In this month's AAPG BULLETIN...

September 2008

Connectivity of fluvial point-bar deposits: An example from the Miocene Huesca fluvial fan, Ebro Basin, Spain

Marinus E. Donselar and Irina Overeem

The Miocene Huesca fluvial fan within the Ebro Basin, Spain, consists of point-bar deposits connected by elongate channel floor sand ribbons. A conceptual model takes into account this connectivity with important implications for reservoir volume, recovery factors, and sweep efficiency.

Families of Miocene Monterey crude oil, seep, and tarball samples, coastal California

Kenneth E. Peters, Frances D. Hostettler, Thomas D. Lorenson, and Robert J. Rosenbauer

Geochemical data were used to better understand the origin and distribution of crude oil samples from wells, seeps, and floating or beached tarballs from coastal California. A classification decision tree was constructed, and samples collected subsequent to storm activity indicate a seep origin, rather than an anthropogenic source.

Early diagenesis of inner shelf phosphorite and iron-silicate minerals, Lower Cretaceous of Orpheus graben, southeastern Canada: Implications for the origin of chlorite rims

Georgia Pe-Piper and Shawna Weir-Murphy

Fe-rich chlorite rims on framework grains have inhibited quartz cementation and improved reservoir quality in the Scotian Basin, offshore eastern Canada. The elevated abundance of phosphorus minerals is associated with such rims and may be an indicator of conditions suitable to their formation.

Paleocene to Eocene deep-water slope canyons, western Gulf of Mexico: Further insights for provenance of deep-water offshore Wilcox Group plays

Angela McDonnell, Robert G. Loucks, and William E. Galloway

The Tertiary Wilcox Group contains a deep-water fan system that is a significant exploration target offshore Texas. Seismic imaging reveals that deeply buried submarine canyons likely connected the basinal turbidites to equivalent-aged onshore deposits.

Geochemically driven exploration models in uplifted areas: examples from the Norwegian Barents Sea

S. E. Ohm, D. A. Karlsen, and T. J. F. Austin

The Norwegian Barents Sea region is traditionally believed to be only gas prone, though most of the world's petroleum provinces reside in similarly uplifted settings. Recent discoveries indicate otherwise; geochemical evidence supports the existence of overlooked petroleum potential in this area.

Episodic petroleum fluid migration in fault zones of the northwestern Junggar Basin (northwest China): evidence from hydrocarbon-bearing zoned calcite cement

Zhijun Jin, Jian Cao, Wenxuan Hu, Yijie Zhang, Suping Yao, Xulong Wang, Yueqian Zhang, Yong Tang, and Xinpu Shi

Zoned calcite cements within the Junggar Basin, China, alternate between hydrocarbon bearing and hydrocarbon free on a micrometer scale. This indicates episodic mixing of basinal fluid with meteroric water due to seismically induced pumping of petroleum-bearing fluid during fault movement.

About the BULLETIN

First published in 1917 as the Bulletin of the Southwestern Association of Petroleum Geologists--AAPG’s predecessor organization--in order to disseminate scientific material from annual meetings of the S.A.P.G., the AAPG Bulletin changed its name one year later when S.A.P.G. became AAPG.

The AAPG Bulletin has been delivering quality research to the scientific world ever since. The first issue contained papers written by the best-known geologists of the day, and included papers on such topics as South America, Europe, and general geologic problems of structure and sedimentation.

While the 21st-century AAPG Bulletin has undergone some changes since 1917, enlarging to 8 ½ x 11” size to incorporate more material and being published digitally as well as in print, it continues to adhere to the primary purpose of the organization, which is to advance the science of geology especially as it relates to petroleum, natural gas, other subsurface fluids, and mineral resources.

Delivered digitally or in print monthly to each AAPG Member as a part of membership dues, the AAPG Bulletin is one of the most respected, peer-reviewed technical journals in existence, with recent issues containing papers focused on such topics as the Middle East, channel detection, China, permeability, subseismic fault prediction, the U.S., and Africa.