Which geological event is associated with the formation of the Monterey Formation?

The formation of the Monterey Formation is primarily associated with Miocene marine sedimentation. This geological event occurred during the Miocene epoch, which spanned from about 23 to 5 million years ago. During this time, the area that encompasses the Monterey Formation was submerged under a marine environment that facilitated the deposition of organic-rich sediments. These sediments are significant because they led to the formation of one of the world's most important petroleum source rocks.

The Monterey Formation is characterized by its rich content of fossilized materials, especially diatoms and other marine organisms, which contributed to the formation of the unique characteristics of the rock. This sedimentation process reflects the environmental conditions of the time, characterized by marine transgressions and regressions that allowed for the accumulation of these organic-rich deposits.

Understanding the role of Miocene marine sedimentation in the development of the Monterey Formation is essential for recognizing its geological significance, particularly in terms of petroleum geology and the evolution of the region's geology over million-year timescales.