USGS National and Global Oil and Gas Assessment Project-Southwestern Wyoming Province, Mesaverde Group and Lance Formation Conventional and Continuous Assessment Unit Boundaries, Assessment Input Data, and Fact Sheet Data Tables

This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Mesaverde Group and Lance Formation in the Southwestern Wyoming Province, Wyoming, Utah, and Colorado. The assessment unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The assessment unit is defined within the context of the higher-level Total Petroleum System. The assessment unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties within the Total Petroleum System, such as source rock, timing, migration pathways, trapping mechanism, and hydrocarbon type. The assessment unit boundary is defined geologically as the limits of the geologic elements that define the assessment unit, such as reservoir rock, geologic structures, source rock, and seal lithologies. The only exception to this are assessment units that border a Federal-State water boundary. In these cases, the Federal-State water boundary forms part of the assessment unit boundary. In addition to the shapefile, for U.S. assessments, allocation tables are provided that enumerate percentages assigned to various land categories. Machine-readable tables are also provided that contain the input and results for each assessment unit summarized in the USGS Fact Sheet. Methodology for assessments are documented in USGS Data Series 547 for continuous assessments (https://pubs.usgs.gov/ds/547) and USGS DDS69-D, Chapter 21 for conventional assessments (https://pubs.usgs.gov/dds/dds-069/dds-069-d/REPORTS/69_D_CH_21.pdf). See supplemental information for a detailed list of files included in this data release.

本次数据发布包含怀俄明州、犹他州与科罗拉多州境内怀俄明州西南部油气省中梅萨维德群（Mesaverde Group）及兰斯组（Lance Formation）内未发现油气资源评估所需的评估单元边界与输入数据集。
评估单元是美国国家未发现油气资源评估项目中采用的基本单元，需在更高层级的全油气系统（Total Petroleum System）框架内完成定义。
本次发布的评估单元以地理边界形式呈现，由负责该油气省的地质学家开展解释、定义与绘图工作，其涵盖了全油气系统内一组具备相似地质、地理与时间属性的已知或推测油气聚集区，包含烃源岩、成藏时序、运移路径、圈闭机制以及油气类型等核心特征。
评估单元边界在地质层面被定义为构成该评估单元的各类地质要素的范围，例如储集岩、地质构造、烃源岩以及盖层岩性等。唯一例外的情形为与联邦-州际水域边界相邻的评估单元，此类情况下，联邦-州际水域边界将作为评估单元边界的组成部分。
除形状文件（shapefile）外，针对美国境内的油气评估，本数据集还提供了枚举各类土地类别占比的分配表；同时附带可机读表格，其中收录了美国地质调查局（USGS）情况说明书中汇总的各评估单元的输入参数与评估结果。
本次评估的方法学文档可参考美国地质调查局数据系列547（USGS Data Series 547）中的连续型资源评估内容（https://pubs.usgs.gov/ds/547），以及美国地质调查局DDS69-D第21章中的常规型资源评估内容（https://pubs.usgs.gov/dds/dds-069/dds-069-d/REPORTS/69_D_CH_21.pdf）。
如需获取本次数据发布所包含文件的详细清单，请参阅补充信息。