Biology: The Unity and Diversity of Life (MindTap Course List)
Biology: The Unity and Diversity of Life (MindTap Course List)
15th Edition
ISBN: 9781337408332
Author: Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr
Publisher: Cengage Learning
bartleby

Concept explainers

bartleby

Videos

Textbook Question
Book Icon
Chapter 16, Problem 1DAA

Discovery of Iridium in the K–Pg Boundary Layer In the late 1970s, geologist Walter Alvarez was investigating the composition of the K–Pg boundary layer in different parts of the world. He asked his father, Nobel Prize–winning physicist Luis Alvarez, to help him analyze the elemental composition of the layer. The Alvarezes and their colleagues tested the K-Pg boundary layer in Italy and Denmark, and discovered that it contains a much higher iridium content than the surrounding rode layers (FIGURE 16.17). Iridium belongs to a group of elements that are much more abundant in asteroids and other solar system materials than they are in Earth’s crust. The Alvarez group concluded that the K–Pg boundary layer must have originated with extraterrestrial material.

Sample Depth Average Abundance of Iridium (ppb)
+2.7m <0.3
+1.2m <0.3
+0.7m 0.36
boundary layer 41.6
–0.5 m 0.25
–5.4 m 0.30

Chapter 16, Problem 1DAA, Discovery of Iridium in the KPg Boundary Layer In the late 1970s, geologist Walter Alvarez was

FIGURE 16.17 Abundance of iridium in and near the K–Pg boundary layer.

Iridium content of rock samples above, below, and at the K–Pg boundary layer in Stevns Klint, Denmark. Sample depths are given as meters above or below the layer. ppb, parts per billion. An average Earth rock contains 0.4 ppb iridium; the average meteorite, 550 ppb. The photo shows Luis and Walter Alverez next to the K–Pg boundary layer in Stevns Klint.

What was the iridium content of the K–Pg boundary layer?

Expert Solution & Answer
Check Mark
Summary Introduction

To determine: The iridium content of the K–Pg boundary layer.

Introduction: The iridium is a chemical element that is abundantly found in the Cretaceous–Paleogene (K–Pg) boundary layer. The iridium level in an average rock is about 0.4 ppb, and in an average meteorite, it is about 550 ppb. This allows scientists to conclude whether the origin of the rocks is from the Earth or from any other sources.

Explanation of Solution

As given in the problem statement, Researcher W examined the composition of the K–Pg boundary layer in various parts of the world. He took help from his father to examine the composition of elements in the layer. Researcher L and his colleagues tested the K–Pg boundary layer in Country D and Country I. They discovered that the iridium content was found to be in large quantity than the surrounding rock layers. They also concluded that the boundary layer may have originated with the extraterrestrial material.

Refer to Fig. 16.17, “Abundance of iridium in and near the K-Pg boundary layer”, in the textbook. The given table shows the average abundance of iridium (ppb), and the sample depth (in meters) in Country D. The chemical element iridium was found in abundance on an average of about 41.6 ppb in the K–Pg boundary layer.

Conclusion

The iridium content was 41.6 ppb in the K–Pg boundary layer.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Preoperative Diagnosis: Torn medial meniscus, left knee Postoperative Diagnosis: Combination horizontal cleavage tear/flap tear, posterior horn, medial meniscus, left knee. Operation: Arthroscopic subtotal medial meniscectomy, left knee Anesthetic: General endotracheal Description of Procedure: The patient was placed on the operating table in the supine position and general endotracheal anesthesia was administered. After an adequate level of anesthesia was achieved, the patient's left lower extremity was prepped with Betadine scrubbing solution, then draped in a sterile manner. Several sites were then infiltrated with 1% Xylocaine solution with Epinephrine to help control bleeding from stab wounds to be made at these sites. These stab wounds were made anterolaterally at the level of the superior pole of the patella for insertion of an irrigation catheter into the suprapatellar pouch area, anterolaterally at the level of the joint line for insertion of the scope and anteromedially at…
UARDIAN SIGNA Life Sciences/ Baseline Test Grade 10 ry must be written in point form. pot in full sentences using NO MORE than 70 words sentences from 1 to 7. only ONE point per sentence. words as far as possible. number of words you have used in brackets at the end GDE/2024 QUESTION 3 The table below shows the results of an investigation in which the effect of temperature and light on the yield of tomatoes in two greenhouses on a farm was investigated. TEMPERATURE (°C) AVERAGE YIELD OF TOMATOES PER 3.1 PLANT (kg) LOW LIGHT LEVELS HIGH LIGHT LEVELS 5 0,5 0,5 10 1,5 2,5 15 3,0 5,0 20 3,6 8,5 25 3,5 7,8 30 2,5 6,2 State TWO steps the investigator may have taken into consideration during the planning stage of the investigation. (2) 3.2 Identify the: a) Independent variables (2) b) Dependent variable (1) 3.3 Plot a line graph showing the results of the average yield of the tomatoes from 5°C to 30°C for low light levels. (6) 3.4 State ONE way in which the scientists could have improved the…
Explain why you chose this mutation. Begin by transcribing and translating BOTH the normal and abnormal DNA sequences. The genetic code below is for your reference. SECOND BASE OF CODON כ FIRST BASE OF CODON O THIRD BASE OF CODON SCAGUCAGUGAGUCAG UUU UUC UCU UAU UGU Phenylalanine (F) Tyrosine (Y) Cysteine (C) UCC UAC UGC Serine (S) UUA UUG Leucine (L) UCA UCG_ UAA UGA Stop codon -Stop codon UAG UGG -Tryptophan (W) CUU CUC CCU CAU CGU Histidine (H) CCC CAC CGC -Leucine (L) Proline (P) CUA CCA CAA CUG CCG CAG-Glutamine (Q) -Arginine (R) CGA CGG AUU ACU AAU AGU AUC Isoleucine (1) Asparagine (N) ACC AAC Threonine (T) AUA ACA AAA Methionine (M) Lysine (K) AUG ACG Start codon AAG AGC-Serine (S) -Arginine (R) AGA AGG GUU GCU GAU GUC GUA GUG GCC Valine (V) -Alanine (A) GCA GCG GAC GAA GAG Aspartic acid (D) GGU Glutamic acid (E) GGC GGA GGG Glycine (G) In order to provide a complete answer to the question stated above, fill in the mRNA bases and amino acid sequences by using the Genetic Code…
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Biology Today and Tomorrow without Physiology (Mi...
Biology
ISBN:9781305117396
Author:Cecie Starr, Christine Evers, Lisa Starr
Publisher:Cengage Learning
Text book image
Biology: The Unity and Diversity of Life (MindTap...
Biology
ISBN:9781337408332
Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr
Publisher:Cengage Learning
Text book image
Biology: The Unity and Diversity of Life (MindTap...
Biology
ISBN:9781305073951
Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr
Publisher:Cengage Learning
Text book image
Biomedical Instrumentation Systems
Chemistry
ISBN:9781133478294
Author:Chatterjee
Publisher:Cengage
Text book image
BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)
Biology
ISBN:9781305967359
Author:STARR
Publisher:CENGAGE L
Text book image
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Fossil: The Language & History of Paleontology; Author: Alliterative;https://www.youtube.com/watch?v=x9yNwRBlKtU;License: Standard youtube license