). Being usually potentially divisi cal assemblages from different sections with certain ble, these units represented in fact (and represent until time intervals (hemerae) indexing them with most now) something resembling sub substages. Mesezhni characteristic species or genera. He arranged the chro kov (1993) termed such an approach as a “strati nological succession of the hemerae correlating suc 2 cessions of characteristic assemblages in many sec graphic impressionism” . tions. The recent revision of Middle Jurassic sections Nevertheless, single or successive infrazonal units formerly studied by Buckman confirmed his strati usually termed as horizons gradually received recogni graphic interpretations (Callomon and Chandler, tion in the Jurassic stratigraphy. This process was 1990). It should be emphasized that in the Buckman’s spontaneous, when different criteria were used for understanding, hemerae were precisely chronological, defining new horizons. Of great significance was the not stratigraphic units representing time equivalents of work by Howarth (1958) dedicated to revision of zones (Buckman, 1902). Because of the ambiguity in ammonites from the family Amaltheidae. Although the use of the term “zone” in different Buckman’s this author has never defined infrazonal units, he con works, Trueman (1923) suggested to use an “epibole” sidered in detail peculiar features in evolution of as a stratigraphic equivalent of the hemera. Amaltheidae representatives paying special attention In his subsequent works, Buckman (1909–1930) to recognition of chronological subspecies, which extended his method practically to the entire Jurassic characterized successive stratigraphic intervals. Being System of England. He united hemerae into “ages” a staunch supporter of using the term “subspecies” largely corresponding to the stratigraphic ranges of exclusively for geographic varieties, Howarth used in particular ammonite families or genera. Buckman the situation under consideration the term “transient” considered the composite sequence of hemerae and (this term was proposed by Bather (1927) as an equiv ages as a geochronological calendar. He emphasized alent of Waagen’s “mutation”). Subsequently, chro that the hemera corresponds to the existence period of nosubspecies became widely used for defining and the index species (Buckman, 1898). Moreover, he indexing biohorizons. noted that in absence of the index species, the use of Callomon (1964, p. 21) was probably the first to another name for designating the corresponding time give an extended definition of a horizon as the smallest interval is undesirable. In order to support this thesis, “infra subzonal” biostratigraphic unit: “At the lower he used the following metaphor (Buckman, 1902, end of divisibility, a stratigraphic unit should meet cer p. 557): “…Temp. Edward VII may date an event in tain minimum requirements to qualify even as a sub Australia as well as in England, even though Edward VII never visits Australia.” 2 This (“impressionistic”) approach itself is inconsistent with In his later publications, Buckman (1920, 1927) optimization of one of the main stratigraphic tasks such as strati graphic subdivision and, as follows from the practice, hampers began defining infrazonal stratigraphic units (termed the solution of another stratigraphic problem, i.e., stratigraphic as horizons, faunal horizons, or faunas) based on bra parallelization (correlation) decreasing its accuracy due to fre chiopods. Establishing primarily two such horizons in quently doubtful increase of the correlation potential.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 215 zone. It should be recognizable over the whole of some Phelps (1985) shares different views on the infra other natural geographical unit, e.g. a whole basin of zonal stratigraphy. As a smallest biostratigraphic unit, deposition, or lithofacies province. As a rough guide this author used a zonule considering it, in fact, as a this seems to indicate distances of order of 300 km. …A sub subzone (in some situations, he defines even suitable term for such units is horizon… The ultimate “subzonules” (Phelps, 1985, fig. 9), although avoiding resolvable and observable stratigraphic unit on the 4 ammonite scale is the thinnest bed or packet of strata this term). Phelps noted that the horizon is a very in a single section, which can be identified by a single widely understood term. According to him, the zonule species.” is a smallest biostratigraphic unit traceable through the paleobiogeographic province, although its application During a short period, such horizons were defined may be limited also by a less spacious area with the in all the Jurassic stages of different regions. Moreover, high degree of endemism. The zonule should readily it was considered that the peculiar features of the hori be distinguishable using the stratigraphic range of the zons were both their insignificant stratigraphic range characteristic species. Phelps (1985, p. 343) suggested and limited geographic distribution (Callomon, 1994). a list of subordinate criteria, which may be used for As was noted in the review of Jurassic stratigraphy of defining the zonules: “(a) in situ transition throughout France (Mouterde et al., 1971), the zones frequently the geographical range, i.e. gradualistic chrono speci correspond to the stratigraphic range of a genus, while ation; (b) quantum evolution of a small population species may be used for more detailed subdivision, (with subsequent migration) showing no stratigraphi although such units are characterized by the limited cal overlap of parent and daughter species; (c) quan geographic distribution. Such an approach to defining tum evolution of a small population, with noticeable horizons was also used in the work dedicated to the overlap of parent and daughter species; (d) acme event Boreal Oxfordian (Sykes and Callomon, 1979). in a short lived species; (e) acme event in a long rang By the beginning of the 1980s, researchers had col ing species.” Thus, when defining zonules, the prefer lected a lot of data on infrazonal successions, which ence is given to ammonite groups that dwelt in shal dictated the necessity in their interpretation. Never low water basins. In general, the stratigraphic resolu theless, the intense activity of experts in Jurassic tion is sacrificed to the correlation potential and ammonites and stratigraphy was ignored by the Inter zonules became smaller units as compared with zones, national Commission on Stratigraphy, which practi although not necessarily potentially indivisible. Nev cally paid no attention to infrazonal units (see below). ertheless, when justly criticizing the usage of a hori zon, which represents as one of the most ambiguous Three works published in the mid 1980s played a stratigraphic terms, applied in different meanings, as a key role in development of views on the infrazonal smallest unit, Phelps used a similarly controversial stratigraphy. term. The Fentons (1928) were the first to introduce In his article dedicated to problems of bio and the term “zonule” into the geological practice likely as chronostratigraphy, Callomon (1984a) provided a def a paleoecological, not stratigraphic term. Although inition of a faunal horizon: “A faunal horizon is a bed the zonule was accepted as the “smallest unit of the or series of beds, characterized by a fossil assemblage, zone” first in the North American Code of 1961 5 within which no further stratigraphical differentia (Zhamoida et al., 1969) and then in the International tions of the fauna and flora (sic!) can be distin Stratigraphic Guide (1976), its application in the geo guished.” In the work dealing with the evolution of 6 ammonites belonging to the family Cardioceratidae logical practice was extremely rare . that was published a year later, Callomon (1985, p. 52) The late 20th century was marked by development emphasizes the significance of phylogeny as a basis for of infrazonal ammonite scales practically for the infrazonal subdivision, and a “horizon is thus defined whole Jurassic System of northwestern Europe and the is a unit in which no further evolutionary change is dis Mediterranean region as well as for separate Jurassic cernible and one that may therefore be treated for all practical purposes as of negligible duration.” 4 Prior to this work by Phelps, the zonules have practically never been used in the Jurassic stratigraphy. Only Imlay (1984) defined When defining faunal horizons, Callomon high several zonules in the Bajocian of Alaska, although he likely lighted chronological subspecies and suggested using considered them as synonyms of subzones. for their designation non Linnean symbols such as 5 These authors (Zhamoida et al., 1969, p. 56) wrote: “The Fen 3 tons… suggested the synonymous term (for a subzone) zonule, Greek letters . As is shown below, such suggestion although the latter is less frequently used. In some works, this cannot be considered as a fortunate one. As a geochro term is used for designating even smaller and more local unit nological equivalent of the faunal horizon, Callomon than the subzone. In England, the similar sense is imparted to used the Buckman’s term “hemera” (see above), the term horizon. 6 In the sense close to that proposed in the penultimate edition of which means in Greek a “day” or “time.” the International Stratigraphic Guide (1976), the term “zonule” was mainly used by experts in the Quaternary System for desig 3 Greek letters were used for similar purposes as well (Phelps, nating very small biostratigraphic units. Now, the use of zonules 1985). is admitted to be undesirable (Murphy and Salvador, 1998).
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 216 ROGOV et al. intervals of other regions. This resulted in almost an tion of a biohorizon is intimately related to the identi order of magnitude increase of stratigraphic resolu fication of the index species/subspecies, the smallest tion and correlation accuracy, which, in turn, offered distinguishable segment of a continuously evolving new opportunities for paleontological and geohistori lineage. Only the occurrence of diagnostic transient cal investigations. species can confirm the presence of a particular bioho Page (1995) summarized the available views on the rizon, but the general generic or specific composition usage of the infrazonal method in the Jurassic stratig of a fauna can be a useful guide to recognition. (2) Bio raphy. Instead of Callomon’s term “faunal horizon”, horizons represent discrete but typically very short 7 intervals of geological time. (3) As the boundaries of this author used in the same sense the term biohorizon . most successive biohorizons are not coincident, a sig This author considered the biohorizons and zonules as nificant time gap is potentially present and is shown as principally different infrazonal units (K. Page uses the an interval between successive units. (4) A sequence of term “intra subzonal”). biohorizons is established by first constructing a suc Page (1995, p. 802) considers the zonule as a cession of faunal associations, and then distinguishing “smallest component sub division of a chronostrati geographically persistent or morphologically distinct graphical hierarchy, defined, as with higher divisions, associations, (5) The sequence of defined biohorizons by a basal boundary stratotype,” which has nothing to can be integrated with the existing scheme of standard do with its primary understanding by the Fentons and subzones. Nevertheless, the current state of strati is inconsistent with its practical use by Phelps. K. Page graphical knowledge inevitably means that boundaries first determined the zonule as a chronostratigraphic of biohorizons and subzones may be not coincident. equivalent of the biohorizon together with a potential (6) Biohorizons are usually named in a dual manner, hiatus. Later, he turned back to the understanding of firstly by consecutive numbering and secondly by 8 the zonule in (Phelps, 1985). Despite the fact that selecting a suitable species as an index” . K. Page continued considering the zonule as a smallest unit of the chronostratigraphic hierarchy, in his prac According to Page, correlation between succes tical investigations, the latter ceased being the chro sions of biohorizons provides its higher accuracy as nostratigraphic equivalent of a single biohorizon with compared with zonal scale, since “(1) Both the bases a potential hiatus, but could correspond to several and tops of each biohorizon can be correlated, (2) The (sometimes, three–four) successive biohorizons. intervals between biohorizons can be as important in correlation as the biohorizons themselves, (3) A bio Following Callomon, Page (1995, p. 802) deter horizon can be correlated with a biohorizon plus the mined the biohorizon as “a bed or series of beds char interval below and/or the interval above, or even a acterized by a fossil assemblage within which no fur sequence of biohorizons, (4) Following on from the ther stratigraphical differentiation of the fauna (or above, every line on the correlation diagram has a very flora) can be made, i.e. a biohorizon is effectively specific meaning and may require some discussion in defined at both its base and top in a single reference accompanying text, (5) Exactly correlated biohori section.” Such a characteristic makes the biohorizon zons form time planes, and can be considered as being different from conventional units of the chronostrati equivalent in event stratigraphy.” graphic hierarchy recognizable based on the lower boundary in a stratotype. The potential discontinuity Page (1995, p. 805) thoroughly analyzed the nature of biohorizons is admissible. Such a situation more of biohorizons defining seven following processes or adequately characterizes their real range in particular factors, which make easier their recognition: “(1) The geological sections, which usually include intervals evolution of one or more ammonite populations/lin that cannot be unambiguously attributed to a certain eages within the biogeographical province under study, biohorizon because of different reasons (rare occur leading to the development of distinguishable tran rence or lack of fossils, their poor preservation, and sients. (2) The evolution and divergence of related others). ammonite populations. (3) The evolution of an Page (1985, pp. 802–803) also considered other ammonite lineage present in the province under study, important features of biohorizons: “(1) The recogni or in a separated area of the same province, followed by the migration of the new form into the study area. 7 In the International Stratigraphic Guide (1976, 1998) and (4) The presence of morphologically complex and Stratigraphic Code of Russia (1992, 2006), the biohorizon is “rapidly evolving” groups. (5) The migration into the defined as a certain boundary (datum plane) that has no thick area being studied, from another basin or province, of ness (which is specially emphasized). In such a manner, the bio a “new” ammonite population/lineage. This migra horizons are largely used by experts in microfossils. Neverthe less, the ammonite biohorizons (horizons or faunal horizons) tion may be short lived (i.e. one transient/biohorizon were long ago introduced into biostratigraphic investigations mostly of the Jurassic and Cretaceous systems as smallest bios 8 The ordered numbers are used for biohorizons only by some, tratigraphic units, although characterized by some stratigraphic mainly British researchers. The introduction of ordered indices range in particular sections. In the English guide to stratigraphi (numbers) into names of biohorizons is unreasonable, since it cal procedure (Whittaker et al., 1991), the biohorizon is adds unnecessary detail and the further complication of the accepted precisely in such a sense. scale.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 217 duration) or may lead to the establishment of a using almost exclusively ammonoids, although there “local,” possibly evolving, population. (6) Changes in are examples of their recognition by belemnites faunal composition including “acme events” (includ (Mitchell, 2005). ing dominance) of certain lineages. (7) The periodical or occasional preservation of suitable ammonite fau nas resulting from fluctuating sedimentary processes.” RECOGNITION AND APPLICATION OF BIOHORIZONS, THEIR CLASSIFICATION, According to Page (1995), the duration of zonules AND SCALES (biohorizons with potential hiatuses) in Jurassic sec tions ranges from 80 to 722 kyr averaging 200– The analysis of the more than a century long his 9 tory of the infrazonal approach in biostratigraphy, 350 kyr . The article by Callomon (1995), which was which was particularly consistent and fruitful during published simultaneously with that by Page, is dedi the last three decades, allows the following definition cated to problems of the infrazonal stratigraphy. Cal of a biohorizon to be proposed (we prefer this term as lomon considered any first and last appearance of a the most frequently used in the following sense): taxon as potential boundaries of biohorizons. Thus, The biohorizon is the smallest correlatable biostrati their ranges (theoretical) were determined by the graphic unit, which encloses a unique integrity of taxa composition of guide fossil assemblages, not by com and is further indivisible based on taxonomic differenti plete stratigraphic ranges of index species. At the same ation of guide fossils (by phylogenetic and/or immigra time, this author emphasized that such “horizons” are tional events that serve as a basis for biohorizon recogni not necessarily of practical significance and that of tion). The necessary and sufficient condition for recogni interest are only horizons, which may be used at least tion of the biohorizon in the particular section is for correlation within the particular region and, con identification of the species/subspecies with the observ sequently, for development of a regional scale. able stratigraphic range corresponding to this biohori In his recent work, Meister (2010) demonstrated zon. The remainder of the guide fossil assemblage is of the constructive approach to the infrazonal stratigra significance for correlation beyond the distribution area phy using the Sinemurian and Pliensbachian stages as of the biohorizon. an example. The last researcher considers biohorizons In other words, the biohorizon is a smallest discrete (for local scales), faunal horizons (for integrated correctable unit (sui generis an atom) of biostratigra regional scales), and standard horizons (for scales of phy. Having, by definition, both the lower and upper biogeographic provinces and realms) as infrazonal boundaries in any section, it principally differs from biostratigraphic units. He understands the zonule as conventional units of the stratigraphic hierarchy, an infrazonal chronostratigraphic unit distinguishable which are and, essentially, go beyond this hierarchy by the lower boundary and corresponding to a stan (for example, one cannot say that zones (subzones) are dard horizon. divisible into biohorizons or that genera (subgenera) Since the 1990s, the infrazonal units became fre are divisible into species). From the viewpoint of “pre quently used by Russian experts in the Jurassic stratig sumption of isochronisms” (Lazarev, 1997), both raphy (Mitta and Starodubtseva, 1998; Gulyaev and boundaries of each biohorizon are principal limits of Kiselev, 1999; Gulyaev, 1999, 2001; Mitta, 1999, 2000; “accuracy of measurements” by the biostratigraphic Kiselev, 2001; Rogov, 2001, and others). In the new method (as minimal divisions of the metrical scale millennium, the development of the infrazonal regardless of its scale). Having a specific status of ele approach in biostratigraphy is continued precisely by mentary biostratigraphic units, the biohorizons are Russian researchers. They proposed nomenclature epistemologically defined (separated) according to the rules for regulating the recognition, description, and principle of the difference (peculiarity) of biostrati practical application of biohorizons (Gulyaev, 2002; graphic features; their sequences may, in turn, be Gulyaev et al., 2010) and analyzed their correlation united into larger units by the conventional way based potential (Rogov et al., 2009). In addition, they con on the principle of similarity of these features sidered the biological nature of biohorizons reducing (Gulyaev, 2002). A century ago, Buckman used a sim all their diversity to two main types: phylogenetic and ilar approach in geochronology (see above), when he immigrational (Zakharov et al., 2007). defined hemerae subsequently uniting them into ages. Similar to the Jurassic System, the infrazonal The same approach is used in any hierarchic taxon approach became widely used in the Cretaceous omy ensuring its development as a “scientific research (Bulot et al., 1992; Vermeulen, 1997; Hoedemaeker program” in the terminology by Lakatos (1995). et al., 2003; and others) and Triassic (Goy, 1995) The main features of the biohorizon are as follows: stratigraphy. The biohorizons are still distinguished (1) indivisibility based on features (phylogenetic or immigrational events) that serve as a basis for its recog 9 Judging from recent data, Pliensbachian and Toarcian chrons nition (more detailed, for example, phylogenetic may differ in duration from each other approximately by an order of magnitude (McArthur et al., 2000), while the minimal investigations may provide grounds for its division, not duration of hemerae (chronological equivalents of biohorizons) subdivision of the biohorizon); (2) identification may be as long as approximately 10–20 kyr. exclusively based on the index species/subspecies;
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(3) occurrence of both the lower and upper boundaries much as the biohorizons are defined using different in any section that are exclusively determined by the principles (evolutionary and migrational) and differ observable distribution of the index species/subspecies ent taxa from the guide fossil group, their overlap is (in the optimal case, the boundaries of neighboring admissible (Figs. 4, 5). biohorizons in the section coincide between each As follows from the practical activity, the biohori other). Inasmuch as these features are separately char zons are most convenient for correlation within pale acteristic of other biostratigraphic units, let us pay obiogeographic provinces and realms, although some attention to their differences from biohorizons. biohorizons or their sequences may frequently be In some cases, the resolution of current zonal traced in several paleobiogeographic realms (Cal scales may almost correspond to that of biohorizon lomon, 2001; Rogov et al., 2009). The correlation sequences (i.e., zones in them are factually indivisi potential of biohorizons is immediately connected ble). At the same time, we should remember that their with paleobiogeographic distribution of guide taxa and construction principles are different. The biohorizons their ecological (adaptive) strategy; indirectly, it reflect the biostratigraphic structure of sections more depends also on the completeness of the geological adequately including also intervals, attribution of record in different regions. which to any biostratigraphic unit is ambiguous. Page (1995, p. 805) outlined several geological and Moreover, of correlative significance are both the bio biological factors that allow recognition of biohori horizons proper and separating intervals (Page, 1995). zons. The geological factors are primarily related to By the principle of their substantiation, the phyloz depositional environments, postdepositional pro ones are most similar to phylogenetic biohorizons. At cesses, and denudation that determine the irregular the same time, they are not indivisible by definition. preservation and occurrence of fossils. All the diversity For example, by their ranges the phylozones in the of biological factors outlined by Page may be reduced Jurassic System usually exceed considerably biohori to two types: phylogenetic and immigrational. This zons. Such zones are based on the succession of provides grounds for defining two corresponding types related ammonite genera or subgenera (for example, of biohorizons (Zakharov et al., 2007): in the Callovian Kosmoceratidae succession), while (1) The phylogenetic biohorizons are distinguishable biohorizons in this interval are distinguishable based by evolutionary events (phyletic speciation) in lineages on successions of species/subspecies. of guide taxa that inhabited the region under consider At the first glance, the biohorizon as a stratigraphic ation. The basis for defining such biohorizons is unit, which may be defined among barren sediments, yielded by both stratigraphic investigations proper and slightly resembles the so called beds with fauna (flora) thorough study of the phylogenesis at the species and (Stratigraficheskii …, 2006). Nevertheless, the latter subspecies levels. The most frequent result of such represent only subsidiary biostratigraphic units and studies is sequences of phylogenetic biohorizons based meet none of requirements to the biohorizons. on evolutionary successions of guide taxa dominant or As was mentioned, the boundaries of successive subdominant in the region under consideration biohorizons may be inconsistent with each other and (Fig. 4). potential hiatuses are presented in stratigraphic scales (2) The immigrational biohorizons are recognizable in form of intervals between neighboring units. This is based on short term invasions of certain species/sub natural and convenient, since only some levels sepa species to the region under consideration (Fig. 5) rated by stratigraphic hiatuses or intervals barren of (Rogov et al., 2009). Such immigrants usually leave no satisfactorily preserved guide fossils appear to be suffi descendant, although they may continue evolving in a ciently characterized by paleontological remains in new region. Two important features should be noted: most sections (Fig. 3). In this case, it is impossible to (a) the stratigraphic range of the index species charac comply with the principle of continuity without spec teristic of the immigrational biohorizon may substan ulative assumptions. In some intervals of sections lack tially be shorter as compared with that of this species ing visible hiatuses and well characterized by guide in the eudemic (primary) part of its distribution area; fossils (and well studied) through their entire thick (b) the same biohorizon may be phylogenetic in some ness, the observed stratigraphic ranges of successive parts of its area and immigrational in the other one. species/subspecies belonging to a single phyletic lin In this case, the migration rate may be ignored. eage may join each other (Figs. 4, 5). In addition, inas According to the phrase by S. Buckman (1909–1930,
Fig. 3. The Upper Bathonian–Lower Callovian section on the left side of the Volga River near the Prosek and Isady settlements of the Lyskovo area in the Nizhni Novgorod region. Stratigraphic ranges of ammonite assemblages (f1–f10), which correspond to biohorizons: (inf) P. infimum, (“am”) “P. cf./aff. ammon”, (jacq) M. jacquoti. (elat) P. elatmase, (sur) C. surensis, (subp) C. subpatruus, (ind) K. indigestus; (curt) L. curtilobus, (gal) K. galilaeii, (call) S. calloviense (index species in lists are designated by asterisks). The biohorizons are separated either by barren intervals lacking of reliably identifiable guide forms or stratigraphic hiatuses (wavy lines). The section stratigraphy and identifi cations of ammonite taxa are given after D.B. Gulyaev. [M] macroconchs; [m] microconchs).
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 219
Rondiceras geerzense (Behrendsen) [M] sensu Mitta, 2000 call f10 Novocadoceras sasonovi (Kiselev) [m] “Pseudocadoceras” sp. [m] gal f9 *Sigaloceras calloviense (Sowerby) [M]
Zone Gulielmina quinqueplicata Buckman [m]
Bed Proplanulites (Crassiplanulites?) sp. ind. [M] Substage Lithology Thickness, m
Biohorizon curt f8 *Kepplerites (Gowericeras) galilaeii (Oppel) [M] km 2 Koenigi Gal. Rondiceras sokolovi (Kiselev) [M] 4 Cadoceras tolype Buckman [M] ind f7 Cadoceras(?) confusum (Gulyaev) [M]
K. C. 3 Novocadoceras cf./aff. sasonovi (Kiselev) [m] subp f6 “Pseudocadoceras” bellator (Kiselev) [m] *Kepplerites (Gowericeras) curtilobus (Buckman) [M] Toricellites curticornutus Buckman [m] Proplanulites (Proplanulites) ferruginosus Buckman [M] P. (P.) cf. excentricus Buckman [m] sur f5 Chamoussetia chamousseti (d’Orbigny) [M] 2g Pseudocadoceras boreale Buckman [m] “Pseudocadoceras” aff. grewingki (Pompeckj) [m] *Kepplerites (Gowericeras) indigestus (Buckman) [M] Toricellites lahuseni (Parana et Bonarelli) [m] Proplanulites (Proplanulites) cf. ferruginosus Buckman [M] P. (P.) cf. excentricus Buckman [m] *Cadochamoussetia subpatruus (Nikitin) [M] Kepplerites (Gowericeras) cf. unzhae Gulyaev [M] 2f Homoeoplanulites sp. ind. [m] *Cadochamoussetia surensis (Nikitin) [M] elat Cadoceras sp. ind. [M] f4 Pseudocadoceras aff. mundum (Sasonov) [m] Kepplerites (Gowericeras) unzhae Gulyaev [M] Toricellites pezhengensis Gulyaev [m]
Lower Callovian Macrocephalites (Macrocephalites) pavlowi Smorodina [M] 2e Homoeoplanulites spp. [M, m] *Paracadoceras (Rossicadoceras) elatmae (Nikitin) [M] Cadoceras quensledti simulans Spath [M] “Pseudocadoceras” mundum (Sasonov) [m] Macrocephalites (Macrocephalites) prosekensis Gulyaev [M] M. (M.) volgensis Gulyaev [M] 2d M. (M.) verus Buckman [M] 2c M. (Pleurocephalites) cf. terebratus (Phillips) [M] jacq 2b f3 M. (Kamptokephalites?) cf. zickendrathi Mitta [m] 2а M. (K.?) sp. juv. [m?] “am” f2 Paracadoceras (Rossicadoceras) ex gr. poultoni Gulyaev [M] “Pseudocadoceras” sp. nov. (aff. pisciculus (Gulyaev)) [m] 1f Kepplerites (Kepplerites) sp. ind. [M] Toricellites sp. ind. [m] *Macrocephalites (Macrocephalites) jacquoti (H. Douville) [M] inf 1d f1 *Paracadoceras (Catacadoceras) cf./aff. ammon (Spath) [M] “Pseudocadoceras” pisciculus (Gulyaev) [m] Kepplerites (Kepplerites) sp. ind. [M] 1c Toricellites cf./aff pauper (Spath) [m] *Paracadoceras (Catacadoceras) infimum (Gulyaev et Kiselev) [M] Infimum Elatmae“Pseudocadoceras” pisciculus Subpatruus (Gulyaev) [m] Kepplerites (Kepplerites) svalbardensis Sokolov et Bodylev [M] 1b Toricellites pauper (Spath) [m] Upper Bathonian
1а
Tatarian scale 1 m Stage Vertical
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 220 ROGOV et al.
, m Lithology Phyletic lineage Substages, Biohorizons zones, subzones of the genus Funiferites Thickness Cor Cordatum datum Costicardia Mariae Oxfordian Lower Lower Lamberti
“Spinosum” K. kuklikum
Funiferites funiferus 1 cm s u er if n fu . F F. patruus Proniae 1 cm Funiferites patruus . sp. nov.” F “
Phaeinum 1 cm F. allae K. phaeinum K. proniae rowlstonense K. Funiferites sp. nov.
K. grossouvrei Grossouvrei K. posterior
Obductum K. crassum K. jason jason Jason Middle Callovian Upper Bathonian 1 cm Jason Сoronatum Athleta Medea K. medea medea Funiferites allae Vertical scale 1 m Vertical
Fig. 4. The Middle–Upper Callovian to Lower Oxfordian section in the Mikhailovtsement quarry near Mikhailov of the Ryazan Oblast, after (Kiselev et al., 2003) modified. Dark gray coloration indicates stratigraphic ranges of evolutionary successive species from the ammonite genus Funiferites (Car doceratidae) and corresponding biohorizons; light gray coloration shows the “standard” sequence of biohorizons based on the stratigraphic distribution in the phyletic lineage of the ammonite genus Kosmoceras (Kosmoceratidae). pt. XXXVII, p. 24), “the rate of ammonite migration units. In the practical activity, such a situation is rare to that of deposition was like the flight of an aeroplane because of insufficient knowledge or incomplete geo to the progress of brick laying.” logical record. The complete sequence of biohorizons In the optimal case, the sequence of biohorizons in a single section cannot usually be established for dif exactly corresponds to the previously established zonal ferent reasons and for constructing the continuous
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 221
Ammonite ranges Appearance/ disappearance levels of Biohorizon taxa (potential efimovi boundaries of cf. Zone assemblagebased Subzone Substage Lithology Thickness, m stratigraphic units) Bed
“P.” puschi 1/67
1/8a, b spp. spp. . sp.
S. neoburgense sp 1/9a–c sp.
Tenuicostatum I. pseudoscythica 1/10 1/11 Franconites P.
“Franconites” Ilowaiskya pavida
1/12 Sphinctoceras I. pavida Fontannesiella Ilowaiskya sokolovi ? Paralingulaticeras (Rogoviceras) spp. Ilowaiskya klimovi
I. sokolovi Paralingulaticeras (Rogoviceras) efimovi ?Danubisphinctes Eosphinctoceras P. efimovi 1/13a, b Sutneria asema Sokolovi Pseudoscythica
N. steraspis 1/14 “Pseudovirgatites” puschi Schaireria neoburgense “N. cf. praecursor” 1/15 I. klimovi Klimovi 1/16–18 Aulacostephanus 9–43= “Pseudovirgatites” tenuicostatum S. ilowaiskii 1/19 Ilowaiskya pseudoscythica cf. zio
9/39–42 praecursor cf. franciscanum Fallax
9/38 cf.
S. fallax Ochetoceras Neochetoceras steraspis 9/36–37 9/34–35 Neochetoceras 9/32–33 taimyrensis 9/29–31 Taramelliceras S. zeissi cf. 9/28 Sarmatisphinctes ilowaiskii
9/25–27 Sarmatisphinctes subborealis Neochetoceras rebouletianum Suboxydiscites sp. 9/23–24 Sarmatisphinctes fallax
9/22 subborealis cf. Autissiodorensis S. subborealis
Subborealis 9/19–21 subsidens Upper Kimmeridgian Lower Volgian Nannocardioceras cf.
9/14–18 anglicum Sarmatisphinctes zeissi cf.
9/13 sp. Sarmatisphinctes 9/12
N. volgae 9/10–11 Neochetoceras Nannocardioceras volgae Sutneria aff. rebholzi Schaireria Nannocardioceras krausei “S. aff. rebholzi” ex gr. 9/9
9/4–6 Nannocardioceras “N.anglicum” 9/3 scale 1 m Eudoxus Vertical subnudatum Neochetoceras Contejeani
Fig. 5. The Upper Kimmeridgian–Lower Volgian section near the Gorodishchi village in the Ul’yanovsk raion of the Ul’yanovsk Oblast. The distribution of ammonites and infrazonal subdivision of the section is shown after (Rogov, 2010) modified. The stratigraphic ranges of ammonite, the phyletic lineages of which are used for constructing the main scale of biohorizons (Sarmatisphinctes– Ilowaiskya–“Pseudovirgatites”) are shown in black; stratigraphic ranges of other ammonite species are given in gray. The phylo genetic and immigrational biohorizons are shown in white and gray, respectively. (P.) Pseudoscythica.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012
222 ROGOV et al.
R. a a S
N am
Samara K
Mar Kazan
Syktyvkar .
R
Nar’yan P
e
c 1
h o r a
R 150 km . R
a olga
. g Cadoch
l V R
o
a V Samara
n
i and repre
v .)– 4 5 D P Volgograd 7 a . ( ? y R
a 6 R n 3 n n r o e ve ez e D S jacquoti M 2 Nizhni Novgorod .) M ( Paracadoceras Ovrag facies Hiatus Beds with Hiatus ? Hiatus ? M. jacquoti Kepplerites unzhae not identified Ch. crobyloides (7) Malinovyi Cadochamoussetia Ammonites are * s of biohorizons in local sections (after Coastalmarine and (subcontinental) Macrocephalites eage of endemic biohorizons. facies Hiatus Hiatus Hiatus C. surensis P. elatmae P. elatmae * C. subpatruus (6) Uzhovka C. uzhovkensis not identified * * Ammonites are Coastalmarine (subcontinental) ammon” ia based on correlated sequence Beds with Yazykovo P. infimum M. jacquoti Inaccessible not identified not identified Cadochamoussetia . cf./aff. for observation Ammonites are Ammonites are e is based on the phyletic lin ( (5) Lazarevka– P. chvadukasyense a, gaps in observations, hiatuses ammon” “P gray. Asterisks designate stratotypes of gray. C. surensis P. elatmae cf./aff. Inaccessible the biohorizon defined by the Tethyan immigrant the biohorizon defined by Tethyan not identified for observation (4) Khvadukasy Ammonites are P. chvadukasyense “P. ” dary interval of European Russ dary interval ammon Gulyaev et al., 2002). The scal Gulyaev Isady Hiatus HiatusHiatus Hiatus Hiatus Hiatus ? Hiatus Beds with Cadoceratinae P. elatmae P. infimum C. surensis M. jacquoti * * (3) Prosek– C. subpatruus not identified . cf./aff. and Ammonites are P Kepplerites (Kepplerites) “ Stratigraphic structure of local sections (see numerals in the map) Biohorizons (gray), beds with faun
Hiatus P. elatmae Inaccessible (2) Pezhenga are not found not identified for observation Ammonites are Ammonites are reference unit. The biohorizons are shown in ” .) representatives; in addition, the scale includes .) representatives; ammon Ch *P. poultoni ( Hiatus
*P. primaevum Shchel’ya
P. elatmae P. infimum cf./aff. jacquoti Inaccessible
for observation M. P. C. tschernyschewi *C. tschernyschewi P. chvadukasyense (1) Churkinskaya “ * Chmoussetia .)– cf./aff. C P. poultoni
P. primaevum P. ( ammon” jacquoti “ C. surensis P. elatmae scale P. infimum
C. subpatruus
Ch. crobyloides M. Biohorizons Regional
C. tschernyschewi
“C. uzhovkensis” “P. chvadukasyense” The regional scale of biohorizons in the Bathonian–Callovian boun The regional scale of biohorizons in the Bathonian–Callovian
niu lta Subpatruus Elatmae Infimum Zone
Substage Upper Bathonian Lower Callovian Lower Bathonian Upper senting an interregional biostratigraphic Gulyaev and Kiselev, 1999; Gulyaev, 1999, 2001, 2005, 2007, 2011; 1999; Gulyaev, and Kiselev, Gulyaev Fig. 6. amoussetia
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 223 regional scale of biohorizons, one should correlate levels of taxa in Fig. 5). In such a situation, most suit their successions in a series of sections scattered some able are parallel sequences and integrated scales of times through a relatively spacious region (Fig. 6). The biohorizons (see above). thorough reconstruction of phyletic lineages among In some cases, the biohorizons are distinguished by guide fossils may be helpful in such correlations. the acme level of the index species (Page, 1995). Such When zonal subdivision and recognition of bioho an approach should also be viewed as undesirable rizons is based on different guide fossil groups, the bio because of the doubtful correlation potential of corre horizon may overlap boundaries of zonal units. In the sponding stratigraphic units, since (1) no uniform cri same stratigraphic interval of a single region (deposi teria exist for boundaries of the acme level and tional basin, paleobiochorema), parallel sequences of (2) acme levels of the same species in different areas biohorizons may be established using different phyl even of the same basin may be not coincident (for etic lineages of guide fossils or invasions of migrating example, due to ecological reasons). species. The distribution areas of such biohorizons and The recognition of biohorizons without the refer their sequences are usually not coincident. At the ence to the particular section interval or, even, the same time, in areas of their co occurrence, these whole section, where they are defined, became the sequences may be integrated into a single complex second undesirable trend in stratigraphy (Mitta and scale, which offers wide opportunities for interre Starodubtseva, 1998; Kiselev, 2005; and others). When gional correlations. It is understandable that bound the researcher has no chance to illustrate in his work aries of parallel biohorizons in the integrated scale may particular sections and stratigraphic intervals or refer not necessarily be coincident (Fig. 7). to their description in earlier publications, he should operate with faunal assemblages (faunas) similarly to NOMENCLATURE AND DESCRIPTION Callomon (1984a, 1993). OF BIOHORIZONS Some researchers define series of “horizons” in irregularly condensed sediments by grouping the co The rapid development and frequently spontane occurring, although presumably different age species ous application of the infrazonal method against the into consecutive assemblages. Moreover, the fact that background of its relatively poor theoretical substanti the term “horizon” implies a certain stratigraphic ation resulted in the unavoidable anarchy in defining range is absolutely ignored. In such a situation, we biohorizons. should speak about provisional faunal assemblages. The thoughtless approach to index taxa became The existing nomenclatural ambiguity determined one of main negative trends. This trend was initiated the necessity in development of a code of basic rules by Callomon (1985), who suggested designating the for recognition and description of biohorizons chronological index species of consecutive biohori (Gulyaev, 2002; Gulyaev et al., 2010). In absence of zons lacking proper names by “non Linnean” sym such a code, further investigations can discredit the bols, i.e., by Greek letters (for example, Cadoceras infrazonal method. In this work, we propose a prelim α, β, γ). Subsequently, some researchers used apertum inary version of such nomenclatural rules based on Roman or Arabic numerals for the same purpose materials that were accumulated after works by Cal (Dietl, 1994; Page, 2003; and others). In addition, the lomon (1984a, 1985), which triggered rapid develop species in the open nomenclature or only genera ment of the infrazonal ammonite based biostratigra (sometimes, with additional numerals or letters) are phy. frequently used for indexing the biohorizons. It is clear that such an approach introduces the ambiguity in the The availability and validity are most important understanding of the defined stratigraphic units, characteristics of any taxon, the stratigraphic unit which should be considered only as conditional (pre included. liminary) units that need to be designated by a suitable The availability is determined by several criteria. index species/subspecies. (1) The name of a biohorizon should include sev In some works (Scweigert, 1998; Page, 2003; Meis eral components: (1) the word “biohorizon” or its ter et al., 2005; and others), two (less commonly, replacing synonym (faunal horizon, horizon); the use three) species from the guide fossil group are used for of its index number in the regional/local succession is indexing the biohorizons. In such situations, one (two) unreasonable; (2) the name of a single suitable index index species appears usually to be superfluous, since taxon (species or subspecies) in its short or complete its stratigraphic range coincides with that of the other form without indication of the author; the use of non index species or exceeds the latter. The recognition of Linnean symbols (letters, numerals) as well as selec biohorizons based on the partial overlap of strati tion of species in the open nomenclature, genera, or graphic ranges of several species is unreasonable, since yet not described taxa as indices are inadmissible: all such an approach may potentially result in recognition such characteristics should be considered as condi of many unimportant stratigraphic units with the dis tional (preliminary) and require further specification; tribution area in common and practically without any (3) the Latin name of the author and year of the bio correlation potential (see appearance/disappearance horizon name publication (establishment). The last
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 224 ROGOV et al. sp. Anaplanulites Anaplanulites difficilis Anaplanulites submutatus Anaplanulites Pseudoperisphinctinae petrosus ? es ex gr. F. allae Perisphinctidae F. patruus F. sp. nov. F. funiferus Funiferites Proplanulitinae Poplanulites cracoviensis Poplanulit , 2000) sp. nov. ? ? Mitta Cardioceratidae ? sp. ? L. alpha Q. henrici ? khudyaevi C. (S.) Q. lamberti L. lahuseni R. tcheffkini R. geerzense R. L. keyserlingi L. stenolobum milaschevici R. milaschevici Q. praelamberti C. (C.) cordatum R. milaschevici C. (S.) bukowskii Q. pseudolamberti C. (C.) costicardia L. praestenolobum (sensu C. (S.) scarburgense C. (S.) praecordatum
C. (S.) alphacordatum
[m=“Q.” paucicostatum]
[m=Protocard. praemartini]
(Scarburgiceras) (Cardioceras)
odcrsLnavcrsQuenstedtoceras Longaeviceras Rondiceras Cardioceras C. pagei S. micans S. calloviense K. (L.) proniae K. (Z.) crassum K. (Z.) posterior K. (L.) kuklikum K. (Z.) obductum K. (Z.) phaeinum K. (L.) geminatim C. enodatum aeeta K. (Z.) grossouvrei K. (G.) jason K. K. jason sedgwickii K. (M.) mojarovskii K. (L.) rowlstonense Oppeliidae K. (G.) medea K. (M.) zudacharicum
C. enodatum K. (G.) medea magnum Subtethyan taxa
C. enodatum planicerclus
Kosmoceratidae
Glemts Zgksoea)Lbksoea)(Mojarovskia) (Zugokosmokeras)(Lobokosmokeras) (Gulielmites) sigaloceras
Taramelliceras baccatum ceras
Kosmoceras Cata Sigalo
Brief mass immigration of
i
n
i
k
f
f
e
. h
c R t F. allae khudyaevi F. patruus milaschevici Q. lamberti F. funiferus T. baccatum L. stenolobum “F. sp. nov.” R. milaschevici R. milaschevici L. praestenolobum A. difficilis P. cracoviensis P. S. micans Q. henrici K. posterior C. cordatum S. calloviense C. costicardia K. jason P. praemattini Q. praelamberti C. scarburgense C. praecordatum C. alphacordatum “Q.” paucicostatum Integrated regional K. jason scale of biohorizons enodatum sedgwickii K. crassum C. enodatum K. proniae K. obductum K. kuklikum C. pagei K. phaeinum K. grossouvrei K. C. bukowskii K. mojarovskii K. medea medea K. rowlstonense planicerclus C. enodatum aeeta K. medea magnum C. enodatum Jason Medea Henrici Proniae Subzone Lamberti Cordatum Phaeinum Bukowskii Enodatum Obductum
Costicardia Calloviense Grossouvrei “Spinosum”
Scarburgense
Praecordatum
Zone alves ao ooau tlt abriMra Cordatum Mariae Lamberti Athleta Coronatum Jason Calloviense
Subzone Lower Upper Мiddle (pars) Lower
Stage Callovian Oxfordian
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 225
Fig. 7. The integrated scale of Callovian and Lower Oxfordian biohorizons for European Russia based on parallel phyletic lineages of low boreal kosmoceratids (gray) and high boreal cardioceratids (dark gray), the geographic distribution areas of which signif icantly overlap each other (after Kiselev, 2001, 2005, 2006; Gulyaev et al., 2002; Kiselev et al., 2003; Kiselev and Meledina, 2004; Kiselev and Rogov, 2005; Gulyaev, 2005; Kiselev et al., 2006; Wierzbowski and Rogov, 2011). The scale includes the immigrational biohorizon based on the sub Tethyan Oppelidae representative, which is of particular importance for correlation. The biohorizons based on subboreal Perisphinctidae species are largely used in areas, where kos moceratids are rare or not found. Horizontal and vertical arrows show immigrations and phylogenetic connections of ammonites, respectively. The dark gray and light colors designate biohorizons based on high boreal cardioceratids and low boreal kosmocer atids, respectively. Other biohorizons are given in white. component is indicated in revisions and descriptions. lication, serves as a main criterion of the validity. In The author of the biohorizon is the researcher, who case of biohorizons, it is reasonable to use the triple first established the corresponding stratigraphic unit priority principle that includes subordinate principles precisely as biohorizon, even though its index coin of (1) minuteness, (2) continuity, and (3) priority. cides with that of previously defined host zone or sub (1) The principle of minuteness is most important 10 zone. The year of publication of the above men among characteristics following from the biohorizon tioned work by Buckman (1893) is considered as a definition proper. According to this principle, the bio starting date for availability of biohorizon names. horizon with the shortest geochronological range is a senior unit relative to its counterparts with wider geo (2) A new name of the biohorizon as well as any chronological ranges (for example, three biohorizons nomenclatural operation or information that may instead two in the same interval). influence the nomenclature should be published in line with same rules, which are accepted in current inter (3) The principle of continuity means that the bio national codes of the zoological and botanical nomen horizon defined by the species (subspecies) of the clatures, same phyletic lineage characteristic of their neighbor (3) An index of the biohorizon should have a suit ing counterparts is senior relative to the biohorizon able, although no necessarily valid name. To avoid dis defined by the species (subspecies) from the other crepancy, the first description of the biohorizon should phyletic lineage, if this is consistent with the minute be accompanied by the reference to the illustration ness principle. It is natural that evolutionary phases and description of the index taxon as well as by illus (cycles) in different phyletic lineages may be not coin tration of available specimens, which presumably cident; in such cases, the purpose of the continuity belong to the latter. principle is to avoid the potential overlap of strati graphic units. If neighboring biohorizons are defined (4) Any biohorizon should have a stratotype. Its by species from different phyletic lineages, but their main purposes are (a) to protect the nomenclatural ranges are similar, the name of the middle biohorizon name (stability of the nomenclature) and (b) to pro should be selected by the conventional way, although vide potential falsifiability (testing) of initial data. In there are always some preferences. In case of the avail addition to the stratotype, the description of the bio ability of parallel phylogenetic and immigrational bio horizon should be provided with indication of the stra horizons, it is reasonable to keep both types of strati totype area, where this unit bears similar paleontolog graphic units within a single scale, since phylogenetic ical and geological characteristics. In case of the loss of biohorizons reflect in the most degree the continuity a holostratotype or impossibility of its establishment, principle, while immigrational biohorizons are usually the latter may be replaced with a lectostratotype. characterized by the higher correlation potential. Beyond the stratotype area, stratigraphic standards (reference sections) may be selected. The latter bear The principle of priority means that the oldest suit no nomenclatural significance and provide an addi able name of the biohorizon is senior relative to its tional characteristic of the biohorizon in the study later names, when this is not inconsistent with the region. It is desirable that the stratotype section in the principles of minuteness and continuity. stratotype area represented also the stratigraphic stan It should be kept in mind that the nomenclature of dard. When the lectostratotype cannot be defined in biohorizons is to a certain extent dependent on the the stratotype area, any of the stratigraphic standards nomenclature of index species. may be defined, if needed, as a neostratotype. (1) When the name of the index species is changed Va l i d i t y. In the zoological and botanical nomencla because of objective reasons (objective synonymy or tures, the principle of priority, application of which is homonymy), i.e., the nomenclatural type is preserved, reduced only to the seniority of the suitable name pub the name of the biohorizon becomes also automati cally changed, although the author remains the same 10 In some works (Hantzpergue, 1989; Biostratigraphie …, 1997), and its last name is taken into parentheses. the authors of senior zonal units are considered, through a mis understanding, as authors of synonymous biohorizons; such an (2) When the name of the index species becomes approach is unacceptable because of principal differences invalid due to subjective synonymy, the name of the between these categories of stratigraphic units. biohorizon becomes invalid as well. This is explained
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 226 ROGOV et al. by the fact that stratigraphic ranges of the senior and subdivision and correlation of Phanerozoic succes junior synonyms may potentially be different. The sions using the experience available from the study of authorship of a new name should belong to the the Jurassic System. Such examples are known: the researcher, who was the first to revise the latter. If the biohorizons are used with progressively growing fre geochronological range of the biohorizon and its posi quency in investigations of the Cretaceous and Triassic tion in the scale remain unchanged, the initial name is systems; belemnite based infrazonal scales are also included into the synonymy of a new name. becoming available. Thus, we may expect the further Following below is the recommended plan for progress in development of detailed biostratigraphic description of biohorizons (“n/o” means a not obliga investigations. tory item). Name (with the author’s name, year of publica ACKNOWLEDGMENTS tions, and a mark “nov.” for new biohorizons). Synonymy (with indication of reasons responsible We are grateful to our colleagues I.S. Barskov, for their rejection for invalid names). V.N. Beniamovsky, A.Yu. Gladenkov, Yu.B. Gladen Index (with the reference to the illustration and kov, V.A. Zakharov, O.A. Korchagin, V.V. Mitta, description). S.V. Naugol’nykh, V.A. Prozorovskii, D. Bert, M. Hart, J. L. Latil, F. Olóriz, and K. Page for joint (Stratotype (with the obligatory indication of a par discussions of the main concepts of this work as well as ticular interval in the published section). to its reviewers B.N. Shurygin and E.Yu. Baraboshkin Stratotype area (n/o). for their valuable recommendations. This work was Stratigraphic standards (n/o). supported by the Russian Foundation for Basic Paleontological characteristic (position of the bio Research, project no. 09 05 00456. horizon in the local scale and correlation with scales Reviewers E.Yu. Baraboshkin and B.N. Shurygin available for other regions). Remarks (n/o). Distribution (regions, where this horizon is distin REFERENCES guishable). Arkell, W.J., The Jurassic System in Great Britain, Oxford: Locality (the list of sections, where this biohorizon Clarendon press, 1933. is recorded by the author). Arkell, W.J., Jurassic Geology of the World. Edinburgh, Lon We are far from the thought that the above list of don: Oliver&Boyd, 1956. nomenclature rules takes into consideration all the Bather, F., Biological Classification: Past and Future, Proc. possible situations and eliminates all the inconsisten Geol. Soc, 1927, vol. LXXXIII, pp. lxii ⎯ civ. cies. In fact, we had no such a purpose. In our opinion, Biostratigraphie du Jurassique Ouest Européen et Méditer it is of importance that this list may serve as a basis for ranéen: zonation paralleles et distribution des invertebres et further developments, investigations, and discussions microfossiles, Bull. Centre, Rech. Elf Explor. Prod., 1997, among interested researchers. The proposed princi Mem. 17. ples of recognition and application of biohorizons Buckman, S.S., The Bajocian of the Sherborne District: Its were recently successfully used in detailed investiga Relation to Subjacent and Superjacent Strata, Quarterly J. tions of Bathonian–Callovian (Gulyaev, 1999, 2001, Geol. Soc., 1893, vol. 49, pp. 479–522. 2005; Kiselev, 2001, 2006; Kiselev and Rogov, 2007; Buckman, S.S., On the Grouping of Some Divisions of So and others) and Kimmeridgian–Volgian (Rogov, Called “Jurassic” Time, Quarterly J. Geol. Soc., 1898, 2005, 2010) sections. vol. 54, pp. 442–462. Buckman, S.S., The Term “Hemera”, Geol. Mag., 1902, vol. IX, no. XII, pp. 554–557. CONCLUSIONS Buckman, S.S., Yorkshire Type Ammonites, London: Wes The use of biohorizons opens new prospects for ley&Sons, 1909–1930, vol. 1–7. solving two main stratigraphic problems: subdivision Buckman, S.S., Paleontological Classification and Com and correlation. Owing to infrazonal units, the solu parison of Certain Jurassic Rocks of Raasay and Skye, The tion of both these problems becomes progressively Mesozoic rocks of Applecross, Raasay, and North East Skye., more easier. It is not incidental that most discussions Lee, G.W., Ed., Edinburgh: Morrison and Gibb, 1920, dedicated to the GSSPs of Jurassic stages are reduced pp. 64–89. to the question: the base of what biohorizon should be Buckman, S.S., Jurassic Chronology: III—Some Faunal used for placing a stratigraphic boundary. Horizons in Cornbrash, Quarterly J. Geol. Soc, 1927, It seems that world infrazonal stratigraphy is now at vol. 83, pp. 1–37. the development stage even for the Jurassic System. Bulot, L., Thieuloy, J. P., Blanc, E., and Klein, J., Le cadre We hope that the ideas discussed in this work may help stratigraphique du valanginien supérieur et de l’hauterivien du researchers, who are engaged in solving stratigraphic Sud Est de la France: définitions des biochronozones et car problems of the Jurassic and other systems based on actérisation de nouveaux bio horizons, Géologie Alpine, 1992, ammonites and other fossil groups, in more detailed vol. 68, pp. 1–56.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 227
Callomon, J.H., Notes on the Callovian and the Oxfordian Russia: Problems of Stratigraphy and Paleogeography), Stages, Colloque du Jurassique, Luxembourg, 1962, C. R. et Moscow: GIN RAN, 2005, pp. 64–70. Mem. Inst. Grand ducal, Sect. Sci. Nat., Phys. Et Math.: Gulyaev, D.B., New Data on Biostratigraphy of Upper Luxembourg, 1964, pp. 269–291. Bathonian Lower Callovian Deposits in the Churkinskaya Callomon, J.H., Biostratigraphy, Chronostratigraphy and Shchel’ya Reference Section (town of Pizhma, Pechora All that again, Int. Symp. Jurassic Stratigr., Erlanger, Sept, River basin), Yurskaya sistema Rossii: problemy stratigrafii i 1984, vol. III, pp. 1–8. paleogeografii. Vtoroe Vserossiiskoe soveshchanie: nauchnye Callomon, J.H., A Review of the Biostratigraphy of the materialy (Proc. 12th All Russia Conf. Jurassic System of Post Lower Bajocian Jurassic Ammonites of the Western the Russia: Problems of Stratigraphy and Paleogeography), and Northern North America, Geol. Assoc. Canada, 1984b. Yaroslavl: Izd. YaGPU, 2007, pp. 49–58. Gulyaev, D.B., Evolution and System of Middle Jurassic Callomon, J.H., The Evolution of the Jurassic Ammonite Boreal Ammonite Genus Paracadoceras Crickmay (Cardi Family Cardioceratidae, Spec. Pap. Palaeontol., 1985, oceratidae) and Infrazonal Subdivision of Bathonian Call no. 35, pp. 49–90. ovian Boundary Deposits in the European Russia Materialy Callomon, J.H., The Ammonite Succession in the Middle nauchnoi konferentsii “K 100 letiyu so dnya rozhdeniya pro Jurassic of East Greenland, Bull. Geol. Soc. Denmark, 1993, fessora A.N. Ivanova” (Proc. Sci. Conf. Devoted to vol. 40, pp. 83–113. 100th anniversary of A.N. Ivanov), Yaroslavl’: Izd. YaGPU, Callomon, J.H., Time from Fossils: S.S. Buckman and (in press). Jurassic High Resolution Geochronology, Milestones in Gulyaev, D.B. and Kiselev, D.N., Boreal Upper Bathonian geology, Le Bas, M.J., Ed., Mem. Geol. Soc.: London, in the Volga River Middle Courses (ammonites and stratig 1995, no. 16, pp. 127–150. raphy), Stratigr. Geol. Correlation, 1999, vol. 7, no. 3, Callomon, J.H., Fossils as Geological Clocks The Age of the pp. 273 ⎯ 293. Earth: from 4004 BC to AD 2002. Lewis, C.L.E. and Gulyaev, D.B., Kiselev, D.N., and Rogov, M.A., Biostratig Knell, S.L., Eds., Geol. Soc. London. Spec. Publ, 2001, raphy of the Upper Boreal Bathonian and Callovian of the vol. 190, pp. 237–252. European Russia, 6th Int. Symp. on the Jurassic System, Sep Callomon, J.H. and Chandler, R., A Review of the Ammo tember 12–22, 2002, Palermo. Abstracts and Program. Mar nite Horizons of the Aalenian Lower Bajocian Stages in the tire, L., Ed., Palermo, 2002, pp. 81–82. Middle Jurassic of Southern England, Mem. Descr. della Gulyaev, D.B., Rogov, M.A., and Kiselev, D.N., Nomen Carta Geol. d’ltal, 1990, vol. 40, pp. 85–112. clature Problems of Ammonite Biohorizons (Faunal Hori zons) in Jurassic and Cretaceous Stratigraphy, Earth Sci. Dietl, G., Der hochstelleri Horizont—ein Ammoniten Frontiers, 2010, vol. 17, Spec. Iss., pp. 91–93. faunen Horizont (Discus Zone, Ober Bathonium, Dog ger) aus dem Schwäbischen Jura, Stuttg. Beitr. Naturk, Hantzpergue, P., Les Ammonites kimméridgiennes du 1994, no. 202. haut fond d’Europe occidentale. Biochronologie, Systé matique, Evolution, Paléobiogéographie. Cahiers de Palé Fenton, C.L. and Fenton, M.A., Ecologic Interpretation of ontologie, édit. C.N.R.S, 1989. Some Biostratigraphic Terms, American Midland Natural ist, 1928, vol. IX, no. 1, pp. 1–23. Hoedemaeker, Ph.J., Reboulet, S., Aguirre Urreta, M.B., et al., Report on the 1st International Workshop of the Goy, A., Ammonoideos del Triasico Medio de España: IUGS Lower Cretaceous Ammonite Working Group, the bioestratigrafía y correlaciones, Cuadernos de Geología Kilian Group (Lyon: 11 July 2002), Cretaceous Res., 2003, Ibérica, 1995, no. 19, pp. 21–60. vol. 24, pp. 89–94. Gulyaev, D.B., Macrocephalitines and Govericeratines Howarth, M.K., Ammonites of the Liassic Family Amalth (Ammonoidea) of the Elatmae Zony and Startigraphy of eidae in Britain, Monograph of the Palaeontographical Soci Lower Callovian of Central Areas of the Russian Platform ety, London, 1958, pp. 1–26. Problemy stratigrafii i paleontologii mezozoya (Problems of Imlay, R.W., Early and Middle Bajocian (Middle Jurassic) Mesozoic Stratigraphy and Paleontology), St. Petersburg: Ammonites from Southern Alaska, US Geol. Surv. Prof. Pap, VNIGRI, 1999, pp. 63–85. 1984, no. 1322, p. 38. Gulyaev, D.B., Infrazonal Ammonite Scale of the Upper Kiselev, D.N., Zones, Sub Zones, and Biohorizons of Mid Bathonian Lower Callovian of Central Russia, Stratigr. dle Callovian in the Central Russia, Trudy Estestvenno Geol. Korrelyatsiya. 2001, vol. 9, no. 1, pp. 68–96. Geograficheskogo Fakul’teta YaGPU. Spets. Vypusk, 2001, Gulyaev, D.B., Ammonite Infrazonal Units in the Jurassic no. 1. Stratigraphy (Determination and Nomenclature). Materi Kiselev, D.N., Parallel Biohorizons of Callovian in the aly molodezhn. konf. “2 e Yanshinskie chteniya”. Sovremen European Russia Based on Findings of Cardioceratids and nye voprosy geologii (Proc. Youth Conf. 2nd Yanshin Read Their Role for Correlation of Callovian Scales of Boreal ings. Contemporary Problems in Geology), Moscow, 2002, and Sub boreal Provinces Yurskaya sistema Rossii: problemy pp. 271–274. stratigrafii i paleogeografii (Jurassic System of the Russia: Gulyaev, D.B., Ammonite Based Infrazonal Subdivison of Problems of Stratigraphy and Paleogeography), Moscow: Upper Bathonian Lower Callovian of the East European GIN RAN, 2005, pp. 119–127. Platform, Materialy Pervogo Vserossiiskogo soveshchaniya Kiselev, D.N., Ammonites and Biostratigraphy of the Call “Yurskaya sistema Rossii: problemy stratigrafii i paleo ovian Beds in the Votcha Sections on the Sysola River, geografii” (Proc. 1st All Russia Conf. Jurassic System of the Novosti Paleontol. Stratigr., 2006, nos. 6–7, pp. 160–186.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 228 ROGOV et al.
Kiselev, D.N. and Meledina, S.V., Ammonite Assemblages Mitchell, S.F., Eight Belemnite Biohorizons in the Cenom and Biohorizons of the Kosmoceras Jason Sub Zone (Mid anian of Northwest Europe and Their Importance, Geol. J., dle Callovian) on the Russian Plate, Novosti Paleontol. 2005, vol. 40, pp. 363–382. Stratigr., 2004, nos. 6–7, pp. 157–175. Mitta, V.V., The Genus Cadochamoussetia in the Phylog Kiselev, D.N. and Rogov, M.A., Zones, Sub Zones and Bio eny of the Jurassic Cardioceratidae (Ammonoidea), horizons of Upper Callovian and Lower Oxfordian of the Advancing Research on Living and Fossil Cephalopods: European Russia Yurskaya sistema Rossii: problemy strati Development and Evolution: Form, Construction, and Func grafii i paleogeografii (Jurassic System of the Russia: Prob tion: Taphonomy, Palaeoecology, Palaeobiogeography, Bios lems of Stratigraphy and Paleogeography), Moscow: GIN tratigraphy, and Basin Analysis, Olóriz, F., and Rodriguez RAN, 2005, pp. 128–134. Tovar, F.J., Eds., New York: Kluwer Academic/Plenum Publishers, 1999, pp. 125–136. Kiselev, D.N., Rogov, M.A., Guzhikov, A.M., et al., Dubki (Saratov Region, Russia), the Reference Section for the Mitta, V.V., Ammonites and Biostratigraphy of Lower Call Callovian/Oxfordian Boundary, Volumina Jurassica, 2006, ovian of the Russian Platform, Bull. KF VNIGNI, 2000, vol. IV, pp. 178–180. no. 3, p. 144. Kiselev, D.N. and Rogov, M.A., Stratigraphy of the Batho Mitta, V.V. and Starodubtseva, I.A., Fieldworks in 1998 and nian Callovian Boundary Deposits in the Prosek Section. Biostratigraphy of Lower Callovian of the Russian Plat (Middle Volga Region). Part 1. Ammonites and Infrazonal form, VM Novitates, no. 2, p. 20. Stratigraphy, Stratigr. Geol. Correlation, 2007, vol. 15, no. 5, Mouterde, R., Enay, R., Cariou, E., et al., Les zones du pp. 485–515. Jurassique en France, C.R. Somm. d. Séances d.l. Soc. Géol. Kiselev, D.N., Gulyaev, D.B., and Rogov, M.A., Origin and France, 1971, no. 2, pp. 76–102. Systematic Position of Funiferites, a New Callovian Cardi Neumayr, M., Ueber Unvermittelt Auftrefende Cepha oceratid Genus (Ammonoidea), Proc. Youth Conf. 3rd lopodentypen im Jura Mitteleuropas, Jb. k.k. Geol. Reich Yanshin Readings. Contemporary. Problems in Geology, sanst, 1878, vol. XXVIII, no. I, pp. 37–80. March 26–28, 2003, Bogdanov, N.A., Vasil’ev, T.I., and Oppel, A., Die Juraformation Englands, Frankreichs und Verzhbitskii, V.E., Eds., Moscow: Nauchy Mir, 2003, des südwestlichen Deutschlands, Jh. Ver. vaterl. Naturk. pp. 271–274.. Würtemberg, 1856 ⎯ 1858, vol. 12–14, p. 857. Lazarev, S.S., Peculiar Features of Typification in Strati Page, K.N., Biohorizons and Zonules: Infra Subzonal graphic Classification, Stratigr. Geol. Correlation, 1997, Units in Jurassic Ammonite Stratigraphy, Palaeontol., 1995, vol. 5, no. 2, pp. 185–197. vol. 38, pp. 801–814. Lakatos, I., Methodology of Scientific Research Programs, Page, K.N., The Lower Jurassic of Europe: Its Subdivision Vopr. Filos., 1995, no. 4, pp. 135–154. and Correlation, Geol. Surv. Denmark and Greenland Bull., McArthur, J.M., Donovan, D.T., Thirlwall, M.F., et al., 2003, no. 1, pp. 23–59. Strontium Isotope Profile of the Early Toarcian (Jurassic) Phelps, M.C., A Refined Ammonite Biostratigraphy for the Oceanic Anoxic Event, the Duration of Ammonite Bio Middle and Upper Carixian (Ibex and Davoei Zones, zones, and Belemnite Palaeotemperatures, Earth Planet. Lower Jurassic) in North West Europe and Stratigraphic Sci. Lett., 2000, vol. 179, pp. 269–285. Details of the Carixian Domerian Boundary, Geobios., Meister, C., Worldwide Ammonite Correlation at the 1985, no. 3, pp. 321–362. Pliensbachian Stage and Substage Boundaries (Lower Rogov, M.A., New Correlation Scheme of Tithonian and Jurassic), Stratigraphy, 2010, vol. 7, no. 1, pp. 83–101. Volgian Stages Based on Data on Occurrence of Tethys Meister, C., Blau, J., Dommergues, J. L., Schlatter, R., Ammonites in Lower Middle Deposits of the central Russia et al., Ammonites from the Lower Jurassic (Sinemurian) of Problemy stratigrafii i paleogeografii boreal’nogo mezozoya. Materialy nauchnoi sessii “Pyatye Saksovskie chteniya”, Tenango de Doria (Sierra Madre Oriental, Mexico). ⎯ Part IV: Biostratigraphy, Palaeobiogeography and Taxo 23 25 aprelya 2001 g. (Problems of Stratigraphy and Paleo nomic Addendum, Revue de Palobiologie, 2005, vol. 24, geography of Boreal Mesozoic. Proc. Sci. Seccion no. 1, pp. 365–384. 5th Saksov’s Readings, April 23–25, 2001), Novosibirsk: CO RAN, GEO branch, 2001, pp. 25–27. International Stratigraphic Guide—A guide to Strati Rogov, M.A., Molluscan Associations in Late Jurassic Sea graphic Classification, Terminology, and Procedure. Hed of the East European Platform, , 2005, berg, H.D., ed. New York, John Wiley and Sons, 1976. Tr. GIN RAN no. 516, pp. 178–199. Murphy, M.A. and Salvador, A., International Stratigraphic Rogov, M.A., Gulyaev, D.B., and Kiselev, D.N., Paleobio Guide—An Abridged Version. Episodes, 1998, vol. 22, ⎯ geography and Correlation Potential of Infrazonal Bios no. 4. pp. 255 272. tratigraphic Units, Paleontologiya i sovershenstvovanie Mesezhnikov, M.S., Phylogenetic Grounds of First Zonal stratigraficheskoi osnovy geologicheskogo kartografirovaniya. Schemes 1880s to 1930s, Trudy XXXV sessii Vsesoyuznogo Materialy LV sessii Paleontologicheskogo obshchestva pri paleontologicheskogo obshchestva (yanvar’ 1989 g., Lenin RAN, 6 ⎯ 10 aprelya 2009 g. (Paleontology and Perfection of grad) (Proc. XXXV Session of All Union Paleontol. Soc., Stratigraphic Base of the Geological Mapping. Proc. January, 1989, Leningrad), St. Petersburg: Nauka, 1993, LV Seccion Paleont. Soc., of the RAS. April 6–10, 2009), pp. 35–41. St. Petersburg: VSEGEI, 2009, pp. 127–129.
STRATIGRAPHY AND GEOLOGICAL CORRELATION Vol. 20 No. 2 2012 BIOHORIZONS AS INFRAZONAL BIOSTRATIGRAPHIC UNITS 229
Rogov, M.A., A Precise Ammonite Biostratigraphy through zone à Sartousiana), Géologie Alpine, 1997, vol. 73, the Kimmeridgian Volgian Boundary Beds in the Gorodis pp. 99 ⎯ 117. chi Section (Middle Volga Area, Russia), and the Base of Waagen, W., Die Formenreiche des Ammonites subradia the Volgian Stage in Its Type Area, Volumina Jurassica, tus, Geogn. Paläont. Beitr, 1869, vol. II, no. II, pp. 179– 2010, vol. III, pp. 103–130. 256. Rogov, M., Zakharov, V., and Kiselev, D., Molluscan Immi grations via Biogeographical Ecotone of the Middle Rus Whittaker, A., Cope, J.C.W., Cowie, J.W., et al., A Guide to sian Sea during the Jurassic, Volumina Jurassica, 2009, Stratigraphical Procedure, J. Geol. Soc. London, 1991, vol. VI, pp. 143–152. vol. 148, pp. 813–824. Schweigert, G., Die Ammonitenfauna des Nusplinger Plat Wierzbowski, H. and Rogov, M., Reconstructing the Palae tenkalks (Ober Kimmeridgium, Beckeri Zone, Ulmense oenvironment of the Middle Russian Sea during the Mid Subzone, Baden Württemberg), Stuttg. Beitr. Naturk. Ser. dle Late Jurassic Transition Using Stable Isotope Ratios of B, 1998, no. 267. Cephalopod Shells and Variations in Faunal Assemblages, Stratigraficheskii kodeks. Izdanie vtoroe, dopolnennoe Palaeogeogr. Palaeoclimatol. Palaeoecol., 2011, vol. 299, (Stratigraphic Codex. The Second Edition Added), pp. 250–264. St. Petersburg: VSEGEI, 1992, p. 120. Zakharov, V.A., Rogov, M.A., and Kiselev, D.N., Correla Stratigraficheskii kodeks Rossii. Izdanie tret’e, utverzhdennoe tion Potential of Zonal and Infrazonal Stratigraphy (on the byuro MSK 18 oktyabrya 2005 g. (Stratigraphic Codex of the Example of Jurassic System), Paleontologiya, paleobio Russia, Adapted by MSC on October 18, 2005), St. Peters geografiya i paleoekologiya. Materialy LIII sessii Paleonto burg: VSEGEI, 2006, p. 96. logicheskogo obshchestva pri RAN, 2 ⎯ 6 aprelya 2007 g. Sykes, R.M. and Callomon, J.H., The Amoeboceras Zona (Paleontology, Paleobiogeography and Paleoecology. Proc. tion of the Boreal Upper Oxfordian, Palaeontol., 1979, LIII Session Paleont. Soc. of the RAS. April 2–6, 2007), vol. 22, pp. 839–903. St. Petersburg: VSEGEI, 2007, pp. 55–57. Trueman, A.E., Some Theoretical Aspects of Correlation, Zhamoida, A.I., Kovalevskii, O.P., and Moiseeva, A.I., Proc. Geol. Assoc., 1923, vol. 34, no. 3, pp. 193–206. Review of Foreign Stratigraphic Codexes, Trudy Mezhve Vermeulen, J., Biohorizons ammonitiques dans le Bar domstvennogo Stratigraficheskogo Komiteta (Proc. Interde rémien du Sud Est de la France (de la zone à Hugii à la partment. Stratigraphic Committee), 1969, vol. 1, p. 103.
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