Chemical analyses of thirteen igneous rocks of East Lothian

Abstract

This short paper is a record of the chemical analyses of thirteen igneous rocks of East Lothian. It is only necessary to say that great care was taken in selecting the best specimens procurable in each case, and in their preparation for analysis. The rocks were as follows: 1. The Teschenite of Links Quarry, Gullane (Table I. 1). This rock is mentioned in the Memoir of the Geological Survey for East Lothian, 1910, p. 114, and fully described by Professor Young, Trans. Edin. Geol. Soc., 1903, vol. viii., pp. 326-35, but there is no published analysis. 2. White trap derived from the teschenite of Corby Craigs, Gullane (Table I. 2), which is an extension of the same sill in which Links Quarry is situated. A good characteristic specimen of white trap. It is intruded into black shales, and preserves roughly the original structure of the dolerite. It is intensely kaolinised and calcified. 3. Monchiquitic Basalt, Sill, Cheese Bay, Gullane (Table I. 3). The analysis was made on a fairly fresh specimen, which was obtained after a prolonged search. The greater part of the basalt has suffered decomposition due to weathering. There is no published analysis. An analcite basalt; much olivine serpentinised, in phenocrysts, many large, some with good crystal edges, and others very corroded; some clear patches of analcite. Crystalline groundmass: many small laths of felspar, much minute augite, some small specks of magnetite. 4. White trap derived from monchiquitic basalt, Cheese Bay, Gullane (Table I. 4). This rock was much decomposed, being in