An exploration well has been drilled in a new lease to test the possibility of a subsurface geophysical high below a Precambrian through Devonian sequence that has been thrust over a Paleozoic shelf sequence. The well penetrated 245 feet of Pleistocene sedimentary fll before entering Upper Devonian sandstones. Regional geologic and geophysical data indicate that the entire allochthonous (out of place, or, "far traveled") sequence dips 45° to the west. Vertically drilled thicknesses of the various formations within the overthrust sequence are as follows (shallow to deep): Allochthonous Sequence WELL LOG Drilled Thickness (1t.) True Thickness (ft.) Fm. Upper Devonian clastic rocks Upper Cambrian sandstones Upper Cambrian shales Middle-Upper Cambrian shale Pre-Cambrian basement 470 112 600 600 320 Geophysical data also indicate that the underlying autochthonous (in place) Paleozoic shelf sequence is sub- horizontal with dips ranging from 1-6° to the west. Preserved cores from the well indicate that this sequence includes (shallow to deep): Autochthonous Sequence WELL LOG Fm. Drilled Thickness (t.) 1240 True Thickness (ft.) Permian Pennsylvanian Lower Mississippian 834 27 – bottom of well Calculate the true thicknesses of the allochthonous Precambrian to Devonian sequence and complete the table. In the space below, be sure to demonstrate how you made your calculations.
An exploration well has been drilled in a new lease to test the possibility of a subsurface geophysical high below a Precambrian through Devonian sequence that has been thrust over a Paleozoic shelf sequence. The well penetrated 245 feet of Pleistocene sedimentary fll before entering Upper Devonian sandstones. Regional geologic and geophysical data indicate that the entire allochthonous (out of place, or, "far traveled") sequence dips 45° to the west. Vertically drilled thicknesses of the various formations within the overthrust sequence are as follows (shallow to deep): Allochthonous Sequence WELL LOG Drilled Thickness (1t.) True Thickness (ft.) Fm. Upper Devonian clastic rocks Upper Cambrian sandstones Upper Cambrian shales Middle-Upper Cambrian shale Pre-Cambrian basement 470 112 600 600 320 Geophysical data also indicate that the underlying autochthonous (in place) Paleozoic shelf sequence is sub- horizontal with dips ranging from 1-6° to the west. Preserved cores from the well indicate that this sequence includes (shallow to deep): Autochthonous Sequence WELL LOG Fm. Drilled Thickness (t.) 1240 True Thickness (ft.) Permian Pennsylvanian Lower Mississippian 834 27 – bottom of well Calculate the true thicknesses of the allochthonous Precambrian to Devonian sequence and complete the table. In the space below, be sure to demonstrate how you made your calculations.
Applications and Investigations in Earth Science (9th Edition)
9th Edition
ISBN:9780134746241
Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Chapter1: The Study Of Minerals
Section: Chapter Questions
Problem 1LR
Related questions
Question
Help with this.
Transcribed Image Text:An exploration well has been drilled in a new lease to test the possibility of a subsurface geophysical high below
a Precambrian through Devonian sequence that has been thrust over a Paleozoic shelf sequence. The well
penetrated 245 feet of Pleistocene sedimentary fill before entering Upper Devonian sandstones. Regional
geologic and geophysical data indicate that the entire allochthonous (out of place, or, "far traveled") sequence
dips 45° to the west. Vertically drilled thicknesses of the various formations within the overthrust sequence are
as follows (shallow to deep):
Allochthonous Sequence WELL LOG
Fm.
Drilled Thickness (ft.)
470
True Thickness (ft.)
Upper Devonian clastic rocks
Upper Cambrian sandstones
Upper Cambrian shales
Middle-Upper Cambrian shale
Pre-Cambrian basement
112
600
600
320
Geophysical data also indicate that the underlying autochthonous (in place) Paleozoic shelf sequence is sub-
horizontal with dips ranging from 1-6° to the west. Preserved cores from the well indicate that this sequence
includes (shallow to deep):
Autochthonous Sequence WELL LOG
Fm.
True Thickness (ft.)
Drilled Thickness (ft.)
1240
Permian
Pennsylvanian
Lower Mississippian
834
27 - bottom of well
Calculate the true thicknesses of the allochthonous Precambrian to Devonian sequence and complete the table.
In the space below, be sure to demonstrate how you made your calculations.
WORK SPACE:
Expert Solution
Intorduction.
To determine the true thickness of subsurface rock formations, it is necessary to know their orientations. True thickness essentially refers to the orthogonal distance between the boundary layers of the formation.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 1 images
Recommended textbooks for you
Applications and Investigations in Earth Science …
Earth Science
ISBN:
9780134746241
Author:
Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:
PEARSON
Exercises for Weather & Climate (9th Edition)
Earth Science
ISBN:
9780134041360
Author:
Greg Carbone
Publisher:
PEARSON
Environmental Science
Earth Science
ISBN:
9781260153125
Author:
William P Cunningham Prof., Mary Ann Cunningham Professor
Publisher:
McGraw-Hill Education
Applications and Investigations in Earth Science …
Earth Science
ISBN:
9780134746241
Author:
Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:
PEARSON
Exercises for Weather & Climate (9th Edition)
Earth Science
ISBN:
9780134041360
Author:
Greg Carbone
Publisher:
PEARSON
Environmental Science
Earth Science
ISBN:
9781260153125
Author:
William P Cunningham Prof., Mary Ann Cunningham Professor
Publisher:
McGraw-Hill Education
Earth Science (15th Edition)
Earth Science
ISBN:
9780134543536
Author:
Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:
PEARSON
Environmental Science (MindTap Course List)
Earth Science
ISBN:
9781337569613
Author:
G. Tyler Miller, Scott Spoolman
Publisher:
Cengage Learning
Physical Geology
Earth Science
ISBN:
9781259916823
Author:
Plummer, Charles C., CARLSON, Diane H., Hammersley, Lisa
Publisher:
Mcgraw-hill Education,