|Latitude & Longitude (WGS84):||34° 53' 60'' North , 110° 10' 60'' West|
|Latitude & Longitude (decimal):||34.90000,-110.18333|
|Locality type:||Meteorite Fall Location|
|Meteorite Class:||L/LL6 chondrite meteorite|
|Meteoritical Society Class:||L/LL6|
|Metbull:||View entry in Meteoritical Bulletin Database|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Ordinary Chondrite (L/LL6; S2; W0)
Fall, 19 July 1912;~250 kg, ~14,000 recovered stones
In the very late afternoon a spectacular meteorite shower was seen over several states before thousands of fragments fell near Holbrook. The largest was 6.6 kg (14.5 pounds) with others as small as a few mg. A number of them had well developed fusion crusts. Chondrules (0.5-1.5 mm in diameter) consist mainly of granular olivine and finely prismatic low-Ca orthopyroxene. They are intergrown within a recrystallized matrix which is also rich in olivine and pyroxene (much finer-grained) and is accompanied by Fe-Ni metal and troilite aggregates. The aggregates are scattered through the matrix and occasionally rim chondrule edges. Minor albitic plagioclase (An15), clinopyroxene, and chromite are in evidence as well as several other very minor accessory phases.
Holbrook is a member of the relatively sparse L/LL ordinary chondrite geochemical group which have total iron abundances intermediate to those of the L and LL chondrites (relatively low and very low iron, respectively). Only 11 witnessed L/LL falls are known to have been recovered (Meteoritical Database, January 2016). More specifically, Holbrook is one of only four witnessed falls listed exactly as L/LL6 ordinary chondrites at the Meteoritical Bulletin Database. The others are Cabezo de Mayo, Trysil, and Sultanpur.
Several additional Holbrook specimens have been recovered in the decades since the original fall of the meteorite shower. While badly weathered, these specimens have allowed for some intriguing studies of the rate of terrestrial weathering. [Estimates of the total mass listed at the Meteorite Bulletin Database and elsewhere are sometimes based only on the initial recovered mass.]
11 valid minerals.
Meteorite/Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
0 - 0.0117 Ma
|Holocene surficial deposits|
Age: Anthropocene (0 - 0.0117 Ma)
Description: Unconsolidated deposits associated with modern fluvial systems. This unit consists primarily of fine-grained, well-sorted sediment on alluvial plains, but also includes gravelly channel, terrace, and alluvial fan deposits on middle and upper piedmonts. (0-10 ka)
Comments: Associated with modern fluvial systems
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
|Early Jurassic - Late Triassic|
174.1 - 237 Ma
|Mesozoic sedimentary rocks|
Age: Mesozoic (174.1 - 237 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.