intrusion


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intrusion

1. Geology
a. the movement of magma from within the earth's crust into spaces in the overlying strata to form igneous rock
b. any igneous rock formed in this way
2. Property law an unlawful entry onto land by a stranger after determination of a particular estate of freehold and before the remainderman or reversioner has made entry

Intrusion

 

a geological term used in two senses:

(1) The process of magma injection into the body of rock that forms the earth’s crust. The solidification of such injected magma leads to the formation of intrusive rock.

(2) An intrusion is a geological body composed of igneous rock and formed in the process of injection and solidification of mag-matic melt in the earth’s crust (intrusion, intrusive body, plutonic intrusion). In relation to the structure of the country rock, intrusions are classified as concordant and discordant. The first group includes sills, laccoliths, and lopoliths, and the second group includes batholiths, stocks, and dikes. Intrusions are classified according to the depths at which the magmatic intrusion occurred as deep-seated intrusions (abyssal) and shallow-depth intrusions (hypabyssal). In this context the conditions of cooling of the magma and its effect on surrounding rock differ sharply. At shallow depths the cooling is rapid and fine crystalline or porphyritic rock is formed, and contact metamorphosis affects a small area of the country rock. At great depths medium-grain and large-grain rock and major changes in the surrounding rock are characteristic.

intrusion

[in′trü·zhən]
(geology)
The process of emplacement of magma in preexisting rock. Also known as injection; invasion; irruption.
A large-scale sedimentary injection. Also known as sedimentary intrusion.
Any rock mass formed by an intrusive process.

intrusion

Unauthorized access to a computer system or network. See intruder and IDS.
References in classic literature ?
However, I have said what I came to say, and, with another apology for this intrusion, I may take myself off.
Dick's shirt was wet; he made a lumbering excuse to go; which Esther explained to herself by a fear of intrusion, and so set down to the merit side of Dick's account, while she proceeded to detain him.
About London, for instance, perhaps half the prettier country is shut in against intrusion.
This appeared to be a favorable opportunity to repair his intrusion.
My good friend," said Albert, "I beg pardon for my intrusion, but I was anxious to know from your own mouth if your master was really out or not.
She received him with her very best politeness, which he returned with as much more, apologising for his intrusion, without any previous acquaintance with her, which he could not help flattering himself, however, might be justified by his relationship to the young ladies who introduced him to her notice.
I trust your majesty will pardon this intrusion on her meditations, but a foreign lord has arrived from England and waits in the parlor, demanding the honor of presenting a letter to your majesty.
Their reputation, as holders of mystic and pernicious principles, having spread before them, the Puritans early endeavored to banish, and to prevent the further intrusion of the rising sect.
As the company recovered from their surprise, they began to feel annoyed at this intrusion.
Secure from female intrusion, there was no restraint upon the hilarity of the warriors, who, like the gentlemen of Europe after the cloth is drawn and the ladies retire, freely indulged their mirth.
They behaved very well, however, to him on the occasion, betraying no exultation beyond the lines about the corners of the mouth, and seemed to think it as great an escape to be quit of the intrusion of Charles Maddox, as if they had been forced into admitting him against their inclination.
They, at that time, were extremely numerous, and conducted the chief navigation and commerce of the Ohio and the Mississippi, as the voyageurs did of the Canadian waters; but, like them, their consequence and characteristics are rapidly vanishing before the all-pervading intrusion of steamboats.