Impact Material catalog

Sierra Madera Impact Breccia - 60g. 60 grams. Approximate size: 1.5" x 1.0" x 0.9". Location: Sierra Madera Crater, Pecos County, Texas. Blockier specimen of impact breccia in Permian limestone. Olive-green angular clasts are visible in a tan matrix, with reddish oxidation staining and a small cavity on one face. This is a sample of impact breccia in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Impact breccias are made of angular, shattered rock fragments held together by a fine-grained matrix or melted rock cement, created by the extreme shock and energy of a meteorite impact. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped provide unambiguous evidence that the Sierra Madera feature is an impact structure. It was created about 100 million years ago by the impact of an asteroid estimated to have been about 0.6 miles in diameter. The impact created an 8–10-mile-wide complex crater (astrobleme) featuring a 5-mile-wide central uplift and crater rim.

Sierra Madera Impact Breccia - 28g. 28 grams. Approximate size: 2.0" x 1.5" x 0.3". Location: Sierra Madera Crater, Pecos County, Texas. Thin slab of impact breccia in Permian limestone. Angular dark clasts sit in a light tan matrix, with smaller mixed fragments and faint pinkish banding along the edge. This is a sample of impact breccia in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Impact breccias are made of angular, shattered rock fragments held together by a fine-grained matrix or melted rock cement, created by the extreme shock and energy of a meteorite impact. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped provide unambiguous evidence that the Sierra Madera feature is an impact structure. It was created about 100 million years ago by the impact of an asteroid estimated to have been about 0.6 miles in diameter. The impact created an 8–10-mile-wide complex crater (astrobleme) featuring a 5-mile-wide central uplift and crater rim.

Sierra Madera Shatter Cone - 190g. 190 grams. Approximate size: 2.0" x 3.0" x 1.0". Location: Sierra Madera Crater, Pecos County, Texas. Well-defined striae on both sides and edges. Side one features radiating coarse-to-fine striae on a concave surface with blunted apex features; side two has moderate striae with at least two small apex features. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.

Sierra Madera Shatter Cone - 457g. 457 grams. Approximate size: 6.0" x 3.2" x 1.0". Location: Sierra Madera Crater, Pecos County, Texas. Well-defined striae on both sides. Side one features fine radiating horsetail patterns and the outline of a Permian brachiopod fossil; side two features coarser striae. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.

Sierra Madera Shatter Cone - 170g. 170 grams. Approximate size: 2.8" x 1.5" x 1.0". Location: Sierra Madera Crater, Pecos County, Texas. Prominent, well-developed striae and very fine feathery features. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.

Sierra Madera Shatter Cone - 143g. 143 grams. Approximate size: 2.2" x 1.4" x 0.7". Location: Sierra Madera Crater, Pecos County, Texas. Prominent fine to grooved shatter cone features on one side, with more muted features on the opposite side. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.

Sierra Madera Shatter Cone - 113g. 113 grams. Approximate size: 2.0" x 1.5" x 1.0". Location: Sierra Madera Crater, Pecos County, Texas. Well-defined shatter cones on all sides including the ends, with coarse to fine branching striae and some blunted apex features. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.

Sierra Madera Shatter Cone - 41g. 41 grams. Approximate size: 2.5" x 1.5" x 0.3". Location: Sierra Madera Crater, Pecos County, Texas. Well-defined grooved striae and feathered patterns on one side, with fine feathered striae and some apex features on the opposite side. This is a shatter cone specimen in Permian limestone from the Sierra Madera Crater in Pecos County, Texas. Shatter cones are rare impact-related structures with distinctive cone-shaped fractures and grooved, radiating striae that form under extreme shock pressure from hypervelocity meteorite impacts. The discovery of shatter cones, impact breccia, and shocked quartz in the 1960s helped confirm Sierra Madera as an impact structure. The crater formed about 100 million years ago and is an 8-10 mile-wide complex impact structure with a central uplift containing folded and faulted carbonate and siliciclastic rocks.