The subject of this field, trip, the Monterey and adjacent formations, will be examined in detail in the Pismo Basin and to a lesser extent in the Huasna Basin. The Pismo basin is ideally suited for this detailed examination for the following reasons:
Excellent geological maps of the area (Hall and Corbato, 1967; Hall, 1973a, and 1973b).
Surdam, Stanley and Kablanow have spent considerable time in the Pismo and Huasna basins studying the Obispo, Monterey, Pismo and Santa Margarita formations. In addition, Stanley has spent two field seasons mapping and evaluating stratigraphic and sedimentologic relations relations in the Monterey Formation in the Santa Maria and Ventura Basins. Lastly and most important, C.A. Hall has provided us with a large high quality data base in the Pismo and Huasna Basins.
A detailed tectonic history of the region has recently been published by C.A. Hall (1981).
The present-day Pismo Syncline outlines a Miocene-Pliocene depositional basin where Monterey and overlying rocks accumulated. Therefore the boundaries and internal geometry of the depositional basin are well delineated (Hall & Corbato, 1967; Hall, 1973a, 1973b).
The Monterey Formation in the Pismo Syncline was originally characterized by three kinds of sediment (diatromaceous ooze, calcareous and phosphatic ooze, and terrigenous sands and muds). In addition, there is abundant organic material (TOC = 1 to 6 wt.%) in the marine rocks and there are petroleum reservoirs in the basin.
In the Pismo Syncline the Monterey Formation unconformably overlies the Obispo Formation. The Obispo Formation consists of 2000 to 3000
Figures & Tables
Stratigraphic, Tectonic, Thermal, and Diagenetic Histories of the Monterey Formation, Pismo and Huasna Basin, California
Stratigraphic, Tectonic, Thermal and Diagenetic Histories of the Monterey Formation, Pismo and Huasna Basin, California - The subject of this field trip, the Monterey and adjacent formations, are examined in detail in the Pismo Basin and to a lesser extent in the Huasna Basin. This guidebook is unconventional in the sense that it is not tied to the individual stops, but instead is a series of old and new articles that are based on observations made at the field trip stops.