REPORT 



ON A 



GEOLOGICAL EXPLORATION OF LEW CHEW 



BY REV. GEORGE JONES, CHAPLAIN U. S. N. 



United States Steamer Mississippi, 



Lew Chew, February 6, 1854. 



Sir: In making the geological report of our recent explorations in Lew Chew, it may he well 

 first to recapitulate, hriefly, some remarks made on a former occasion, respecting the geology 

 of the southern portion of the island. 



Commencing at the southern end, we have uniformly an aluminous rock, sometimes pretty 

 compact, and sometimes running into shell; from it comes all the clay or common soil of this 

 part of Lew Chew. This rock or clay is pierced and overlaid hy limestone of a most singular 

 character, generally in belts, running N. ahout 60° E., and rising into pinnacled ridges, so much 

 like ruins of ancient huildings, as to deceive the eye at the distance of only a few hundred feet. 

 This portion of the island is, hy far, the richest and hest cultivated, and owes its fertility, doubt- 

 less, to the admixture of lime with the argillaceous soil. I will notice the limestone rock again, 

 hy-and-by. 



Ahout seventeen miles north of Napha, a very coarse gneiss begins to make its appear- 

 ance, and soon becomes the prevalent rock, overhanging the sea-shore in bluffs of most con- 

 torted stratification, or running out in great ledges of jagged forms ; the vegetation here 

 changes, and the surface of the island rises into mountains so unfavorable to cultivation that 

 the whole region is abandoned to pines and other forest-trees, except where the ravines open to 

 the sea. The limestone rock is, however, seen yet occasionally, running slantingly across the 

 island, in broken ridges, as before. 



At forty miles from Napha, on the western shore, we come to a small extent of granite hills, 

 piercing through the gneiss. It is the only granite that I have seen on the island ; and, 

 though having all the characteristics of that rock, is remarkable for being so soft as to be easily 

 cut with a knife. It is white, and, when it is broken, the black mica is seen lying on the sur- 

 face of the fracture, in regular elongated hexagons, finely contrasted with the white. Beyond 

 this, the gneiss begins to be mixed up with strata of clay-slate, to which it at length entirely 

 gives place ; and at Farnigi, fifty-five miles north from Napha, on the promontory of Fort Mel- 

 ville, we came to a coarse conglomerate, which gave us the first promise of a possibility of coal. 

 The conglomerate soon passed into a coarse, and then into a finer sandstone ; and, in this region, 



