Book reviews and Book notice

Book reviews and Book notice from Volume 2, Number 2, 1968 of Earth Science Journal

A petrologist in South Africa: Frederick Henry Hatch and the Witwatersrand Goldfield

The English geologist, Frederick Henry Hatch (1864–1932), today mainly recalled for a textbook on igneous petrology, emigrated to South Africa, where, in the years between 1892 and 1906, he became one of the pioneers of the geology of the Transvaal and the Witwatersrand Goldfield. This article reviews his life and, in particular, his work during this period which led to his becoming a mining geologist with connections to many of the world's goldfields, set against the political background of the Boer War which influenced the course of his work

Composition and evolution of the continental crust: Retrospect and prospect

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Geólogos de origem russa na América Latina

We describe here the life and career of geologists   who beyond their nationality (Russian, Ukrainian, Tatar, German, etc.), were born on the territory of the Russian Empire, the Soviet Union or the Russian Federation  and  their descendants that  became geologists, all of whom  lived and worked in Latin-American  countries (where Spanish and Portuguese languages prevail).We include  also geologists from USSR who worked temporary in some countries of Latin America and left contributions to geology in form of publications.Se describe la vida y trayectoria de geólogos que más allá de su nacionalidad (rusa, ucraniana, tártara, alemana, etc.), nacieron en territorios que pertenecieron al Imperio Ruso, la Unión Soviética o la Federación Rusa, y de sus descendientes graduados en geología, todos los cuales vivieron y trabajaron en países de Latinoamérica (en los cuales las lenguas que prevalecen son el español y el portugués). También se incluyen geólogos de la URSS que trabajaron temporariamente en algunos países de Latinoamérica y que con sus publicaciones contribuyeron a la Geología.Descreve a vida e a trajetória de geólogos que, além de sua nacionalidade (russos, ucranianos, tártaros, alemães, etc.), nasceram em territórios pertencentes ao Império Russo, à União Soviética ou à Federação Russa, e seus descendentes se formaram em geologia, todos os quais viveram e trabalharam em países latino-americanos (nos quais as línguas dominantes são o espanhol e o português). Também estão incluídos geólogos da URSS que trabalharam temporariamente em alguns países da América Latina e que contribuíram para a Geologia com suas publicações

MINERAL PARAGENESIS OF A PARTIALLY SERPENTINIZED DUNITE IN EAST DOVER, VERMONT

Ultramafic rocks exposed on the Earth’s surface offer a rare opportunity to directly study the petrology of the upper mantle. The Appalachian Mountains of Vermont contain variably serpentinized ultramafic rocks that mark the suture zone for the Ordovician Taconic Orogeny. In southern Vermont, the serpentinized ultramafic rocks were subsequently metamorphosed to amphibolite facies during the Devonian Acadian Orogeny. Key localities of partially serpentinized ultramafic rocks and their surrounding lithologies in East Dover, Vermont were sampled to better understand the mineral petrogenesis and metamorphic history of the East Dover meta-dunite. This thesis documents the first occurrence of podiform chromitite, platinum group minerals, arsenic minerals, and metamorphic olivine in ultramafic rocks from the Vermont Appalachian Mountains. Rare chromitite occurs as pods within the dunite and is highly brecciated. Cr# (Cr/Cr+Al) is extremely high in podiform chromitite (0.7 - 0.9) suggesting that it formed via fluid/melt-rock interaction during partial melting of upper mantle peridotite in a supra-subduction zone setting. Rare inclusions of platinum group mineral alloys were found as inclusions in podiform chromitite. Many of these platinum group minerals contained arsenic. Small nickel arsenide minerals are common in serpentinized ultramafic rocks. Whole rock geochemical analyses (XRF) indicate much higher concentrations of arsenic in the more serpentinized samples, suggesting that arsenic was introduced into the ultramafic rocks during serpentinization. In the meta-dunite, the composition of olivine ranges from Fo92 in spinel inclusions to Fo96 in neoblastic olivine. Olivine neoblasts likely formed from serpentine dehydration during peak metamorphic temperatures associated with regional metamorphism during the Devonian Acadian Orogeny. Decussate amphibolite and late stage coarse acicular serpentine likely formed as the region slowly cooled following Devonian orogenesis. Recent near-surface lateritic weathering produced local areas of nickel mineralization. Chromite, platinum group minerals, and nickel minerals do not appear to occur in quantities sufficient for exploitation from the East Dover area. Our findings illustrate the need for an investigation into the mineralogy of other ultramafic bodies in Vermont to better understand the relative timing of mineral petrogenesis and the societal implications of the presence of arsenic bearing minerals in ultramafic rocks