Open AccessDistribution of Biomicrofacies and Cement Types in the Changxing Formation (Upper Permian), Western Hubei-eastern Sichuan Provinces, South China
Author(s) -
Mutwakil Nafi,
Xia Wenchen
Publication year - 2005
Publication title -
american journal of applied sciences
Language(s) - English
Resource type - Journals
eISSN - 1554-3641
pISSN - 1546-9239
DOI - 10.3844/ajassp.2005.452.464
Subject(s) - permian , china , distribution (mathematics) , geology , cement , geography , mining engineering , archaeology , paleontology , mathematics , structural basin , mathematical analysis
The Changxing formation is subdivided into lower, middle and upper parts. Four types of
microfacies were recognized in the Changxing formation. They include SMF-3, SMF-6, SMF-7 and
SMF-19. The Changxing Formation is composed of deep basin margin, platform margin and open
restricted platform environments. The lower, middle and upper parts are dominated by deep basin
margin facies, platform margin facies and open restricted platform facies, respectively. The lower part
contains foraminifera, radiolarian and mollusk organisms. The middle part is characterized by presence
of crinoids, sponge, rugose, ostracods, trilobite, brachiopods, abundant bryozoans, mollusks and
foraminifera organisms. The upper part is marked by dolomite, pyrite and abundant mollusks. Most of
these organisms were concentrated within the middle part. The types of cements in the Changxing
Formation consist of coarse grain sparite, micrite, microspar, silica and radiaxial cements. The lower
part is dominated by silica cement. The middle part shows presence of abundant coarse grain sparite,
micrite, microspar and radiaxial cements. The upper part is dominated by micrite, microspar cements