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The Sheahan Diamond Literature Reference Compilation - Scientific and Media Articles based on Major Keyword - Orogeny
The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcements called the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The references are for personal use information purposes only; when available a link is provided to an online location where the full article can be accessed or purchased directly. Reproduction of this compilation in part or in whole without permission from the Sheahan Diamond Literature Service is strictly prohibited. Return to Diamond Keyword Index
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years
Each article reference in the SDLRC is tagged with one or more key words assigned by Pat Sheahan to highlight the main topics of the article. In an effort to make it easier for users to track down articles related to a specific topic, KRO has extracted these key words and developed a list of major key words presented in this Key Word Index to which individual key words used in the article reference have been assigned. In most of the individual Key Word Reports the references are in crhonological order, though in some such as Deposits the order is first by key word and then chronological. Only articles classified as "technical" (mainly scientific journal articles) and "media" (independent media articles) are included in the Key Word Index. References that were added in the most recent monthly update are highlighted in yellow.
Orogeny refers to what happens when tectonic plates encounter each other, something which lay people might characterize as transformational ecstasy but which geologists less imaginatively characterize as "deformation". If the encounter involves a denser oceanic plate and a lighter continental crust, the result will be subduction as the denser oceanic plate slides beneath the lighter continental crust. Subduction releases energy in the form of heat which causes melting that drives magmatism which in turn builds mountain chains through igneous intrusions or volcanic extrusions. When blocks of continental crust with similar density collide, the result can be mountain building in the style of the Rockies, the Alps or the Himalayas which force existing crust skywards. Alternatively the energy generated through the collision can result in deformation, the compression of crustal rocks so that they undergo folding and metamorphism on a regional scale. Because this activity takes place close to the earth's surface there is not much relevance to diamonds, but it is of great relevance to deposit formation both because of structural preparation created by deformation and because of large scale "orogenic" fluid mobilization which harvests metals from crustal rocks and drops them out under the right geochemical and structural conditions.
Harper, C.T., Van Breeman, O., Wodick,N., Pehrsson, S., Heaman, L., Hartlaub, R.
The Paleoproterozoic lithostructural history and thermotectonic reactivation of the Archean basement in southern Hearne domain of northeastern Saskatchewan.
GAC Annual Meeting Halifax May 15-19, Abstract 1p.
Upper mantle temperature determined from combining mineral composition, electrical conductivity laboratory studies and magnetotelluric field observations.
Earth and Planetary Science Letters, Advanced in press,
Chalapathi Rao, N.V., Burgess, R., Anand, M., Mainkar, D.
Evidence for a Phanerozoic (478 Ma) Diamondiferous kimberlite emplacement epoch in the Indian Shield from 40 Ar/ 39Ar dating of the Kodomali kimberlite: implications ....
Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 103-106.
India, Bastar Craton, Rodinia
Tectonics - Kodomali, Pan African , Geothermometry
Trace element fractionation during high grade metamorphism and crustal melting - constraints from ion microprobe dat a of metapelitic, migmatitic and igneous garnets and implications for Sn Nd garnet chronology
Two episodes of zircon growth due to fluid availablility during subduction and exhumation of continental crust: U Pb age, Hf and O isotope evidence from ultrahigh pressure eclogite
Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 259-260.
Two episodes of zircon growth due to fluid availablility during subduction and exhumation of continental crust: U Pb age, Hf and O isotope evidence from ultrahigh pressure eclogite
Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 259-260.
St.Onge, M.R., Van Gool, A.M., Garde, A.A., Scott, D.J.
Correlation of Archean and paleoproterozoic units between northeastern Canada and western Greenland: constraining the pre-collisional upper plate accretionary history
Geological Society of London, Special Publication Earth Accretionary systems in Space and Time, No. 318, pp. 193-235.
Abstract: Strata in the Huron (2.5-2.0 Ga) and Animikie (2.2-1.85 Ga) basins were deposited on the southern margin of the Archean Superior province. These rocks were deformed during the Penokean orogeny (?1850 Ma) followed by subsequent accretionary orogens to the south at 1750 Ma (Yavapai) and 1630 Ma (Mazatzal). Strain patterns are unique to each orogenic belt with no far-field effect: Archean Wawa terrane rocks in the Penokean foreland preserve deformation associated with Archean accretion with no younger Penokean, Yavapai or Mazatzal strain overprint. The Penokean orogeny deformed Huron-Animikie basin sediments into a north-vergent fold-and-thrust belt with no Yavapai or Mazatzal strain overprint. Yavapai orogen strains (SW-NE margin-parallel shortening) are unique when compared to the younger Mazatzal shortening (N20°W) shortening, with no strain overprint. Penokean deformation is characterized by shortening from the south including uplifted Archean gneisses and a northerly thin-skinned fold-and-thrust belt, with north-vergent nappes and a gently-dipping foreland. Our study of finite and calcite twinning strains (n=60) along (?1500 km) and across (?200 km) the Penokean belt indicate that this orogeny was collisional as layer-parallel shortening axes are parallel across the belt, or parallel to the tectonic transport direction (?N-S). Penokean nappe burial near the margin resulted in vertical shortening strain overprints, some of which are layer-normal. The Sudbury impact layer (1850 Ma) is found across the Animikie basin and provides a widespread deformation marker with many local, unique strain observations. We also report new geochronology (U-Pb zircon and apatite) for the gneiss-mafic dike rocks at Wissota (Chippewa Falls, WI) and Arbutus (Black River Falls, WI) dams, respectively, which bears on Penokean-Yavapai deformation in the Archean Marshfield terrane which was accreted during the Penokean orogen. Pseudotachylite formation was common in the Superior province Archean basement rocks, especially along terrane boundaries reactivated by contemporaneous Penokean, Trans-Hudson, Cape Smith and New Quebec deformation. In the hinterland (south), the younger Yavapai orogen (1750 Ma; n=8) deformation is preserved as margin-parallel horizontal shortening (?SW-NE) in Yavapai crust and up to 200 km to the north in the Penokean thrust belt as a strain and Barrovian metamorphic overprint. Mazatzal deformation (1630 Ma; n=16) is preserved in quartzites on Yavapai and Penokean crust with layer-parallel and layer-normal shortening strains oriented N20°W.
Geophysical Research Letters, doi:10.1029/2021GL093312
Mantle
orogeny
Abstract: Orogenesis is the process whereby tectonic plates converge and mountain systems are created. In the case of the Andes and Himalayas, orogenesis resulted in significant thickening of the continental crust. Recent attempts to provide geochemical proxies for crustal thickness have allowed geologists to track the thickness of the crust through geologic time. One period of time in particular between 1850 and ?850 million years ago-the mid-Proterozoic-was characterized as having relatively thin crust. Some have argued this is evidence for a period of "orogenic quiescence." However, the geologic record is rife with ancient orogenic belts during this time as evidenced by the metamorphic and igneous rock records. In particular, the metamorphic rocks display higher than normal temperature/pressure ratios indicating unusually hot crust. We propose that the thin crust at this time is a product of high temperatures resulting in greater crustal flow and therefore lower mountain ranges.
