PASADENA, Calif. -- The Spirit rovers first detailed look at the soil of Mars show it to be a complex jumble of surface materials, akin to that found at the Viking and Mars Pathfinder landing sites.

Using Spirit-deployed science gear to study a select patch of Mars at Gusev Crater, silicon, sulfur, chlorine, calcium, iron, and nickel have been detected.

"Its going to take a long time to puzzle through thisbut the key is weve got the tools to do it," said Steve Squyres, Principal Investigator for the Mars Exploration Rover project.

Preliminary science findings from two key German-built instruments -- the Mssbauer Spectrometer and Alpha-Particle-X-Ray Spectrometer -- were unveiled here today at a Jet Propulsion Laboratory (JPL) press briefing.

"There are some puzzles. There are some surprises. We have much that we still have to learnbut were starting to put together an interesting story," Squyres explained. "Mars is not going to give up its secrets easily."

Every element tells a story, explained Johannes Brueckner, Science Team Member from the Max Planck Institute for Chemistry in Germany, detailing first findings from the Alpha-Particle-X-Ray Spectrometer, or APXS.

Squyres said that the Mssbauer Spectrometers finding of olivine in the soil is a "significant finding" and a puzzler. He added that it is not known whether the mineral measurements taken by the two German devices are actually related to Gusev crater, or brought into the region by global dust storms.

Squyres reported that the small grains of Mars soil now appear not to be held together by static cling. Salts seem to serve as "chemical glue" that holds the grains together, he said, as suggested by the APXS data. But how these salts came to the area, by water or volcanic processes is yet to be resolved.

In the days, weeks and months to come, having Spirit uncover the real Gusev Crater will demand subsurface research.

Squyres said that the Mars rover team has an enormous capability to sample Gusev Crater over a huge range of depths - from microns to depths of over 150 feet (50 meters). Those deeper subsurface looks are possible by driving to Mother Natures drilling rig -- craters, he said.

Near at hand is use of the rover to trench on Mars.

"Both the engineers and the scientists are kind of itching to do some simple trenching activities," Squyres told SPACE.com .

Spirit rolls along on six wheels. Each wheel hub has a motor. In order to dig a hole on Mars, five wheel motors will be shut down leaving one wheel to spin in place.

Like an automobile stuck in snow, this action churns up the soil and leaves a hole in the ground about half a foot deep. Rover science instruments will then take a close up look at what was once hidden from view.

But the real scientific bonanza awaits Spirits trek to a nearby crater. Once there, Gusev Craters interior should be visible, both by looking down crater walls, as well as inspecting material ejected during the craters formation.

An okay is likely forthcoming to start using the rovers Rock Abrasion Tool (RAT) at some time tonight into early tomorrow morning. The RAT will grind into Adirondack, the selected rock deemed by scientists excellent for scrutiny.

"Were ready to goready to RATand chomping at the bit," Jennifer Trosper, Mission Manager for the Mars Exploration Rover project told SPACE.com .

Scientists are eager to compare the makeup of Adirondack to the new observations of soil minerals. "Im highly convinced we will see a difference," added Brueckner.

The rover remains in excellent shape for trundling over to the nearby crater, Trosper said. "The spacecraft continues to amaze me. Theres nothing to make me think that this vehicle isnt going to last a long time," she concluded.

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