Close up of boulder of metamorphosed tonalite.


According to Goldsmith et al. (1988), rock is part of the Mqd unit – Metamorphosed quartz diorite and tonalite – Gray, usually medium- to coarse grained, generally foliated rock composed dominantly of plagioclase, quartz, biotite, hornblende, and epidote.  Biotite, hornblende, and epidote commonly  associated in clots replacing original mafic phenocrysts; clots may be smeared out, thus defining foliation.


Formation or Unit: Tonalite of the metamorphosed quartz diorite and tonalite unit

Association:  Example of intrusive rocks within Charlotte terrane

Terrane: Charlotte terrane

 

Source of boulder: Lake Norman Quarry

Quartz diorite to tonalite

Enlargement of photograph above showing texture of boulder of metamorphosed tonalite.


According to Goldsmith et al. (1988), rock is part of the Mqd unit – Metamorphosed quartz diorite and tonalite – Gray, usually medium- to coarse grained, generally foliated rock composed dominantly of plagioclase, quartz, biotite, hornblende, and epidote.  Biotite, hornblende, and epidote commonly  associated in clots replacing original mafic phenocrysts; clots may be smeared out, thus defining foliation.


Formation or Unit: Tonalite of the metamorphosed quartz diorite and tonalite unit

Association:  Example of intrusive rocks within Charlotte terrane

Terrane: Charlotte terrane

 

Source of boulder: Lake Norman Quarry

Quartz diorite to tonalite

Close up of boulder of metamorphosed tonalite showing zone of concentration of mafic minerals.


According to Goldsmith et al. (1988), rock is part of the Mqd unit – Metamorphosed quartz diorite and tonalite – Gray, usually medium- to coarse grained, generally foliated rock composed dominantly of plagioclase, quartz, biotite, hornblende, and epidote.  Biotite, hornblende, and epidote commonly  associated in clots replacing original mafic phenocrysts; clots may be smeared out, thus defining foliation.


Formation or Unit: Tonalite of the metamorphosed quartz diorite and tonalite unit


Association:  Example of intrusive rocks within Charlotte terrane

Terrane: Charlotte terrane

Source of boulder: Lake Norman Quarry

Quartz diorite to tonalite
Boulder of metamorphosed tonalite with abundant enclaves of gabbro.  Enclaves have jigsaw-like fit boundaries.  Boulder may represent an injection breccia in which tonalitic magma (light color matrix) intruded gabbroic magma or rock causing brecciation of the gabbro. Penny for scale.


According to Goldsmith et al. (1988), rock is part of the Mqd unit – Metamorphosed quartz diorite and tonalite – Gray, usually medium- to coarse grained, generally foliated rock composed dominantly of plagioclase, quartz, biotite, hornblende, and epidote.  Biotite, hornblende, and epidote commonly  associated in clots replacing original mafic phenocrysts; clots may be smeared out, thus defining foliation.


Formation or Unit: Tonalite of the metamorphosed quartz diorite and tonalite unit


Association:  Example of intrusive rocks within Charlotte terrane


Terrane: Charlotte terrane

 

Source of boulder: Lake Norman Quarry

tonalite and gabbro

Close up of above boulder showing jigsaw-like fit boundaries of mafic enclaves. Penny for scale.


Formation or Unit: Tonalite of the metamorphosed quartz diorite and tonalite unit


Association:  Example of intrusive rocks within Charlotte terrane


Terrane: Charlotte terrane

 

Source of boulder: Lake Norman Quarry

tonalite and gabbro