Biostratigraphy: Interpretations of Oppel's zones

    Biostratigraphy: Interpretations of oppel’s zones G.H. Scott PII: DOI: Reference:

S0012-8252(13)00146-3 doi: 10.1016/j.earscirev.2013.08.013 EARTH 1896

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Earth Science Reviews

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14 December 2012 23 August 2013

Please cite this article as: Scott, G.H., Biostratigraphy: Interpretations of oppel’s zones, Earth Science Reviews (2013), doi: 10.1016/j.earscirev.2013.08.013

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ACCEPTED MANUSCRIPT BIOSTRATIGRAPHY: INTERPRETATIONS OF OPPEL’S ZONES

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G.H. Scott

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GNS Science, P.O. Box 30368, Lower Hutt, New Zealand [email protected] Tel. +64 4 570 1444 Fax +64 4 570 4600

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Abstract

Zones like those of Oppel and Hedberg’s Oppel-Zone are commonly interpreted as rock units

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delimited temporally. A more restricted view is that they are rock units empirically defined

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by bioevents that occur in the same order in all sections. Methods used by Oppel and definitions proposed by Hedberg are reviewed to assess their adequacy for definition of

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biostratigraphic units and their ability to support temporal inferences. Although they are usually interpreted as chronostratigraphic units, Oppel defined his zones in stratigraphic space, without temporal reference. In contrast, Hedberg required that bioevents for his OppelZone should be approximately isochronous across their distribution but provided no operational way to identify such bioevents. Neither author clearly indicated how boundaries should be defined. Recourse to a principle of biosynchroneity to support inferences that stratigraphically ordered bioevents are temporal markers conflicts with knowledge of the biogeographies of modern taxa. Evolutionary theory explains why some bioevents occur in the same stratigraphic order but does not support the inference that they are isochronous events. Since its inception biostratigraphy has focused on ordered classifications, like those

ACCEPTED MANUSCRIPT of Oppel. Stratigraphic codes should allow for a complementary category of biofacies zones

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that reflect depositional environments and are not constrained to occur in a particular order.

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Keywords Biostratigraphy, Homotaxis, Chronostratigraphy, Biofacies, Stratigraphic

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Classification

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1. Introduction

While there is unanimity that Albert Oppel’s work on the European Jurassic is a founding

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study on the use of fossils to classify strata, there are fundamentally different interpretations

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of his and similarly defined zones. Oppel (1856-8) used joint occurrences of selected taxa to define units that in all sections occurred in fixed stratigraphic order. The empirical view is

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that he created an ordered classification of strata from observations on the distributions of fossils (Fig. 1B). The putative view is that, because his method arranges zones in depositional order, it is a temporal classification – a zone identifies bodies of rock that were deposited in the same interval of past time and whose boundaries are isochronous (Fig. 1C). The first view makes no inferences about the temporal relations of a unit over its spatial extent. The second hypothesizes that the bioevents are unscaled temporal markers such that event alpha in section 1 is isochronous with event alpha in section 2, 3….n. With reference to the stratigraphic categories defined by Hedberg (1976) zones interpreted empirically are biostratigraphic units. Interpreted putatively they are chronostratigraphic units.

Overwhelmingly, biostratigraphers have promoted the putative view of zones like Oppel’s.

ACCEPTED MANUSCRIPT Jurassic ammonite workers have been at the forefront (Callomon, 1995; 2001). Buckman’s (1893; 1902) introduction of ‘hemera’ as the time equivalent of the Oppelian zone was an

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early attempt to formalize the putative view that led to the concept of biochronology.

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Callomon (1995) held that Oppel’s zones are standard chronozones as did Page (2003) who

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formally cited Oppel’s Ammonites planorbis Zone as the Planorbis Chronozone. Warrington et al. (2008) proposed that the lowest record of Psiloceras planorbis in a West Somerset

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section as a candidate Global Stratotype Section and Point for the base of the Jurassic

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System. With equal zeal Oppelian zones have been interpreted temporally and influentially advocated in several subdisciplines by Berry (1968), Berggren and Van Couvering (1978),

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Kleinpell (1979) and Lindsay (2003). Walsh (2001) advocated that the geochronological

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category in stratigraphic classifications should include biochronological units.

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The empirical interpretation of biostratigraphy has earlier roots (Marr, 1898; Şengör and Sakmç, 2001) but was principally presented by Huxley (1862) who proposed ‘homotaxis’ for similarity of stratigraphic arrangement to remove any connotation of synchrony. At the level of empirical science Huxley asked for evidence that similarity in stratigraphic order indicates similarity in time of deposition. He believed there was none. Viewed as a measurement issue, his argument is that an ordered sequence of faunal events does not translate to a temporal scale. Ecologically, his view is that biogeography, and particularly the rates at which taxa disperse, are significant factors that are ignored in the putative interpretation. Huxley’s examples of possibly undetected diachroneity (e.g., Devonian biota in the British Isles might be contemporaneous with Silurian biota in North America) did not assist acceptance of his argument and were even viewed as heretical by Woodford (1963). Marr (1887; 1898)

ACCEPTED MANUSCRIPT critically assessed homotaxis but Wooldridge (in Stamp, 1925, p. 26) believed that geology had successfully repelled Huxley's “attack”. Neither founder of temporal terms for bioevents

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(Buckman, 1893; 1902; Williams, 1901), considered the import of Huxley’s thesis, a practice

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since commonly followed.

At the birth of modern stratigraphic classifications Schenck and Muller (1941) did not refer

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to Oppel but their time-stratigraphic category is conceptually similar to the putative

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interpretation of Oppel’s zones: “…stratal units defined by time” (Schenck and Muller 1941, p. 1420). Hedberg (1976) greatly advanced stratigraphic classification by proposing a

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category for units defined by biostratigraphic data That he placed ‘Oppel-Zone’ in this

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category, which indicates an empirical interpretation, rather than under chronostratigraphy, is an interesting enigma. However, Hedberg’s Oppel-Zone has found little support. Some

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Cenozoic microfossil biostratigraphers had already moved to the use of range zones whose limits were defined by 1-2 faunal events (e.g., Blow, 1959; Jenkins, 1960). Disuse of OppelZone is reflected in its removal from the second edition of the International Stratigraphic Guide (Salvador, 1994). Yet it remains valued in recent commentaries on microfossil biostratigraphy (MacLeod, 2005; McGowran, 2005). Carter (2007) suggested that it should be re-introduced in the International Code.

These topics are of more than of historical interest. Examination of Oppel's zones and Hedberg's attempt to formalize them opens useful perspectives on the scope of biostratigraphy and its methodology. Here I attempt to clarify Oppel's methods and to identify problems in Hedberg's interpretation of Oppel's zones. From the review of Oppel (1856-8)

ACCEPTED MANUSCRIPT and Hedberg (1976) two topics are pursued: the use of stratal arrangement as a meta-criterion in biostratigraphic codes to distinguish Oppelian stratigraphies from biofacies stratigraphies

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and the status of biostratigraphy as a geohistorical discipline.

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2. Oppel's zones

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Oppel worked at a time prior to clear definitions of stratigraphic concepts. As he did not

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explicitly define ‘zone’, much reliance has been placed on Oppel (1856-8, p. 3) which states that his method results in an ideal profile wherein strata of the same age are characterized by

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the same species. Arkell (1933, p. 17) recognized the significance of Oppel’s work in the

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development of biostratigraphy but excused the latter’s failure to define ‘zone’ by stating that its meaning was “apparent on almost every page”. Hancock (1977, p.21) wrote that

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“…Oppel’s ideas were so comprehensive that no simple definition of “zone” as used by Oppel is possible.” Nevertheless, an examination of Oppel’s zones serves to clarify his methodology.

Oppel’s primary objective (1856-8, p. 1-2) was to develop a biostratigraphic classification which was applicable across the Jurassic basins of northwestern Europe. He acknowledged that Smith had founded research on Jurassic stratigraphy and the importance Smith attached to fossils for identifying strata, but thought that a classification that was independent of lithofacies was needed. As the unit of classification he adopted d’Orbigny’s zone. In retrospect, this acknowledged that Smith was a geognost who attempted to resolve the structural relations of strata rather than a biostratigrapher who interpreted them

ACCEPTED MANUSCRIPT geohistorically (Rudwick, 2005). While there is no indication that Oppel adhered to d’Orbigny’s catastrophist interpretation of earth history, his approach to the use of fossils to

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classify strata closely followed d’Orbigny’s. Compare Oppel‘s (1856-8, p. 3) concept of

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“...zones which, through the constant and exclusive occurrence of certain species, mark

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themselves off from their neighbours as distinct horizons" (from Arkell 1933, p. 16) with d’Orbigny (1852, p. 426): “…each zone has shown a special fauna, distinct from the ones of

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the underlying and overlying zones,.” (from Monty 1968, p. 697).

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Consider Oppel’s lower Jurassic zones1. For each he lists previously named formations in

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which the zone is present, the taxonomic criteria, its geographic distribution and lithofacies,

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and gives a detailed stratigraphic column through the zone at a Swabian locality. Important taxa, particularly ammonites, are cited2. Generally, these were diagnostic taxa that he deemed

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to be restricted to the zone. They are distinguished from taxa that are significant criteria, but not restricted to the zone. Some first and last occurrences are noted. The stratigraphic extent of a zone is sometimes ill-defined. In the Swabian section shown for the Ammonites planorbis Zone (Oppel 1856-8, p. 25) the two key ammonites are confined to bed c (Fig. 2A) but he allows that specimens in bed e may mark the highest occurrence of Ammonites planorbis. If the zone is delimited by the presence of the restricted taxa then it is confined to beds c-e. This renders the zone non-contiguous with the adjoining zones. While higher zones are shown as contiguous (e.g., Fig. 2B) their limits are at lithostratigraphic boundaries and some are not coincident with ranges of the critical taxa.

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Oppel’s nomenclature and text styles are used. They are termed “wichtigsten arten” for the Ammonites planorbis and Ammonites angulatus Zones; variations of “leitende” for the Pentacrinus tuberlatus Zone, Ammonites obtusus Zone and Ammonites raricostatus Zones. 2

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Berry (1968) stated that Oppel plotted the stratigraphic distribution of every species at each

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locality. These data are not included in Oppel (1856-8). The stratigraphy of his zones in

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northwest Europe is presented at a reconnaissance level without the detail given for the

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Swabian sections he figured3. For example, he noted that the Ammonites planorbis Zone is well developed in England. Near Lyme Regis he identified the two critical ammonites and

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some significant bivalves in several sections. No data on their distribution are given but he

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concluded that they occur at the same level as in Swabia. He located the higher Ammonites Bucklandi Zone but did not find taxa from the intervening Ammonites angulatus Zone.

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Reasons for its apparent absence are not discussed. Similarly, he does not interpret the major

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faunal and environment contrast between the Bonebed and the Ammonites planorbis Zone, which accommodates the end Triassic mass extinction, although the change in diversity is

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noted. d’Orbigny’s approach is quite different. Strata near the town of Semur are proposed as the standard for the lowest Jurassic Semurian Stage (d’Orbigny, 1842, p. 604) but a section is not shown; two zone fossils are named but their stratigraphic distribution is not detailed (recall that d’Orbigny uses ‘zone’ for the faunal content of a stage (Rioult, 1969)). While Oppel is little interested in the stratigraphic contacts of his zones, this is a focus of d’Orbigny who, for example, investigates and draws conclusions about the stratal relations, especially “discordances”, of the Sinemurian Stage, and its paleoenvironments e.g., d’Orbigny, 1852, p. 437-442.

Oppel’s description of the lower Jurassic zones is about their order, stratigraphic extent and 3

The omission of data on taxon distributions in sections beyond Swabia largely accounts for the difficulty Arkell (1933) and Hancock (1977) found in defining Oppel’s zones.

ACCEPTED MANUSCRIPT the regional contrasts in lithofacies. He uses observational terms about stratigraphic order: above, below; higher, lower; not younger, older (Teichert, 1958)4. Much attention is paid to

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the contrast between the lithostratigraphy and his novel biostratigraphy but there is minimal

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interpretation. Chapters are headed “Die Schichten des (name of index ammonite)”. Zones in

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his columns are labeled as beds e.g., Angulatusbett, Raricostatusbett. The title to his summary compilation of the lower Jurassic zones (p.74) simply refers to their succession

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(Aufeinanderfolge) through northwestern European, not to their ages. Although Oppel

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indicates in his overview (p. 3) that his zones can be interpreted in a time dimension, the body of his work is strictly empirical biostratigraphy, as in Fig. 1B. He eschews d’Orbigny’s

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3. Hedberg’s Oppel-Zone

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speculative discussions.

Hedberg (1976) defined biostratigraphic units as bodies of rock unified by their fossil content. Oppel-Zone was placed in the biostratigraphic classification as a subcategory of range zone; this was defined (p. 53) as "...the body of strata representing the total range of occurrences of any selected element of the total assemblage of fossil forms in a stratigraphic sequence". These definitions parallel those used in the lithostratigraphic classification. Both concern bodies of rock that are unified by a set of observed features. Temporal relationships are not mentioned. However, Oppel-Zone was defined (p. 58) as "...a zone characterized by an association or aggregation of selected taxons of restricted and largely concurrent range, chosen as indicative of approximate contemporaneity". This suggests that the unit is part of 4

Schindewolf (1957, p. 397) dismisses this interpretation as “…a somewhat inexact wording, not conclusive for the one or the other interpretation.”

ACCEPTED MANUSCRIPT the chronostratigraphic classification which concerns bodies of rock “..formed during a specific interval of geologic time … and bounded by isochronous surfaces” (Hedberg 1976,

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p. 67). Berry (2008) believed that Hedberg's definition reflected the influence of R.M

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Kleinpell; their association is detailed by Walsh (2005).

The equivocal status of Oppel-Zone may have contributed to its omission in the revised

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International Stratigraphic Code (Salvador, 1994). Significantly, Hedberg's definition does

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not address how taxa indicative of approximate contemporaneity are to be identified in practice. MacLeod's account (2005, p.6) reveals the difficulty: “The rationale underlying this

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concept is that chronostratigraphical correlations are desirable and that, through long years of

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patient study, biostratigraphers can become sufficiently familiar with subtle morphological signals within their fossil faunas and floras that a higher level of time-based correlation than

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that afforded by any other zone concept can be achieved.” This "...slippery area where fossils meet time" (McGowran, 1986, p. 34) arises because recognition of events/units that occur in unique stratigraphic order is insufficient evidence of their isochroneity.

Compounding the problem of identifying faunal events that serve as time-proxies, is the question of which events identify the zone. Hedberg (1976, p. 58) listed supplementary attributes of his Oppel-Zone. Those concerning boundaries are difficult to reconcile.

1. “The lower part of the zone is commonly marked largely by first appearance and its upper part by last appearance of certain taxons.”

ACCEPTED MANUSCRIPT 2. “The boundaries of an Oppel-Zone are the limits of distribution of the ensemble of fossil

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forms considered distinctive of the zone.”

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3. “Because of the complexity and indefiniteness of Oppel-zone criteria, boundary positions

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are to a considerable extent subject to the worker’s judgment.”

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These ambiguities are not addressed in Hedberg (1976, Fig. 8) which does not clarify the

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stratigraphic implications for zone identification using subsets of taxa. For Hedberg, the Oppel-Zone concept was that of a loosely defined concurrent range zone. This was defined

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(p. 55) as “ … the concurrent or coincident parts of the range-zones of two or more specified

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taxons selected from among the total forms contained in a sequence of strata”. In contrast, for Oppel-Zones (p. 58) “..not all of the taxons considered diagnostic need be present…”.

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Logically, the distinction that Hedberg attempts is between a conjunctive definition (concurrent range zone) and a disjunctive definition (Oppel-Zone). Kingsbury and McKeown-Green (2009) argue that disjunction may lead to dysfunction. The potential dysfunction here is that each of the disjunctive criteria may occur at different horizons in the rock body. Section 1 (Fig. 3) includes all taxa cited in the definition of Zone A; if disjunctive criteria are allowed, then the extents of the zone in Sections 1-4 differ.

4. Oppel and Hedberg compared

Although Oppel (1856-8, p. 3) makes a putative interpretation of his results, the underlying research is strictly observational. His zones are based on hypotheses generated by

ACCEPTED MANUSCRIPT enumerative induction about the order of faunal events. They are disprovable by observation. Events should maintain their stratigraphic order in all sections (conform with the ideal

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profile). If Ammonites planorbis is found above Ammonites angulatus, the use of one or

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other of these taxa as zonal criteria is to be rejected. Hedberg's methodology for Oppel zones

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departs from this standard of evidence because it conflates ordination of stratigraphic events with resolution of the time of their origin. Observational data on the position of faunal events

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can detect when they depart from hypothesized order, but they cannot detect that an event is

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approximately isochronous wherever it occurs (Huxley's argument). For this, signatures

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related to temporal scales are required.

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Both authors employ disjunctive concepts. Multiple taxa are cited as criteria but no one taxon is essential to identify a zone. This is explicit in Hedberg (1976). Oppel does not address the

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question directly but disjunction is suggested by his usage e.g., the Ammonites planorbis Zone at some localities is identified by the presence of that taxon and at others by the presence of Ammonites Johnstoni.

Hedberg’s Oppel-Zone does not have a type locality. This relates to a caveat (Hedberg 1976, p. 70) about the use of biostratigraphic zones as bases for chronozones. The boundaries, and therefore the time span, of biostratigraphic zones, he argued, varies as knowledge of their taxonomic criteria and ranges changes. He counseled against their use as subdivisions of stages. Implicitly, this recognizes that resolution of stratigraphically ordered faunal events is necessarily based on data from many sections, and that the stratotype data have no special status (Scott, 1960). Hedberg’s Oppel-Zone is an ambiguous concept. When defining Oppel-

ACCEPTED MANUSCRIPT Zone he requires that criteria should indicate “approximate contemporaneity” but when discussing chronostratigraphy cautions about their use in that role. Oppel did not propose

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type sections for his zones. Illustrated sections in Swabia served as examples; later workers

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have not recognized them as types, e.g., the type section of the Planorbis Zone is in southwest

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England (Page, 2003).

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Oppel defined his zones by content. For each zone most of the cited important (am

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wichtigsten) taxa are restricted but even in the exemplar section boundaries are not necessarily defined by faunal events. While Hedberg uses faunal events to delimit his zones,

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5. Discussion

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he fails to clearly state which should be used.

5.1 Biostratigraphic classifications

Whether interpreted empirically or putatively, Oppel’s zones are rock units that are arranged in a particular stratigraphic order, his ideal profile. Biostratigraphy, defined by Hedberg (1976) as the classification of strata using fossils, is a broader concept. Particularly, it admits, in addition to ordered units, a complementary class of fossil-defined units whose stratigraphic position is unconstrained; that is, they may occur in any above:below relation to similarly defined units and may recur (Fig. 4). In ordered classifications the delimiting fossils are selected such that a rock unit has a unique stratigraphic position relative to adjacent similarly defined units. Unconstrained biostratigraphic classifications are similar to lithostratigraphic classifications but use only the fossil content. Such biofacies units map the biotic response to

ACCEPTED MANUSCRIPT the depositional environment. They were termed spatial biostratigraphic units by Ludvigsen et al. (1986). In contrast, if fossil assemblages are viewed as a combination of environmental

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and evolutionary signals, in Oppelian zones the order constraint tends to block environmental

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components and pass the evolutionary.

Since d’Orbigny introduced ‘zone’ it has been predominantly used in ordered classifications,

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like Oppel’s. This usage is strongly reflected in stratigraphic codes. They do not distinguish

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between ordered and unconstrained units. The Geological Society of London’s guide (Whittaker et al., 1991) included only ordered units; their biozone is a putative interpretation

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of zones like Oppel’s. The focus of North American Commission on Stratigraphic

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Nomenclature (2005) and Thierry and Galeotti (2008) is similar. Neglect of the distinction has led to quite equivocal discussion of assemblage zone. Hedberg (1976, Fig. 4) shows a

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stack of zones, which suggests that assemblage zones belong to the ordered class. But he noted that they may recur, which places them in the unconstrained class. Clearly the preoccupation with ordered classifications relates to use of their units as temporal proxies. This might justify the omission of unconstrained classifications in stratigraphic codes, but inclusion of the ordered:unconstrained dichotomy as a meta-classifier of biostratigraphic categories should clarify the various applications of assemblages in biostratigraphy. Presently, its use as an unconstrained unit in biofacies studies (e.g., Fillon, 2009) is conceptually quite different from the Paratethys assemblage zone biostratigraphy of Steininger (1977). In wider perspective, codes should anticipate that, as the research program on ordered biostratigraphies for deciphering earth history is gradually supplanted by chronometry (Gradstein et al., 2012), biostratigraphy will move towards a core role of

ACCEPTED MANUSCRIPT contributing to the environmental interpretation of the sedimentary record.

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5.2 The quest for time

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The pre-occupation of stratigraphic codes with the putative interpretation suggests that it is

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the central subject of biostratigraphy and defines its scope. It is appropriate therefore to

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revisit Huxley's claim that there was no evidence that similarity in stratigraphic position indicates similarity in time of deposition. Several approaches are reviewed. The focus is on

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methods by which the isochroneity of bioevents (Fig. 1C) might be inferred from

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5.2.1 Catastrophism

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biostratigraphical data.

In the early 19th century the principal proponent that fossils “delineate time horizons” (Şengör and Sakmç, 2001) was Georges Cuvier whose studies in comparative morphology led him to hypothesize that strata preserved a sequence of distinctive biota, abruptly separated by environmental revolutions that caused extinctions (Rudwick, 1997). That d’Orbigny adopted Cuvier’s theory accounts for his focus on ‘discordances’ between his stages. Oppel’s neglect of this question, and minimal reference to d’Orbigny’s research, is consistent with that of an empiricist skeptical of Cuvier’s theory (Rioult, 1969). Nevertheless, the theory was widely accepted by paleontologists early in the 19th century (Newell, 1984) and has left an enduring imprint on biostratigraphic classifications, particularly in the Mesozoic. Oppel (1856-8) may have been skeptical of the theory but grouped his zones into d'Orbigny's stages. But Cuvier's

ACCEPTED MANUSCRIPT theory lacked mechanisms and eventually catastrophism fell into disrepute at the hands of

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Lyell and the uniformitarians.

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Cuvier and d'Orbigny would have noted with approval that, in a volume marking renewed

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attention to catastrophic events in earth history (Berggren and Van Couvering, 1984), paleobiologists focused on mass extinctions of regional or global extent. Insofar as major

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environmental catastrophes are of very short duration and generate very rapidly dispersing

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signals whose effects are preserved as extinction bioevents, they are a potential source of temporal markers. As yet, the jury is out on a major exemplar: there are basic disputes about

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biotic and stratigraphic data related to the Chicxulub impact at the Cretaceous – Paleocene

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boundary (Schulte et al., 2010; Archibald et al., 2010). Much less attention has been given to the use of regional bioevents related to rapid environment change as temporal markers.

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Cannariato and Kennett (1999) mapped very rapid changes in the composition of Holocene benthic foraminiferal assemblages on the Santa Lucia Bank on the central Californian margin, and suggested that they were synchronous with similar events in Santa Barbara Basin (Cannariato, Kennett and Behl, 1999). Repeated replacements of oxic by dysoxic assemblages were abrupt, possibly at a centennial scale. The magnitude of the turnovers in assemblage composition and their rapidity justify their interpretation as catastrophic events for the benthic foraminiferal biota. Note that, although faunal signatures suggested that the events may have occurred rapidly, turnover times were established using chronometric tools.

5.2.2 Biosynchroneity as a covering principle

ACCEPTED MANUSCRIPT To step from homotaxis to time Callomon (2001, p. 240) invoked the principle of biosynchroneity: “…beds with similar fossils are of the same age..”. Qualifications followed.

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‘same’ means “more or less the same” which implies that “… time correlations by means of

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fossils are approximations.” Some species are better for time correlations than others and are

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selected as guide fossils. The selection procedure is not explained. Callomon attributed the principle to William Smith but Laudan (1976) had refuted this claim in her study on Smith’s

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use of fossils in his stratigraphy5. To Rudwick (2005) Smith was a geognosist who used

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fossils to identify particular strata; Torrens (2001) thought that Smith was a creationist whose views on geological time were confused. Clearly, the principle cannot be attributed to Smith.

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More importantly, as stated by Callomon, faunal similarity might with more reason imply

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principle is ambiguous.

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similarity in biofacies, rather than temporal equivalence. Callomon’s statement of the

A better defence of biosynchroneity was offered by Teichert (1958, p. 102) who related it to the unidirectional and irreversible character of organic evolution: “… the over-all effect of evolutionary processes … was felt all over the world at the same time and at the same rate. On this uniformity of the over-all result depends paleontologic correlation….”. In Teichert’s defence, he recognized that biostratigraphy was highly empirical; guide fossils were considered to be almost infallible but the role of homotaxis in filtering good from bad was recognized. While the unidirectional pattern of evolution noted by Teichert explains why many bioevents occur in a unique stratigraphic order, theory and observations indicate that

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Laudan’s (1976) analysis does not support Berry’s (1968, p. 57) claims that Smith’s map was based “..on a thorough knowledge of the succession of faunas” and that his greatest contribution “…was the demonstration of the validity of the principle of faunal succession”.

ACCEPTED MANUSCRIPT origins and extinctions of taxa, the principal events used in biostratigraphy, do not disperse in the manner he claims. Allopatric speciation (Mayr, 1963) is pervasive (Turelli et al., 2001)

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and commonly involves small geographic isolates. Observed or modeled patterns indicate

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that extinction is ecologically controlled (Griffen and Drake, 2008). Viewed as signals, both

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types of event are commonly locally generated and have significant and variable transmission times. This underlies Huxley’s principal criticism of the putative interpretation of Oppelian

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zones. The contrast with the transmission of polarity signals generated by geomagnetism is

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immediate. Use of a principle of biosynchroneity to justify inferences that bioevents are

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isochronous events does not withstand analysis.

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5.2.3 Biostratigraphic events as unobservable entities in past time

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Huxley was an empiricist who, following Hume, wanted evidence based on observation, as in Fig. 1B. Realist philosophy, which views science as a process of discovery of real entities whether observable or not, provides a useful perspective on the status of the temporal interpretation of Oppelian biostratigraphy. McMullin (1984) seeks to explain the advances geologists have made in interpreting strata (observable) as bearing records of life in deep time (unobservable). In his example the Devonian is construed as a theoretical entity for which theory has provided temporal boundaries. Devonian taxa too are viewed as theoretical entities. Our knowledge of these unobservable entities is gained through retroduction (McMullin’s term for abduction, section 5.2.4): models are proposed to account for the entities being studied. McMullin does not elaborate on the selection of models but since Lyell, the preferred model used to understand life in the unobservable past is based on

ACCEPTED MANUSCRIPT observables - knowledge of relationships within the modern biota. While modeling of unobservable entities is a principal tool in stratigraphic research (Miall and Miall, 2001;

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Miall, 2004), the ability to reconstruct the dispersal in time of a fossil taxon given only data

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on its observed stratigraphy is problematic.

The view that biostratigraphic entities are unobservable draws attention to their dual

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interpretation. McMullin supposes that (unspecified) theory permits temporal boundaries to

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be defined for biostratigraphic units like the Devonian, so locating them in past time and beyond observation. He does not recognize that research on Oppelian units is conducted

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using modern observations and stratigraphic metrics. The Psiloceras planorbis Zone includes

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beds 13-42 at St. Audrie’s Bay (Warrington et al., 2008). In this context the zone is not a theoretical entity; there is no historical reference and the methodology is that underlying Fig.

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1B. The concept of the Psiloceras planorbis Zone at St. Audrie’s Bay differs from that of the Lias Group primarily by use of homotaxial bioevents for its recognition. This is not to deny the reality in past time of the zone. But it again demonstrates that biostratigraphic units like Oppel’s are defined in stratigraphic space. Although dual concepts are implied in the term ‘time stratigraphy’ their distinction was blurred at its introduction by Schenck and Muller (1941, p. 1420): “Since the fossils usually serve as our nearest approach to time-markers, it follows that the units of this standard column are stratal units defined by time”. This overlooks how the standard column (Oppel’s ideal profile) is constructed from bioevents.

5.2.4 Realist solutions to Huxley’s demand for evidence

ACCEPTED MANUSCRIPT If Oppelian biostratigraphies are created from events observed in stratigraphic sequences, and that there are no principles that underwrite their interpretation as isochronous events, what

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inferences might/can be made from modern observations about their properties as theoretical

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entities in past time? Figure 1 shows some primary data for an Oppelian biostratigraphy, e.g.,

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bioevent b2 is located above b1 and below b3 in both sections. It may be known also that this relationship applies in all sections in which the events occur. These data show only that

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the transmission times of these events was less than the elapsed times between the events.

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They do not address the hypothesis that b2 at sections I and II are isochronous events. But there are other observational data that may be available. They include the intrinsic properties

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of the event in both sections, particularly its signature. If it represents a change in

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morphology, how well is it defined? If it is a first/last record, what is the fossil's abundance signature (Signor and Lipps, 1982)? Is it similar at both sites? What is the state of

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preservation? Information about the dispersal ability of modern analogs of the taxon might be appraised. Also important are data extrinsic to the taxon, e.g., similarity of associated taxa; sedimentary features such as evidence of diastems and bioturbation in the vicinity of the event (Zalasiewicz et al., 2007). Because the hypothesis concerns the rate of dispersal of the event, the palinspastic distance between the sections is significant. This is not a comprehensive list of potentially relevant data but it covers some of those often available. A feature in common is that none has properties that are linear functions of time. Singly or conjointly, they are insufficient to determine whether or not b2 is a synchronous event. The apparent underdetermination of the hypothesis by the data is yet another expression of Huxley's criticism of the putative view of Oppelian biostratigraphy.

ACCEPTED MANUSCRIPT Realist philosophers counter that abductive inference identifies the the best explanation. To Harman (1965) the best explanation is the most plausible explanation. To Lipton (2004) it is

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the hypothesis that provides the 'loveliest' explanation (Ladyman, 2005) that which, if true,

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expands our understanding of the data. How might the most plausible (credible or reasonable)

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hypothesis be identified? If bioevent b1 (Fig. 1B) has the same signature at both localities and the sections are in the same structure in similar lithofacies in the same sedimentary basin, a

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biostratigrapher might accept as plausible that the records are isochronous. If the sections

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have the same geospatial relation as before but bioevent b2 has a different signature in section I than at section II, is immediately below b3 (cf. its separation at section II), and there

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is evidence of a diastem at section I, a biostratigrapher might accept as plausible that the

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relation is diachronous. Such analyses are seldom explicitly reported. They involve multiple comparisons of evidence and become difficult when events are traced between basins,

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provinces, and around the globe. Isochrony is neither measured nor tested but comparisons of observations may indicate its plausibility.

5.2.5 Biogeography and isochroneity

The kernel issue raised by the quest for time from homotaxial bioevents is biogeographical: can their dispersal times (originations, extinctions) be overlooked. Huxley (1862) thought not but it is assumed by the principle of biosynchroneity and unsupported by evolutionary theory. In the quest for time biostratigraphers gave little consideration to the significance of biogeography. In their defence, this reflects the absence of suitable data until chronometric tools enabled evidence-based research on the isochroneity of bioevents and overcame the

ACCEPTED MANUSCRIPT underdetermination problem imposed by use of strictly biostratigraphic observations. An early result was promising. Berggren and Van Couvering (1978, p.51) wrote of "..essentially

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'instantaneous' geochronological linkages" and suggested that some microfossil taxa initially

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migrated throughout their adaptive range in <10 kyr. Consistent with this interpretation

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Sexton and Norris (2008) argued against the significance of oceanic and tectonic barriers for the dispersal of plankton and presented fossil data that complemented genetic evidence of

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high rates of gene flow in planktonic foraminifera across the oceans. But these results are

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contrary to those of Dowsett (1986), Spenser-Cervato et al. (1994) and Darling et al. (2007) who showed the effect of vicariant isolation on the distribution of fossil and living plankton.

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Whether or not vicariant isolation is an appropriate null model for historical biogeography

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(Ronquist, 1997) may be equivocal but at last is potentially testable.

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Present practice with chronometric tools is date bioevents at a few locations for use as proxies for points on a time scale. Little attention is given to the biogeography of the taxa. This procedure is widely applied in Cenozoic microfossil biostratigraphy (e.g., Berggren et al., 1995; Wade et al., 2011; Backman et al., 2012). It does not focus on testing the isochroneity of bioevents and overlooks problems inherent in such research. Many bioevents are in morphotaxa defined by typological criteria (Scott, 2011). This tends to conceal genetic diversity and may lead to comparisons of bioevents that are only nominally identical, taxonomically. Other uncertainties include those associated with event definition and with the associated age data. Parnell et al. (2008) addressed these statistical issues in connection with radiocarbon dating of pollen data and raised the question as to whether an event is a single point in time or a (stratigraphic) depth/time range. Their study points to the inadequacy of

ACCEPTED MANUSCRIPT data like those assembled by Wade et al. (2011) for analysis of isochroneity of events. Planktonic foraminiferal biostratigraphers typically report taxon ranges as presence:absence

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data. Minimal information on taxon signatures is provided by such data which are very likely

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to under-estimate taxon ranges (Strauss and Sadler, 1989). Moreover, the great majority of

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bioevents are not point events in time, as might be generated by a bolide impact. Rather they reflect population shifts over an interval of time and their detailed signature is needed for

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definition of a common point for analysis of their spatial synchroneity. For long, tools for

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testing isochroneity of bioevents were unavailable. Now the issue has shifted to the suitability

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of many of the bioevent databases for this purpose.

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5.2.6 Communicating the putative view

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Past time in The Geological Time Scale 2012 (Gradstein et al., 2012) is shown on a linear scale which is based on isotopic data, geomagnetism, and orbital tuning. These methods have theoretical foundations that support their application to the construction of a scale of past time. Biostratigraphy lacks such foundations. A principle of biosynchroneity lacks credibility, evolutionary theory does not support inferences that homotaxial bioevents are isochronous, biogeographies are usually unresolved, and abductive reasoning without chronometric data leads only to plausible inferences about temporal relationships. Progress in testing for isochroneity with chronometric tools is impeded by lack of data about bioevent signatures. Since the birth of biostratigraphy the logical gap between bioevent order and bioevent synchroneity has been masked by nomenclature. Commonly, an Oppelian biostratigraphy is called a 'relative time scale'. Following Steno, a table of ordered stratigraphic bioevents like

ACCEPTED MANUSCRIPT Oppel's, or units based thereon, is temporally ordered. But 'scale' in scientific usage refers to measurement and usually to a set of uniformly spaced markers in a measurement system

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(Middle English derivation from Latin scala (ladder). Even if 'scale' is loosely applied to

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bioevents whose spacing in time is unknown and may be unequal, its use is inappropriate

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because the observational data do not warrant that a marker bioevent event in one section represents the same point in time in another section. Similarly, 'same age' and 'relative age'

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refer to positions in an ordered set of bioevents, not to a time scale. These quite transparent

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criticisms may be dismissed as pedantry. Nevertheless, the usages obfuscate the scope of Oppelian biostratigraphy. Ager (1984, p. 92) wrote: “...there are rocks, which still remain,

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and there is time, which has passed and can never be recovered. All the rest is semantic

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confusion.” That there is confusion is suggested by some usages in Table 1. Of importance is that, apart from using nomenclature that may confuse or mislead the wider stratigraphic

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community, it seems that we biostratigraphers are ourselves confused about the basis of Oppelian biostratigraphy.

However, the putative interpretation of bioevents (Fig. 1C) has served as a paradigm for biostratigraphy that has been widely accepted since the early 19th century. In the search for past time it has been inspirational, as witnessed by the epithet that biostratigraphers are "...The High Priests of Time..." (Berggren et al. (1995, p. vi). In the light of Ager's criticism, why does it retain this status? One answer is that it is based in empirical science (Fig. 1B), with Oppel (1856-8) as the exemplar. The power of his method lies in the use of a filter that catches bioevents that do not maintain order-invariance. These can be reasonably inferred to be diachronous in past time. The fallacy of the putative view lies in its acceptance that those passing the filter are isochronous when the data support only statements that they are not

ACCEPTED MANUSCRIPT diachronous within the resolution of the homotaxial set. This is the import of Ager's

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criticism, as it was with Huxley’s.

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6. Conclusions

Oppel’s zones are rock units whose defining fossils occur in a particular stratigraphic order.

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His genius was to show that an ordered biostratigraphy can complement lithostratigraphy by

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facilitating inter-basinal syntheses of sedimentary history.

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Oppel’s method is strictly empirical as his ideal profile (order of zones) can be checked by

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observation. However, the incentive to resolve the sedimentary record historically has led biostratigraphers to interpret ordered classifications as relative time scales. This putative

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interpretation has stimulated great refinement of ordered zonations but asserts temporal relationships that cannot be tested by the order of fossil events alone. Contrary to our knowledge of modern biogeographies of taxa, it assumes that origination and extinction events are synchronous throughout their distribution. Basing this inference on a principle of biosynchroneity is unreasonable. Evolutionary theory accounts for the order of many bioevents but does not support inferences that they are spatially isochronous.

Oppelian biostratigraphies are based primarily on induction - selection of bioevents that maintain invariant stratigraphic order. However, from additional stratigraphic observations a biostratigrapher may infer that it is plausible that certain bioevents are isochronous. But such arguments do not test isochroneity.

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As a prototype for ordered biostratigraphy Oppel did not clearly resolve boundaries and

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probably allowed disjunctive definitions. These are also demerits of Hedberg’s Oppel-Zone

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and do not support its re-introduction into stratigraphic codes. Nevertheless, with refinement,

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Oppel’s method has since formed the basis of zonal biostratigraphy.

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The focus of biostratigraphy on ordered classification is strongly reflected in its codes which

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do not distinguish this from biofacies classification whose units need not be stratigraphically ordered. Particularly, assemblage zone is a category that is employed in both types of

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Acknowledgements

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classification. To avoid ambiguity biostratigraphic codes should recognize this basic duality.

I am grateful to Dick Fillon for use of material shown in Fig. 4, to Kristin Garbett for assistance with literature, and to the referees for good advice.

References

Ager, D.V., 1984. The stratigraphic code and what it implies. In: W.A. Berggren, J.A. Van Couvering (Editors), Catastrophes and Earth History. Princeton University Press,

ACCEPTED MANUSCRIPT Princeton, NJ, pp. 91-100.

PT

Alroy, J. 1994. Appearance event ordination: a new biochronologic method. Paleobiology 20:

SC

RI

191-207.

NU

Archibald, J.D., et al., 2010. Cretaceous extinctions: multiple causes. Science 328: 973.

MA

Arkell, W.J., 1933. The Jurassic System in Great Britain: Clarendon Press, Oxford, 681 pp.

D

Backman, J., Raffi, I., Rio, D., Fornaciari, E., Pälike, H., 2012. Biozonation and

TE

biochronology of Miocene through Pleistocene calcareous nannofossils from low and middle

AC CE P

latitudes. Newsletters on Stratigraphy 45: 221-244.

Berggren, W.A., Van Couvering, J.A., 1974. The late Neogene: biostratigraphy, geochronology and paleoclimatology of the last 15 million years in marine and continental sequences. Palaeogeography, Palaeoclimatology, Palaeoecology 16: 1-216.

Berggren, W.A., Van Couvering, J.A., 1978. Biochronology. In: G.V. Cohee, M.F. Glaessner, H.D. Hedberg (Editors), Contributions to the Geological Time Scale. American Association of Petroleum Geologists, Tulsa, Studies in Geology 6. pp. 39-55.

Berggren, W.A., Van Couvering, J.A., (Editors), 1984. Catastrophes and Earth History. Princeton University Press, Princeton, NJ, 464 pp.

ACCEPTED MANUSCRIPT

Berggren, W.A..Kent, D.V., Aubry, M-P., Hardenbol, J., 1995. Introduction. In: W.A.

PT

Berggren, D.V. Kent, M-P. Aubry, J. Hardenbol (Editors), Geochronology, Time Scales and

RI

Global Stratigraphic Correlation. Tulsa, Society for Sedimentary Geology, Special

SC

Publication 54. pp. v-vi.

NU

Berggren, W.A., Kent, D.V., Swisher, C.C.III, Aubry, M-P., 1995. A revised Cenozoic

MA

geochronology and chronostratigraphy. In: W.A. Berggren, D.V. Kent, M-P. Aubry, J. Hardenbol (Editors), Geochronology, Time Scales and Global Stratigraphic Correlation.

TE

D

Tulsa, Society for Sedimentary Geology, Special Publication 54. pp. 129-212.

Berry, W.B., 1968. Growth of a prehistoric time scale based on organic evolution. W.H.

AC CE P

Freeman, San Francisco, 158 pp.

Berry, W.B., 2008. Robert M. Kleinpell: founder of the Berkeley school of stratigraphic paleontology. Earth Sciences History 27: 100-112.

Blow, W.H., 1959. Age, correlation, and biostratigraphy of the upper Tocuyo (San Lorenzo) and Pozón Formations, Eastern Falcón, Venezuela. Bulletins of American Paleontology 39 (178): 1-251.

Buckman, S.S., 1893. The Bajocian of the Sherbourne district: its relation to subjacent and superjacent strata: Quarterly Journal of the Geological Society of London, 49: 479-522.

ACCEPTED MANUSCRIPT

PT

Buckman, S.S., 1902. The term ‘Hemera’: Geological Magazine 4th series, 9: 55-557.

RI

Callomon, J.H., 1995. Time from fossils: S. S. Buckman and Jurassic high-resolution

SC

geochronology. In: M.J. Le Bas (Editor), Milestones in Geology. Geological Society, London,

NU

Memoir 16, pp. 127-150.

MA

Callomon, J.H., 2001. Fossils as geological clocks. In C.L.E. Lewis, Knell, S.J. (Editors), The

D

Age of the Earth. Geological Society, London, Special Publication 190, pp. 237-252.

TE

Cannariato, K.G., Kennett, J.P., 1999. Climatically related millenial-scale fluctuations in

975-978.

AC CE P

strength of California margin oxygen-minimum zone during the past 60 k.y. Geology 22:

Cannariato, K.G., Kennett, J.P., Behl, R.J., 1999. Biotic response to late Quaternary rapid climate switches in Santa Barbara Basin: ecological and evolutionary implications. Geology 27: 63-66.

Carter, R.M., 2007. Stratigraphy into the 21st century. Stratigraphy 4: 187-193.

Darling, K.F., Kucera, M., Wade, C.M., 2007. Global molecular phylogeography reveals persistent Arctic circumpolar isolation in a marine planktonic protist. Proceedings of the National Academy of Sciences 104: 5002-5007.

ACCEPTED MANUSCRIPT

d’Orbigny, A., 1842. Paleontologie francaise: Terrains jurassiques. [Cephalopodes] Cosson,

RI

PT

Paris. Tome 1. 642 pp.

SC

d’Orbigny, A., 1852. Cours ölémentaire de Paléontologie et de Géologie stratigraphiques.

NU

Masson, Paris. Tome 2, fascicle II. 483 pp.

MA

Dowsett, H.J., 1988. Diachrony of late Neogene microfossils in the southwest Pacific Ocean:

D

application of the graphic correlation method. Paleoceanography 3: 209-222.

TE

Fillon, R.H., 2009. Linked micropaleontology and lithology of Cenozoic deep-water sediments: applications of multiple overlapping foraminiferal lithobiofacies to cuttings-based

AC CE P

analysis of reservoir properties. In T.D. Demchuk, A.C. Gary (Editors), Geologic Problem Solving with Microfossils: a volume in honor of Garry D. Jones. SEPM Special Publication 93, pp. 323-336.

Gradstein, F.M., Ogg, J.G., Schmitz, M.D., Ogg, G.M., 2012. The Geological Time Scale 2012. Oxford, Elsevier. 1176 pp.

Griffen, B.D., Drake, J.M., 2008. A review of extinction in experimental populations. Journal of Animal Ecology 77: 1274-1287.

Hancock, J.M., 1977. The historic development of concepts of biostratigraphic correlation.

ACCEPTED MANUSCRIPT In: E.G. Kauffman, J.E. Hazel (Editors), Concepts and Methods of Biostratigraphy. Dowden,

PT

Hutchinson & Ross, Stroudsburg, PA. pp. 3-22.

RI

Harman, G.H., 1965. The inference to the best explanation. The Philosophical Review 74:

SC

88-95.

MA

NU

Hedberg, H.D., 1976. International Stratigraphic Guide. Wiley, New York, 200 pp.

Huxley, T.H., 1862. The anniversary address. Quarterly Journal of the Geological Society

TE

D

18: xl-liv.

Jenkins, D.G., 1960. Planktonic foraminifera from the Lakes Entrance oil shaft, Victoria,

AC CE P

Australia. Micropaleontology 6: 345-371.

Kingsbury, J., Mckeown-Green, J., 2009. Definitions: does disjunction mean dysfunction? Journal of Philosophy 106: 568-585.

Kleinpell, R.M., 1979. Criteria in Correlation: Relevant Principles of Science. Pacific Section, American Association of Petroleum Science, Bakersfield, CA. 44 pp.

Ladyman, J. A. C., 2005. Wouldn't it be lovely: explanation and scientific realism. Metascience, 14: 331-338.

ACCEPTED MANUSCRIPT Laudan, R., 1976. William Smith. stratigraphy without palaeontology. Centaurus 20: 210-

PT

226.

SC

RI

Lipton, P., 2004. Inference to the Best Explanation: Routledge, London. 232 pp.

Lindsay, E., 2003. Chronostratigraphy, biochronology, datum events, mammal ages, stages of

NU

evolution, and appearance ordination events. In: L. J. Flynn et al. (Editors), Vertebrate fossils

MA

and their context: contributions in honor of Richard H. Tedford. Bulletin of the American

D

Museum of Natural History 279, pp. 212-230.

TE

Ludvigsen, R., Westrop, S.R., Pratt, B.R., Tuffnell, P.A., Young, G.A., 1986. Dual

AC CE P

biostratigraphy: zones and biofacies. Geoscience Canada 13: 139-154.

MacLeod, N., 2005. Biozones. In: R.C. Selley et al. (Editors), Encyclopaedia of Geology. Academic Press, London, pp. 294-306.

Mayr, E., 1963. Animal Species in Evolution. Belknap Press of the Harvard University Press, Cambridge, MA. 797 pp.

Marr, J.E., 1887. On homotaxis. Proceedings of the Cambridge Philosophical Society 6: 7483.

Marr, J.E., 1898. The Principles of Stratigraphical Geology. University Press, Cambridge.

ACCEPTED MANUSCRIPT 304 pp.

PT

McGowran, B., 1986. Beyond classical biostratigraphy. Petroleum Exploration Society of

SC

RI

Australia Journal 9: 28-41.

NU

McGowran, B., 2005. Biostratigraphy. Cambridge University Press, Cambridge. 459 pp.

MA

McMullin, E., 1984. A case for scientific realism. In: J. Leplin (Editor), Scientific Realism.

D

University of California Press, Berkeley, CA. pp. 8-40.

TE

Miall, A.D., 2004. Empiricism and model building in stratigraphy: the historical roots of

AC CE P

present-day practices. Stratigraphy 1: 3-25.

Miall, A. D., Miall, C.E., 2001. Sequence stratigraphy as a scientific enterprise: the evolution and persistence of conflicting paradigms. Earth-Science Reviews 54: 321-348.

Monty, C.L.V., 1968. d’Orbigny’s concepts of stage and zone. Journal of Paleontology 42: 689-701.

Newell, N.D., 1984. Mass extinction: unique or recurrent causes? In: W.A. Berggren, J.A. Van Couvering (Editors), Catastrophes and Earth History. Princeton University Press, Princeton, pp.115-127.

ACCEPTED MANUSCRIPT North American Commission on Stratigraphic Nomenclature, 2005. North American

PT

Stratigraphic Code. American Association of Petroleum Geologists Bulletin 89: 1547-1591.

RI

Oppel, A., 1856-8. Die Juraformation Englands, Frankreichs und des südwestlichen

SC

Deutschlands: Ebner & Seubert, Stuttgart, 857 pp.

NU

Page, K.N., 2003. The Lower Jurassic of Europe: its subdivision and correlation. Geological

MA

Survey of Denmark and Greenland Bulletin 1, 25-59.

TE

EOS Transactions 77, 379.

D

Paillard, D., Labeyrie, L., Yiou, P., 1996. Macintosh program performs time-series analysis.

AC CE P

Parnell, A.C., Haslett, J., Allen, J.R.M., Buck, C.E., Huntley, B., 2008. A flexible approach to assessing synchroneity of past events using Bayesian reconstructions of sedimentation history. Quaternary Science Reviews 27: 1872-1885.

Rioult, M., 1969. Alcide d’Orbigny and the stages of the Jurassic. The Mercian Geologist 3, 1-30.

Ronquist, F., 1997. Dispersal-vicariance analysis: a new approach to the quantification of historical biogeography. Systematic Biology 46: 195-203.

ACCEPTED MANUSCRIPT Rudwick, M.J.S., 1997. Georges Cuvier, Fossil Bones and Geological Catastrophes.

PT

University of Chicago Press, Chicago. 318 pp.

RI

Rudwick, M.J.S., 2005. Bursting the limits of time: the reconstruction of geohistory in the

SC

age of revolution. University of Chicago Press, Chicago. 732 pp.

NU

Saito, T., 1984. Planktonic foraminiferal datum planes for biostratigraphic correlation of

MA

Pacific Neogene sequences -1982 status report. In: N. Ikebe, R. Tsuchi (Editors), Pacific

D

Neogene Datum Planes. University of Tokyo Press, Tokyo, pp. 3-10.

TE

Salvador, A., 1994. International Stratigraphic Guide, Second Edition. Geological Society of

AC CE P

America, Boulder, Co., 214 pp.

Schenck, H.G., Muller, S.W., 1941. Stratigraphic terminology. Bulletin of the Geological Society of America 52: 1419-1426.

Schindewolf, O.H., 1957. Comments on some stratigraphic terms. American Journal of Science 255: 394-399.

Schulte, P., et al., 2010. The Chicxulub asteroid impact and mass extinction at the Cretaceous – Paleogene boundary. Science 327: 1214-1218.

Scott, G.H., 1960. The type locality concept in time-stratigraphy. New Zealand Journal of

ACCEPTED MANUSCRIPT Geology and Geophysics 3: 580-584.

PT

Scott, G.H., 2011. Holotypes in the taxonomy of planktonic foraminiferal morphospecies.

SC

RI

Marine Micropaleontology 78: 96-100.

Şengör, A.M.C., Sakmç, M., 2001. Structural rocks: stratigraphic implications. In: U. Briegel,

MA

NU

W. Xiao (Editors), Paradoxes in Geology. Elsevier Science, Amsterdam, pp. 131-227.

Sexton, P.F., Norris, R.D., 2008. Dispersal and biogeography of marine plankton: long-

TE

D

distance dispersal of the foraminifer Truncorotalia truncatulinoides. Geology 36: 899-902.

Signor, P.W., Lipps, J.H., 1982. Sampling bias, gradual extinction patterns and catastrophes

AC CE P

in the fossil record. In L.T. Silver, P.H. Schultz (Editors), Geological Implications of Large Asteroids and Comets on the Earth. Geological Society of America Special Publication 190, pp. 291-296.

Spencer-Cervato, C., Thierstein, H.R., Lazarus, D.B., Beckmann, J.-P., 1994. How synchronous are Neogene marine plankton events? Paleoceanography 9: 739-763.

Stamp, L.D., 1925. Some practical aspects of correlation – a criticism. Proceedings of the Geologists Association 36: 11- 27.

Steininger, F.F., 1977. Integrated assemblage-zone biostratigraphy at marine-nonmarine

ACCEPTED MANUSCRIPT boundaries: examples from the Neogene of central Europe. In: E.G. Kauffman, J.E. Hazel (Editors), Concepts and Methods of Biostratigraphy. Dowden, Hutchinson & Ross,

RI

PT

Stroudsburg PA., pp. 235-256.

SC

Strauss, D., Sadler, P.M., 1989. Classical confidence intervals and Bayesian probability

NU

estimates for ends of local taxon ranges. Mathematical Geology 21: 411-427.

MA

Teichert, C., 1958. Some biostratigraphical concepts. Geological Society of America Bulletin

D

69: 99-120.

TE

Thierry, J., Galeotti, S., 2008. Biostratigraphy. In: J. Rey, S. Galeotti, Stratigraphy:

AC CE P

Terminology and Practice. Editions OPHRYS, Paris, pp. 65-90.

Torrens, H.S., 2001. Timeless order: William Smith (1769-1839) and the search for raw materials 1800-1820. In: C.L.E. Lewis, S.J. Knell (Editors), The Age of the Earth: from 4004 BC to AD 2002. Geological Society, London, Special Publications 190. pp. 61-83.

Torrens, H.S., 2002. Some personal thoughts on stratigraphic precision in the twentieth century. Geological Society, London, Special Publications 192, pp. 251-272.

Turelli, M., Barton, N.H., Coyne, J.A., 2001. Theory and speciation. Trends in Ecology and Evolution 16: 330-343.

ACCEPTED MANUSCRIPT Wade, B.S., Pearson, P.N., Berggren, W.A., Pälike, H., 2011. Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic

RI

PT

and astronomical time scale. Earth-Science Reviews 104: 111-142.

SC

Walsh, S.L., 1998. Fossil datum and paleobiological event terms, paleontostratigraphy, chronostratigraphy, and the definition of land mammal “age” boundaries. Journal of

MA

NU

Vertebrate Paleontology 18: 150-179.

Walsh, S.L., 2001. Notes on geochronologic and chronostratigraphic units. Geological

TE

D

Society of America Bulletin 113: 704-713.

Walsh, S.L., 2005. The role of stratotypes in stratigraphy Part 2. The debate between

AC CE P

Kleinpell and Hedberg, and a proposal for the codification of biochronological units. EarthScience Reviews 70: 47-73.

Warrington, G., et al., 2008. The St Audrie’s Bay – Doniford Bay section, Somerset, England: updated proposal for a candidate Global Stratotype Section and Point for the base of the Hettangian Stage, and of the Jurassic System. International Subcommission on Jurassic Stratigraphy Newsletter 35/1. (available from http://jurassic.earth.ox.ac.uk/__data/assets/pdf_file/0013/10615/ISJS_Newsletter_No_35_pt_ 1.pdf)

Whittaker, A., Cope, J.C.W., Cowie, J.W., Gibbons, W., Hailwood, E.A., House, M.R.,

ACCEPTED MANUSCRIPT Jenkins, D.G., Rawson, P.F., Rushton, A.W.A., Smith, D.G., Thomas, A.T., Wimbledon, W.A., 1991. A guide to stratigraphical procedure. Journal of the Geological Society, London

RI

PT

148: 813-824.

SC

Williams, H.S., 1901. The discrimination of time-values in geology. Journal of Geology 9:

NU

570-585.

MA

Woodford, A.O., 1963. Correlation by fossils. In: C.C. Albritton Jr. (Editor), The Fabric of

D

Geology. Addison-Wesley, Reading, Mass., pp.75-111.

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Zalasiewicz, J., Smith, A., Hounslow, M., Williams, M. Gale, A., Powell, J., Waters, C., Barry, T.L., Bown, P.R., Brenchley, P., Cantrill, D., Gibbard, P., Gregory, F.J., Knox, R.,

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Marshall, J., Oates, M., Rawson, P., Stone, P., Trewin, N., 2007. The scale-dependence of strat-time relations: implications for stratigraphic classification. Stratigraphy 4: 139-144.

Figure and Table Captions

Fig. 1. Comparison of lithostratigraphic and ordered biostratigraphic classifications of two hypothetical stratigraphic sections. B shows a classification using bioevents that occur in a fixed order. As with a lithostratigraphic classification (A) it is based directly on observations of rock constituents and is mapped in stratigraphic space. C is a temporal mapping (Analyseries, Paillard et al., 1996) of B using bioevents b1 – b4 as isochronous tie points. Such classifications are commonly regarded as chronostratigraphic.

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Fig. 2. A. Württemberg column for Ammonites planorbis Zone redrawn from Oppel (1856-8,

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p. 25); bed notation a-g added. The Triassic – Jurassic boundary is now located above the

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Oppel (1856-8, p. 63); zone names repositioned.

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Bonebed. B. Upper part of Swabian column for Ammonites raricostatus Zone redrawn from

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Fig. 3. Oppel-Zone definition using disjunctive criteria: “Not all of the taxons considered diagnostic need be present at any one place…”. (Hedberg, 1976, p. 58). In Section 1 the

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stratigraphic distribution of taxa is similar to that in Hedberg (1976, Fig. 8). Only subsets of

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accordingly.

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these taxa are present in Sections 2-4 and the stratigraphic extent of the zone varies

Fig. 4. A meta-classification refers to a classification of classifications.. The meta-criterion applied here is whether or not units in biostratigraphic classifications should be ordered. A shows a lithobiofacies classification based on Fillon (2009, Table 1-2) and http://www.paleodata.com/downloads/LithoBiofaciesBrochure.pdf (4 December 2012); in which the units map repeating sedimentary environments. B is extracted from the table in Oppel (1856-8, p. 71) titled “Compilation of the individual members of the lower Lias after their succession at different localities in Englant, France and southwest Germany”. This classification is order-invariant.

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Figure 1

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ACCEPTED MANUSCRIPT Table 1 Term biochron

Usage/Definition “the time equivalent of a fauna or flora”

ideal profile (Oppel)

Teichert, 1958 p. 103 Berggren and Van Couvering, 1974 p. 6 Berggren and Van Couvering, 1978 p. 39 Saito, 1984 p. 3

biochronology

“…an abstract scheme of ideal chronologic units characterized by certain index fossils.” “…dating of geological events by biostratigraphic methods…” “when divorced from its lithostratigraphical context … becomes, de facto…a biochron” (defined) “…organization of geological time by the irreversible process of evolution….” “…instantaneous or synchronous time plane …” (objective) “…define a global sequence of … first and last appearance events.” “The span of time between the beginning of one assemblage biochron and the beginning of another assemblage biochron.” (must be used) “…in relation to statements about time equivalence or synchrony…” “…interval of geologic time that can be recognized … by a characterizing assemblage of mammals.” (defined) “by biochronology: associations of species and phyletic events”

biochronology

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datum level or plane biochronology

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biostratigraphical age

Oppel biochron

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Alroy, 1994 p. 191 Walsh, 1998 p. 162

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Author Williams, 1901 p. 583 Schindewolf, 1957 p. 397

correlation

Lindsay, 2003 p. 222

land mammal age

McGowran, 2005 Table 7.4

biostratigraphic units

Walsh, 2005 p. 52

datum plane

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Torrens, 2002 p. 251-2

“… first appearance of a taxon in the stratigraphic record…”.