The Coldwater Beds are a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

of the

Okanagan Highlands The Okanagan Highland is an elevated hilly plateau area in British Columbia, Canada, and the U.S. state of Washington (where it is spelled Okanogan Highlands). Rounded mountains with elevations up to above sea level and deep, narrow valleys are ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, Canada. They preserve fossils dating back to the

Ypresian In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian ...

stage of the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

, or

Wasatchian The Wasatchian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 55,400,000 to 50,300,000 years BP lasting . It is usually c ...

in the NALMA classification.Coldwater Beds
at Fossilworks.org The formation comprises mudstones, shales and

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

s deposited in a

lacustrine A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

and has provided many insect fossils, as well as indeterminate birds and fossil flora.Quilchena
at Fossilworks.org

Description

The Coldwater Beds were defined by Dawson (1895) based on a section along the Coldwater River in the

. The formation reaches a thickness of , and comprises mudstones, shales and

deposited in a

. U-Pb dating of thick

tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they re ...

, combined with Ar-Ar dates of

sanidine Sanidine is the high temperature form of potassium feldspar with a general formula K(AlSi3O8). Sanidine is found most typically in felsic volcanic rocks such as obsidian, rhyolite and trachyte. Sanidine crystallizes in the monoclinic crystal sys ...

from same bed provided an Early Eocene age. The tephra was deposited within insect-bearing shales.

Climate

During the Early Eocene, the climate of much of northern North America was warm and wet, with mean annual temperatures (MAT) as high as , mean annual precipitation (MAP) of , mild frost-free winters (coldest month mean temperature >), and climatic conditions that supported extensive temperate forest ecosystems. The Quilchena fossil locality is dated to 51.5 ± 0.4 Ma corresponding to the Early Eocene Climatic Optimum (EECO), and is reconstructed as the warmest and wettest of the Early Eocene upland sites from the Okanagan Highlands of British Columbia and northern Washington State. Mean annual temperature (MAT) is estimated from leaf margin analysis as and . Using bioclimatic analysis of 45 nearest living relatives, a moist mesothermal climate is indicated (MAT ; cold month mean temperature (CMMT) and mean annual precipitation (MAP) of /yr. Leaf size analysis estimates MAP at /y.Mathewes, 2015, p.2

Fossils

Buprestis saxigena Scudder 1890 pl2 Fig24

Buprestis sepulta Scudder 1890 pl2 Fig26

Buprestis tertiaria Scudder 1890 pl2 Fig23

Cercyon terrigena Scudder 1890 pl2 Fig21

Nebria paleomelas Scudder 1890 pl2 Fig20

A wide variety of fossils occur in the formation, including abundant fish remains,

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s, and plants, and rare occurrences of molluscs,

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typi ...

s, and

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

Flora

Fossil plants were first reported from the Coldwater Beds at the Quilchena site and nearby by Penhallow (1908) with an expanded taxonomic list given by Mathewes ''et al'' (2016). ;Pteridophytes *''

Azolla ''Azolla'' (mosquito fern, duckweed fern, fairy moss, water fern) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, looking nothing like other typical ferns but more rese ...

'' ;Ginkgophytes *''

Ginkgo ''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus with ...

'' ;Pinophytes *''

Abies Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related t ...

'' * cf ''Amentotaxus'' *''

Calocedrus ''Calocedrus'', the incense cedar (alternatively spelled incense-cedar), is a genus of coniferous trees in the cypress family Cupressaceae first described as a genus in 1873. It is native to eastern Asia and western North America. The generic n ...

'' *'' Chamaecyparis'' *''

Glyptostrobus ''Glyptostrobus'' is a small genus of conifers in the family Cupressaceae (formerly in the family Taxodiaceae). The sole living species, '' Glyptostrobus pensilis'', is native to subtropical southeastern China, from Fujian west to southeast Yu ...

'' *''

Keteleeria ''Keteleeria'' is a genus of three species of coniferous trees in the family Pinaceae first described as a genus in 1866. The genus name ''Keteleeria'' honours J.B. Keteleer (1813–1903), a French nurseryman. The group is related to the genera ...

'' *''

Metasequoia ''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of conifers known as redwoods. The living species '' Metasequoia glyptostroboides'' is native to Lichuan county in Hubei province, China. Althou ...

'' *'' Picea'' *''

Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden ...

'' *''

Pseudolarix ''Pseudolarix'' is a genus of coniferous trees in the pine family Pinaceae containing three species, the extant '' Pseudolarix amabilis'' and the extinct species '' Pseudolarix japonica'' and '' Pseudolarix wehrii''. ''Pseudolarix'' species are ...

'' *'' Sequoia'' *''

Taxodium ''Taxodium'' is a genus of one to three species (depending on taxonomic opinion) of extremely flood-tolerant conifers in the cypress family, Cupressaceae. The generic name is derived from the Latin word ''taxus'', meaning "yew", and the Greek ...

'' *''

Thuja ''Thuja'' ( ) is a genus of coniferous tree or shrub in the Cupressaceae (cypress family). There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to ''Thujopsis''. M ...

'' *''

Tsuga ''Tsuga'' (, from Japanese (), the name of ''Tsuga sieboldii'') is a genus of conifers in the subfamily Abietoideae of Pinaceae, the pine family. The common name hemlock is derived from a perceived similarity in the smell of its crushed folia ...

'' ;Angiosperms *'' Acer'' * cf. ''Aesculus'' *†''

Alnus parvifolia ''Alnus parvifolia'' is an extinct species of flowering plant in the family Betulaceae related to the modern birches. The species is known from fossil leaves and possible fruits found in early Eocene sites of northern Washington (state), Washing ...

'' *†'' Betula leopoldae'' *

Bignoniaceae Bignoniaceae is a family of flowering plants in the order Lamiales commonly known as the bignonias or trumpetvines.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Book ...

*†'' Castaneophyllum'' *†'' Comptonia columbiana'' *''

Cornus ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrub ...

'' *''

Corylopsis ''Corylopsis'' is a genus of nearly 30 species of shrubs in the witch hazel family, Hamamelidaceae, native to eastern Asia with the majority of species endemic to China but with some also in Japan, Korea, and the Himalayas. This genus is also ...

'' *''

Dipteronia ''Dipteronia'' is a genus with two living and one extinct species in the soapberry family Sapindaceae. The living species are native to central and southern China, The fossil species has been found in Middle Paleocene to Early Oligocene sediments ...

'' * cf. ''Disanthus'' *†''

Eucommia montana ''Eucommia montana'' is an extinct species of flowering plant in the family Eucommiaceae. ''E. montana'' is known from fossil fruits found in Eocene deposits of the northwestern United States southeastern British Columbia south to Oregon and e ...

'' *†''

Eucommia rolandii ''Eucommia rolandii'' is an extinct species of flowering plant in the family Eucommiaceae. ''E. rolandii'' is known from four fossil leaves found in Middle Eocene deposits of British Columbia, Canada and Mississippi, United States. ''E. rolan ...

'' * cf. ''Exbucklandia'' *''

Fagus Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

'' *†'' Florissantia quilchenensis'' *'' Fraxinus'' *'' Hovenia'' *†'' Joffrea''/'' Nyssidium'' *'' Nyssa'' *'' Pieris'' *†'' Plafkeria'' * cf. ''Pterocarya'' *'' Rhus'' * cf. ''Sambucus'' *''

Sassafras ''Sassafras'' is a genus of three extant and one extinct species of deciduous trees in the family Lauraceae, native to eastern North America and eastern Asia.Wolfe, Jack A. & Wehr, Wesley C. 1987. The sassafras is an ornamental tree. "Middle ...

'' *''

Ternstroemia ''Ternstroemia'' is a genus of flowering plants in the family Pentaphylacaceae. It is distributed in tropical and subtropical regions in Africa, Asia, and the Americas. * cf. ''Gordonia'' *'' Tilia'' *''

Trochodendron ''Trochodendron'' is a genus of flowering plants with one living species, '' Trochodendron aralioides'', and six extinct species known from the fossil record. It was often considered the sole genus in the family Trochodendraceae, though botanist ...

'' *†''

Ulmus okanaganensis ''Ulmus okanaganensis'' is an extinct species of flowering plant in the family Ulmaceae related to the modern elms. The species is known from fossil leaves, flowers, and fruits found in the early Eocene deposits of northern Washington state, Un ...

Pollen taxa

;Ginkgophytes *''

'' ;Pinophytes *'' Picea'' *''

'' * cf ''Sciadopitys'' *''

'' ;Angiosperms *''

Alnus Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

'' *''

Carya Hickory is a common name for trees composing the genus ''Carya'', which includes around 18 species. Five or six species are native to China, Indochina, and India (Assam), as many as twelve are native to the United States, four are found in Mexi ...

'' *†'' Liliacidites'' *''

Liquidambar ''Liquidambar'', commonly called sweetgum (star gum in the UK), gum, redgum, satin-walnut, or American storax, is the only genus in the flowering plant family Altingiaceae and has 15 species. They were formerly often treated in Hamamelidaceae ...

'' *†'' Pistillipollenites mcgregorii'' * cf. ''Platanus'' *''

Pterocarya ''Pterocarya'', often called wingnuts in English, are trees in the walnut family Juglandaceae. They are native to Asia. The botanic name is from Ancient Greek (''pteron'') "wing" + (''karyon'') " nut". Description ''Pterocarya'' are deciduous ...

'' *†'' Sabal ?florisanti'' *'' Tilia'' *''

Ulmus Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of Nor ...

Molluscs

Mark Wilson (1987) noted, without taxonomic identification, that unidentified small bivalves are a component of the Quilchena invertebrate paleofauna.

Insects

The insect fossils studied by Wilson (1987) showed Bibionidae dominating the paleoentemofauna, at 28% of all specimens examined at that time. An additional 13% of the fossils were other dipterans while up to 41% of all insects still had attached wings. The invertebrates trace fossils included two undescribed species of Trichoptera larval cases and burrowing or tracks in the sediment. ;Blattaria * Diplopterinae indet. ;Coleoptera * '' cf. Amara sp.'' * †'' Buprestis saxigena'' * †'' Buprestis sepulta'' * †'' Buprestis tertiaria'' * Carabidae indet. * †'' Cercyon? terrigena'' * Curculionidae indet. * cf. Erotylidae indet. * †'' Nebria paleomelas'' * Omaliinae indet. * Pachymerina sp. * Scarabaeoidea indet. ;Dermaptera * Forficulina indet. ;Diptera * '' Plecia angustipennis'' * '' Plecia canadensis'' * '' Plecia pictipennis'' * Mycetophilidae indet. * Pipunculidae indet. * Pipunculinae indet. * Pleciinae indet. * Syrphidae indet. * Tipulidae indet. ;Hemiptera * '' Telmatrechus defunctus'' * Aphididae indet. * Cercopoidea indet. * Cicadellidae indet. * Cydnidae indet. * Gerridae indet. * Megymeninae indet. * cf. Pentatomidae indet. ;Hymenoptera * '' Eosphecium naumanni'' * '' Halictus? savenyei'' * Braconidae indet. * Formicidae indet. * Ichneumonidae indet. * Tenthredinidae indet. * Trigonalidae indet. * Vespidae indet. ;Mecoptera * '' Eorpa jurgeni'' * ''Eorpa (genus), Eorpa sp.'' * ''Panorpoidea, Panorpoidea sp.'' ;Neuroptera * ''Polystoechotites, Polystoechotites sp.'' * ''Palaeopsychops dodgeorum'' * ''Palaeopsychops douglasae'' * ''Wesmaelius mathewesi'' ;Orthoptera * Prophalangopsidae, Prophalangopsidae indet. ;Trichoptera * Phryganeidae, Phryganeidae indet. * Trichoptera, Trichoptera indet.

Fish

*''Amia (fish), Amia sp.'' scales *''Amyzon (genus), Amyzon brevipinne''

Birds

* Aves, Aves indet. feathers

Mammals

* Insectivore, Insectivorous mammalian indet. tooth

Correlations

The formation has been correlated with the Eocene Okanagan Highlands floras including the Allenby Formation, Kamloops Group, Horsefly shales, and Driftwood Canyon Provincial Park, Driftwood Canyon site of

, along with the Klondike Mountain Formation of Washington State. Additionally its correlated with the Margaret Formation of Ellesmere Island, Nunavut, the Chickaloon Formation of Alaska, Wishbone Formation, Wishbone, Chuckanut Formation, Chuckanut and Iceberg Bay Formations, all of similar age. The flora of the Coldwater Beds has been correlated to the Chu Chua Formation of southeastern British Columbia. The formation also correlates with the Springbrook Formation, Springbrook, Kettle River Formation, Kettle River and O'Brien Creek Formations in Washington, United States.

References

{{reflist, 3 Ypresian North America Paleontology in British Columbia Coldwater Beds

Description

Climate

Fossils

Flora

Pollen taxa

Molluscs

Insects

Fish

Birds

Mammals

Correlations

See also

References