chert, chert nodule

   1. Black, brown or grey rock, consisting of very fine-grained silica, that occurs as horizons of nodules and discontinuous bands, generally less than 200mm thick, within many limestones. It is very hard and almost insoluble in water, so commonly it projects from cave walls where it forms passage or shaft ledges and waterfall lips [9].
   2. Light-cream or gray to black rock composed of silica, found occurring as nodules or layers in limestone, or as a replacement of limestone [10].

A Lexicon of Cave and Karst Terminology with Special Reference to Environmental Karst Hydrology. . 2002.

Look at other dictionaries:

  • nodule —    A small, irregularly rounded knot, mass, or lump of a mineral or mineral aggregate, normally having a warty or knobby surface and no internal structure, and usually exhibiting a contrasting composition from the enclosing sediment or rock… …   Lexicon of Cave and Karst Terminology

  • Nodule (geology) — A nodule in petrology or mineralogy is a secondary structure, generally spherical or irregularly rounded in shape. Nodules are typically solid replacement bodies of chert or iron oxides formed during diagenesis of a sedimentary rock. Nodules may… …   Wikipedia

  • nodule — /noj oohl/, n. 1. a small node, knot, or knob. 2. a small, rounded mass or lump. 3. Bot. a tubercle. [1590 1600; < L nodulus a little knot, equiv. to nod(us) NODE + ulus ULE] * * * In geology, a rounded mineral concretion that is distinct from,… …   Universalium

  • Knapping — A knapper is a person who shapes flint, chert, obsidian or other stone through the process of knapping or lithic reduction to manufacture stone tools, strikers for flintlock firearms, or to produce flat faced stones for building or facing walls,… …   Wikipedia

  • включение кремнистой породы — — [http://slovarionline.ru/anglo russkiy slovar neftegazovoy promyishlennosti/] Тематики нефтегазовая промышленность EN chert nodule …   Справочник технического переводчика

  • Flint — (or flintstone) is a hard, sedimentary cryptocrystalline form of the mineral quartz, [ [http://webmineral.com/data/Quartz.shtml General Quartz Information] Webmineral.com (page contains java applets depicting 3d molecular structure)] [… …   Wikipedia

  • Concretion — For other uses, see enterolith and nodule (geology). Septaria redirects here. For the genus of gastropods, see Septaria (gastropod). Concretions on Bowling Ball Beach (Mendocino County, California) weather out of steeply tilted Cenozoic mudstone… …   Wikipedia

  • Agate — For other uses, see Agate (disambiguation). Agate Banded agate (agate like onyx); the specimen is 2.5 cm (1 inch) wide General Category …   Wikipedia

  • Flint tool — Chipped stone tools were made by stone age peoples worldwide. Paleolithic tools were relatively simple, repeated small flakes being struck or pressed from a cobble or nucleus until the required shape was achieved. This is called knapping. Freshly …   Wikipedia

  • Silicosis — Classification and external resources ICD 10 J62 ICD 9 502 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.