### Updated tops file for Cretaceous and lower Tertiary units, Piceance Basin, northwest Colorado

By: Ronald C. Johnson**John D. DietrichTracey J. Mercier**

                            https://doi.org/10.3133/ofr20151036

#### Links

-                                                                                                                             Document:                                                                                                                                                                                                                                                  **Report**                                                                                                     (3.96 MB pdf)                                                                                                                                     
- Companion Files:                               - **Colorado Boreholes and Tops Fieldname Descriptions**                            (40.5 kB xlsx)                        
  - **Latests Tops Piceance**                            (4.40 MB xlsx) 
- Download citation as:  RIS                         |                         Dublin                            Core

#### Introduction

First posted August 4, 2015

**For additional information, contact:**
Director, Central Energy Science Center U.S. Geological Survey P.O. Box 25046 Denver, CO 80225http://energy.usgs.gov/

Depths to selected Cretaceous and lower Tertiary stratigraphic units in the Piceance Basin, northwestern Colorado are presented here for 1,563 wells. This file is updated from the Piceance Basin Oil Shale Database with data for additional new drill holes. Also included in this report are elevations for the base of the Long Point Bed of the Eocene Green River Formation for 347 surface locations obtained by determining locations and elevations from published 7 1⁄2-minute quadrangle maps for the Piceance Basin listed in the “Geologic Maps Used to Generate Long Point Control Points” section.

Each entry for the base of the Long Point Bed was obtained at a location where the mapped Long Point Bed intersects a contour line on the published maps. Precision of each elevation is therefore dependent on the precision of the maps and the placement of the mapped contact by the authors.

#### Suggested Citation

Johnson, R.C., Dietrich, J.D., and Mercier, T.J., 2015: Updated tops file for Cretaceous and lower Tertiary units, Piceance Basin, northwest Colorado: U.S. Geological Survey Open-File Report 2015–1036, 16 p., http://dx.doi.org/10.3133/ofr20151036.

ISSN: 2331-1258 (online)

#### Study Area

#### Table of Contents

- Introduction
- Cretaceous Units
- Lower Tertiary Units
- References Cited
- Geologic Maps Used to Generate Long Point Control Points
- Figures

Part or all of this report is presented in Portable Document Format                        (PDF). For best results viewing and printing PDF documents, it is recommended that you download                        the documents to your computer and open them with Adobe Reader. PDF documents opened from your                        browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information                        about viewing, downloading, and printing report files can be found at the common download problems FAQ.

Part of this report is presented in Microsoft Excel format (XLSX); the                        latest version of Excel Viewer is required to view it. Download the latest version of Excel Viewer, free                        of charge.