Stratigraphic Terms Research Articles

The term ‘Anthropocene’ in the context of formal geological classification

Abstract In recent years, ‘Anthropocene’ has been proposed as an informal stratigraphic term to denote the current interval of anthropogenic global environmental change. A case has also been made to formalize it as a series/epoch, based on the recognition of a suitable marker event, such as the start of the Industrial Revolution in northern Europe. For the Anthropocene to merit formal definition, a global signature distinct from that of the Holocene is required that is marked by novel biotic, sedimentary and geochemical change. Although there is clear evidence of anthropogenic effects in geological sequences, it is uncertain whether these trends are sufficiently distinct, consistent and dated for the proposal for a Holocene/Anthropocene boundary to be substantiated. The current view of the Earth-Science community is that it should remain informal. For formal definition a Global Stratigraphic Section and Point (GSSP) is required. Adoption of the term ‘Anthropocene’ will ultimately depend on recognition of a global event horizon. Without this, there is no justification for decoupling the Anthropocene from the Holocene. If the Anthropocene is deemed to have utility, it should be as an informal historical designation rather than a formally defined stratigraphic unit (of whatever status) within the geological timescale.

Precambrian Nomenclature in Kansas

The informal stratigraphic term "Precambrian" is replaced by formal nomenclature--Proterozoic and Archean Eonothems/Eons--and the informal term Hadean. The Phanerozoic Eonothem/Eon, representing all rocks younger than the Proterozoic, is added. The Proterozoic is further divided into Paleoproterozoic, Mesoproterozoic, and Neoproterozoic Erathems/Eras. The name Rice Formation (Scott, 1966) is abandoned, and the use of the informal term "Rice unit" is recommended. The proposed name Rice Series (Berendsen, 1994) is not accepted. These changes are adopted by the Kansas Geological Survey (KGS) and the stratigraphic nomenclature of Zeller (1968) has been revised accordingly.

Pleistocene sequence stratigraphy of the shallow continental shelf, offshore New Jersey: Constraints of Integrated Ocean Drilling Program Leg 313 core holes

We used cores and logs from Integrated Ocean Drilling Program (IODP) Expedition 313 to generate biostratigraphic, lithofacies, biofacies, and geochemical data that constrain the ages and paleoenvironments of Pleistocene sequences. We integrate sequence stratigraphy on cores with new seismic stratigraphic data to interpret the Pleistocene history of the Hudson shelf valley and paleoenvironmental and sea-level changes on the inner to middle continental shelf. Improved age control compared to previous studies is provided by integrated calcareous nannofossil biostratigraphy, Sr isotopic stratigraphy, and amino acid racemization. We recognize four upper Pleistocene–Holocene sequences: sequence uP1 is correlated with Marine Isotope Chrons (MIC; “chron” is the correct stratigraphic term for a time unit, not “stage”) 7 or 5e, sequence uP2 with MIC 5c, sequence uP3 with MIC 5a, and sequence uP4 with the latest Pleistocene to Holocene (MIC 1–2). However, within our age resolution it is possible that sequences uP2 and uP3 correlate with MIC 4–3c and 3a, respectively, as suggested by previous studies. Lower Pleistocene sequences lP1 and lP2 likely correlate with peak interglacials (e.g., MIC 31 and MIC 45 or 47, respectively). Thus, we suggest that preservation of sequences occurs only during peak eustatic events (e.g., MIC 45 or 47, MIC 31, and MIC 5), unless they are preserved in eroded valleys. The architecture of the Pleistocene deposits at Sites M27 and M29 is one of thin remnants of highstand and transgressive systems tracts, with lowstand deposits only preserved in the thalwegs of incised valleys. Incised valleys at the bases of sequences uP3 (IODP Site M27) and uP2 (IODP Site M29) document more southward courses of the paleo–Hudson valley, compared to the more southeastward course of the MIC 1–2 paleo–Hudson valley. The patchy distribution of Pleistocene sequences beneath the New Jersey inner-middle continental shelf is due to low accommodation during an interval of large eustatic changes; this predicts that sequences in such settings will be discontinuous, patchy, and difficult to correlate, consistent with previous studies in Virginia and North Carolina.

Late Quaternary river terraces in the Central Mountain Range of Taiwan: A study of cover sediments across a terrace section along the Tachia River

The existence of fluvial terraces in the high mountains of Taiwan has been known for a long time already, but these terraces have not yet been studied in detail. This paper studies cover sediments across a terrace section in the Central Mountain Range located at the midstream reaches of the Tachia River at an elevation of 1430m asl. Sediments were dated by means of optically stimulated luminescence and radiocarbon dating, yielding robust ages between 54.8±7.0ka and 0.42±0.09cal. ka BP. These dates are in good agreement with ages known for the laterite terraces (LT) in the mountain foreland. Deeply weathered reddish soils, comparable to those in the mountain forelands, are absent. Hence, in stratigraphic terms, the terraces in the high mountains cannot be correlated with those in the mountain foreland. Cover sediments comprise eolian sand and silt and various colluvial layers. Eolian sediments provide paleoenvironmental evidence of a relatively dry phase in early MIS 3 that coincides with the maximum extent of the glaciations in the Hsueh Shan Mountain area. Widespread colluvial sediments indicate a high frequency of mass movements around 38.5ka, a period of time known to correlate with dominantly wet conditions. In the last 1000 years, wildfire appears as a possible trigger of mass movements. The geochronological data indicate a local bedrock strath incision rate of 0.8±0.1mmy−1, a value that appears to be in agreement with the local decadal scale erosion rate.

The Geological Conservation Review (GCR) in Great Britain—Rationale and methods

Geoconservation – protecting, managing and enhancing natural geological features and materials, and geomorphological landforms and processes – is especially important in Great Britain, a place sometimes described as the ‘cradle’ of the science of geology. For such a small area of land, Britain has an unusually diverse geological make-up, with rocks from every geological period present. Many stratigraphical terms used internationally were devised here, and British sites provide key study areas where important new geological theories were developed in the pioneering era of the Earth sciences. Therefore, with such a wealth of geology, and Britain's seminal place in the science itself, it is particularly important to conserve and protect key localities here for future generations. A first step in that process is the auditing of the geology and geomorphology of Britain, by carrying out a scientific evaluation exercise according to standard criteria, and creating an inventory of the most important sites for science. In the mid-1970s, the Nature Conservancy Council (NCC) began an ambitious programme for assessment and documentation of the most important sites for the scientific study of geology and geomorphology in Great Britain, building on previous statutory site conservation activity that had already been started in 1949 by the former Nature Conservancy. As a result, the ‘Geological Conservation Review’ (GCR) was formally launched in 1977. The GCR was a world-first project of its type in the systematic assessment of the whole geological heritage of a country, from first principles. Widespread consultation with geologists and geomorphologists across Great Britain was co-ordinated; their guidance and involvement was a key component of the site selection process. Almost 3000 nationally or internationally important sites had been selected for around 100 site-selection categories for the GCR register by 1990. Almost all the GCR sites are now conserved under British law as Sites of Special Scientific Interest (SSSIs), the GCR information providing the scientific evidence-base that underpins that designation. As part of the site-selection process – which is still active – a considerable archive of information about geological sites was amassed. A major publication exercise detailing all the GCR sites in what was to become the GCR Series of books was devised early on in the GCR programme. Thirty-six volumes of the GCR Series have been seen to completion by NCC and the Joint Nature Conservation Committee, and many GCR site reports have been many made freely available on the World Wide Web. As a new venture, the remaining nine volumes will now be published by Elsevier Science Publishers as Special Issues of the Proceedings of the Geologists’ Association. Each GCR volume includes an overview of the subject and outlines the history of study of the relevant branch of the Earth sciences, but most importantly contains detailed accounts of the features of geological importance in the sites described. A scientific interpretation is provided for each site account, which includes supportive illustrations, tables and photographs and an extensive reference list. The GCR rationale, methods and information resource have been invaluable in almost every aspect of geoconservation carried out in Britain, including World Heritage Site nominations, protection of stratotypes, justifying the scientific conservation value of sites at Public Inquiries, in stimulating geological research and in providing a readily available information resource for local, regional, national and international geoconservation activities.

Autochthonous to parautochthonous bivalve concentrations within transgressive marginal marine strata of the Upper Jurassic of Portugal

Bivalve concentrations are a conspicuous feature of the Upper Jurassic rock succession of the central Lusitanian Basin. In order to illustrate the mode of their formation and their palaeoecological and sequence stratigraphic significance, we describe and interpret in detail 27 assemblages of bivalves based on their taphonomic and ecological features. Bivalve concentrations are particularly widespread in marginally marine, salinity-controlled environments and less common in open shelf settings. Only the Eomiodon and Myophorella concentrations are dominated by a shallow infaunal bivalve; all other concentrations are composed mainly of epi- or endobyssate [Isognomon (Rostroperna), I. (Isognomon), Pteria, Alaperna, Juranomia] and cementing taxa (Praeexogyra, Actinostreon). Most of the concentrations are mono- to paucispecific, except for the highly diverse Alaperna polita–Pteria credneriana concentrations, which occur in nearshore shelf environments. Lack of sorting, a high percentage of articulated shells, and shells preserved in growth position are evidence that, with few exceptions, the concentrations are autochthonous. Main factors leading to their formation are, apart from a gregarious life habit, a high productivity and a reduced rate of sedimentation. Autogenic and allogenic successional stages can be recognized on the basis of their spatial separation. The time involved in the formation of the concentrations is generally in the order of 102–103 years. Due to the lack of compositional changes within concentrations, time-averaging played no or only a minor role, except in the Alaperna polita–Pteria credneriana concentrations. In sequence stratigraphic terms, most of the concentrations are the product of the maximum flooding zone, but in some cases they constitute the transgressive systems tract. Invariably, they are useful tools for defining depositional sequences. Several of the concentrations described here are not restricted to the Lusitanian Basin but also occur elsewhere in the epicontinental seas bordering the northern margin of the Neotethys.

Microfacies of the Triassic limestones in the Izvorul Malului klippe (Rarău Syncline, Transylvanian Nappes, Eastern Carpathians, Romania)

The Transylvanian Nappes belongs to the Central – East – Carpathian Nappes System (the Dacides Medianes) which forms. The Transylvanian Nappes have a superior position in the Carpahian tectonic system that favored their fragmentation in the obduction process and slow gravitational decollement. This process makes difficult to establish the exclusively Mesozoic Transylvanian sedimentary series, especially because the majority of the litostratigraphic members occur only as isolated klippe in the Hauterivian-Aptian wildflysh filling (the superior formation belonging to the Bucovinian Nappe) of the Rarau Syncline. The allochtonous sedimentary succesion of the Transylvanian Nappes is almost exclusively represented by pelagic carbonate deposits. The amazing fossil diversity offered mainly by the klippes of the Rarau Syncline facilitated the reconstruction of the Triassic lithological column which contains all stratigraphical terms confirmed by a rich paleontological material. The Upper Triassic carbonate deposits cropp out in few metric (Piatra Zimbrului, Popii Raraului) or submetric blocks (the klippes on the Cailor, Maces, Izvorul Malului brooks, on the springs of the Timon brook etc.) occuring in the Rarau Syncline. The studied limestone klippe is located on the left side of the Izvorul Malului brook, about 2,5 – 3 km up from his confluence with the Moldova river. The klippe which is almost totally exploited consists of few white and gray limestone submetric blocks with Halobia. Microcrystalline carbonates are represented by muddy sediments accumulated in lowenergy quiet waters on the sea floor. The sediment consists of skeletal debris and unattached precipitates or of attached non-sketetal precipitates. The last two cases corespond to the autochthonous organomicrites and are characterized by common peloidal fabric. The formation of peloids requires low or moderate rates of sediment input. Tethyan Carnian, Norian and Rhaetian carbonate platform are characterized by specific benthic foraminiferal assemblages. They have proved to be extremely useful in recognising facies zones. The distribution was controlled by substrate conditions and salinity, nutrient requirements, specific life behavior, the topography of depositional environment, water depth and light. The microscopic analysis of the carbonate klippe made on 30 thin sections allowed the differentiation of several microfacies types whose micropaleontological content covers the Upper Triassic time. The Carnian microfacies are: biomicrites with pelmicrites and sparites. The biomicrites contain a fossil assemblage consist of few foraminifera, alga, sponges, incertae sedis, (e.g. Agathammina austroalpina Kristan-Tollmann & Tollmann, Trochammina alpina Kristan, Glomospirella aff. facilis Ho, Endoteba ex. gr. obturata Bronnimann & Zaninetti, Glomospira sp., Solenopora simionescui Dragastan, Solenopora cassiana Flugel, Cryptocoelia zitteli Ott, Spiriamphorella carpathica gemerica Borza & Samuel), microgastropods etc. The Norian – Rhaetian microfacies, according to their frequency, are: crinoid biosparites, biomicrites and pelmicrites. The foraminiferal assemblage contains a few species: Agathammina austroalpina Kristan-Tollmann & Tollmann, Variostoma catilliforme Kristan- Tollmann, Trochammina alpina Kristan, Glomospira inconstans Michalik, Glomospirella friedli Kristan-Tollmann, Glomospirella sp., Endoteba ex. gr. obturata Bronnimann & Zaninetti, Diplotremmina sp. Aerobic conditions are indicated by a gastropod-ostracod-foraminifera community and a monotypic bivalve assemblage. Diagenetic microfacies criteria are cements, neomorphic alterations, dissolution features and fracturing. Calcite cements occur predominantly within the shell interior (marine radial fibrous cement and late diagenesis recrystallized blocky cement). The limestones were affected by near-surface and marine diagenesis (inversion of aragonite, radial fibrous cement) and burial diagenesis (coarse blocky calcspar cement). Microfacies features prove the depositional settings of the limestones of the Izvorul Malului klippe: flat platform top within euphotic zone sufficiently connected with the open sea to maintain salinity and temperature close to that of the adjacent sea; shallow-water (water depths a few meters to ten of meters). The studied limestones are the inner platform carbonates. (open marine and restricted area of the inner platform).

Approaches to stratigraphy of the paleogene volcanogenic sequences in northwestern Kamchatka

“Volcanogenic Complex” as a stratigraphic term is substantiated. Also discussed are peculiarities of the volcanic process, the nature and evolution time of the volcanic structures, the complete and incomplete volcanic cycles. Data of comprehensive geological, stratigraphic and paleovolcanologic study are used to subdivide the Kinkil’skii Formation of Paleogene volcanogenic rocks in the northwestern Kamchatka, which has undivided previously, into the Shamanka, Rebro, Bozhedomova, and Geeklen volcanogenic complexes of concurrent or different ages. As a result, two epochs of volcanism (the late Ypresian-Lutetian and late Bartonian-Priabonian) are distinguished. A hiatus separating the epochs was a time of intense scouring and leveling the landforms and of the weathering crust formation. In conclusions, some problems of the paleogeography in Kamchatka and adjacent territories are discussed.

Vorwort/Preface

Abstract. In this volume, the Quaternary Subcommission of the German Stratigraphic Commission presents a description of the major stratotypes and stratigraphical terms for the Quaternary in Germany, focusing on climatostratigraphical terms that relate to cold and warm stages and have been incorporated into a regional chronostratigraphy.

Stratigraphische Begriffe für das Quartär des Periglazialraums in Deutschland

Abstract. Only a few Quaternary deposits of the periglacial area in Germany can be described in paleoecological or palynological - and therefore climatostratigraphical - terms. This paper provides a supplementary description of the most important (bio)stratigraphical terms relating to the warm and cold stages of the Lower and Middle Pleistocene, especially those allowing correlations with the glaciated regions of northern and southern Germany (e.g. in STEPHAN & MENKE 1993; Litt et al., this volume). The chronostratigraphical subdivision into Lower, Middle and Upper Pleistocene is based on the Stratigraphical Table of Germany 2002 (STD 2002) and on the climatostratigraphical regional division into cold and warm stages for continental northwestern Europe and Germany (LITT et al. 2005), which follows the traditional positioning of the Pliocene/Pleistocene boundary at the transition between the Reuverian and Pretiglian stages (Zagwijn 1960). According to international agreement on the location of the GSSP at Vrica (Italy), the sections of the Pretiglian stage and the Tiglian Complex belong to the Gelasian, which is still assigned to the Pliocene. The Gelasian/Calabrian boundary was set at about 1.8 million years at the Vrica section at the top of the Olduvai magnetozone and therefore represents the internationally agreed base of the Pleistocene. The practical value of this boundary – which does not take prior major climatic events into account – has been a matter of controversy. By international consensus, the boundary between the Lower and Middle Pleistocene has been set at the palaeomagnetically defined Brunhes/Matuyama boundary at 780 ka; the Upper Pleistocene begins with the last interglacial, the Eemian stage (MIS 5e).

The Tertiary and the Quaternary are here to stay

In 1989 and 2000, the International Commission on Stratigraphy (ICS) published geologic time scales in which the term Tertiary had been eliminated. In the time scales published by the ICS in 2004, the term Quaternary was also eliminated, the Cenozoic shown as composed of two systems, the Paleogene and the Neogene, the Neogene extending to the present. Was there any logical basis for these changes? A review of the geologic literature since 1980 (19 journals of extensive distribution and a considerable number of geologic maps, time scales, and stratigraphy textbooks as well as the GeoRef) clearly indicates that the Tertiary and the Quaternary have long been (and are now) in widespread use by geologists the world over, and that their use has not declined at all during the last 25 yr. They are very useful terms in geologic work, essential for clear communication among geologists. Paleogene and Neogene have received increasing use during the last 10 yr because they are also useful terms. Quaternary is probably the stratigraphic term most frequently used in the geologic literature. Tertiary is used as the pre-Quaternary part of the Cenozoic by most geologists; some, however, prefer to use Paleogene and Neogene instead of Tertiary. But it should not be a question of either Tertiary or Paleogene and Neogene; all three are needed, as are Cenozoic, Paleocene, Eocene, Oligocene, Miocene, and Pliocene, to express various degrees of precision in stratigraphic assignation and dating. All should be recognized as units of a standard geologic time scale. Geologists should retain a choice of what they think better fits their needs. The preferred time scale, therefore, should have the Cenozoic Erathem comprising the Tertiary and Quaternary systems, and the Tertiary including the Paleogene and Neogene subsystems. Past attempts to eliminate the Tertiary and Quaternary have been ignored. Recent attempts will not succeed either. The Tertiary and the Quaternary are here to stay, certainly as long as geologists continue to use them, as they have, and continue to oppose the ill-advised efforts to discard them from the geologic time scale.

Annotated Bibliography of Quaternary Vertebrates of Northern North America: With Radiocarbon Dates. Edited by C R Harington; annotated by , D Naughton, C R Harington, A Dalby, M Rose, and , J Dawson; radiocarbon‐date table compiled by , G Harington. Published by the University of Toronto Press, Toronto (Canada), in collaboration with the Canadian Museum of Nature, Ottawa (Canada). $120.00.

Previous articleNext article No AccessPaleontologyAnnotated Bibliography of Quaternary Vertebrates of Northern North America: With Radiocarbon Dates. Edited by C R Harington; annotated by , D Naughton, C R Harington, A Dalby, M Rose, and , J Dawson; radiocarbon‐date table compiled by , G Harington. Published by the University of Toronto Press, Toronto (Canada), in collaboration with the Canadian Museum of Nature, Ottawa (Canada). $120.00. xxii + 539 p; ill.; indexes of scientific names, common names, localities and stratigraphic terms, personal names and institutions, and subjects. ISBN: 0–8020–4817–X. 2003.PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 79, Number 2June 2004 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/423058 Views: 5Total views on this site PDF download Crossref reports no articles citing this article.

The stratigraphic framework for the Upper Pleistocene of the glaciated Russian Arctic: changing paradigms

The development of stratigraphic ideas and terminology for the area of Late Pleistocene glaciation beyond the limit of the Fennoscandian ice sheet is discussed. The original meaning and subsequent distortions of the Siberian stratigraphic terms Zyryanka, Karginsky, Sartan and others are described. Stratigraphic schemes traditionally used in Siberia and in the Russian European Arctic contain similar mistakes due to poor sedimentology obtained from simplistic log descriptions. Indiscriminate use of radiocarbon dating, in disregard to the sedimentological complications, have eroded the value of the old stratigraphic terms and depleted their usefulness. Modern data on widespread glaciotectonic activity and redeposition of organics by shelf-based ice sheets, on retarded melting of buried glacial ice, on ubiquitous permafrost and aeolian processes, coupled with new geochronometric results make it impossible to employ the old framework based on the presumption of undisturbed stratification and slow unperturbed sedimentation. A more structurally complicated model, to which traditional stratigraphic labels are not applicable, is suggested for the uppermost sedimentary formations of arctic plains. It is derived from a wider view of the glacigenic complex by lateral tracing of study objects as a necessary complement to conventional log descriptions. The old Siberian stratigraphic scheme, being obsolete and misleading, is not recommended for further use.

MARKET STRATIGRAPHY—THE 25-YEAR ODYSSEY OF THE AUSTRALIAN PUBLICLY-LISTED OIL AND GAS SECTOR (IS THE SMALLER E&P COMPANY THREATENED WITH EXTINCTION?)

A market view of the population of publicly listed oil and gas companies during the past 25 years provides insights to the survival of the smaller exploration and production company. Mapping the life span of companies, and company population against parameters such as oil price and market activity, demonstrates that oil price is not the crucial driver for the industry as one would expect. The number of exploration companies existing at any one time is independent of oil price and discovery levels, but is more closely related to market sentiment and external influences. The benefits of success are apparent, but the vulnerability of smaller companies to that success is also apparent. While the ASX Energy Index has significantly out-performed the market, and the resources sector in general over this period, it is still considered a high-risk investment area, which fails to attract substantial investment funds.At a time of an apparently sustainable higher oil price, and record market levels, why is the level of new corporate activity so limited? In stratigraphic terms, is the survival of this species threatened? Was Darwin right—will the strong get stronger and will the small E&P company be driven to extinction?

Greenland from Archaean to Quaternary. Descriptive text to the Geological map of Greenland, 1:2 500 000

The geological development of Greenland spans a period of nearly 4 Ga, from the earliest Archaean to the Quaternary. Greenland is the largest island in the world with a total area of 2 166 000 km2, but only c. 410 000 km2 are exposed bedrock, the remaining part being covered by an inland ice cap reaching over 3 km in thickness. The adjacent offshore areas underlain by continental crust have an area of c. 825 000 km2. Greenland is dominated by crystalline rocks of the Precambrian shield, which formed during a succession of Archaean and early Proterozoic orogenic events and which stabilised as a part of the Laurentian shield about 1600 Ma ago. The shield area can be divided into three distinct types of basement provinces: (1) Archaean rocks (3100-2600 Ma old, with local older units) almost unaffected by Proterozoic or later orogenic activity; (2) Archaean terraines reworked during the early Proterozoic around 1850 Ma ago; and (3) terraines mainly composed of juvenile early Proterozoic rocks (2000-1750 Ma old). Subsequent geological developments mainly took place along the margins of the shield. During the later Proterozoic and throughout the Phanerozoic major sedimentary basins formed, notably in North and North-East Greenland, and in places accumulated sedimentary successions which reached 10-15 km in thickness. Palaeozoic orogenic activity affected parts of these successions in the Ellesmerian fold belt of North Greenland and the East Greenland Caledonides; the latter also incorporates reworked Precambrian crystalline basement complexes. Late Palaeozoic and Mesozoic sedimentary basins developed along the continent-ocean margins in North, East and West Greenland and are now preserved both onshore and offshore. Their development was closely related to continental break-up with formation of rift basins. Initial rifting in East Greenland in latest Devonian to earliest Carboniferous time and succeeding phases culminated with the opening of the North Atlantic in the late Paleocene. Sea-floor spreading was accompanied by extrusion of Tertiary plateau basalts in both central West and central and southern East Greenland. During the Quaternary Greenland was almost completely covered by ice sheets, and the present Inland Ice is a relic of the Pleistocene ice ages. Vast amounts of glacially eroded detritus were deposited on the continental shelves offshore Greenland. Mineral exploitation in Greenland has so far mainly been limited to one cryolite mine, two lead-zinc deposits and one coal deposit. Current prospecting activities in Greenland are concentrated on the gold, diamond and lead-zinc potential. The hydrocarbon potential is confined to the major Phanerozoic sedimentary basins, notably the large basins offshore East and West Greenland. While proven reserves of oil or gas have yet to be found, geophysical data combined with extrapolations from onshore studies have revealed a considerable potential for offshore oil and gas. The description of the map has been prepared with the needs of the professional geologist in mind; it requires a knowledge of geological principles but not previous knowledge of Greenland geology. Throughout the text reference is made to the key numbers in the map legend indicated in square brackets [ ] representing geological units (see Legend explanation, p. 79), while a Place names register (p. 83) and an Index (p. 87) include place names, geological topics, stratigraphic terms and units found in the legend. The extensive reference list is intended as a key to the most relevant information sources.

Sequence concepts at seismic and outcrop scale: the distinction between physical and conceptual stratigraphic surfaces

The sequence stratigraphic terms maximum flooding surface and downlap surface, as currently applied, are ambiguous. Examples of these intra-sequence surfaces are summarised from high frequency mid-Pleistocene sequences and from a Cretaceous–Recent seismic megasequence, both from New Zealand. At any one locality, a mid-Pleistocene sequence contains up to four stratal discontinuities, in ascending order: the sequence boundary, ravinement surface, local flooding surface and downlap surface. These physical surfaces, which occur in outcrop, are regionally diachronous and should be differentiated from theoretical isochronous horizons such as the time of maximum flooding (horizon corresponding to maximum shoreline transgression) and the time of peak eustatic or local relative sea-level (horizons corresponding to the highpoint of the eustatic and relative sea-level cycles, respectively). In seismic studies, the boundary between the transgressive and highstand systems tracts is usually located at the downlap surface. On the basis of a major thermo-tectonic sea-level cycle in the Canterbury Basin, it is shown that the downlap surface is not a single regional surface, and that the change in slope associated with toes of successive prograding clinoforms rises in stratigraphic height basinwards. The downlap surface therefore does not usually coincide with the maximum flooding horizon. In Plio–Pleistocene cyclothems, a discrete unit — the mid-cycle shellbed — straddles the contact between the transgressive and highstand systems tracts. This unit might be classified within its own systems tract (the condensed section systems tract; CSST). Alternatively, the position of the boundary between the transgressive and highstand systems tracts can remain unspecified or unknowable.

The Cenozoic Era: Lyellian (chrono)stratigraphy and nomenclatural reform at the millennium

Abstract The historical and intellectual framework and contemporary influences and sources leading to, and associated with, Charles Lyell’s studies of Tertiary stratigraphy are reviewed. The nomenclatural hierarchy into which some of Lyell’s stratigraphic terms have been subsequently grouped is then analysed. Lyell’s terms ‘Eocene’, ‘Miocene’, ‘Pliocene’ (1833) and ‘Pleistocene’ (1839) were essentially biostratigraphic/biochronologic in nature. Together with the subsequently defined ‘Oligocene’ (1854) and ‘Paleocene’ (1874), they have gradually aquired a chronostratigraphic connotation over the past 100 years. The term ‘Neogene’ (Hörnes 1853, 1856, 1864), when transferred from its original biostratigraphic/biochronologic (Lyellian) to a chronostratigraphic connotation, includes the stratigraphic record of the Miocene, Pliocene, Pleistocene and Recent (subsequently termed Holocene) epochs (equivalent to the ‘periods’ of Lyell). Thus a Neogene/Quaternary boundary is wholly inappropriate as a standard chronostratigraphic boundary. The ‘Palaeogene’ (Naumann 1866) now comfortably accomodates the stratigraphic record of the Paleocene, Eocene and Oligocene epochs The terms ‘Palaeogene’ and ‘Neogene’ should be used as period/system subdivisions of the Cenozoic Era. ‘Tertiary’ and ‘Quaternary’ should be abandoned, relicts of a now outmoded, and inappropriate, pre-Lyellian stratigraphy. Retention of the term ‘Quaternary’ for geopolitical purposes (institutional affiliation or scientific/professional identification), as opposed to its retention as part of the standard stratigraphic hagiography, is recommended and would reduce, if not eventually eliminate, continuing but unnecessary, and unscientific, rancorous debate over standard Cenozoic chronostratigraphic terminology.

Discussion: Upper Lower Cambrian depositional sequence in Avalonian New Brunswick

The authors (E. Landing and S.R. Westrop) wish to abandon most of the local stratigraphic nomenclature of the Saint John Group in southern New Brunswick, in order to emphasize the broader tectonic significance of these lower Paleozoic platformal rocks throughout the Avalon terrane. Their approach, based in part on biostratigraphic data, is to use a somewhat arbitrary mixture of stratigraphic terms taken from widely separate type sections in New Brunswick and Newfoundland. Thus, the Ratcliffe Brook Group (a formation defined in New Brunswick), would include the Rencontre and Chapel Island formations (both defined in Newfoundland), whereas the Chamberlain's Brook Formation (defined in Newfoundland) would include the Fossil Brook Member (defined in New Brunswick). The Saint John Group, which clearly has historical precedence (Williams et al. 1985), is left out of their stratigraphic scheme. Since the establishment of a formal lithostratigraphic unit requires that its lower and upper boundaries be explicitly defined, it is difficult to see how this can be accomplished when the supposedly adjacent units are from type sections or reference sections located about 1000 krn apart. Even if separate sections contain similar successions, it is unlikely that lithological boundaries would be identical over large areas in such an episodically high-energy shelf environment. Difficulties in adequately describing formational boundaries are compounded in the case of the Hanford Brook Formation since, as the authors point out, it does not even occur in the Newfoundland type section where the underlying and overlying strata are defined. The two type sections are, therefore, not truly homotaxial, so extrapolation of Newfoundland terminology to New Brunswick may not be justified. The authors insist on placing the upper part of the Glen Falls Formation into the overlying Hanford Brook Formation since they claim a major unconformity exists within the former. Although such a revision is not unreasonable, it is not required. Stratigraphic nomenclature is supposed to be based on empirical lithological changes rather than interpretive depositional history, so the traditional lithological components of the Glen Falls Formation could be retained even if the claimed unconformity were proven to exist. In conclusion, the authors have made a significant contribution to the understanding of tectonic controls on the development of Paleozoic shelf facies covering the Avalon terrane. However, this could have been accomplished without resorting to wholesale name changes, the sole purpose of which is to create a general stratigraphic nomenclature to encompass what is surely a complex depositional setting containing many depocentres. A standard correlation chart retaining local terminology would be a more practical way to convey the reasoning behind the authors' tectono-stratigraphic synthesis. I believe that the composite stratigraphic column proposed by Landing and Westrop creates more problems than it solves and is unlikely to be adopted by others working in this part of the northern Appalachians.

Reassessment of the position of the Plio-Pleistocene boundary: Is there a case for lowering it to the Gauss-Matuyama palaeomagnetic reversal?

A substantially updated version of the correlation table showing chronostratigraphical subdivisions of late Cenozoic geological time, spanning the last 2.7 million years is presented. It provides scientists, students, professionals and the general public with a ready reference to stratigraphical terms and schemes in use in different areas for similar periods. The updates comprised the status of Quaternary chronostratigraphic subdivision, the combined age-modelled geomagnetic and isotope records from ocean drilling records, and revised regional correlation schemes, notably for eastern Europe. The paper describes the chart in its 2019 QI-500 form and contains sections on its types of usage and formal subdivision status, besides reference and description of the contents of the various columns. The paper also describes and discusses the resolution of correlations in younger and older parts of the last 2.7 Ma.

The key to earth history: an introduction to stratigraphy

Preface. Illustrations. Introduction: What is Stratigraphy? PRINCIPLES. Uniformitarianism or Actualism. Establishing the Sequence of Events. Geological Time. Interpreting the Stratigraphical Record. The Evolution and Closure of Sedimentary Basins: The Role of Plate Tectonics. The Stratigraphical Tool Kit: Case Studies. Summary of Part One: The Stratigraphical Tool Kit. THE PATTERN OF EARTH HISTORY. Introduction to Part Two. The Stratigraphical Record and Global Rhythm. The North Atlantic Region: A Journey Through Time. The Precambrian: Peering into Deep Time. Pangaea: Birth of a Giant. Pangaea and the Opening of the Atlantic. Summary of Part Two: The Pattern of Earth History. Lexicon of Stratigraphical Terms. Index.