| Database to accompany geologic map of the Katmai Volcanic Cluster, Katmai National Park, Alaska | |
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Data format: ArcInfo Coverage File or table name: a2-bndry Coordinate system: Transverse Mercator Theme keywords: volcanoes, pumice, geology, 1912, stratovolcano, explosive eruptions, lava flows |
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Abstract:
This digital publication contains all the geologic map information used to publish U.S. Geological Survey Geologic Investigations Map Series I-2778 (Hildreth and Fierstein, 2003). This is a geologic map of the Katmai volcanic cluster on the Alaska Peninsula (including Mount Katmai, Trident Volcano, Mount Mageik, Mount Martin, Mount Griggs, Snowy Mountain, Alagogshak volcano, and Novarupta volcano), and shows the distribution of ejecta from the great eruption of June, 1912 at Novarupta. Widely scattered erosional remnants of volcanic rocks, unrelated to but in the vicinity of the Katmai cluster, are also mapped. Distribution of glacial deposits, large landslides, debris avalanches, and surficial deposits are a snapshot of an ever-changing landscape. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
This digital publication contains all the geologic map information used to publish U.S. Geological Survey Geologic Investigations Map Series I-2778 (Hildreth and Fierstein, 2003). This is a geologic map of the Katmai volcanic cluster on the Alaska Peninsula (including Mount Katmai, Trident Volcano, Mount Mageik, Mount Martin, Mount Griggs, Snowy Mountain, Alagogshak volcano, and Novarupta volcano), and shows the distribution of ejecta from the great eruption of June, 1912 at Novarupta. Widely scattered erosional remnants of volcanic rocks, unrelated to but in the vicinity of the Katmai cluster, are also mapped. Distribution of glacial deposits, large landslides, debris avalanches, and surficial deposits are a snapshot of an ever-changing landscape.
This database was constructed in order to produce a geologic map as a basis for understanding processes involved in the eruptions that built the Katmai volcanoes and to produce a volcano hazards assessment of the Katmai area.
All the geologic map information used to publish U.S. Geological Survey Geologic Investigations Series I-2778 is contained in this digital publication. This map shows the distribution and relations of volcanic and bedrock units in an area of Katmai National Park and vicinity. This metadata document contains information for the entire set of ArcInfo coverages included in this database. Where relevant information for individual coverages differs from that of the others, each coverage is documented separately in sequence in that metadata section. The following coverages are documented here: (the quadrangle name is represented by wildcard characters, **) **-geo, geologic polygons; **-bndry, quadrangle boundary; isopach, isopach map; samps, radiometric sample locations; vents, vent locations; struc, locations of structure measurements.
The information in this report is the most up-to-date available at the time of publication.
Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited for a scale of 1:63,360 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:63,360 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data. Acknowlegdement of the U.S. Geological Survey would be appreciated in products derived from these data.
Volcano Hazards Team, MS 910
preferred contact by e-mail
The database was compiled mainly in 1996-2001 from original geologic mapping by Wes Hildreth and Judy Fierstein (Hildreth and Fierstein, 2003). Initial preparation of the database was done by Tracey Felger. Joel Robinson and Dave Ramsey provided most of the GIS-expertise to bring the database and metadata to completion.
See Entity_Attribute_Information
Polygon and arc (chain-node) topology present in appropriate ArcInfo coverages. Other coverages are point, annotation or raster and do not require topologic relationships.
The report is intended to describe completely the igneous and volcanic products, volcanic vent locations, structural features and structural measurements at 1:63,360 scale. Geological information appropiatley mapped at larger scale has been omitted.
Well located data items are intended to have a horizontal poitional accuracy better than 0.5 mm at 63,360 scale, or within 31 meters on the ground. The general positional accuracy of each line in the database is indicated qualitatively within the LTYPE field in the Arc Attribute Table (see Attribute_Domain_Values). Points in the database are generally well located. The position of each data item is derived from a USGS 1:63,360 topographic base map, and therefore additonal inaccuracies may also be encountered that are within National Map Accuracy Standards.
No vertical positional data recorded
reference for identifying Horseshoe Island, now buried under Katmai caldera lake; and first recorded sighting of fumarole field on lower SE flank of Trident I
First recorded description of the "Mageik Landslide"
First-hand descriptions of Horseshoe Island (which is now buried under 250 m of lakewater)
First-hand descriptions of Horseshoe Island (which is now buried under 250 m of lakewater)
Horseshoe Island observations
Horseshoe Island observations, Katmai phreatic mud layers (description, interpretation)
geologic map
West Mageik Lake sill complex, interpretation
West Mageik Lake sill complex, interpretation
Tertiary volcanic rocks, commonly altered, are widespread north and south of upper Katmai River as mapped by Riehle and others, 1993. These are lumped with other basement rocks in unit bu by Hildreth and Fierstein (2003), as the rocks are unmapped and unstudied by those authors.
Distribution of Novarupta 1912 ejecta
interpretation of seismic records from 1912 eruption
Geologic linework was compiled on USGS 1:63,360 topographic maps by Hildreth and Fierstein. The linework was then scanned at 400 dpi, georeferenced, converted to vector data using the ArcInfo command GRIDLINE , and edited on-screen to repair errors visible at map scale by Joel E Robinson, David W Ramsey and Tracy Felgar. Polygon topology was created and each arc and polygon tagged on-screen. Structural information was digitized by hand on-screen. Plotfiles were created in ArcPlot. Individual quadrangles were then plotted with topography and check by Hildreth and Fierstein. Metadata created.
345 Middlefield Road
MS 910
Metadata imported.
Metadata imported.
Internal node number for the beginning of an arc (from-node).
ESRI
Internal node number for the end of an arc (to-node).
ESRI
Internal node number for the left polygon.
ESRI
Internal node number for the right polygon.
ESRI
Length of feature in internal units.
ESRI
Internal feature number.
ESRI
User-defined feature number.
ESRI
Internal feature number.
author
Boundary between geologic units; well located
authors
boundary between geologic units, approximately located
authors
boundary between geologic units, concealed
authors
boundary between individual lava flows within the same geologic unit
authors
boundary between geologic units, inferred
authors
margin of glacial ice
topographic base map, ice margins modified by authors
boundary of geologic unit (khi) concealed by 250 m of lakewater
Griggs, 1922; Fenner, 1930, 1950; authors
margin of body of water
topographic base map, authors
margins of map
authors
boundary between geologic unit and unmapped terrain
authors
margin of caldera
authors
margin of phreatic crater
authors
margin of volcanic crater
authors
headwall scarp of landslide
authors
crest of ejecta ring that accumulated around Novarupta vent
authors
arcuate faults around Novarupta vent
authors
rhyolite sills of West Mageik Lake (Pliocene)
Lowenstern and Mahood, 1991; Lowenstern and others, 1991; authors
Tertiary porphyritic granitoid dikes (Pliocene? and Miocene)