TERTIARY, a color, as citrine, russet, or alive, produced by the mixture of the two secondary colors. More correctly speaking, they are grays, and are either red-gray, or yellow-gray, when these pri maries are in excess, or they are violet gray, orange-gray, or green-gray, when these secondaries are in excess. In ec clesiastical affairs, a member of a Third Order, whether living in the world or in community.
In geology, the third leading division of fossiliferous sedimentary rocks; called also the Cainozoic or Kainozoic. The succession and importance of the Pri mary (Palaeozoic) and the Secondary (Mesozoic) rocks were understood before the nature and extent of the Tertiary were recognized, these last strata being confounded with the superficial alluvi ums. They were observed to occur in patches (some of fresh-water and others of marine origin) in small areas or bas ins in the Secondary rocks. The first properly understood strata of Tertiary age were those in the vicinity of Paris, described by Cuvier and Brongniart in 1810. Other Tertiary strata were short ly afterward discriminated in England, in London, in Hampshire, in Suffolk, in the Subapennine hills in Italy, near Bor deaux and Dax in the S. of France, and elsewhere. As early as 1828, Mr. (after ward Sir Charles) Lyell had conceived the idea that the Tertiary strata might be classified by the percentage of extinct species of shells which they contained. He found in 1829 that Deshayes of Paris had independently come to the same conclusion, and the latter geologist, after comparing 3,000 fossil with 5,000 living shells, intimated that in the Lower Tertiary strata about 3% per cent. of the species were identical with recent ones; in the Middle Tertiary about 17 per cent.; in the Upper Tertiary, in the oldest beds 35-50, and in the more modern ones 90-95 per cent. To these three Lyell gave the names Eocene, Miocene, and Pliocene respectively, words which have since gained universal currency. The foregoing percentages are now known to be only approximately accurate. Next the newer Pliocene beds were called by Lyell Pleistocene, a name afterward transferred to the Post Tertiary, and Oligocene was proposed by Beyrich for beds intercalated between the Eocene and the Miocene. A gap, as yet only partially
filled, occurs between the Chalk and the Eocene. This gap has been utilized to draw a natural line between the Secon dary and the Tertiary beds. It probably arose from an upheaval of the sea bed. Thus, with the Eocene, as the name im ports, the dawn of the present system of things began, and the percentage of shell species shows that the transition has gone on without stoppage or hiatus till now. Other classes present evidence of the same kind; but, as Lyell was the first to point out, which he did in 1830, Shell species have a longevity far exceeding that of the Mammalia. No recent mam mal appears in the Eocene, though in Eocene strata various mammalian fami lies which have well-known living repre sentatives appear for the first time. Among the animals the Tertiary is the age of Mammals; among plants it is the age of Dicotyledons, the Cycads and Con ifers of the Upper Secondary rocks having given place to plants belonging to many orders and a vegetation only less varied than now. For the most part evi dences of gold are lacking in rocks of the tertiary period.
Also in geology the period of time dur ing which the Tertiary strata were depos ited. It cannot yet be measured even approximately. When it commenced, England, as proved by the fruits in the London clay at Sheppey, was a tropical or sub-tropical country. The tempera ture fell till the Newer Pliocene, by which time the climate was semi-Arctic. Dur ing the deposition of the Tertiary, there was a great increase of land both in Europe and America.
In the plural, in ornithology the ter tials; wing feathers having their origin from the humerus. They are a portion of the quills. They are not scapulars, though Cuvier calls them by this name; nor do they cover the scapulars. Their use is to fill up the interval between the body and the expanded wing, and to op pose a broader surface of resistance to the air.