Coquina

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coquina

[kō′kē·nə]
(invertebrate zoology)
A small marine clam of the genus Donax.
(petrology)
A coarse-grained, porous, easily crumbled variety of limestone composed principally of mollusk shell and coral fragments cemented together as rock.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Coquina

 

limestone consisting primarily of the shells of marine animals or fragments of shells. Coquina usually forms in the littoral or sublittoral zones. Depending on the shells of which it is composed, coquina is subdivided into brachiopod, gastropod, ostracod, and other types. It corresponds to gravelpebble sediments in granulometric composition. Coquina has a very high porosity of 22–60 percent. Its specific gravity is 1,100-2,240 kg/m3, and its heat conductivity coefficient is 0.29-0.99 watt/(m-°K), or 0.25-0.85 kcal/(hr-m-°C). Its breaking point upon compression is 0.4-28 MN/m2 (4-280 kg/cm2).

Coquina is easily sawed, trimmed, and worked in various other ways. It is used extensively in construction as a wall and facing material; chipped rock and sand from coquina are used as a filler for light concrete. In addition, coquina is used in the production of lime and other binding materials. It is extracted in quarries.

Coquina is widespread in the Neogene beds of the southern USSR: in the Moldavian SSR, in the Crimean (the Mamai, Kutur-Kaia, Bagerovo, and Karalar deposits) and Odessa oblasts of the Ukrainian SSR, in the Azerbaijan SSR (the Apsheron Peninsula), and in the Turkmen SSR. Abroad, coquina is found in Poland and Rumania.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

coquina

A soft limestone formed primarily of broken shells and coral; cut into blocks and used in construction.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
When SL was compared between sites during a monthly sample collection, coquinas from BAS and RDB differed significantly (P < 0.012) during all months except February 2007 (Mann-Whitney U-test, U = 107,758, [N.sub.1] = 328, [N.sub.2] = 336, P = 0.598) using the sequential Bonferroni correlation correction.
ABSTRACT Coquina clams (Donax variabilis) were sampled monthly at 2 sites in Pinellas County, Florida, to document recruitment and growth.
KEY WORDS: Donax variabilis, coquina, reproduction, life cycle, recruitment, biology
The section was sampled during fieldwork in 1987 as follows: pebbles from the basal conglomerate of the Ulgase Formation (N-62), lingulate brachiopod shells from the Ulgase Formation (N-63 and N-63A), and basal lingulate shell coquina of the Kallavere Formation (N-60).
Dig beneath the coquinas and watch them bury themselves again.
The studied succession consists of 7 lithofacies expanded from Barnolas and Simo (1987) including: boulder-pebble conglomerates, graded pebble conglomerates, graded peloidal-ooid packstones, graded oolites, calcilutites, Posidonia coquina and cherty mudstones.
These coquina accumulations locally alternate with thin layers of pelagic mud (Fig.
The coquina clam, Donax variabilis, lives on southeastern North American shores on coarse-grained, sandy beaches with moderate to high waves.