Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/453

1869.] acting British Vice-Consul at Ciudad Bolivar, has kindly furnished me with the following statement concerning the gold produce of the Caratal district:—

These numbers represent the quantities shipped by the Ciudad Bolivar merchants ; and all this gold has been produced from the alluvial diggings, the "tierra de flor," and gold quartz crushed by hand in mortars. I should say that at the present time the gold obtained from lodes by far exceeds in quantity that obtained from other sources.

The whole of the present workings are comprised within a circle of $3 1⁄2$ miles radius, with Nueva Providencia as its centre; but it must not for a moment be imagined that this is the whole of the auriferous region. Two American gentlemen, Messrs. Davis and Austen, found gold on the river Paragua; and just before leaving I heard of the discovery of a lode of gold-quartz in the hills to the south of Pastora. A little gold has been found at Upata. Dr. Plassard also tells me that a lode of auriferous quartz traverses the bed of the Yuruari at Cura; and I have heard the same report from Senor Carlos Siegert. It is further known that gold has been found, and even worked on the banks of the Cuyuni in British Guiana. All these facts tend to prove that the auriferous rocks are spread over a very considerable area indeed.

4. Notes on the Geology of Guyana, in By, Assoc. Linn. Soc, F.G.S. &c.

I. — The observations on which this notice is based were made during a trip of some two months' extent in the latter part of last year, and though having reference to a small section of the province of Guyana, in Venezuela, yet are applicable to an extensive area. The leading geological features are presented in a line of section from the Orinoco, proceeding in a southerly direction; my examination extended to the newly discovered auriferous district of Caratal, distant about 140 miles in a right line from Las Tablas, on the Orinoco.

A few words in elucidation of the physical features of the country, will assist the reader in tracing out the leading geological characteristicsof Guyana.

Skirting the Orinoco are the Llanos; these, as elsewhere, are characterized by a growth of coarse grass, Cyperaceoe, and shrubby trees, the chief of which, and often the only species, is the chaparro (Curtella Americana); the soil is of the poorest description, being a loose sand, highly absorbent and of great heat-radiating power.