Stop O: Hearst Tower Courtyard - Building Stone Walking Tour of Uptown Charlotte (sitios de interés)
Descripción del sitio
Stop O: Hearst Tower courtyard
214 North Tryon Street
O1: Hearst Tower: Exterior cladding and plaza seating wall lower stone
The black walls flanking the entrance to the Hearst Tower (as well as accent seating and unpolished pavers throughout the courtyard) are composed of anorthosite (a plagioclase feldspar-dominated igneous intrusive rock) with variable plagioclase crystal sizes belonging to the Cambrian Lac-Saint-Jean anorthosite suite from Quebec, Canada. This stone (Figure 48) has the trade name of “Peirbonka granite”. In certain light, the phenocrysts (large crystals) in this rock have a lovely blue iridescence.
O2: Entry way pavers
The lighter colored pavers in the Hearst Tower courtyard is a quartz granodiorite (Figure 49) containing quartz and dominated by plagioclase feldspar (often rectangular, creamy light gray) with mafic phenocrysts (large, dark crystals in a fine-grained ground mass) of the mineral amphibole (small black crystals). Large xenoliths are present in this rock, too.
Note the well-formed plagioclase crystal laths which show evidence of compositional
zoning (growth rings) which indicate the slow cooling rates of the magma which formed this rock.
O3: Seating wall upper and unpolished paver intersections
This granodiorite (Figure 50) is weakly metamorphosed as evidenced by the subtle
alignment of elongated crystals.
Who can find the largest plagioclase xenocryst? We found one that is 10cm long!
Can you differentiate the xenocrysts from the xenoliths of other igneous rocks that were likely included as ‘hitch hikers’ as the magma from this rock intruded into the country rock?
Both the xenocrysts and xenoliths show reaction rims, halos around the crystals and rock fragments that represent partial assimilation with the magma after they were picked up.
O4: Montaldo’s Department Store (220 North Tryon) exterior cladding
The former five story Montaldo’s Department Store on the northwest corner of the Hearst Tower plaza was designed 1920 by Louis Asbury Sr. in Italian Renaissance Revival style. The building housed the Mint Museum of Craft + Design from 1999-2010. It is clad in white travertine (Figure 51) similar to that seen at stops E and K.
214 North Tryon Street
O1: Hearst Tower: Exterior cladding and plaza seating wall lower stone
The black walls flanking the entrance to the Hearst Tower (as well as accent seating and unpolished pavers throughout the courtyard) are composed of anorthosite (a plagioclase feldspar-dominated igneous intrusive rock) with variable plagioclase crystal sizes belonging to the Cambrian Lac-Saint-Jean anorthosite suite from Quebec, Canada. This stone (Figure 48) has the trade name of “Peirbonka granite”. In certain light, the phenocrysts (large crystals) in this rock have a lovely blue iridescence.
O2: Entry way pavers
The lighter colored pavers in the Hearst Tower courtyard is a quartz granodiorite (Figure 49) containing quartz and dominated by plagioclase feldspar (often rectangular, creamy light gray) with mafic phenocrysts (large, dark crystals in a fine-grained ground mass) of the mineral amphibole (small black crystals). Large xenoliths are present in this rock, too.
Note the well-formed plagioclase crystal laths which show evidence of compositional
zoning (growth rings) which indicate the slow cooling rates of the magma which formed this rock.
O3: Seating wall upper and unpolished paver intersections
This granodiorite (Figure 50) is weakly metamorphosed as evidenced by the subtle
alignment of elongated crystals.
Who can find the largest plagioclase xenocryst? We found one that is 10cm long!
Can you differentiate the xenocrysts from the xenoliths of other igneous rocks that were likely included as ‘hitch hikers’ as the magma from this rock intruded into the country rock?
Both the xenocrysts and xenoliths show reaction rims, halos around the crystals and rock fragments that represent partial assimilation with the magma after they were picked up.
O4: Montaldo’s Department Store (220 North Tryon) exterior cladding
The former five story Montaldo’s Department Store on the northwest corner of the Hearst Tower plaza was designed 1920 by Louis Asbury Sr. in Italian Renaissance Revival style. The building housed the Mint Museum of Craft + Design from 1999-2010. It is clad in white travertine (Figure 51) similar to that seen at stops E and K.