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see Triassic periodTriassic period
, first period of the Mesozoic era of geologic time (see Geologic Timescale, table) from 205 to 250 million years ago.

Throughout the Triassic, E North America, as a result of the mountain-building episode that formed the Appalachians in the late Paleozoic
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A dark-colored igneous rock having a fine-grained, more or less columnar structure.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.


2, traprock
1. any fine-grained often columnar dark igneous rock, esp basalt
2. any rock in which oil or gas has accumulated
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
The geology comprises part of the Warroo land system, generally referred to as Traprock. The study site, in the areas of Treverton Creek headwater, is visibly eroded by channel incisions and re-incision of alluvial deposits in valley floors and sheet erosion due to the lack of vegetative cover.
Specialty concrete floors, which include the superflat and traprock systems, will be displayed.
In the early 1960s, however, Hudson County leased Laurel Hill to a traprock quarry, which proceeded to demolish three-quarters of it within five years, lowering its height by 50 feet in the process.
To avoid the tilting slope of the railbed (even for adults, the traprock gravel makes for hard traveling), they must have walked along the tracks for nearly two miles, the older children jumping from tie to tie, until the Shoreliner, sprung from Providence, erased them from the earth.
Flames leap in a fireplace of sooty traprock, and a black-and-white cat stands near a card table looking at the window where the doctor looks in.
Or, you can order it hauled in a dump truck from any aggregate or traprock supplier to the building trades.
At the Kehler-corner auction, Wilson offered $5,100 worth of his services to the Traprock Peace Center in Deerfield, in memory of a local tax agent who had died in an accident.
Other sizable materials include granite (13 percent), traprock (6 percent), with smaller shares of sandstone, quartzite, marble, volcanic cinder and scoria, calcareous marl, slate, shell, and miscellaneous stone.
Congo Action Now mobilized hundreds of Massachusetts residents and brought together over 50 local, national, and international organizations to endorse and work for the legislation (among them, the Congolese Women Association of New England, Amnesty International USA, Africa Faith and Justice Network, Congolese Community of Massachusetts, Global Witness, Physicians for Human Rights, Mwinda Catholic Congolese Community, Our Bodies Ourselves, and Traprock Center for Peace and Justice).
She had two books published in 2012: "The Ravelling Braid" from Tebot Bach, and "Gertrude," from Traprock.