Questions tagged [earth-history]

Questions relating to Historical Geology.

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3
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0answers
307 views

Puzzle using relative dating principles

This isn't directly looking at a real life ecological example kind of thing, but it requires knowledge of relative dating, so I thought I would come here. Here is what was told: -"Worms" (curved ...
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2answers
288 views

Earth's orbit and historical sun-earth distance

Purpose of my question: I create program to calculate solar radiation and I need to calculate radius between sun and earth. The based on book "Guide to HTML, JavaScript and PHP" For Scientists and ...
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1answer
100 views

What is a “tar shower?”

I'm reading about Sodom and Gomorrah on Wikipedia when I come across this: "One such idea is that the Dead Sea was devastated by an earthquake between 2100 and 1900 BCE. This might have unleashed ...
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Distribution of thermometric devices on earth

In complex climate models, measurements of Earth-based thermometers are used. What is their geographic distribution - historically? Does each measurement get equal weight?
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A circle shape in Madagascar

I was seeing Madagascar on Google Maps and accidentally i saw a circle shape near Bebao. Coordinates are 17.4317443°E and 44.644248°S. Please, to satisfy my curiosity, can you tell me why is this ...
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2answers
571 views

Was the Earth's sea-level significantly lower in ancient times?

A lot of times, ancient artifacts or even whole ancient civilizations are found buried very deep into the ground surface of the earth. Entire civilizations that had high buildings have been found ...
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3answers
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Why does the earth spin clockwise?

Why does earth rotate in a clockwise direction? Did a large meteor collide with earth causing earth to rotate? If that is what happened, could another, larger meteor cause earth to reverse its ...
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1answer
643 views

How much have global GPP and biomass changed over Earth's history?

I'm curious about how much is known about this topic: how much has the total amount of life on Earth changed over the 4 billion years or so that it has existed on this planet? Are there estimates of ...
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What is the tectonic setting for the formation of the Great Dividing Range in Australia?

Australia's Great Dividing Range is the largest mountain range on the continent, running down the length of the eastern part of the continent, as shown in the Geoscience Australia map as a dark line, ...
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1answer
41 views

Sediment boundarys produced by largest meteors? Vredefort, Sudbury and Chicxulub

Chicxulub crater is the third largest crater on earth, which is said to have produced the KT boundary. What is the sediment layer produced by the 1st and 2nd largest craters? Also, there many ...
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1answer
47 views

Approximation of ancient landmasses using current ocean floor data

I am wondering how accurate such an approximation would be. I wish to take a current height map of the earth (including the ocean floor) and approximate the form of ancient landmasses by changing the ...
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387 views

What fraction of Earth's crustal material survives the supercontinent cycle?

I know that things are not as simple, but for the sake of argument I'll assume a supercontinent cycle of $\sim$400 Myr periodicity is active on Earth. If that is the case, then my naive ...
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1answer
111 views

gamma ray burst, extinction-level event

From this subsection in Wikipedia's aricle on extinction event: A nearby gamma-ray burst (less than 6000 light years away) would be powerful enough to destroy the Earth's ozone layer, leaving ...
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Did Theia collide directly with proto-Earth?

I was learning about the formation of Earth on Kahn Academy where it was mentioned that a protoplanet named Theia had a glancing impact with the earth and formed the moon. It seems like there is also ...
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1answer
571 views

How much energy released by the Theia-Gaia impact?

I read somewhere that the Chicxulub impact released the energy equivalent of anywhere from 100-300 teratons of TNT. That's an impressive amount of energy. Assuming a head on collision (according to ...
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2answers
618 views

Have the landmasses of North and South America ever been part of the same continent?

I know this question have been asked very often, but I could not find a proper answer around StackExchange, so I thought this might be a good place to ask: Have the landmasses of North and South ...
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2answers
445 views

Determining the paleoelevation of mountain ranges

In New Delhi, a lot of people say that the Aravali range used to be as tall as the Himalayas. How do scientists know that some mountain range used to be a lot taller millions of years ago, and what ...
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1answer
150 views

Is there any place on Earth that is permanently a desert?

I am interested to know if there is any place on Earth that is permanently a desert (except Antarctica). By permanent I do not mean to be the physical meaning of forever. It means the place has to be ...
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4answers
876 views

Are craters on Earth covered by vegetation?

When you look at other planets and moons in our solar system most of them have lots of craters. If Earth had no vegetation and water would it also look like this image of Charon? Image Credit: NASA/...
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1answer
2k views

For how long has the Earth been habitable for humans?

Let's imagine that a human (male or female) could be sent to the past, anytime after the birth of our planet. What would be their survival probability over time? If this question is too hard to ...
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1answer
235 views

Surface temperature in early hadean period

I am considering earth's internal heat budget for a project in university. For this I need an estimate on the temperature of the earth shortly after it had formed. In Kelvin's On the Secular cooling ...
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2answers
950 views

How are the banded-iron-formation iron-ores formed?

Many of the richest and purest iron ores are found in so called banded iron formations, cm thick magnetite or hematite layers intermixed with iron poor rock layers. Since these are usually of pre-...
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Pangaea, supercontinent formation and fragmentation [duplicate]

Is there a widely accepted model for the supercontinent cycles ? From the novice point of view, it is not obvious why the continents would be fragmented all over the earth as now, but 300 millions ...
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2answers
653 views

Speed of tectonic plate movement

I'm doing some research about tectonic plates and at which speeds they move and in which directions, because I'm writing a program to simulate the movement of the tectonic plates and also calculate ...
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1answer
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Difference between the oxygen/$CO_2$ ratio during the period of the dinosaurs and the present

Here's the base of my question: Was volcanic activity more prevalent when the dinosaurs roamed? Is it true that during the time of the dinosaurs, both the oxygen requirements (by all living creatures ...
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1answer
277 views

Why is the concept of “mass extinction” a relatively recent development in geology?

The concept of "mass extinctions", with its catastrophic connotations, is a relatively recent development in the geological sciences. It evolved in the early 1980s, driven by two landmark publications ...
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How do we know the asteroids formed at the same time as earth?

In continuation of the question Why is Earth's age given by dating meteorites rather than its own rocks?, what evidence do we have that the asteroids indeed formed at the same time as earth? Is there ...
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1answer
246 views

Why do we see the limestone on top of Cambrian layer?

The official story says like Cambrian Ordovician transition was caused/accompanied by animals learned how to build the Ca-based skeletons. These skeletons and shells started to fall upon the sea bed ...
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1answer
574 views

The age of tectonic plates

There is information which says that East European Platform sticks out at the Baltic Sea and, therefore, we can see the ordovican layer in Estonia whereas ...
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1answer
224 views

Why is Great Oxidation Event associated with Iron oxidation but not Aluminum or Silicon?

Just to build up on my previous success with oxygen origin in the atmosphere, I want to expand the question as was advised in the answers. The official heresy, despite denied in the comments and ...
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2answers
609 views

Were all of Earth's minerals created before Earth's formation, during, or after?

I've heard that during the accretion of proto-planets that formed the earth, 60 minerals were created through the reactions of atoms and molecules in the nebula. Do these first minerals still make up ...
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1answer
218 views

How does water still exist on the Earth?

Almost all the theories that explain the origin of Earth says, it was way hot back then. That means It was in a lava state in its early days. Then gradually cooled down to the current state. If ...
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1answer
183 views

If we assume the mega impact hypothesis for the formation of Moon, where on Earth is the impact point?

Given that Pangaea had C-shape can we assume that the point of impact was in the center of this C-shape? In modern world it would be under Tibet? Or should we assume the oldest shape of the ...
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3answers
351 views

What is the age of the earliest traces of life on Earth?

In the article Oldest rocks, earliest life, heaviest impacts, and the Hadean–Archaean transition (Moorbath, 2005), the author states (based on previous referenced research) that the $\ce{^13C}$ ...
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What composition would the early cratons have? [closed]

I am trying to get into early-Earth geochemistry, and the cratons piqued my interest. They would need a very specific density to float, and the right heat resistance to not melt. What composition ...
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3answers
2k views

What is the age of the earth's oil?

Oil in the ground is found under the oceans and seas. It is made of dead fish. But from what period are those fish? I heard they are about 119 million years old. But fish exist much longer than that. ...
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1answer
192 views

What caused the earth's climate to stabilise ~10 thousand years ago?

We can see that the last glacial period ended 12-10K years ago. Interestingly enough, this also appears to coincide with the rise of large human civilisations. My question is: What caused the earth'...
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1answer
214 views

Did an impact crater influence the formation of uranium deposits in South Australia?

As a supplementary question Did an impact crater cause the formation of the gas fields in north eastern South Australia . South Australia is a well documented uranium province. Could an impact crater, ...
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2answers
295 views

Change in earth mass since the time of the dinosaurs

Is there a significant difference in the mass of the Earth between now and the time of the dinosaurs (250 - 75 million years ago)? I was just wondering if the force of gravity on dinosaurs would have ...
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3answers
265 views

How have global sedimentation rates changed over the last billion years?

Do we have a graph of how sedimentation rates changed over time?
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1answer
108 views

Future super-continent

What will the earth look like when the continents recollide? What will the climate be like? Assume global warming has been taken care of.
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1answer
155 views

How did the intensity of Earth's magnetic field change through geological time?

Looking at the wikipedia article on the Earth's magnetic field, I see that its strength varies through time. How did Earth's magnetic field change throughout its history, from the beginning of the ...
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2answers
630 views

What was the likely composition of Earth's early crust (how did crustal composition evolve)?

Was the first crust entirely mafic (oceanic) crust which was later distilled via volcanic arcs along subduction zones to make felsic rocks or did the earth start with bits of felsic crust? Are the ...
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1answer
137 views

Why haven't weeds overtaken the entire planet?

Given how rapidly weed plants spread and grow, choking out all other plant life, how come after millions of years we haven't ended with forests full of thistle or pokeweed, as opposed to pines or oak ...
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Is this scientific explanation of The Bible flood accurate?

I googled "the flood and freshwater fish" and came up with this question Christianity StackExchange: How did Noah preserve fresh water fish?. The writer makes a lot of claims like how the salinity of ...
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When was the last time there was a landlocked body of water bigger than the Caspian?

Was it the Mediterranean before it dried into small lakes? What was the biggest one before that?
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1answer
347 views

Did Jupiter really make Earth (in)habitable?

A new study by Batygyin and Laughlin suggest that a Jupiter migration toward the inner region of the Solar System during the early stages of system formation cleared the habitable region (Goldilocks ...
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1answer
227 views

What caused a fall in atmospheric oxygen about 1.9 billion years ago?

Using chromium isotopes geochemistry, Frei et al. 2009, describe in the article Fluctuations in Precambrian atmospheric oxygenation recorded by chromium isotopes that after the Great Oxidation Event (...
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1answer
517 views

What is the earliest tropical cyclone in record?

The question is simple: what is the earliest tropical cyclone (hurricane or typhoon) described in the historical record?
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1k views

Was volcanic activity more prevalent when the dinosaurs roamed?

Popular film culture often depicts much volcanic activity during the time of the dinosaurs. Assuming "time of the dinosaurs" as the Jurassic (200 million years ago) until the end of the Cretaceous (...