Geology might seem an odd framework within which to analyze jazz, but Cecil Taylor's liner notes to his 1966 Unit Structures (Blue Note) sheds light on his music by referring to terms like "strata." Two new CDs by Matthew Shipp, arguably the most significant avant-garde jazz pianist/composer since Taylor, demonstrate the value of looking at challenging jazz in terms of geological images. In fact, keeping the notion of "strata" in mind may be the best way to hear the fullness of Shipp's talent, a mature and original voice at age 36.

The earthshaking event of this jazz season is the arrival of Shipp's Critical Mass (213CD), his fourth album as a leader, and his first marking a fruitful association with Boston violinist Mat Maneri. Also on board are longtime associates bassist William Parker and drummer Whit Dickey. Shipp's previous recordings with rough-and-tumble saxophonists Rob Brown and David S. Ware occasionally limited him to maintaining a traditional melodic line in the face of industrial-strength sax wails. Critical Mass showcases Maneri's voice as one never threatening to overwhelm Shipp's; the violinist emerges as a perky stimulator of Shipp's fertile imagination. The quality of dialogue between violinist and pianist is constantly provocative and stirring, recalling recordings by violinist Leroy Jenkins with Cecil Taylor.

The album title refers to an abstract reformulation of a Catholic Mass into three aptly named movements: "Critical Mass," "Virgin Complex," and "Density and Eucharist." The density of Shipp's playing is stunning. There are stretches of ominous bass rumbles, shards of melancholy melodies that seem like hybrids of Rachmaninov and Cecil Taylor, jarringly juxtaposed dissonant tone clusters, nervously pounded single-note insinuations. Here are the sounds of Heaven and Hell breaking loose as translated through one pianist who invariably entertains ideas simultaneously.

There's more than a little punk sensibility operating in Shipp -- he's not on Henry Rollins's 213CD label by chance -- so occasionally you'll find him thrashing a melody into submission. Zo, his earlier duo album with bassist Parker on Rise Records, featured a version of Gershwin's "Summertime" full of sweaty angst. Critical Mass makes a similar punching bag out of the trappings of church music and ritual. Shipp keeps mining, layer after layer, the dramatic possibilities inherent within traditional musical forms -- blues, hymns, Tin Pan Alley, Classical Romanticism, Ellingtonia -- all the while offering the pleasures of unexpectedly destabilizing conventional structures. He's aided in this quest by Dickey's wildly irregular drumming, Parker's exploratory bass lines, and Maneri's angular and shrilly exciting phrasing.

Despite the difficulty of keeping track, strata after strata, of all of the layers of musical activity on Critical Mass, the emotional and intellectual rewards of such jazz are enormous. This is the most accomplished recording of Shipp's career, a breathtaking summary of his complex sense of musical form and lava-like flow of unstoppable imagination.

Symbol Systems (available only through No More Records, Box 334, Woodmere, New York 11598, $15 postpaid) is a very different side of Shipp. These 13 solo compositions are less a summation of the pianist's career than a fascinating notebook of thoughtfully drafted sketches. Pensive, moody, full of flinty melodies that remind you Shipp's classical roots are firmly planted in Russian soil, these compositions haunt and unsettle. Living up to its witty title, "Algebraic Boogie" sounds like a boogie-woogie riff deconstructed into something you could hear at a Knitting Factory jam session. His love for European classical abstraction notwithstanding, it also appears that Shipp never strays far from his African-American identity. "Bop Abyss" sprinkles trademarks of Thelonious Monk's fractured stride style through roiling textures that are uniquely Shipp's. "Dance of the Blue Atoms" may make you imagine what the molecules in your walls are thinking when you listen to John Lee Hooker recordings.

Shipp also can be heard in fine form on Dao, by the David S. Ware Quartet (Homestead). Ware sounds as fevered and free in his raw sax improvisations as ever; Parker and Dickey offer the same probing and provocative rhythmic support they give Shipp in his band. And Shipp? He's determined to be more than a melodic anchor and harmonic compass for the gale-force saxman, thus making this the best Ware-Shipp collaboration to date. Shipp and Ware are forces of the earth to be reckoned with. You'd need a skilled geologist's vocabulary to describe the wondrous, multilayered roar they create. Suffice to say that they make the earth move under your feet.