GEOLOGICAL MEMORANDUM; BEING A DESCRIPTION OF THE SPECIMENS OF ROCKS COLLECTED AT MACAO AND THE LADRONE ISLANDS, AND ON THE SHORES OF THE YELLOW SEA, THE WEST COAST OF COREA, AND THE GREAT LOO-CHOO ISLAND. GEOLOGICAL MEMORANDUM. It is greatly to be regretted, that, during this voyage, our means of gaining information on this interesting subject were so limited. In China we were restrained, sometimes by the jealousy of the Chinese, and sometimes by an apprehension on our part of giving offence, or of exciting suspicion, by following up enquiries, the nature of which it was impossible to explain when interrogated by the inhabitants. On the coast of Corea, the still greater jealousy of the natives rendered it impossible to prosecute geological investigations beyond the beach. Both in China and on the coast of Corea our stay at each place was very short, and our time being often necessarily occupied by avocations foreign to such enquiries, many opportunities were lost merely for want of time. Even at the Great Loo-choo Island, where we remained much longer, our researches were confined to a coast which offered nothing interesting. Having therefore nothing of a general or striking nature to offer to the scientific world on this subject, I shall merely give an account of the specimens collected at the various places which we touched at during this voyage, accompanied by brief explanations from memorandums made on the spot. The geologist will be struck with the resemblance which the rocks in this remote quarter of the globe bear to those with which he has been familiarly acquainted. SPECIMENS FROM CHINA. MACAO. 1. Granite, composed of white quartz, porcelain clay, and greenish steatite, with veins of white quartz intersecting each other. 2. Fine-grained granite, composed of yellowish feldspar, white quartz, and black mica. Quartz dykes of great magnitude traverse the granite which forms this peninsula. HONG-KONG, ONE OF THE LADRONE ISLANDS, OFF MACAO. 3. Lead-coloured compact quartz rock, with imbedded crystals of flesh-coloured feldspar. GREAT LEMMA, ONE OF THE LADRONE ISLANDS, OFF MACAO. 4. Coarse-grained granite, with distinct crystals of feldspar. SOUTHERN SHORE OF THE YELLOW SEA. CHE-A-TOW. 5. Fine-grained gneiss, composed of white quartz, white feldspar, and black mica, with a vein containing hornblend and crystals of feldspar. 6. The strata are here very much contorted; the cliffs at some places being folded up like webs of cloth. 7. Granular primitive lime-stone, containing greenish steatite. 8. Quartz rock, alternating with gneiss. 9. A specimen containing amorphous pieces of iron. CUNG-CUNG-CHEEN ISLANDS. 10. Very fine-grained gneiss, composed of white quartz, flesh-coloured feldspar, and black mica. 11. Coarser variety of the same. 12. Compact blueish-grey feldspar, with grains of quartz. OEI-HAI-OEI. 13. Gneiss, composed of yellowish feldspar, white quartz, and black mica. LUNG-CUNG-TAO ISLANDS. 14. Coarser variety of the rock described above. |