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Lithostratigraphy Of The Miocene Monterey/Modelo Formation Along Camino De La Cumbre, Sherman Oaks, CA


The Middle to Upper Miocene Modelo or Monterey Formation outcrops along a roadcut on the northern flank of the Santa Monica Mountains in Sherman Oaks, CA. This 1400 foot section of interbedded sandstone, diatomite and mudstone provides an opportunity to study the detailed stratigraphy of this interval and compare with sections previously identified by Hoots (1930), Rummelhart and Ingersoll (1997 and 1999), Redin (1984), and Wright (1991). According to these authors, the Monterey/Modelo Formation in this location was deposited during the subsidence of the Los Angeles Basin as part of a system of sandstone turbidites, fine-grained gravity flows, and hemipelagic sedimentation. While much is known about the sandstones within the Modelo Formation, very little is known about the relationship between the sandstones and associated fine-grained rocks. This independent research project aims to produce detailed characterization of a section of Middle to Upper Monterey/Modelo Formation through the use of handheld spectral gamma ray readings at two foot intervals in conjunction with lithologic description including key sedimentary features such as graded beds, speckled beds, varve-like laminations, scoured surfaces, bioturbation, etc. This project holds significance by aiding in correlation and interpretation of subsurface well logs as well as improving the understanding of facies relationships in mixed-clastic, diatomaceous sedimentary systems.