Anatomically preserved plants from the Middle Eocene (Allenby Formation) of British Columbia

1977 ◽  
Vol 55 (14) ◽  
pp. 1984-1990 ◽  
Author(s):  
James F. Basinger ◽  
Gar W. Rothwell
Keyword(s):  
British Columbia ◽  
Plant Material ◽  
Developmental Stages ◽  
Middle Eocene ◽  
Vegetative Organs ◽  
Preliminary Examination ◽  
Early Tertiary ◽  
Plant Remains

Well preserved, permineralized plant material from the Middle Eocene, Allenby Formation of British Columbia provides the basis for this description of an extensive Tertiary flora. The flora comprises a diverse assemblage of abundant plant remains in a chert matrix which outcrops south of Princeton, B.C., Canada. Preliminary examination of this material reveals numerous fertile and vegetative organs of angiosperms, conifers, ferns, bryophytes, and fungi, most of which represent presently unknown taxa. Initial studies indicate that we are dealing with the most diverse Eocene permineralization flora ever discovered. Superb anatomical preservation, including developmental stages of various organs, characterize many of the taxa and promise to significantly increase our knowledge of early Tertiary plants.

Fossil Mosses from the Bisaccate Zone of the Mid-Eocene Allenby Formation, British Columbia

1974 ◽  
Vol 11 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Marian Kuc
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Plant Tissues ◽  
Plant Remains ◽  
Lake Bottom ◽  
White Colour

New fossil taxa (Ditrichites fylesi, Muscites maycocki, M. ritchiei, Palaeohypnum jovet-asti and P. steerei); unnamed moss and moss-like fossils, detrital fragments of various plant tissues, and paleobotanical evidence of the bisaccate zone are described from the Middle Eocene Allenby Formation near Princeton, British Columbia. These remains occur in laminated, tuffaceous, silty and pyroclastic shale, deposited under lacustrine conditions.Detailed examination of the various laminae indicates that beds of white colour and composed of coarser silt grains are poor in fossils and could be related to periods of decreasing bioproduction; less silty and darker coloured beds are rich in macro- and microfossils and could be related to periods of extensive bioproduction. The rock features, lamination, and distribution of macrofossils indicate the slow and undisturbed accumulation of plant remains on a lake bottom.

Sapindaceous flowers from the Middle Eocene Princeton chert (Allenby Formation) of British Columbia, Canada

1990 ◽  
Vol 68 (9) ◽  
pp. 2025-2034 ◽  
Author(s):  
Diane M. Erwin ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
Key Words ◽  
Developmental Stages ◽  
Middle Eocene ◽  
Anther Wall

Seventeen small, staminate flowers, 3.0–4.5 mm long × 1.0–1.5 mm wide, representing two developmental stages of the same type of flower have been recovered from the Middle Eocene Princeton chert locality of British Columbia. Some specimens are immature buds with overlapping perianth parts enclosing the stamens; others represent mature flowers with an open perianth. Flowers are pedicellate with a small flat receptacle bearing a perianth of at least three sepals and up to four petals. Five specimens show a three- to four-lobed rudimentary pistil surrounded by an intrastaminal nectary disk. The 10 stamens are included or barely exserted with nonconnate filaments, 1.2–2.0 mm long, attached by a slender connective to large dithecal anthers up to about 0.9 mm long that open by longitudinal slits. The anther wall is represented by a palisadelike endothecium composed of cells that are thick-walled and radially elongated relative to the long axis of the anther. Abundant in situ pollen is semitectate–columellate, tricolporate, subprolate to prolate, and prominently striated with equatorially bridged colpi. This fossil combines flower and pollen characteristics similar to those of the Sapindaceae, resembling most closely the tribe Dodonaeeae. Key words: Sapindales, Dodonaeeae, Tertiary, permineralization, flowers, pollen.

Metasequoia milleri n.sp., anatomically preserved pollen cones from the Middle Eocene (Allenby Formation) of British Columbia

1979 ◽  
Vol 57 (8) ◽  
pp. 958-970 ◽  
Author(s):  
Gar W. Rothwell ◽  
James F. Basinger
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Metasequoia Glyptostroboides ◽  
Plant Remains ◽  
Exine Ornamentation ◽  
Pollen Sacs ◽  
Pollen Cone ◽  
Fertile Region ◽  
A New Species ◽  
Subtending Leaves

The discovery of well preserved, permineralized plant remains in Eocene sediments near Princeton, British Columbia, provides an opportunity to describe Metasequoia milleri, a new species of taxodiaceous pollen cone. Individual specimens are up to 3.0 mm long and 2.9 mm in diameter and are subtended by a vegetative zone of scale-like leaves. Approximately 30 microsporophylls are attached to the axis, and each bears three ovoid pollen sacs. The distal-most subtending leaves imbricate and enclose the fertile region. Pollen is ovoid to subspheroidal with an erect, protruding leptoma. Grains measure 19–27 μn in diameter and have verrucate exine ornamentation with numerous orbicules. These fossils show that pollen cones anatomically similar to those of extant Metasequoia glyptostroboides were present as early as Middle Eocene time.

Palynology and geochronology of Eocene beds from Cheslatta Falls and Nazko areas, central British Columbia

1988 ◽  
Vol 25 (8) ◽  
pp. 1268-1276 ◽  
Author(s):  
G. E. Rouse ◽  
W. H. Mathews
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Late Eocene ◽  
Early Oligocene ◽  
Early Tertiary ◽  
International Boundary ◽  
Climatic Cooling ◽  
Warm Temperate ◽  
Subtropical Environment

Early Tertiary lavas and sediments were collected from two areas west and south of Prince George, British Columbia, and processed for K/Ar dating and palynoassemblages.Samples from Cheslatta Falls gave K/Ar dates of 36.5 and 37.7 Ma and yielded a palynoassemblage very similar to that from the Jackson Group in Alabama and Mississippi. This Late Eocene assemblage is interpreted as having developed in a humid subtropical environment, prior to a climatic cooling that, we believe, should be assigned to Early Oligocene time.The Tertiary lavas and sediments from the Nazko area, west of Quesnel, gave three Middle Eocene dates and over 60 species of palynomorphs. These correlate with other rocks and palynoassemblages of Kamloops Group equivalents that occur southward across the International Boundary and north to latitude 55°N. The paleoclimate was wet and in the range of very warm temperate to humid subtropical.

Paleoecology of Eocene lacustrine varves at Horsefly, British Columbia

1977 ◽  
Vol 14 (5) ◽  
pp. 953-962 ◽  
Author(s):  
M. V. H. Wilson
Keyword(s):  
British Columbia ◽  
Depositional Environment ◽  
Middle Eocene ◽  
Lacustrine Sediments ◽  
Late Summer ◽  
Coarse Grained ◽  
Temperate Climate ◽  
Fish Scales ◽  
Plant Remains ◽  
Warm Temperate

Middle Eocene lacustrine sediments, cropping out in the valley of the Horsefly River, British Columbia, contain abundant fossils of fishes, fish scales, fish coprolites, insects, leaves, and diatoms. The fish scales, insects, and leaves are preserved in at least three sequences of alternating light tuff and dark sapropel laminae, separated stratigraphically by coarse-grained structureless sequences. The proportions of the main types of fossils occurring in the light laminae compared with the dark laminae are significantly different, and are consistent with the hypothesis that the laminations are varves, with dark organic winter laminae and light inorganic summer laminae. Occasional graded sandy layers contain carbonized allochthonous plant remains and represent turbidity deposits caused by storms in the drainage basin.It is proposed here that the varves were deposited in the deeper regions of a stratified, monomictic or meromictic lake in a warm temperate climate. The depositional environment was anaerobic, containing abundant hydrogen sulphide, and was free of turbulence and benthos. Fish were entombed mostly during the winter, insects during the spring and summer, coprolites during the summer, and deciduous leaves during the late summer and autumn. The fish died of starvation and (or) overturn-induced anoxia.

Shackanite and related analcite-bearing lavas in British Columbia

1978 ◽  
Vol 15 (10) ◽  
pp. 1669-1672 ◽  
Author(s):  
B.N. Church
Keyword(s):  
British Columbia ◽  
Great Depth ◽  
Bulk Rock ◽  
Rock Composition ◽  
Bulk Rock Composition ◽  
South Central ◽  
Early Tertiary ◽  
Broad Field ◽  
New Localities

New localities of shackanite and related analcite-bearing lavas have been discovered in a broad field of early Tertiary phonolite and mafic phonolite in south-central British Columbia. The development of primary and secondary analcite in these rocks is probably the result of cooling lava during and shortly after extrusion.The possibility of leucite to analcite transformation in Daly's shackanite is unlikely because of lack of petrographic evidence and a preponderance of Na2O over K2O in bulk rock composition. It is also unlikely that analcite, and particularly groundmass analcite, crystallized at great depth and was transported to surface during eruption.

Eocene age for Ag–Pb–Zn–Au vein and replacement deposits of the Kokanee Range, southeastern British Columbia

1992 ◽  
Vol 29 (1) ◽  
pp. 3-14 ◽  
Author(s):  
G. Beaudoin ◽  
J. C. Roddick ◽  
D. F. Sangster
Keyword(s):  
British Columbia ◽  
Middle Jurassic ◽  
Middle Eocene ◽  
Hanging Wall ◽  
Spatial Association ◽  
High Heat ◽  
Time Interval ◽  
Genetic Link ◽  
Metasedimentary Rocks ◽  
Magmatic Event

The Ag–Pb–Zn–Au vein and replacement deposits of the Kokanee Range, southeastern British Columbia, are hosted by the Middle Jurassic Nelson batholith and surrounding Cambrian to Triassic metasedimentary rocks in the hanging wall of the transcrustal Slocan Lake Fault, Field relations indicate that mineralization is younger than the Nelson batholith and a Middle Jurassic foliation in the Ainsworth area but coeval or older than Eocene unroofing of the Valhalla metamorphic core complex in the footwall of the Slocan Lake Fault. Lamprophyre and gabbro dykes are broadly coeval with mineralization and have biotite and hornblende K–Ar ages defining a short-lived Middle Eocene alkaline magmatic event between 52 and 40 Ma. An older, Early Cretaceous alkaline magmatic event (141 – 129 Ma) is possible but incompletely documented.K–Ar and step-heating 40Ar/39Ar analyses on hydrothermal vein and alteration muscovite indicate that hydrothermal fluids were precipitating vein and replacement deposits 58–59 Ma ago. Crosscutting relationships with lamprophyre dykes indicate the Kokanee Range hydrothermal system lasted for more than 15 Ma. Eocene crustal extension resulted in a high heat flow and structures which were probably responsible for hydrothermal fluid movement and flow paths.A 100 Ma time interval is documented between batholith emplacement and spatially associated mineralization, ruling out any genetic link between the two. Similar large age differences between granite intrusion and peripheral mineralization have recently been documented for two world-sea le Ag–Pb–Zn vein districts, which suggest that spatial association between granite and Ag–Pb–Zn mineralization is not sufficient to infer a genetic link.

Late Cretaceous and early Tertiary plutonism and deformation in the Skagit Gneiss Complex, North Cascade Range, Washington and British Columbia

1991 ◽  
Vol 103 (10) ◽  
pp. 1297-1307 ◽  
Author(s):  
RALPH A. HAUGERUD ◽  
PETER VAN DER HEYDEN ◽  
ROWLAND W. TABOR ◽  
JOHN S. STACEY ◽  
ROBERT E. ZARTMAN
Keyword(s):  
British Columbia ◽  
Late Cretaceous ◽  
Cascade Range ◽  
Gneiss Complex ◽  
Early Tertiary
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