Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
The deposits of upper carbon – lower Permian are presented by biotite granite, weak
cataclaziled, carbonized with hypidiomorphosisgrain structure.
Mesozoic group - Mz
Jurassic system - J
The Jurassic deposits are bedded on the deposits of upper Paleozoic with washout
and cross bedding.
Lower Jurassic section - J 1
The lower Jurassic deposits have binominal structure. It is mainly sandy thickness of
toar and lower the deposits are presented by thickness of alternating in the cross-section
grey colored non-calcareous sandstones, siltstones and mudstones, with stratified structure
(it is horizontal, thin in mudstones, unidirectional, slanting in sandstones), with a
considerable admixture of the charred vegetative substance, siderite and quite often pyrite.
The border between upper Triassic – lower Jurassic deposits and overlying thickness of toar
is clear and corresponds to change of alternating mudstones and sandstones mainly sandy
rocks.
The toar deposits are mainly composed by sandstones with interlauer of siltstones
and mudstones. Lithologically the sandstones are grey, medium-fine-grained, with grains of
coarse-grained sandy fraction and gravelites, silty micaceous with the mixed cement of
porous-film type, with inclusion of charred vegetative detritus. Open porosity of these
sandstones is 3.85-7.64 %.
Siltstones are grey, dark grey, black, anisomerous, silty micaceous with micaceousclay
cement and inclusion of the charred vegetative substance and siderite.
Mudstones are dark grey, sandy-silt, fine-scaled with inclusion of fragments of the
carbonizated tissues of plants, with interlayers of grey siltstone and fine-grained sandstone.
Mudstones are dense, impermeable, their open porosity is 1.75-2.42%.
Middle Jurassic section - J 2
Litholigically, these deposits are presented by terrigenous thickness of alternation of
grey colored sandy-siltstone-clay rocks of the alluvial and lake-marsh continental genesis
gradually passing into shallow water-sea.
Middle Jurassic deposits are composed by grey and dark grey silty micaceous
sandstones, siltstones, mudstones and their transitive differences with inclusion of the
charred vegetation, pyrite and siderite.
Sandstones are grey, greenish-grey in the top of cross-section, from small - to coarsegrained,
micaceous, dense, silty micaceous, with the mixed carbonaceous-micaceous-clay
cement. The sandy material is poorly sorted in aalen-bayos and is better sorted in batsk
deposits.
Siltstones are dark grey, silty micaceous, strong, dense.
Mudstones are dark grey and greenish-grey, fine-washed, lensing-fine-horizontally
layered, sandy and silt in tops of cross-section. Rocks contain the numerous rests of the
Volume 2. Part 1. EIS Project for Surgil field construction
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