TY - JOUR

T1 - New results of stable isotope and petrographic studies of Jurassic glendonites from Siberia

AU - Vasileva, Kseniia Y.

AU - Rogov, Mikhail A.

AU - Ershova, Victoria B.

AU - Pokrovsky, Boris G.

PY - 2019/10/2

Y1 - 2019/10/2

N2 - We present the results of an optical microscopy, cathodoluminoscopy and isotopic study on nine glendonite concretions (calcite pseudomorphs replacing metastable hexahydrate ikaite) from Lower-Middle Jurassic sediments of Northeast Russia (Anabar Bay and Lena River region). Glendonite concretions are mainly found within Late Pliensbachian, Toarcian, Aalenian, Bajocian and Lower Bathonian clastic sediments, correlating to episodes of global climatic cooling as determined by independent paleoclimate proxy data. Stable carbon and oxygen isotopic values of glendonite concretions suggest that the primary source of carbon was derived from diagenetically altered organic matter, and the source of oxygen was from seawater. The secondary diagenetic cement is characterized by a significantly lighter δ18O and significantly heavier δ13C signature than the isotopic characteristics of the bulk rock glendonite concretion. This secondary diagenetic cement is thought to have precipitated rapidly during burial diagenesis and since it occupies a significant volume of the glendonite concretion, it has the potential to significantly influence the isotopic composition of bulk rock glendonites.

AB - We present the results of an optical microscopy, cathodoluminoscopy and isotopic study on nine glendonite concretions (calcite pseudomorphs replacing metastable hexahydrate ikaite) from Lower-Middle Jurassic sediments of Northeast Russia (Anabar Bay and Lena River region). Glendonite concretions are mainly found within Late Pliensbachian, Toarcian, Aalenian, Bajocian and Lower Bathonian clastic sediments, correlating to episodes of global climatic cooling as determined by independent paleoclimate proxy data. Stable carbon and oxygen isotopic values of glendonite concretions suggest that the primary source of carbon was derived from diagenetically altered organic matter, and the source of oxygen was from seawater. The secondary diagenetic cement is characterized by a significantly lighter δ18O and significantly heavier δ13C signature than the isotopic characteristics of the bulk rock glendonite concretion. This secondary diagenetic cement is thought to have precipitated rapidly during burial diagenesis and since it occupies a significant volume of the glendonite concretion, it has the potential to significantly influence the isotopic composition of bulk rock glendonites.

KW - diagenesis

KW - Glendonites

KW - paleoclimate

KW - stable isotopes

KW - RADIAXIAL-FIBROUS CALCITES

KW - CARBON

KW - RECORD

KW - IKAITE

KW - SEEP

KW - SEA

KW - CLIMATE

UR - http://www.scopus.com/inward/record.url?scp=85073988129&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/new-results-stable-isotope-petrographic-studies-jurassic-glendonites-siberia

U2 - 10.1080/11035897.2019.1641549

DO - 10.1080/11035897.2019.1641549

M3 - Article

AN - SCOPUS:85073988129

VL - 141

SP - 225

EP - 232

JO - GFF

JF - GFF

SN - 1103-5897

IS - 4

ER -