M. J. Orchard

M. J. Orchard
Natural Resources Canada | NRCan · Geological Survey of Canada

PhD

About

280
Publications
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Introduction
M. J. Orchard is an Emeritus Scientist with Geological Survey of Canada, Earth Science Sector, Natural Resources Canada in Vancouver. M. does research on conodont microfossils, particularly Triassic.

Publications

Publications (280)
Article
The taxonomy and biostratigraphy of poorly known neogondolellin conodonts from mostly Spathian (upper Olenekian, Lower Triassic) strata are described from widespread localities in North America: high latitude Canadian Arctic, mid‐latitude British Columbia (BC), and lower latitudes in the USA. The occurrence of the neogondolellins in key sections an...
Article
As one of the most important intervals in Earth life evolution, the latest Permian to earliest Triassic witnessed the greatest mass extinction and most profound recovery of marine biotas. In this period, gondolellid conodonts went through a major faunal turnover and morphologic change marked by platform reduction during the late Griesbachian to Die...
Article
The Guryul Ravine section in Kashmir, northern India is an important reference section for global Lower Triassic stratigraphy. Once a candidate Global Stratotype Section and Point (GSSP) for the Permian-Triassic Boundary (PTB), the section has attracted intense attention for the PTB beds, but few studies have concerned the entire Lower Triassic str...
Article
Investigation of the end-Permian mass extinction (EPME) has been greatly facilitated by high-resolution conodont biostratigraphic studies. To date, however, a detailed biostratigraphic framework has been lacking for shallow-marine successions of the Tethys region. In the present study, we analyzed carbonate microfacies, conodont biostratigraphy, an...
Data
Corrected levels of Spathian ammonoid column that had been accidentally slightly shifted in original figure.
Data
Corrected levels of Spathian ammonoid column that had been accidentally slightly shifted in original figure.
Article
Full-text available
The Norian Stage is the longest stage in the Phanerozoic, and some members of the boundary working group have been evaluating suitable Carnian-Norian boundary sections for roughly two decades. This has identified two possible candidate boundary sections, at Black Bear Ridge (British Columbia, Canada) and Pizzo Mondello (Sicily, Italy). After a form...
Article
The Earn Group of central Yukon records the transition from a passive to an active margin along western Laurentia in the Late Devonian. Fine-grained clastic rocks and chert of the lower Earn Group contain late Early to Middle Devonian fossils and were deposited in an offshelf environment. The upper Earn Group comprises a mixture of sandstone and co...
Article
The Early Triassic is a critical interval recording episodic climatic, environmental, and biotic events after the end-Permian mass extinction. A precise global timescale for this epoch is essential to understand the sequence of events during this crisis. The undefined Induan–Olenekian stage boundary (IOB), long disputed, is a crucial element in pro...
Article
The Carnian-Norian (C-N) transition (Late Triassic) has long been postulated as an interval of major climatic changes, though the nature of such changes and their ecological impact remains largely unexplored. We use oxygen isotopes measured on monogeneric conodont assemblages (δ 18 O PO4) from the Canadian Cordillera to trace seawater temperature e...
Presentation
Full-text available
Examination of existing Early Triassic conodont fauna from wells in the Carnarvon and North Perth basin of Western Australia: 1. The Limestone Marker in the northern Perth Basin is a time correlative of the Cunaloo Limestone Member in the Carnarvon Basin. Timing of these events needs finer radiometric age correlation and more (core) dated limestone...
Chapter
Full-text available
The Triassic is bound by two mass extinctions that coincide with vast outpourings of volcanic flood basalts. The Mesozoic begins with a gradual recovery of plant and animal life after the end-Permian mass extinction. Conodonts and ammonoids are the main correlation tools for marine deposits. The Pangea supercontinent has no known glacial episodes d...
Article
The Cunaloo Limestone Member of the Locker Shale (Kockatea Shale facies) from the Carnarvon Basin contains a distinctive conodont zone also seen in the informally named ‘Limestone Marker’ in the lower Kockatea Shale of the northern Perth Basin. The boundary between the Induan (Dienerian) and the Olenekian (Smithian) is selected at the base of the i...
Article
The transition from the Smithian substage to the Spathian substage of the Olenekian stage of the late Early Triassic was a critical time marked by a series of biological and environmental changes during the multimillion-year recovery interval following the end-Permian mass extinction. However, the Smithian/Spathian boundary (SSB) does not yet have...
Article
Markedly di!erent conodont faunas occur on either side of the known Lower–Middle Norian boundary (LMNB) identi"ed in the Pardonet Formation of northeast British Columbia (Canada). A faunal gap separates ammonoids of the Lower Norian Magnus and those of the Middle Norian Rutherfordi zones, and conodonts of, respectively, the Ancyrogondolella triangu...
Article
Full-text available
Lower Triassic conodont biostratigraphy has been well studied around the world in the past decades, but the Induan-Olenekian boundary (IOB) remains undecided. The Novispathodus waageni group has been taxonomically re-assessed based on abundant new materials from the Jianshi and Chaohu sections, South China. New study shows that Nv. waageni typicall...
Article
Conodonts have proven to be excellent index fossils to study the subsurface Montney Formation given their small size and regular occurrence in most marine facies. Twenty uppermost Permian to Lower Triassic conodont biozones are summarized and the sequence biostratigraphic framework provides a template demonstrating the correlation potential of the...
Article
The new conodont genus Magnigondolella is recognized based on specimens recovered from the Anisian (Middle Triassic) of British Columbia in Canada, and Nevada in the USA. This new genus encompasses problematic specimens with high carinas, which have recently been collectively referred to as Neogondolella ex gr. regalis Mosher. Ten species from Nort...
Article
The Kamura section, located in the Chichibu Belt of Kyushu Island in southern Japan, contains a succession of uppermost Permian to Upper Triassic shallow-marine atoll sediments from the mid-Panthalassic Ocean. In the present study, carbonate microfacies, conodont biostratigraphy, and carbonate carbon isotopes were analyzed, making it possible to co...
Article
Full-text available
In: Geological Fieldwork 2016, British Columbia Ministry of Energy and Mines, British Columbia Geological Survey Paper 2017-1, pp. 153-178. Stikine terrane is one of the largest crustal blocks in the Cordillera, measuring more than 1100 km long and 250 km wide. In northern British Columbia it is well known for its large porphyry Cu-Au ±Mo-Ag dep...
Article
We present recent study results of the Lower Triassic conodont succession from the Ganxi and Jianshi areas of Enshi city, western Hubei Province, South China, which were situated on a carbonate ramp at the northeastern margin of the Upper Yangtze Platform. Therein, the uppermost Permian to Lower Triassic succession is well exposed and yielded abund...
Article
Eight new species of the conodont Neogondolella are described from the Anisian (Middle Triassic) of northeastern British Columbia. The subtlety of morphological variation in this conodont genus has hampered biostratigraphical correlation, but large, often independently dated collections have enabled the description of N . cuneiforme , N . curva , N...
Article
New isotopic ages have been obtained from euhedral, first-cycle zircon grains recovered from Rhaetian strata preserved at the Black Bear Ridge section in northeastern British Columbia. Two statistically significant populations are present: an older population ca. 224 Ma, and a dominant younger population ca. 205 Ma. The younger population includes...
Article
Full-text available
We report a new ichthyopterygian assemblage from Lower Triassic horizons of the Prida Formation at Fossil Hill in central Nevada. Although fragmentary, the specimens collected so far document a diverse fauna. One partial jaw exhibits isodont dentition with blunt tipped, mesiodistally compressed crowns and striated enamel. These features are shared...
Article
Full-text available
Triassic rocks of the Western Canada Sedimentary Basin (WCSB) have previously been interpreted as being deposited on the passive margin of North America. Recent detrital zircon provenance studies on equivalent Triassic rocks in the Yukon have suggested that these rocks were in part derived from the pericratonic Yukon–Tanana terrane and were deposit...
Article
Full-text available
Abstract: The taxonomy, diversity, evolutionary lineages, and stratigraphical distributions of Middle and early Late Triassic conodonts are reviewed and re-evaluated. Twentyfive genera are recognized in the Middle and early Late Triassic, including a new genus cited in open nomenclature. Of these, 24 genera are assigned to two families and seven su...
Article
Full-text available
We report a new ichthyopterygian assemblage from Lower Triassic horizons of the Prida Formation at Fossil Hill in central Nevada. Although fragmentary, the specimens collected so far document a diverse fauna. One partial jaw exhibits isodont dentition with blunt tipped, mesiodistally compressed crowns and striated enamel. These features are shared...
Article
Full-text available
We report a new ichthyopterygian assemblage from Lower Triassic horizons of the Prida Formation at Fossil Hill in central Nevada. Although fragmentary, the specimens collected so far document a diverse fauna. One partial jaw exhibits isodont dentition with blunt tipped, mesiodistally compressed crowns and striated enamel. These features are shared...
Article
Full-text available
The Black Bear Ridge section in northeastern British Columbia, Canada, consists of a continuously exposed sequence of Upper Carnian through Lower Norian (Upper Triassic) continental margin strata. The section has been proposed as a candidate Global Stratotype Section and Point (GSSP) for the Carnian/Norian boundary (CNB). In order to assess Late Ca...
Article
Conodont biostratigraphy of the upper Montney and Doig formations in the subsurface of northeastern British Columbia provides the first age constraints on the boundary between these two formations. Previously presumed to be broadly but uniformly equivalent to the Spathian-Anisian boundary, it is shown herein to be highly diachronous, ranging from S...
Article
Conodonts from the Carnian-Norian Boundary (CNB) interval at the Global Stratigraphic Section and Point (GSSP) candidate section at Black Bear Ridge (BBR), British Columbia, Canada, include five previously introduced genera (Acuminatella, Kraussodontus, Parapetella, Primatella, Quadralella), 71 new species (plus nine previously named, and 13 more i...
Article
Elasmobranchs are reported for the first time from Lower Triassic deposits in Oman. The well-preserved remains consist of isolated teeth, dermal denticles and fin spines, recovered from conodont residues. The low-palaeolatitude sections consist of Lopingian–Olenekian shallow and pelagic carbonates in exotics, olistoliths and breccia blocks that hav...
Article
The Upper Carnian-Lower Norian (Upper Triassic) Luning Formation at Berlin-Ichthyosaur State Park (BISP) in central NV (USA) has been sampled using for the first time the bed-by-bed approach for ammonoids, pelagic bivalves, and conodonts, more than 60 years after its first description by Silberling (U.S. Geological Survey Professional Paper 322: 1–...
Chapter
The Triassic Period is approximately 51 million years of Earth history, from 201–252 million years ago. Rocks and fossils of Triassic age are found on all the modern continents and indicate the unity of a single Triassic supercontinent, Pangaea. Triassic Pangaea was surrounded by a single world ocean, Panthalassa, which had a westward extending arm...
Data
Full-text available
Forty-four radiolarian faunules from the Carnian-Norian Boundary (CNB) beds of the Peril Formation at 11 localities in Haida Gwaii are grouped into 7 radiolarian assemblages that are independently dated by conodonts and macrofossils. The age and stratigraphic distribution of 140 radiolarian species are determined by reference to the conodont zonati...
Article
Full-text available
The 34-million-year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., end-Triassic extinction event), but this scenario remains controversial because of a lack of stratigraphic re...
Article
Several fused clusters of conodont elements of the genera Neospathodus and Novispathodus were recovered from limestone beds at the Dienerian–Smithian and Smithian–Spathian boundaries, respectively, from several localities in Guangxi province, South China. Conodont clusters are otherwise extremely rare in the Triassic, and these are first described...
Article
The First Appearance Datum (FAD) of the conodont Chiosella timorensis has been recently proposed as an index for the worldwide recognition of the Olenekian-Anisian Boundary (OAB, Early-Middle Triassic boundary). We here report the co-occurrence of C. timorensis with the ammonoids Neopopanoceras haugi (Hyatt and Smith), Keyserlingites pacificus (Hya...
Article
Full-text available
The Jesmond succession of the Cache Creek Terrane in southern British Columbia records late Early Triassic peritidal carbonate sedimentation on a mudflat of a buildup resting upon a Panthalassan seamount. Conodont and foraminiferal biostratigraphy dates the succession as the uppermost Smithian to mid-Spathian. The study section (ca. 91 m thick) is...
Article
Full-text available
The origin of jaws remains largely an enigma that is best addressed by studying fossil and living jawless vertebrates. Conodonts were eel-shaped jawless animals, whose vertebrate affinity is still disputed. The geometrical analysis of exceptional three-dimensionally preserved clusters of oro-pharyngeal elements of the Early Triassic Novispathodus,...
Article
The stratigraphy and geological relationships of upper Paleozoic limestones in the Cariboo gold belt are discussed in the light of 49 new conodont collections. Combined with lithological criteria, these define three units: the Lower Mississippian Greenberry Formation, the new Alex Allan Formation, and the new (informal) Sugar limestone. The Greenbe...
Article
Six lithologic units, including two newly named formations, were mapped on Randall, Dunira, and nearby islands. The islands are characterized by greenschist-facies metamorphism and westerly directed thrusting. The oldest unit is a Late Mississippian, massive limestone on Ducie Island. The Dunira Formation, composed of thin-bedded limestone and silt...
Article
Conodonts have played an important role in the construction of a Triassic timescale. Each of the stage boundaries is reviewed in the context of their evolving conodont faunas. The base Triassic (Induan) is defined by the appearance of Hindeodus parvus, which developed from H. praeparvus; a parallel zonation is provided by Neogondolella species. For...
Article
Full-text available
New detrital mineral age and whole-rock geochemical data provide the first constraints on the composition and source of North American Triassic strata in the northern Canadian Cordillera. Conodont-bearing Triassic strata collected from five locations across west-central to southeastern Yukon contain trace-element ratios ((La/Yb)- = ~8; Eu/Eu* = -0....
Article
Full-text available
The upper Ludington and lower Pardonet formations at Black Bear Ridge, northeastern British Columbia, Canada represent a continuously exposed succession through the upper Carnian and lower Norian (medial Upper Triassic). These strata were deposited in a deep marine setting (distally steepened carbonate ramp / medial to distal slope) on the northwes...
Article
La Formation de Sulphur Mountain dans le secteur de Wapiti est subdivisee en quatre membres : Phroso, Meosin, Mountain (nouveau) et Vega qui, ensemble, recouvrent une grande partie du Trias inferieur. Les faunes conodontes du Smithien sont particulierement bien developpees et forment la base de trois zones a conodontes partiellement nouvelles, soit...
Article
Whitehorse trough is a frontier basin in south-central Yukon that is thought to contain gas and possibly oil. It consists of up to 7000 m of sedimentary and volcanic rocks referred to as the Lewes River Group (Triassic), Laberge Group (Jurassic), and Tantalus Formation (Jura-Cretaceous). The Lewes River Group is informally subdivided into the Povoa...
Article
Conodont faunas are described from the type sections of Lower Triassic stages in the Canadian Arctic. The collections come largely from ammonoid-bearing strata of the Strigatus (upper Griesbachian), Candidus (lower Dienerian), Romunduri and Tardus (lower and upper Smithian), and Subrobustus (upper Spathian) zones. These demonstrate that diverse lat...
Article
Full-text available
Conodont faunas are described from Triassic sections of Svalbard, and their occurrences are locally correlated with established ammonoid zones. With a synthesis of previous conodont-based publications, the current work presents a taxonomically up-to-date compilation of conodont data for the Triassic of Svalbard that is used to construct a conodont-...
Article
An integrated biomagnetostratigraphic study of the latest Early Triassic to the upper parts of the Middle Triassic, at Milne Edwardsfjellet in central Spitsbergen, Svalbard, allows a detailed correlation of Boreal and Tethyan biostratigraphies. The biostratigraphy consists of ammonoid and palynomorph zonations, supported by conodonts, through some...
Article
  The apparatus of an Early Triassic conodont Neostrachanognathus tahoensisKoike, 1998 from Oritate, Kumamoto Prefecture, Japan, and a species of Neostrachanognathus from Oman were reconstructed. On the basis of five natural assemblages from the Oritate area, the three-dimensional apparatus model of N. tahoensis is interpreted as bilaterally symmet...
Article
Full-text available
Chaohu is located in a deep part of carbonate ramp on the Lower Yangtze Block, which belonged to the low-latitude eastern Tethyan archipelago during the Early Triassic. Fossils were very rich in the Lower Triassic of Chaohu. Bivalves, ammonoids, conodonts were very common throughout the Lower Triassic, while fish fossils were generally rich in some...