About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
Journal of Sedimentary Research (SEPM)
Abstract
Late Oligocene-Early Miocene Facies and Lacustrine Sedimentation, Upper Ruby River Basin, Southwestern Montana
Stewart Monroe
ABSTRACT
Sediments deposited in and around a closed, shallow, perennial lake (Lake Passamari) constitute the late Oligocene-early Miocene Passamari Member of the Renova Formation. Three sedimentary facies are recognized: 1) lacustrine-nearshore and open lacustrine environments; 2) marginal lacustrine-deltaic and fluvial-lacustrine environments; and 3) alluvial-meandering stream, braided delta-distributary system, and allivial fan environments.
Within the basin, a central core of limestones and fine-grained clastics of the lacustrine facies is flanked on the north and west by coarse-grained deposits of the marginal lacustrine and alluvial facies. Along the north margin of Lake Passamari, extensive intertonguing of facies occurs, while on the west facies intertonguing is much more restricted.
Vertical lithologic repetitions in the lacustrine facies are attributed to lake-level fluctuations in response to climatic changes. Marginal lacustrine and alluvial facies lithologic repetitions were also controlled, in part, by lake-level fluctuations. However, they were also sensitive to rapid depositional episodes largely unrelated to overall climatic conditions.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |