Southern California Bight Sedimentary Rocks

This dataset represents the state of knowledge about the distribution of sedimentary rocks along the Southern California continental shelf as of 1974. The data are derived from a single map. The purpose of this project was to create digital, GIS format versions of the California continetnal shelf seafloor substrate using existing hard copy (paper) maps from a variety of sources.

Created using map from US Department of Interior, Bureau of Land Management, Pacific Outer Continental Shelf Office, 1974. The map illustrates 8 substrate types which we distilled into three: Sedimentary Rocks, Undifferentiated Rocks, and Vulcanic Metamorphic Rocks. Original 8 substypes were: Pre-upper Cretaceous sedimentary igneous & metamorphic rocks; Eocene & Paleocene sedimentary rocks; Miocene vulcanic rocks; Oligocene sedimentary rocks (non-marine); Miocene intrusive igneous rocks & pre-upper cretaceous igneous; sedimentary and metamorphic rocks (undifferentiated); Miocene igneous & sedimentary rocks (undifferentiated); Holocene Pleistocene & Plicene sediments and sedimentary rocks; and Miocene sedimentary rocks.

Data digitized from Channel Islands Area Map created by the US Department of the Interior Beurea of Land Management, Pacific Continental Shelf Office, 1974. UCSB library call number: 9507, .N2446, 1974, .U5, graphic #11. Source data from the map were prepared by the U.S. Geological Survey, 1974 (Geologic Division).

本数据集记录了截至1974年，南加利福尼亚大陆架（Southern California continental shelf）沉积岩（Sedimentary Rocks）分布的认知现状。数据源自单幅专题地图。本项目旨在基于多来源的纸质硬拷贝地图，制作加利福尼亚大陆架海底基底的数字化地理信息系统（GIS）格式版本。

本数据集基于美国内政部（US Department of the Interior）土地管理局（Beurea of Land Management）太平洋外大陆架办公室（Pacific Outer Continental Shelf Office）1974年发布的地图制作。该原始地图标注了8种基底类型（substrate types），我们将其归纳为三类：沉积岩（Sedimentary Rocks）、未分异岩石（Undifferentiated Rocks）以及火山变质岩（Vulcanic Metamorphic Rocks）。原始8个子类型分别为：上白垩统前沉积岩、火成岩与变质岩；始新统（Eocene）与古新统（Paleocene）沉积岩；中新统（Miocene）火山岩；渐新统（Oligocene）陆相（non-marine）沉积岩；中新统侵入火成岩（intrusive igneous rocks）与上白垩统前火成岩；沉积岩与变质岩（未分异）；中新统火成岩与沉积岩（未分异）；全新统（Holocene）、更新统（Pleistocene）与上新统（Plicene）沉积物及沉积岩；以及中新统沉积岩。

数据源自美国内政部土地管理局太平洋大陆架办公室1974年编制的海峡群岛区域地图（Channel Islands Area Map），加州大学圣巴巴拉分校图书馆馆藏索书号：9507, .N2446, 1974, .U5, 图表编号11。该地图的源数据由美国地质调查局（U.S. Geological Survey）地质调查处（Geologic Division）1974年编制。