OCR A-Level Geology rock-forming minerals and igneous processes overview quiz quiz
14questions. Pick an answer and you'll see why right away.
What is the chemical formula of the silica tetrahedron, the building block of all silicate minerals?
In which silicate group does every tetrahedron share all four of its oxygen atoms?
A dark mineral has two cleavages meeting at about 120 degrees and forms long prismatic crystals. What is it?
Which mineral has a perfect basal cleavage that lets it split into thin sheets?
Which mineral crystallises FIRST from a cooling magma according to Bowen's reaction series?
How does fractional crystallisation change the silica content of a residual magma?
Using Bowen's series, which mineral is MOST resistant to chemical weathering at the surface?
An igneous rock has more than 63 percent silica and is pale with abundant quartz. How is it classified?
What does a coarse-grained (phaneritic) texture tell you about how an igneous rock formed?
A rock has large phenocrysts set in a fine-grained groundmass. What does this porphyritic texture record?
Which igneous body is discordant, cutting across the bedding of the country rock?
In an intrusion, where is the CHILLED margin and what causes it?
What does a baked margin in the country rock prove about the relative age of an intrusion?
How does a buried lava flow differ from a sill in its baking relationships?