Overview

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1999-07 edition. Excerpt: ...present. A group of concentric rings on a fracture surface (fig. 43G) consists of alternating dark layers of siderite and lighter layers of calcite or aragonite that react with HCl. Similar concentric rings or hemispherical shells of carbonate deposits in other drill cores sometimes have a core of clay or even black magnetite or reddish iron oxide. minutes. The range of unglycolated (00l) basal reflections suggests that there is some variation in the exchangeable cations (Grim, l968). Semiquantitative chemical analyses of several clay samples by EDS shows the presence of Si, Al, and Fe in all the samples analyzed; Ti, Mg, Ca, Na, and K are also present in one or more of the analyzed clays. The mean index of refraction for one of the green Fe-rich clay samples, -l.58 to l.59, suggests that the smectite species probably is nontronite. Crystal habit generally takes the form of randomly oriented, open-textured, sheet-like orplaty crystals (fig. 44A) or densely packed platy crystals (fig. 44B). However, green smectite (identified by XRD) vesicle fillings in one sample from the GEO-N2 drill core have a fuzzy or fibrous surface coating (fig. 44C). According to Phillips and Griffen (l98l). nontronite may sometimes have a fibrous crystal habit. Figure 40.--Scanning electron micrographs and photomicrograph of calcite crystals from Newberry volcano. A. Blocky aggregates of calcite crystals and associated chlorite that line fracture at 847.6-m depth in USGS-N2 drill core. B. Needle-like rhombic calcite crystals from fracture filling in basaltic sandstone at 308.9-m depth in USGS-N2 drill core. C. Photomicrograph of l-cm-long vesicle filling of multiple alternating layers of calcite (Cc), green (iron-rich?) smectite (Sm). and red iron oxide (Fe). From..

Full Product Details

9781236479983

Table of Contents

Reviews

Author Information

Tab Content 6

Customer Reviews

Recent Reviews

Countries Available