BGS Geology - 50k (DiGMapGB-50) Bedrock version 8

Data identifying areas (shown as polygons) attributed with geological names and rock type descriptions. The scale of the data is 1:50 000 scale providing bedrock geology. Onshore coverage is provided for all of England, Wales, Scotland and the Isle of Man. Bedrock geology describes the main mass of solid rocks forming the earth’s crust. Bedrock is present everywhere, whether exposed at surface in outcrops or concealed beneath superficial deposits or water bodies. The bedrock geology of Great Britain is very diverse and includes three broad classes based on their mode of origin: igneous, metamorphic and sedimentary. The data includes attribution to identify each rock type (in varying levels of detail) as described in the BGS Rock Classification Scheme (volumes 1-3). The bedrock has formed over long periods of geological time, from the Archean eon some 7500 million years ago, to the relatively young Pliocene, 58 million years ago. The age of the rocks is identified in the data through their BGS lexicon name (published for each deposit at the time of the original survey or subsequent digital data creation). For stratified rocks i.e. arranged in sequence, this will usually be of a lithostratigraphic type. Other rock types for example intrusive igneous bodies will be of a lithodemic type. More information on the formal naming of UK rocks is available in the BGS Lexicon of Named Rock Units. Geological names are based on the lithostratigraphic or lithodemic hierarchy. The lithostratigraphic scheme arranges rock bodies into units based on rock-type and geological time of formation. Where rock-types do not fit into the lithostratigraphic scheme, for example intrusive, deformed rocks subjected to heat and pressure resulting in new or changed rock types; then their classification is based on their rock–type or lithological composition, using visible features such as texture, structure, mineralogy. The data are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.

本数据集用于标识以多边形形式呈现的区域，并为其赋予地质名称与岩石类型描述信息。该数据集比例尺为1:50000，内容涵盖基岩地质（bedrock geology）信息，其陆上覆盖范围涵盖英格兰、威尔士、苏格兰全境及马恩岛。
基岩地质指构成地壳的主体固态岩石群。基岩广泛分布于地表各处，既可裸露形成露头，也可被表层沉积物或水体覆盖埋藏。大不列颠岛的基岩地质类型极为多样，依据成因可划分为三大类别：火成岩（igneous）、变质岩（metamorphic）与沉积岩（sedimentary）。
本数据集包含对各类岩石类型的属性标注（详细程度各不相同），分类依据为英国地质调查局（British Geological Survey，BGS）岩石分类方案（第1-3卷）。数据集涵盖的基岩形成于漫长的地质时期，时间跨度从约75亿年前的太古宙（Archean eon）至距今约5800万年的上新世（Pliocene）。
数据通过英国地质调查局命名岩石单元词典（BGS Lexicon of Named Rock Units）的名称来标识岩石年代，该词典条目会在原始调查或后续数字化数据创建阶段针对对应沉积体同步发布。对于呈层序排列的层状岩石，其分类通常属于岩石地层单位（lithostratigraphic）类型；而其他岩石类型，如侵入火成岩体，则属于岩石体单位（lithodemic）类型。
关于英国岩石正式命名的更多细节，可查阅《英国地质调查局命名岩石单元词典》（BGS Lexicon of Named Rock Units）。地质名称的命名依据为岩石地层或岩石体单位分级体系。岩石地层分类体系依据岩石类型与形成地质年代，将岩体划分为不同单位。对于无法归入岩石地层分类体系的岩石类型，例如经历热压作用形成新类型或发生蚀变的侵入型变形岩石，其分类将基于岩石类型或岩性组成，通过纹理、结构、矿物组成等可见特征进行判定。
本数据集以矢量格式提供，包含每个要素的几何信息与对应属性数据库记录，格式为ESRI形状文件（ESRI shapefiles），可依据英国地质调查局数据许可协议获取使用。