page_title: Green River Formation
hierarchical_section_title: Green River Formation
caption_attribution_description: Deutsch: Priscacara liops Fundort: Fossil-Lake, Wyoming, USA Zeitalter&#160;: Eozän - 55,8 Millionen Jahren und dauerte bis vor etwa 33,9 Millionen Jahren Größe: 11.5cm English: Priscacara liops Stage&#160;: Eocene from 55,8 ± 0,2 Ma to 33,9 ± 0,1 Ma (million years ago) Locality: Fossil-Lake, Wyoming, USA Size&#160;: 11.5 cm Français&#160;: Priscacara liops Etage&#160;: Eocène 55,8 ± 0,2 à 33,9 ± 0,1 millions d’années avant le présent, Green River Formation. Localité: Fossil-Lake, Wyoming États-Unis Taille: 11,5 cm
context_page_description: The Green River Formation is an Eocene rock formation on the eastern side of the Rocky Mountains. It records sediment from a group of intermountain lakes. Its fine fossils make this a lagerstätte, a place of exceptional preservation.
  The various fossil beds of the Green River Formation span a 5 million year period, dating to between 53.5 and 48.5 million years ago. During this period the climate moved from the moist early Eocene climate and the slightly drier mid-Eocene.
  The sediments are deposited in very fine layers, in pairs: a dark layer from the growing season, and a light-hue inorganic layer in winter.
  Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
  The sedimentary layers were formed in a large area named after the present-day Green River, a tributary of the Colorado River. The formation is in three separate basins around the Uinta Mountains of northeastern Utah:
  an area in northwestern Colorado east of the Uintas
context_section_description: The Green River Formation is an Eocene rock formation on the eastern side of the Rocky Mountains. It records sediment from a group of intermountain lakes. Its fine fossils make this a lagerstätte, a place of exceptional preservation.
  The various fossil beds of the Green River Formation span a 5 million year period, dating to between 53.5 and 48.5 million years ago (mya). During this period the climate moved from the moist early Eocene climate and the slightly drier mid-Eocene.
  The sediments are deposited in very fine layers, in pairs: a dark layer from the growing season, and a light-hue inorganic layer in winter.
  Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
  The sedimentary layers were formed in a large area named after the present-day Green River, a tributary of the Colorado River. The formation is in three separate basins around the Uinta Mountains of northeastern Utah:
  an area in northwestern Colorado east of the Uintas
  a larger area in the southwest corner of Wyoming just north of the Uintas known as Lake Gosiute
  another area, in Fossil Butte National Monument, Lincoln County, Wyoming is Fossil Lake. It has exceptionally well preserved fish fossils. The most productive zone — the split fish layer — is a series of laminated or varved lime muds about 6 ft (1.8 m) thick. They contains abundant fish and other fossils. The rock is easily split along the layers to reveal the fossils. This thin zone took about 4000 years to deposit.
  the largest area, in northeastern Utah and western Colorado south of the Uintas, known as Lake Uinta
caption: Fossil fish from Fossil Butte National Monument
exif: {"Image ImageDescription": "Priscacara liops Green River Formation", "Image Make": "SONY", "Image Model": "DSLR-A850", "Image Orientation": "Horizontal (normal)", "Image XResolution": "240", "Image YResolution": "240", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS5 Windows", "Image DateTime": "2011:02:20 10:15:44", "Image Artist": "Didier Descouens", "Image ExifOffset": "2392", "Image XPTitle": "[80, 0, 114, 0, 105, 0, 115, 0, 99, 0, 97, 0, 99, 0, 97, 0, 114, 0, 97, 0, ... ]", "Image XPAuthor": "Didier Descouens", "Image XPKeywords": "[80, 0, 114, 0, 105, 0, 115, 0, 99, 0, 97, 0, 99, 0, 97, 0, 114, 0, 97, 0, ... ]", "Image Padding": "[]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "5208", "Thumbnail JPEGInterchangeFormatLength": "4788", "EXIF ExposureTime": "1/160", "EXIF FNumber": "13", "EXIF ExposureProgram": "Manual", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2011:02:20 10:03:08", "EXIF DateTimeDigitized": "2011:02:20 10:03:08", "EXIF ShutterSpeedValue": "915241/125000", "EXIF ApertureValue": "7400879/1000000", "EXIF BrightnessValue": "3/2", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF LightSource": "Flash", "EXIF Flash": "Flash fired, compulsory flash mode", "EXIF FocalLength": "105", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "5736", "EXIF ExifImageLength": "3258", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Manual Exposure", "EXIF WhiteBalance": "Manual", "EXIF FocalLengthIn35mmFilm": "105", "EXIF SceneCaptureType": "Standard", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF Padding": "[]"}