Transactions of the Cambridge Philosophical SocietyUniversity Press, 1822 |
من داخل الكتاب
النتائج 1-5 من 25
الصفحة 98
... porphyritic ; the three constituents forming a granular base in which are imbedded large crystals of felspar . We may observe also that these large crystals often exhibit a bright clear fracture , while the felspar of the base is dull ...
... porphyritic ; the three constituents forming a granular base in which are imbedded large crystals of felspar . We may observe also that these large crystals often exhibit a bright clear fracture , while the felspar of the base is dull ...
الصفحة 100
... porphyritic , with large and very brilliant crystals of white felspar . The large crystals sometimes prevailed nearly to the exclusion of the base : and the face of the rock then exhibited a very uncommon appearance . In some of the ...
... porphyritic , with large and very brilliant crystals of white felspar . The large crystals sometimes prevailed nearly to the exclusion of the base : and the face of the rock then exhibited a very uncommon appearance . In some of the ...
الصفحة 106
... porphyritic , containing flesh- coloured crystals of felspar . These crystals are often decomposing . In some instances they have disappeared altogether , and the base then resembles a scoria . Specimens were obtained from the south ...
... porphyritic , containing flesh- coloured crystals of felspar . These crystals are often decomposing . In some instances they have disappeared altogether , and the base then resembles a scoria . Specimens were obtained from the south ...
الصفحة 127
... porphyritic rocks , which are associated with the killas . They sometimes appear in the form of beds , having the same dip and direction with * See some communications in the Edinburgh Philosophical Journal by Professor Jameson . the ...
... porphyritic rocks , which are associated with the killas . They sometimes appear in the form of beds , having the same dip and direction with * See some communications in the Edinburgh Philosophical Journal by Professor Jameson . the ...
الصفحة 128
... porphyritic rock : the base of fine granular felspar , with imbedded crystals of quartz . The fracture is often dull and earthy . 2. A porphyritic rock : the base of granular quartz , with crystals of felspar . 3. Hornstone porphyry . 4 ...
... porphyritic rock : the base of fine granular felspar , with imbedded crystals of quartz . The fracture is often dull and earthy . 2. A porphyritic rock : the base of granular quartz , with crystals of felspar . 3. Hornstone porphyry . 4 ...
طبعات أخرى - عرض جميع المقتطفات
عبارات ومصطلحات مألوفة
ABCD acid angle Apophyllite appearance axis ball beds carbonate of lime centre character chlorite schist clay slate cliffs coast colour compact composed considerable Cornwall Cove crystalline crystals cube cylinder decomposing decomposition described deviation direction distance district dyke earthy East equation examination exhibited Fellow felspar fissures formation fracture fragments function Galvanic gazometer granite granite veins granular green green-stone greywacké Helford river horizontal hornblende hydrogen inches instance intermixed irregular killas laminæ limestone Llanbabo Llaneilian Llanerchymedd Llanfaelog Llangefni Llanrhyddlad magnetic mass mica mineral muriate Nare point nature nearly needle North observed occur old red sandstone parallel particles passing perpendicular phenomena piston plane plate polarization porphyritic portion present pyroxene quartz quartz rock resembling Rhoscolyn schistose schorl serpentine side slaty South specimens steatite strata structure substance surface texture trace Trin ureters variety vertical whole wire