Essexit

Essexite in the route iron map

Essexit is a dark, gabbroide , igneous rock .

Rock description and mineral inventory

Essexit occurs as a mesotype , melanocrates and sodium-rich deep rock . The rock was named after Essex County in the US state of Massachusetts and is similar to gabbro .

In contrast to gabbro, however, Essexit also contains high-sodium alkali feldspar , which is often found as a border around plagioclase . In addition, mainly diopside augite occurs. Side effects are sodium amphibole , biotite and serpentinized olivine .

history

The first scientific description comes from John Henry Sears (1843-1910) from 1891. Sears was curator (1892-1910) of the areas of mineralogy, geology and botany at the Peabody Museum in Salem , Massachusetts .

Occurrence

Essexit is known from countless places. In Germany, Essexit occurs in the Kaiserstuhl or in the Siebengebirge . Other occurrences are known for example from Russia on the Taimyr Peninsula , from the region of Kuznetsk - Minussinsk in Tuva and on the Kamchatka -Halbinsel, from the area of Omolon , from Sakhalin and from the Primorye . Essexit is also found near Roztoky in the Bohemian Central Uplands in the Czech Republic , in Norway near Oslo near Carclout in Ayrshire , Scotland , on Mount Royal near Montreal in Canada and on Okenyenya in Namibia . Essexite also runs the Dekkan-Trapp in the Indian province of Kathiawar .

literature

Roland Vinx: Rock determination in the field . Munich (Elsevier) 2005 ISBN 3-8274-1513-6
Wolfhard Wimmenauer : Petrography of igneous and metamorphic rocks . Stuttgart (Enke) 1985 ISBN 3-432-94671-6

Individual evidence

^ FJ Loewinson-Lessing / EA Struve: Petrografitscheski Slowar . Moskwa 1937, p. 386
^ John Henry Sears: Bulletin of the Essex Institute, Vol. XXIII, MG 1896, p. 247
↑ Russia - E of Urals. The Eudialyte homepage
↑ essexite, rock Encyclopædia Britannica Online
↑ SF Sethna and P. Javeri: Essexite occurrence in the Deccan volcanic province of Saurashtra, western India. Journal of Asian Earth Sciences, Vol. 18, No. 2, 2000, pp. 151-154 doi : 10.1016 / S1367-9120 (99) 00029-2

[1] FJ Loewinson-Lessing / EA Struve: Petrografitscheski Slowar . Moskwa 1937, p. 386

[2] John Henry Sears: Bulletin of the Essex Institute, Vol. XXIII, MG 1896, p. 247

[3] Russia - E of Urals. The Eudialyte homepage

[4] essexite, rock Encyclopædia Britannica Online

[5] SF Sethna and P. Javeri: Essexite occurrence in the Deccan volcanic province of Saurashtra, western India. Journal of Asian Earth Sciences, Vol. 18, No. 2, 2000, pp. 151-154 doi : 10.1016 / S1367-9120 (99) 00029-2