Metachert is metamorphosed chert. The physical properties of chert and metachert are quite similar (in some cases, not distinctive at all) - hard, dense, relatively smooth surfaces, sharp …

Jan 8, 2020 · Metachert is the name for chert that has been metamorphosed but still looks like chert. In outcrops, metamorphosed chert may retain its original bedding but adopt different …

Visually indistinguishable from normal chert but metamorphic state of directly adjacent rocks gives hints.

Metachert occurs as lenses in a sheared argillitic matrix, as gray rhythmically bedded metachert with thin argillitic interbeds, and as small irregularly shaped bodies of red, green, or gray …

Oct 12, 2015 · Knowland Park’s knockers include several different rock types, and the largest number of them are high-grade chert, or metachert. Unlike the red chert that’s typical of the …

Feb 2, 2021 · Metachert Green metachert breccia. with quartz-filled fractures. Metachert rock like this is common in the lower Franciscan Formation (Jurassic) in the central Coastal California …

This is a sample of green metachert that displays crenulation. The original sedimentary chert layers have been tightly folded. The metachert is from the Jurassic-age Franciscan Formation.

Feb 2, 2021 · Metachert (jasper) Jasper (a variety of red chert) with quartz-filled fractures. Metachert rock like this is common in the lower Franciscan Formation (Jurassic) in the central …

Oct 6, 2020 · The Asima metachert samples of this study form four groups based on geochemistry, petrography and field association: (1) black hematitic, (2) green epidote-chlorite …