IMPORTANT TO OUR MISSION: Olivine is named for its typically olive-green color, thought to be a result of traces of nickel, though it may alter to a reddish color from the oxidation of iron.

Igneous Olivine was found on Martian soil by the Curiosity rover at “Rocknest” on 10/17/12. It is formed from volcanoes and not likely to contain fossils.

When you step through the airlock to enter Jezero Crater, see if you can identify Olivine before drilling it and collecting a sample.

FUN FACT:

• Translucent olivine is sometimes used as a gemstone called peridot (French word for olivine).
• Translucent olivine is also called chrysolite (Greek for gold and stone).

LEVEL UP LEARNING


• Olivine occurs in both mafic and ultramafic igneous rocks and as a primary mineral in certain metamorphic rocks.

• Mg-rich olivine crystallizes from magma that is rich in magnesium and low in silica. That magma crystallizes to mafic rocks such as gabbro and basalt.

• Olivine and high pressure structural variants constitute over 50% of the Earth's upper mantle, and olivine is one of the Earth's most common minerals by volume.

• Mg-rich olivine is stable to pressures equivalent to a depth of about 410 km (250 mi) within EarthExperiments have documented that olivine at high pressures (e.g., 12 GPa, the pressure at depths of about 360 km (220 mi)) can contain at least as much as about 8900 parts per million (weight) of water, and that such water content drastically reduces the resistance of olivine to solid flow.

• Because olivine is so abundant, more water may be dissolved in olivine of the mantle than is contained in Earth's oceans.

Dolomite (aka Calcium Magnesium Carbonate, CaMg(CO3)2)

Dolomite is a carbonate. Carbonates are rocks and minerals which contain a molecule made of both carbon and oxygen known as CO32-. Limestone is an example of a calcium carbonate, CaCO3, which means a combination of calcium (Ca2+) and carbonate (CO32-). Two other examples of carbonates include calcite and marble.

On Earth, carbonate rocks on are formed by (1) a purely chemical process or (2) via the action of living things. Both means require liquid water.

IMPORTANT TO OUR MISSION

When marine organisms that produce carbonates for shells die, the shells sink to the bottom, accumulate and eventually form a carbonate deposit. Blackboard chalk is an example of such a carbonate, and comprises the majority of carbonates in the Earth’s crust.

Not only are carbonates often a product of life, but they are hardy enough to survive in fossil form for billions of years, including seashells, coral and some stromatolites.

When you step through the airlock to Jezero Crater, try to identify the dolomite before you drill it. Then collect it because it may contain fossils!

FROM THE MOUTH OF AN EXPERT!

“If you were lucky enough to find some carbonates in the layered terrains on Mars, scientists would get very excited about it,” said Ken Nealson, director of the Center for Life Detection at NASA’s Jet Propulsion Laboratory. “It would be just a zinger of a finding.”

“Not only are carbonates often a product of life, they preserve the life that was in and around them very well,” Nealson continued. “The whole notion of looking for certain mineral types that… tend to harbor life here on Earth is an important part of the search strategy [for signs of life on Mars].”

Stromatolites are layered mounds, columns, and sheet-like sedimentary rocks formed by the growth of layer upon layer of cyanobacteria, which is a single-celled photosynthesizing microbe.

IMPORTANT TO OUR MISSION

Fossilized stromatolites provide records of ancient life!

When you step through the airlock to Jezero Crater, look for stromatolite. Drill it and collect it, for that sample could very well contain fossil algae!

SHALE is a fine-grained, clastic sedimentary rock, composed of mud.

Clastic = rocks composed of broken pieces of older rocks.

It is a mixture of clay mineral flakes and tiny mineral fragments (especially quartz and calcite) . It is the most common sedimentary rock.

IMPORTANT TO OUR MISSION

"We see distinct, thick layers of rock within craters and other depressions for which a number of lines of evidence indicate that they may have formed in lakes or shallow seas. We have never before had this type of irrefutable evidence that sedimentary rocks are widespread on Mars," said Dr. Michael Malin, principal investigator for the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft at Malin Space Science Systems (MSSS), San Diego, CA. "These images tell us that early Mars was very dynamic and may have been a lot more like Earth than many of us had been thinking."

When you step through the airlock to Jezero Crater, try to identify Shale before drilling it. Be sure to collect it as it is clay rich and may contain fossils!

FUN FACT

Sedimentary Rock covers 73% of the Earth’s current land surface.

Often rocks look similar to each other. Density is a common method to identify unknown substances. Density can be calculated using the formula Density = Mass/Volume. The mass can be determined from a triple beam balance or digital scale. Volume can be measured either by water displacement which is how much water level rises when the object is put in water. Or geometrically, for example the Volume of a rectangular solid is length x width x height. The Densities of rocks on Mars are in grams/milliLiter are:
Olivine: 3.2-4.4,
Dolomite: 2.84-2.86,
and shale is 2.4 - 2.8.

Yes this image is very colorful, but it is not a fossil. These are just iron stains on the rocks. The lack of any structure in the rock suggests it is not a fossil. There is plenty of iron on Mars, so these rocks will be common.

Sure, this is obviously a shell, so it is a fossil. Notice the structure of radial lines as well as the shape. NASA would love to find a fossil like this on Mars!