Longiscitula houghae; a new genus of dissorophid amphibian from the Permian of Texas / Robert E. DeMar, Asst. Professor of Geology, University of Illinois, Chicago Circle Campus.

v.16:no.2(1966)

Famous diamonds/ by Oliver C. Farrington, Curator of Geology.

no.10(1929)

A classification of the Conularida / G. Winston Sinclair, Dept. of Geology, University of Michigan.

v.10:no.13(1952)

Amber: its physical properties and geological occurrence / by Oliver C. Farrington, Curator of Geology.

no.3(1923)

Meteorites / by Oliver C. Farrington, Curator of Geology.

no.4(1923)

Introduction and index to Fieldiana: Geology volume 33 / Eugene S. Richardson, Jr. -- William D. Turnbull --.

v.33:no.31(1981)

Cement / by Henry W. Nichols, Assoc. Curator of Geology.

no.12(1929)

The Mammalian faunas of the Washakie Formation, Eocene Age, of Southern Wyoming. Introduction: The geology, history, and setting / William D. Turnbull --.

v.33:no.30(1978)

Rhode Island, Geology, 1840 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A geological map of Rhode-Island, by Charles T. Jackson. It was published in 1840. Scale [1:190,080]. Covers Rhode Island and a portion of southeastern Massachusetts. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Rhode Island State Plane Coordinate System (Feet) (FIPS 3800). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as geological features, mines, mills, railroads, hotels, selected residences with names of property owners, drainage, town and county boundaries, and more. Relief shown by hachures. This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Chicago, Illinois, surficial geology, 1936 (Raster Image)

This layer is a georeferenced raster image of the historic, paper map entitled: Surficial geology of the Chicago Loop quadrangle, by J. Harlen Bretz. It was published by State Geological Survey Division ca. 1936. Scale 1:24,000. Topographic base surveyed in cooperation with the U.S. Geological Survey, 1926; 1936. Geologically surveyed 1930-1932. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Illinois East State Plane Coordinate System NAD27 (in Feet) (Fipszone 1201). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This is a typical topographic map colored to show surficial geology. It portrays both natural and manmade features. It shows and names works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. It also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 5 feet. Includes legend and map index. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

A Mineralogical Study of a Dravitic Tourmaline from the Grenville Province

Tourmaline from a gem-quality deposit in the Grenville province has been studied with X-ray diffraction, visible-near infrared spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, electron microprobe and optical measurements. The tourmaline is found within tremolite-rich calc-silicate pods hosted in marble of the Central Metasedimentary Belt. The crystals are greenish-greyish-brown and have yielded facetable material up to 2.09 carats in size. Using the classification of Henry et al. 2011 the tourmaline is classified as a dravite, with a representative formula shown to be (Na0.73Ca0.2380.032)(Mg2+2.913Fe2+0.057Ti4+0.030) (Al3+5.787Fe3+0.017Mg2+0.14)(Si6.013O18)(BO3)3(OH)3((OH,O)0.907F0.093). Rietveld analysis of powder diffraction data gives a = 15.9436(8) Å, c = 7.2126(7) Å and a unit cell volume of 1587.8 Å3. A polished thin section was cut perpendicular to the c-axis of one tourmaline crystal, which showed zoning from a dark brown core into a lighter rim into a thin darker rim and back into lighter zonation. Through the geochemical data, three key stages of crystal growth can be seen within this thin section. The first is the core stage which occurs from the dark core to the first colourless zone; the second is from this colourless zone increasing in brown colour to the outer limit before a sudden absence of colour is noted; the third is a sharp change from the end of the second and is entirely colourless. These events are the result of metamorphism and hydrothermal fluids resulting from nearby felsic intrusive plutons. Scanning electron microscope, and electron microprobe traverses across this cross-section revealed that the green colour is the result of iron present throughout the system while the brown colour is correlated with titanium content. Crystal inclusions in the tourmaline of chlorapatite, and zircon were identified by petrographic analysis and confirmed using scanning electron microscope data and occur within the third stage of formation.

Age constraints on the tectonic evolution of the Itremo region in Central Madagascar

The Itremo region in Central Madagascar comprises a deformed metasedimentary sequence (Itremo Group) that has undergone greenschist to lower amphibolite facies metamorphism. During a first phase of deformation (D1) Itremo Group sediments were deformed into a fold-and-thrust belt and transported toward the E to NE on top of migmatitic gneisses rocks of Anatananarivo block. A second phase of deformation (D2) affected both the fold-and-thrust belt and structurally underlying units, and formed large-scale N-S trending folds with steeply dipping axial planes. A Late Neoproterozoic Th–U–Pb XRF monazite age (565±17 Ma) dates the emplacement of a granite that truncates first-phase structures in the Itremo Group, and indicates that the fold-and-thrust belt formed prior to ≈565 Ma. Th–U–Pb electron microprobe dating was applied to elongated monazites that lie within the first-phase foliation of Itremo Group metapelites. The detrital cores of zoned monazites reveal two distinct age populations at ∼2000 and 1700 Ma, the latter age giving a maximum depositional age for the Itremo Group. Statistical analysis of ages determined from the rims of zoned monazites and from unzoned monazites indicates three Late Proterozoic–Early Paleozoic monazite growth events at about 565–540, 500 and 430 Ma. The oldest age population is contemporaneous within error, with the intrusion of the dated granite. The two younger age populations are found both in the Th–U–Pb and Ar–Ar data; together with the perturbation of the Rb–Sr system we interpret both ages as due to alteration related to fluid circulation events, possibly connected to the emplacement of pegmatite fields in Central Madagascar. Syn-D1 tectonic growth of contact metamorphism minerals such as andalusite has been observed locally in metapelites along the margin of Middle Neoproterozoic (≈800 Ma) granites, suggesting that D1 in the Itremo Group is contemporaneous with the intrusion of granites at ≈800 Ma. The N-S trending D2 folds are associated with ≈E-W shortening during the final assembly of Gondwana in Late Neoproterozoic–Early Cambrian times.