Miocene Epoch

The principal marine deposits were formed during the Tertiary period and more particularly the upper Miocene epoch. Deposits of freshwater origin date from the PHocene to Miocene epochs to more recent times, dating to as late as 100,000 years ago. U.S. commercial deposits are at or comparatively near the surface. Bog deposits are exploited and lake beds are dredged for use in other parts of the world. 

The ancient evaporites of the Phanerozoic eon were deposited at rates as fest as 100 m per lOOOy. These rapid rates are thought to have been caused by a lowering of sea level associated with tectonic activity and glaciation. Some of the largest of the salt giants are the Messinian evaporites that formed in the Mediterranean Sea during the late Miocene epoch, 5.5 to 6.5mybp. 

It is important to realise that clay can be exposed to many processes after it has been depos-ited. The periods are the Miocene Epoch (26 - 7 million years old), the Pliocene Epoch (7-2 millions years old), the Pleistocene Epoch (2 million to 15,000 years old) and the Holocene Epoch (up to approximately 15,000 years old). In The Netherlands no primary clay deposits are found, i.e. all clay is secondary, i.e. formed elsewhere and transported by wind, ice or water. 

Amber can be formed by any plant that produces sap or resin. It is not specific to pine trees, as is commonly believed. The amber found in the Baltic region of Eastern Europe was indeed formed in a huge pine forest that covered that area about 10 million years ago, during the Miocene Epoch. Much of today s commercial amber is mined in Mexico and the Dominican Republic. These deposits are older than the European amber, and were formed by large shrubs in the Pea family. 

Twenty years later, first attempts were made to apply fire flooding at a sector of the Zybza field selected for the study. The so-called "lense" of Horizon IV of the Sarmatsk stage of Miocene epoch was the target of this EOR test. The air injected into the ignition well flowed quickly through the reservoir rocks, as through a pipe, and into the production well. After the initial displacement and, at times, violent ejection of some crude oil, only injected air flowed into the production wells. When the latter were shut in, their wellhead pressures built up almost inunediately to those... 

Oligocene The third geological epoch of the Palaeogene period. It began about 34 million years ago, following the Eocene epoch, and extended for about 11 million years to the beginning of the Miocene epoch. The epoch was characterized by the continued rise of mammals the first pigs, rhinoceroses, and tapirs made their appearance. 

Most commercial marine diatomite deposits exploit accumulations resulting from large blooms of diatoms that occurred ia the oceans during the Miocene geological epoch. Diatomite sediments older than the Jurassic period are rare in the fossil record. Commercial deposits of diatomite are accumulations of the fossil skeletons, which can occur in beds as thick as 900 m in some locations (5). Marine deposits must have been formed on the bottom of protected basins or other bodies of quiet water, undisturbed by strong currents, in an environment similar to the existing Santa Barbara Channel or Gulf of California (3,6). 

Miocene. Referring to an epoch of the upper Tertiary period of the geologic time scale commenced approximately 280 million years ago. 

Pliocene The second epoch of the Neogene period. Preceded by the Miocene and followed by the Pleistocene, it extended from about 5 million years ago to 1.8 million years ago. Mammals similar to modern forms existed during the epoch and the australo-pithecines (seeAustralopithecus), early forerunners of humans, appeared. 

Since Early Miocene (22-20 Ma), the ice-sheet in continental Antarctica became a semi-permanent feature. There are evidences for glacier advances and retreats, even for interglacial-type warming epochs (during Pliocene). However, the succession and ages of the Middle Miocene through Pleistocene events are still inadequately known. 

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