Assessment of Shallow Biogenic Gas Resources in Montana
http://www.cspg.org/documents/Conventions/Archives/Annual/2001/4AB-P-045.pdf

J. L. Ridgley, T. C. Hester, S. M. Condon, L. O. Anna, P. G. Lillis, E. L. Rowan, G. T. Snyder, Canadian Society of Petroleum Geologists


This 6-page PDF abstract by the Canadian Society of Petroleum Geologists is a reassessment of a USGS study of methane gas reserves in shallow Cretaceous deposits in northern Montana. The study is based on current production, hypothetical "plays," and the similarity of potentially productive facies in Montana to the facies that host shallow biogenic resources in southeastern Alberta and southwestern Saskatchewan. Formations assessed include the Eagle Sandstone, the Belle Fourche, the Greenhorn, the Niobrara, the Milk River, the Carlile and the Judith River.

This resource is referenced here:
Subject: Environmental Science:Ecosystems:Biogeochemical cycling
Resource Type: Scientific Resources:Research Results
Focus on the Cretaceous: Economic Resources
Topics: Energy/Material cycles