Open AccessClay minerals in sediments from contact zones with basalt sills
Author(s) -
Victor B Kurnosov,
B. A. Sakharov,
A. R. Geptner,
Yu. I. Konovalov,
E. O. Goncharov
Publication year - 2019
Publication title -
litologiâ i poleznye iskopaemye
Language(s) - English
Resource type - Journals
ISSN - 0024-497X
DOI - 10.31857/s0024-497x20193234-247
Subject(s) - clay minerals , geology , chlorite , illite , sill , geochemistry , basalt , terrigenous sediment , mica , kaolinite , actinolite , saponite , mineralogy , plagioclase , sedimentary rock , epidote , paleontology , quartz
Clay minerals (fraction <0.001 mm) of Upper Pleistocene clayey-sandy-silty sediments recovered by DSDP Holes 481 and 481A in the Northern Trough, Guaymas Basin, Gulf of California, were studied by X-ray based on the modeling of diffraction patterns and their comparison with experimental diffractograms. Terrigenous clay minerals are represented mainly by dioctahedral micaceous varieties (mixed-layer disordered illite-smectites, illite) with the chlorite admixture and by kaolinite in the upper section of unaltered sediments. Intrusion of hot basalt sills (total thickness of the complex is about 27 m) provoked alterations in the phase composition of clay minerals in sediments (7.5 m thick) overlying the sill complex. These sediments include newly formed triooctahedral layered silicates (mixed-layer chlorite-smectites, smectite). Sediments inside the sill complex include trioctahedral mixed-layer mica-smtctite-vermiculite or trioctahedral smectite. The trioctahedral mixed-layer chlorite-smectite coexisting with smectite was found in a single sample of the same complex.