In Archibald Geikie's words, " they consist in large proportion of altered sedimentary strata, now found in the form of mica-schist, graphite-schist, andalusite-schist, phyllite, schistose grit, greywacke and thrusting.
32.
The subsurface geologic reservoir may be a highly permeable and porous sedimentary strata, a depleted hydrocarbon field, a depleting hydrocarbon field, a depleted oil field, a depleting oil field, a depleted gas field, or a depleting gas field.
33.
The principle becomes quite complex, however, given the uncertainties of fossilization, the localization of fossil types due to lateral changes in habitat ( facies change in sedimentary strata ), and that not all fossils may be found globally at the same time.
34.
When they were found at a Dockum Group quarry in the Texas panhandle in 1984, in a sedimentary strata of a Triassic river delta, the fossils were a jumbled cache of disarticulated bones that may reflect an incident of mass mortality following a flash flood.
35.
Homoclinal ridges are the expression of regional outcrops of moderately dipping strata, typically sedimentary strata, that consist of alternating beds of hard, well-lithified strata, i . e . sandstone and limestone and weak or loosely cemented strata, i . e . shale, mudstone, and marl.
36.
Hogbacks are a typical regional topographic expression of outcrops of steeply dipping strata, commonly sedimentary strata, that consist of alternating beds of hard, well-lithified strata, i . e . sandstone and limestone, and either weak or loosely cemented strata, i . e . shale, mudstone, and marl.
37.
The hanging wall to the deposit can be volcanic units essentially contiguous and coeval with the footwall rocks, indicating mineralisation was developed in an inter-eruptive pause; it may be volcanic rock dissimilar to the footwall volcanics in bimodal volcanic subtypes, or it could be sedimentary strata if mineralisation occurred toward the end of an eruptive cycle.
38.
In the wake of the periodic inundation of Southern California by the ocean, most of the Aliso Creek watershed is underlain by several layers of marine sedimentary strata, the oldest dating from the Eocene ( 55.8 33.9 MYA ) and the most recent, the Pliocene ( 5.33 2.59 MYA ).
39.
The clear truncation of near-vertical Silurian sedimentary strata by well-bedded conglomerates and sandstones belonging to the Upper Old Red Sandstone allowed Hutton to demonstrate the existence of significant breaks in the geological record, in this case a break separating strata that were then called " alpine schistus " and " secondary strata ."
40.
Because the slope of a homoclinal ridge dips in the same direction as the sedimentary strata underlying it, the dip angle of this bedding ( ? ) can be calculated by v / h = tan ( ? ) where v is equal to the vertical distance and h is equal to the horizontal distance perpendicular to the strike of the beds.
