25th International Meeting on Organic Geochemistry IMOG 2011

P-094
Marine transgressional event during the Early Cretaceous in
southeastern China: organic petrological and biomarker
evidences
Zhijun Jin 1 , Jian Cao 2 , Xulong Wang 3 , Wenxuan Hu 2 , Suping Yao 2
1 Exploration and Production Research Institute, SINOPEC, Beijing, China, 2 Department of Earth Sciences,
Nanjing, China, 3 PetroChina Xinjiang Oilfield Company, Karamay, China (corresponding
author:jcao@nju.edu.cn)
The Early Cretaceous in southeastern China has
been widely believed to feature a volcanic eruption
intercalated with non-marine deposition, with the
exception of some marine records (paleontological in
particular) along the roughly NE-SW trending
coastline due to marine transgression. Furthermore,
the transgression has been suggested to be held up
by the famous NE-SW trending Zhenghe-Dapu fault,
which is roughly parallel to the coastline. However,
the fault may not activate during the Early Cretaceous
and has started to activate since the Late Cretaceous
according to some tectonic studies. Thus, whether the
transgression has records in the area west to the fault
is an important scientific issue, implying for the activity
of the fault and the intensity of marine transgression.
In this study, dark mudstones samples were
collected from sites west to the Zhenghe-Dapu fault,
including mudstones from the Bantou Formation (K1b)
in Fujian province, Shouchang (K1s) and Guantou
formations (K1g) in Zhejiang province. They were
conducted by an integrated paleontological and
biomarker study. The paleontological
microobservation showed that typical marine fossils
such as red and brown alga are present besides
higher plants. Biomarker features also indicate marine
signatures, such as detection of gammacerane with
the ratio of gammacerane to C30 hopane ranging from
0.11 to 0.18, detection of C30 diahopane,