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The table contains oxide and cation compositions of olivine grains from drill core of the Duluth Complex, Minnesota. The oxides were determined by electron probe microanalysis (EPMA) and are reported in weight percent (wt%). The cations were calculated based on the oxide compositions and are reported in mole percent (mol%). Olivine is a magnesium iron orthosilicate mineral with the formula (Mg2+, Fe2+)2SiO4. Olivine forms a solid solution series with magnesium (Mg) at one end and iron (Fe) at the other. Forsterite (Mg2SiO4) is the magnesium endmember and fayalite (Fe2SiO4) is the iron endmember. Minor elements can substitute into the crystal structure, such as manganese (Mn) and nickel (Ni). To better understand...
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The table contains oxide and cation compositions of pyroxene grains from drill core in the Duluth Complex. The oxides were determined by electron probe microanalysis (EPMA) and are reported in weight percent (we%). The cations were calculated from the oxide concentrations and are reported in mole percent (mol%). Pyroxene minerals are a group of rock-forming inosilicate minerals with calcium (Ca), iron (Fe), and magnesium (Mg) endmembers. Wollastonite (Wo) is the Ca-endmember with the formula Ca2Si2O6. Ferrosilite (Fs) is the Fe-endmember with the formula Fe2Si2O6, and enstatite (En) is the Mg-endmember with the formula Mg2Si2O6. In order to better understand the chemical compositions of the pyroxenes, the percent...
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The table contains oxide and cation compositions of feldspar grains from drill core of the Duluth Complex. The oxides were determined by electron probe microanalysis (EPMA) and are are reported in weight percent (wt%). The cations were then calculated and are reported in mole percent (mol%). Feldspar grains are a group of rock-forming tectosilicate minerals with potassium (K), sodium (Na), and calcium (Ca) endmembers. Anorthite has a chemical formula CaAlSi3O8; albite has the formula NaAlSi3O8; and orthoclase has the chemical formula KAlSi3O8. To better understand the composition of the measured feldspars, we calculated the anorthite content (An%) as (Ca/(Ca+Na+K)) x 100 and report the values in mol%. Albite (Ab%)...
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This report is one in a series of digital maps, data files, and reports generated by the US Geological Survey (USGS) to provide geologic information for the Interior Columbia Basin Ecosystem Management Project (ICBEMP), a US Forest Service and Bureau of Land Management interagency project. The various digital maps and data files that were provided by teh USGS and that are available in this and other reports are being used in a geographic information system (GIS)-based ecosystem assessment. The assessment will include a comprehensive analysis of past, present, and future ecosystem conditions within the general area of the Columbia River Basin east of the Cascade Mountains.
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This table reports major, minor, and trace element compositions of bulk drill core samples from the Duluth Complex, Minnesota. Major elements were measured using wavelength dispersive X-ray fluorescence (XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES); minor and trace elements were determined using ICP-AES, inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HGAAS). Total carbon, carbonate carbon, and total sulfur were also analyzed. Total carbon was measured by combustion followed by infrared detection on LECO instrumentation. Carbonate carbon in the bulk rock samples was determined as carbon dioxide by coulometric titration. Total...
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The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have been compiled from 52 studies, documenting 59 sites from northern California to Vancouver Island, British Columbia that contain known or potential tsunami deposits. Bibliographical references are provided for all sites included in the database. Cascadia tsunami deposits are usually seen as anomalous sand layers in coastal marsh or lake sediments. The studies cited in the database use numerous criteria based on sedimentary characteristics to distinguish tsunami deposits from sand layers deposited by other processes, such as river flooding and storm surges....


    map background search result map search result map Low- to moderate-temperature geothermal springs and wells in the Pacific Northwest Cascadia tsunami deposit database Oxide and Cation Compositions of Pyroxene Grains from Drill Core of the Duluth Complex, Minnesota Oxide and Cation Compositions of Olivine Grains from Drill Core in the Duluth Complex, Minnesota Major, Minor, and Trace Element Compositions of Bulk Drill Core Samples from the Duluth Complex, Minnesota Oxide and Cation Compositions of Feldspar Grains from Drill Core of the Duluth Complex, Minnesota Oxide and Cation Compositions of Pyroxene Grains from Drill Core of the Duluth Complex, Minnesota Oxide and Cation Compositions of Olivine Grains from Drill Core in the Duluth Complex, Minnesota Major, Minor, and Trace Element Compositions of Bulk Drill Core Samples from the Duluth Complex, Minnesota Oxide and Cation Compositions of Feldspar Grains from Drill Core of the Duluth Complex, Minnesota Low- to moderate-temperature geothermal springs and wells in the Pacific Northwest Cascadia tsunami deposit database