from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A dark igneous rock, having porphyritic texture, in which both the phenocrysts and the matrix consist of hornblende, pyroxene, and biotite.
from The Century Dictionary.
- noun The name given by Gümbel to rocks, considerably varied in lithological character, occurring in dikes in strata of Paleozoic age.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun geology An uncommon, small-volume ultrapotassic
igneous rockprimarily occurring as dikes, lopoliths, laccoliths, stocksand small intrusions.
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
The occurrence of low-volatile coal in certain coalfields in India is attributed to the carbonization of coal seams by the intrusion of mica lamprophyre which is a mica-rich ultrabasic rock containing altered olivine, calcite (or dolomite), bronze-coloured mica and apatite.
In Fergus County, Montana, they are mined from decomposed dikes of lamprophyre (a basic igneous rock).
The diamond-bearing lamprophyre breccia is coincident with a crudely circular magnetic low as defined by an airborne magnetic survey.
- Moreover, a zone of lamprophyre dykes and lamprophyric breccias has been delineated within a
Drillholes LR-026 and LR-027 show the halo mineralization is concentrated at the intersection of northwest oriented lamprophyre dike and northeast trending fractured zone.
- This diamond discovery was from a multi-phased xenolith-bearing lamprophyre dyke system, approximately 6 metres wide in its surface exposure.
- A 9.3 kilogram sample of lamprophyre core from one of the drill holes contained 4 macro-diamonds, the largest being 1. 36mm by 1. 20mm by 1. 12mm, and 91 micro-diamonds.
Exploration by IMMC has focused on only two of the more than 20 known lamprophyre zones.
This is strikingly similar to the Company's "Mockingbird" Gold Property geology, where the gold is also hosted in lower plate Precambrian gneiss, and is frequently associated spatially with lamprophyre dikes.
Follow up work will focus on assessment of priority kimberlite targets and additional evaluation of the most prospective of the lamprophyre breccias.