River of Tar
Fresh oil/ tar oozes up in cracks that formed in the harded tar at the surface of a tar stream in the McKittrick Oil Field on the western side of the San Joaquin Valley in California. This hydrocarbon stream is fed by a natural seep, one of the many that make up an area known as The McKittrick Tar Pits, sits just to the west of the town of McKittrick in Kern County. In some areas, one of the first clues that oil is present in the subsurface is the fact that it sometimes finds its way to the surface through faulting or porous rock. Places where oil, asphalt or tar naturally comes to the surface are called an oil / tar seep or brea. Sands that are saturated with heavy asphalt or tar are called tar sands. The tar pits here lie on the western flank of the Temblor Range where alluvium covers Holocene alluvial gravels, fluvial sandstone, and lacustrine shales. These in turn overlie the kerogen-rich Miocene Monterey Formation. Most of the kerogen represent the preserved bodies of microscopic organism such as diatoms that live in the upper few meters of the ocean. The Monterey has many diatom rich beds called diatomaceous shales. Heat and time changed the soft body parts into liquid hydrocarbon and associated gas. About the same time, movement of the San Andres and associated faults help form the Temblor Range. Faulting and cracking of the rocks formed pathways for the oil to migrate up out of the Monterey, Some of the oil became trapped beneath an impermeable cap of Monterey Formation that slid of the Mountains. Most of the tar seeps occur in place where erosion has removed the Monterey cap (deposited by the landslide) and allowed the porous sandstone beds to be exposed and leak the oil.
As with its famous cousin, the La Brea Tar Pits, to the south, McKittrick's oil seeps also trapped its fair share of animals. Paleontologic studies of these seeps began in the early 1900's. Both the University of California and the Kern County Museum excavated the site in the 1940s. As of 1968, paleontologists identified over 43 different mammals and 58 different bird species. Bison, saber-toothed cat, dire wolf, camel and elephant, as well as smaller animals have been identified. Some of these species are now extinct. Most of the animal remains date back to the Pliestocene (10000 to 40000 years ago).
The Tulumne Yokut were the first people known to exploit the tar. Spanish explorers noted that they used it as a glue, a waterproofing agent, and related uses. It was so useful they found other tribes willing to trade for it. Early European settlers found similar uses, In the early 1860's the Buena Vista Petroleum Company began digging the tar at the seeps. In some cases Mining techniques were employed. A worker would be lowered down into the mine, then would fill buckets with the asphalt, while someone at the surface would pull it up. It was incredibly dirty and hot, As a result many miners chose to work naked and be washed at the end of the day. The Job had it dangers too, The workers not only had to contend with the tar in the pits, but also the hot weather of the San Joaquin Valley and noxious fumes from the oil, tar and gas. In the end, the mines were not very economical. The first oil well, The Standard Oil #1, was drilled in 1899. The well discovered oil and McKittrick Field was born. It became a major oil producer and is still producing today,
River of Tar
Fresh oil/ tar oozes up in cracks that formed in the harded tar at the surface of a tar stream in the McKittrick Oil Field on the western side of the San Joaquin Valley in California. This hydrocarbon stream is fed by a natural seep, one of the many that make up an area known as The McKittrick Tar Pits, sits just to the west of the town of McKittrick in Kern County. In some areas, one of the first clues that oil is present in the subsurface is the fact that it sometimes finds its way to the surface through faulting or porous rock. Places where oil, asphalt or tar naturally comes to the surface are called an oil / tar seep or brea. Sands that are saturated with heavy asphalt or tar are called tar sands. The tar pits here lie on the western flank of the Temblor Range where alluvium covers Holocene alluvial gravels, fluvial sandstone, and lacustrine shales. These in turn overlie the kerogen-rich Miocene Monterey Formation. Most of the kerogen represent the preserved bodies of microscopic organism such as diatoms that live in the upper few meters of the ocean. The Monterey has many diatom rich beds called diatomaceous shales. Heat and time changed the soft body parts into liquid hydrocarbon and associated gas. About the same time, movement of the San Andres and associated faults help form the Temblor Range. Faulting and cracking of the rocks formed pathways for the oil to migrate up out of the Monterey, Some of the oil became trapped beneath an impermeable cap of Monterey Formation that slid of the Mountains. Most of the tar seeps occur in place where erosion has removed the Monterey cap (deposited by the landslide) and allowed the porous sandstone beds to be exposed and leak the oil.
As with its famous cousin, the La Brea Tar Pits, to the south, McKittrick's oil seeps also trapped its fair share of animals. Paleontologic studies of these seeps began in the early 1900's. Both the University of California and the Kern County Museum excavated the site in the 1940s. As of 1968, paleontologists identified over 43 different mammals and 58 different bird species. Bison, saber-toothed cat, dire wolf, camel and elephant, as well as smaller animals have been identified. Some of these species are now extinct. Most of the animal remains date back to the Pliestocene (10000 to 40000 years ago).
The Tulumne Yokut were the first people known to exploit the tar. Spanish explorers noted that they used it as a glue, a waterproofing agent, and related uses. It was so useful they found other tribes willing to trade for it. Early European settlers found similar uses, In the early 1860's the Buena Vista Petroleum Company began digging the tar at the seeps. In some cases Mining techniques were employed. A worker would be lowered down into the mine, then would fill buckets with the asphalt, while someone at the surface would pull it up. It was incredibly dirty and hot, As a result many miners chose to work naked and be washed at the end of the day. The Job had it dangers too, The workers not only had to contend with the tar in the pits, but also the hot weather of the San Joaquin Valley and noxious fumes from the oil, tar and gas. In the end, the mines were not very economical. The first oil well, The Standard Oil #1, was drilled in 1899. The well discovered oil and McKittrick Field was born. It became a major oil producer and is still producing today,