page_title: Contact (geology)
section_title: Angular unconformity
hierarchical_section_title: Contact (geology) / Types of contacts / Depositional / Non-conformable / Angular unconformity
caption_attribution_description: English: Hutton's Unconformity, Siccar Point Famous for Hutton's observations that provided evidence for geological evolution. Here, Silurian greywackes, laid down approximately 425 million years ago are underneath Devonian sandstone deposited approximately 345 million years ago. More information here http://www.geos.ed.ac.uk/undergraduate/field/siccarpoint/
context_page_description: A geological contact is a boundary which separates one rock body from another. There are three different types of contacts, which are divided into primary contacts and secondary contacts. Primary contacts include depositional, unconformable, and intrusive contacts. Secondary contacts include those induced by tectonic activity such as fault contacts and shear zones.
context_section_description: This type of unconformity separates layers above and below that are not parallel to each other. Relatively flat younger strata overlay steeply dipping older strata. An example of this type of unconformity is the Hutton Unconformity at Siccar Point, Scotland, UK. Other angular unconformities may not be as obvious. Regional context is essential when identifying angular unconformities.
caption: Hutton's Angular Unconformity, Siccar Point, Scotland, UK.
exif: {"Image Make": "Canon", "Image Model": "Canon PowerShot S80", "Image Orientation": "Horizontal (normal)", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2006:04:22 18:57:43", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "196", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "180", "Thumbnail YResolution": "180", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1530", "Thumbnail JPEGInterchangeFormatLength": "13324", "EXIF ExposureTime": "1/6", "EXIF FNumber": "16/5", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:04:22 18:57:43", "EXIF DateTimeDigitized": "2006:04:22 18:57:43", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "83/32", "EXIF ApertureValue": "107/32", "EXIF ExposureBiasValue": "0", "EXIF Flash": "80", "EXIF FocalLength": "909/125", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3264", "EXIF ExifImageLength": "2448", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "3264", "Interoperability RelatedImageLength": "2448", "EXIF InteroperabilityOffset": "1358", "EXIF FocalPlaneXResolution": "1632000/143", "EXIF FocalPlaneYResolution": "1224000/107", "EXIF FocalPlaneResolutionUnit": "2", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Custom", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Manual", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Landscape"}